Accelerated cosmological expansion without tension in the Hubble parameter. Fast evolution of the Hubble parameter H(z)

NASA Astrophysics Data System (ADS)

van Putten, Maurice H. P. M.

2018-01-01

The H0-tension problem poses a confrontation of dark energy driving latetime cosmological expansion measured by the Hubble parameter H(z) over an extended range of redshifts z. Distinct values H0 ≃ 73 km s-1 Mpcs-1 and H0 ≃ 68 km s-1 Mpcs-1 obtain from surveys of the Local Universe and, respectively, ΛCBM analysis of the CMB. These are representative of accelerated expansion with H'(0) ≃ 0 by and, respectively, H'(0) > 0 in ΛCDM, where is a fundamental frequency of the cosmological horizon in a Friedmann-Robertson-Walker universe with deceleration parameter q(z) = -1 + (1+z)H-1 H'(z). Explicit solution H(z) = H0 and, respectively, H(z) = H0 are here compared with recent data on H(z) over 0 ≲ z ≲ 2.The first is found to be free of tension with H0 from local surveys, while the latter is disfavored at 2:7σ A further confrontation obtains in galaxy dynamics by a finite sensitivity of inertia to background cosmology in weak gravity, putting an upper bound of m ≲ 10-30 eV on the mass of dark matter. A C0 onset to weak gravity at the de Sitter scale of acceleration adS = cH(z), where c denotes the velocity of light, can be seen in galaxy rotation curves covering 0 ≲ z ≲ 2 Weak gravity in galaxy dynamics hereby provides a proxy for cosmological evolution.

Cosmic variance and the measurement of the local Hubble parameter.

PubMed

Marra, Valerio; Amendola, Luca; Sawicki, Ignacy; Valkenburg, Wessel

2013-06-14

There is an approximately 9% discrepancy, corresponding to 2.4 σ, between two independent constraints on the expansion rate of the Universe: one indirectly arising from the cosmic microwave background and baryon acoustic oscillations and one more directly obtained from local measurements of the relation between redshifts and distances to sources. We argue that by taking into account the local gravitational potential at the position of the observer this tension--strengthened by the recent Planck results--is partially relieved and the concordance of the Standard Model of cosmology increased. We estimate that measurements of the local Hubble constant are subject to a cosmic variance of about 2.4% (limiting the local sample to redshifts z > 0.010) or 1.3% (limiting it to z > 0.023), a more significant correction than that taken into account already. Nonetheless, we show that one would need a very rare fluctuation to fully explain the offset in the Hubble rates. If this tension is further strengthened, a cosmology beyond the Standard Model may prove necessary.

Hubble Observations of the Exomoon Candidate Kepler-1625b I

NASA Astrophysics Data System (ADS)

Teachey, Alexander; Kipping, David; Torres, Guillermo; Bakos, Gaspar A.; Nesvorný, David; Buchhave, Lars; Huang, Chelsea Xu; Hartman, Joel D.

2018-01-01

The exomoon candidate Kepler-1625b I was identified by the Hunt for Exomoons with Kepler (HEK) collaboration in August 2016 following an extensive program to characterize the occurrence rate of exomoons. Follow-up observations of the candidate for the purpose of validating the existence of the moon and constraining its properties were carried out on the Hubble Space Telescope on October 28th-29th 2017, using slitless spectroscopy on Wide Field Camera 3. We report preliminary results of that observation.

How does the cosmic large-scale structure bias the Hubble diagram?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleury, Pierre; Clarkson, Chris; Maartens, Roy, E-mail: pierre.fleury@uct.ac.za, E-mail: chris.clarkson@qmul.ac.uk, E-mail: roy.maartens@gmail.com

2017-03-01

The Hubble diagram is one of the cornerstones of observational cosmology. It is usually analysed assuming that, on average, the underlying relation between magnitude and redshift matches the prediction of a Friedmann-Lemaître-Robertson-Walker model. However, the inhomogeneity of the Universe generically biases these observables, mainly due to peculiar velocities and gravitational lensing, in a way that depends on the notion of average used in theoretical calculations. In this article, we carefully derive the notion of average which corresponds to the observation of the Hubble diagram. We then calculate its bias at second-order in cosmological perturbations, and estimate the consequences on themore » inference of cosmological parameters, for various current and future surveys. We find that this bias deeply affects direct estimations of the evolution of the dark-energy equation of state. However, errors in the standard inference of cosmological parameters remain smaller than observational uncertainties, even though they reach percent level on some parameters; they reduce to sub-percent level if an optimal distance indicator is used.« less

Local gravitational physics of the Hubble expansion. Einstein's equivalence principle in cosmology

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei M.

2015-01-01

We study physical consequences of the Hubble expansion of Friedmann-Lemaıtre-Robertson-Walker (FLRW) manifold on measurement of space, time and light propagation in the local inertial frame. We use the results of this study to analyse the Solar System radar ranging and Doppler tracking experiments and time synchronization. FLRW manifold is covered by the coordinates ( t, y i ), where t is the cosmic time coinciding with the proper time of the Hubble observers and identified with the barycentric coordinate time (TCB) used in ephemeris astronomy. We introduce the local inertial coordinates x α = ( x 0, x i ) in the vicinity of a world line of a Hubble observer with the help of a special conformal transformation that respects the local equivalence between the tangent and FLRW manifold. The local inertial metric is Minkowski flat and is materialized by the congruence of time-like geodesics of static observers being at rest with respect to the local spatial coordinates x i . The static observers are equipped with the ideal clocks measuring their own proper time which is synchronized with the cosmic time t measured by the Hubble observer. We consider the geodesic motion of test particles and notice that the local coordinate time x 0 = x 0( t) taken as a parameter along the world line of the particle, is a function of Hubble's observer time t. This function changes smoothly from x 0 = t for a particle at rest (observer's clock), to x 0 = t + (1/2) Ht 2 for photons, where H is the Hubble constant. Thus, the motion of a test particle is non-uniform when its world line is parametrized by the cosmic time t. NASA JPL Orbit Determination Program operates under the assumption that the spacetime is asymptotically flat which presumes that the motion of light (after the Shapiro delay is excluded) is uniform with respect to the time t but it does not comply with the non-uniform motion of light on cosmological manifold. For this reason, the motion of light in the Solar System

Bayesian `hyper-parameters' approach to joint estimation: the Hubble constant from CMB measurements

NASA Astrophysics Data System (ADS)

Lahav, O.; Bridle, S. L.; Hobson, M. P.; Lasenby, A. N.; Sodré, L.

2000-07-01

Recently several studies have jointly analysed data from different cosmological probes with the motivation of estimating cosmological parameters. Here we generalize this procedure to allow freedom in the relative weights of various probes. This is done by including in the joint χ2 function a set of `hyper-parameters', which are dealt with using Bayesian considerations. The resulting algorithm, which assumes uniform priors on the log of the hyper-parameters, is very simple: instead of minimizing \\sum \\chi_j2 (where \\chi_j2 is per data set j) we propose to minimize \\sum Nj (\\chi_j2) (where Nj is the number of data points per data set j). We illustrate the method by estimating the Hubble constant H0 from different sets of recent cosmic microwave background (CMB) experiments (including Saskatoon, Python V, MSAM1, TOCO and Boomerang). The approach can be generalized for combinations of cosmic probes, and for other priors on the hyper-parameters.

Detecting opportunities for parallel observations on the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Lucks, Michael

1992-01-01

The presence of multiple scientific instruments aboard the Hubble Space Telescope provides opportunities for parallel science, i.e., the simultaneous use of different instruments for different observations. Determining whether candidate observations are suitable for parallel execution depends on numerous criteria (some involving quantitative tradeoffs) that may change frequently. A knowledge based approach is presented for constructing a scoring function to rank candidate pairs of observations for parallel science. In the Parallel Observation Matching System (POMS), spacecraft knowledge and schedulers' preferences are represented using a uniform set of mappings, or knowledge functions. Assessment of parallel science opportunities is achieved via composition of the knowledge functions in a prescribed manner. The knowledge acquisition, and explanation facilities of the system are presented. The methodology is applicable to many other multiple criteria assessment problems.

The new European Hubble archive

NASA Astrophysics Data System (ADS)

De Marchi, Guido; Arevalo, Maria; Merin, Bruno

2016-01-01

The European Hubble Archive (hereafter eHST), hosted at ESA's European Space Astronomy Centre, has been released for public use in October 2015. The eHST is now fully integrated with the other ESA science archives to ensure long-term preservation of the Hubble data, consisting of more than 1 million observations from 10 different scientific instruments. The public HST data, the Hubble Legacy Archive, and the high-level science data products are now all available to scientists through a single, carefully designed and user friendly web interface. In this talk, I will show how the the eHST can help boost archival research, including how to search on sources in the field of view thanks to precise footprints projected onto the sky, how to obtain enhanced previews of imaging data and interactive spectral plots, and how to directly link observations with already published papers. To maximise the scientific exploitation of Hubble's data, the eHST offers connectivity to virtual observatory tools, easily integrates with the recently released Hubble Source Catalog, and is fully accessible through ESA's archives multi-mission interface.

Hubble Observes Surface of Titan

NASA Technical Reports Server (NTRS)

1994-01-01

Scientists for the first time have made images of the surface of Saturn's giant, haze-shrouded moon, Titan. They mapped light and dark features over the surface of the satellite during nearly a complete 16-day rotation. One prominent bright area they discovered is a surface feature 2,500 miles across, about the size of the continent of Australia.

Titan, larger than Mercury and slightly smaller than Mars, is the only body in the solar system, other than Earth, that may have oceans and rainfall on its surface, albeit oceans and rain of ethane-methane rather than water. Scientists suspect that Titan's present environment -- although colder than minus 289 degrees Fahrenheit, so cold that water ice would be as hard as granite -- might be similar to that on Earth billions of years ago, before life began pumping oxygen into the atmosphere.

Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory and his team took the images with the Hubble Space Telescope during 14 observing runs between Oct. 4 - 18. Smith announced the team's first results last week at the 26th annual meeting of the American Astronomical Society Division for Planetary Sciences in Bethesda, Md. Co-investigators on the team are Mark Lemmon, a doctoral candidate with the UA Lunar and Planetary Laboratory; John Caldwell of York University, Canada; Larry Sromovsky of the University of Wisconsin; and Michael Allison of the Goddard Institute for Space Studies, New York City.

Titan's atmosphere, about four times as dense as Earth's atmosphere, is primarily nitrogen laced with such poisonous substances as methane and ethane. This thick, orange, hydrocarbon haze was impenetrable to cameras aboard the Pioneer and Voyager spacecraft that flew by the Saturn system in the late 1970s and early 1980s. The haze is formed as methane in the atmosphere is destroyed by sunlight. The hydrocarbons produced by this methane destruction form a smog similar to that found over large cities, but is much

A Sneak Peek at the JWST Era: Observing Galaxies Below the Hubble Limit with Gravitational Lensing

NASA Astrophysics Data System (ADS)

Livermore, Rachael C.

2016-01-01

The installation of WFC3 on the Hubble Space Telescope pushed the frontier of high-redshift galaxy studies to only 500 Myr after the Big Bang. However, observations in this epoch remain challenging and are limited to the brightest galaxies; the fainter sources believed to be responsible for reionizing the Universe remain beyond the grasp of Hubble. With gravitational lensing, however, we can benefit from the magnification of faint sources, which brings them within reach of today's telescopes. The Hubble Frontier Fields program is a deep survey of strongly lensing clusters observed in the optical and near-infrared. Unfortunately, detecting highly magnified, intrinsically faint galaxies in these fields has proved challenging due to the bright foregound cluster galaxies and intracluster light. We have developed a technique using wavelet decomposition to overcome these difficulties and detect galaxies at z~7 with intrinsic UV magnitudes as faint as MUV = -13. We present this method and the resulting luminosity functions, which support a steep faint-end slope extending out to the observational limits. Our method has uncovered hundreds of galaxies at z > 6 fainter than any that have been seen before, providing our first insight into the small galaxy population during the epoch of reionization and a preview of the capabilities of JWST.

Hubble-V

NASA Image and Video Library

1999-12-10

Resembling curling flames from a campfire, a magnificent nebula in a nearby galaxy observed by NASA Hubble Space Telescope provides new insight into the fierce birth of stars as it may have occurred in the early universe.

Revisiting the stellar velocity ellipsoid-Hubble-type relation: observations versus simulations

NASA Astrophysics Data System (ADS)

Pinna, F.; Falcón-Barroso, J.; Martig, M.; Martínez-Valpuesta, I.; Méndez-Abreu, J.; van de Ven, G.; Leaman, R.; Lyubenova, M.

2018-04-01

The stellar velocity ellipsoid (SVE) in galaxies can provide important information on the processes that participate in the dynamical heating of their disc components (e.g. giant molecular clouds, mergers, spiral density waves, and bars). Earlier findings suggested a strong relation between the shape of the disc SVE and Hubble type, with later-type galaxies displaying more anisotropic ellipsoids and early types being more isotropic. In this paper, we revisit the strength of this relation using an exhaustive compilation of observational results from the literature on this issue. We find no clear correlation between the shape of the disc SVE and morphological type, and show that galaxies with the same Hubble type display a wide range of vertical-to-radial velocity dispersion ratios. The points are distributed around a mean value and scatter of σz/σR = 0.7 ± 0.2. With the aid of numerical simulations, we argue that different mechanisms might influence the shape of the SVE in the same manner and that the same process (e.g. mergers) does not have the same impact in all the galaxies. The complexity of the observational picture is confirmed by these simulations, which suggest that the vertical-to-radial axis ratio of the SVE is not a good indicator of the main source of disc heating. Our analysis of those simulations also indicates that the observed shape of the disc SVE may be affected by several processes simultaneously and that the signatures of some of them (e.g. mergers) fade over time.

The Hubble Constant.

PubMed

Jackson, Neal

2015-01-01

I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H 0 values of around 72-74 km s -1 Mpc -1 , with typical errors of 2-3 km s -1 Mpc -1 . This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68 km s -1 Mpc -1 and typical errors of 1-2 km s -1 Mpc -1 . The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.

Constraining the evolution of the Hubble Parameter using cosmic chronometer

NASA Astrophysics Data System (ADS)

Scarlata, Claudia; Dickinson, Hugh

2018-01-01

The Lambda-CDM model of Big Bang cosmology relies heavily on the assumption that two components - dark energy and dark matter - encompass 95% of the energy density of the Universe. Despite the dominant influence of these components, their nature is still entirely unknown.We present the initial results from a project that aims to provide new insights regarding the Dark Energy component. We do this by deriving independent constraints on the time-evolution of the Hubble parameter (H_0) using the “cosmic chronometer” method.By analyzing the HST NIR spectra from a large archival sample of passively evolving galaxies in distinct redshift bins between 1.3 and 2 we measure the typical stellar population ages (A) for the galaxies in each bin. The differential evolution of stellar population age with redshift (dA/dz) can be used to infer the corresponding evolution of H_0 which will provide important constraints on the nature of Dark Energy and its equation of state.

Hubble Observes One-of-a-Kind Star Nicknamed ‘Nasty’

NASA Image and Video Library

2015-03-21

Astronomers using NASA’s Hubble Space Telescope have uncovered surprising new clues about a hefty, rapidly aging star whose behavior has never been seen before in our Milky Way galaxy. In fact, the star is so weird that astronomers have nicknamed it “Nasty 1,” a play on its catalog name of NaSt1. The star may represent a brief transitory stage in the evolution of extremely massive stars. First discovered several decades ago, Nasty 1 was identified as a Wolf-Rayet star, a rapidly evolving star that is much more massive than our sun. The star loses its hydrogen-filled outer layers quickly, exposing its super-hot and extremely bright helium-burning core. But Nasty 1 doesn’t look like a typical Wolf-Rayet star. The astronomers using Hubble had expected to see twin lobes of gas flowing from opposite sides of the star, perhaps similar to those emanating from the massive star Eta Carinae, which is a Wolf-Rayet candidate. Instead, Hubble revealed a pancake-shaped disk of gas encircling the star. The vast disk is nearly 2 trillion miles wide, and may have formed from an unseen companion star that snacked on the outer envelope of the newly formed Wolf-Rayet. Based on current estimates, the nebula surrounding the stars is just a few thousand years old, and as close as 3,000 light-years from Earth. Credits: NASA/Hubble

Star from the Lizard Constellation Photobombs Hubble Observation

NASA Image and Video Library

2017-12-08

In space, being outshone is an occupational hazard. This NASA/ESA Hubble Space Telescope image captures a galaxy named NGC 7250. Despite being remarkable in its own right — it has bright bursts of star formation and recorded supernova explosions— it blends into the background somewhat thanks to the gloriously bright star hogging the limelight next to it. The bright object seen in this Hubble image is a single and little-studied star named TYC 3203-450-1, located in the constellation of Lacerta (The Lizard). The star is much closer than the much more distant galaxy. Only this way can a normal star outshine an entire galaxy, consisting of billions of stars. Astronomers studying distant objects call these stars “foreground stars” and they are often not very happy about them, as their bright light is contaminating the faint light from the more distant and interesting objects they actually want to study. In this case, TYC 3203-450-1 is million times closer than NGC 7250, which lies more than 45 million light-years away from us. If the star were the same distance from us as NGC 7250, it would hardly be visible in this image. Credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Laryngeal findings and acoustic changes in hubble-bubble smokers.

PubMed

Hamdan, Abdul-latif; Sibai, Abla; Oubari, Dima; Ashkar, Jihad; Fuleihan, Nabil

2010-10-01

The purpose of our investigation was to evaluate the laryngeal findings and acoustic changes in hubble-bubble smokers. A total of 42 subjects with history of hubble-bubble smoking were recruited for this study. A corresponding group with a history of cigarette smoking and controls were matched. All subjects underwent laryngeal video-endostroboscopic evaluation and acoustic analysis. In the hubble-bubble smoking group, 61.9% were males. The average age was 30.02 +/- 9.48 years and the average number of years of smoking was 8.09 +/- 6.45 years. Three subjects had dysphonia at the time of examination. The incidence of benign lesions of the vocal folds in the hubble-bubble group was 21.5%, with edema being the most common at 16.7% followed by cyst at 4.8%. The incidence of laryngeal findings was significantly higher in the hubble-bubble group compared to controls. In the cigarette-smoking group, the most common finding was vocal fold cyst in 14.8% followed by polyps in 7.4%, and edema, sulcus vocalis and granuloma. These findings were not significantly different from the hubble-bubble group except for the thick mucus, which was significantly higher in the latter. There were no significant changes in any of the acoustic parameters between hubble-bubble smokers and controls except for the VTI and MPT, which were significantly lower in the hubble-bubble group. In comparison with the cigarette-smoking group, hubble-bubble smokers had significantly higher Fundamental frequency and habitual pitch (p value 0.042 and 0.008, respectively). The laryngeal findings in hubble-bubble smokers are comparable to cigarette smokers. These laryngeal findings are not translated acoustically, as all the acoustic parameters are within normal range compared to controls.

Dark energy and the quietness of the local Hubble flow

NASA Astrophysics Data System (ADS)

Axenides, M.; Perivolaropoulos, L.

2002-06-01

The linearity and quietness of the local (<10 Mpc) Hubble flow (LHF) in view of the very clumpy local universe is a long standing puzzle in standard and in open CDM (cold dark matter) cosmogony. The question addressed in this paper is whether the antigravity component of the recently discovered dark energy can cool the velocity flow enough to provide a solution to this puzzle. We calculate the growth of matter fluctuations in a flat universe containing a fraction ΩX(t0) of dark energy obeying the time independent equation of state pX=wρX. We find that dark energy can indeed cool the LHF. However the dark energy parameter values required to make the predicted velocity dispersion consistent with the observed value vrms~=40 km/s have been ruled out by other observational tests constraining the dark energy parameters w and ΩX. Therefore despite the claims of recent qualitative studies, dark energy with time independent equation of state cannot by itself explain the quietness and linearity of the local Hubble flow.

Dark Energy and the Hubble Law

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Dolgachev, V. P.; Domozhilova, L. M.

The Big Bang predicted by Friedmann could not be empirically discovered in the 1920th, since global cosmological distances (more than 300-1000 Mpc) were not available for observations at that time. Lemaitre and Hubble studied receding motions of galaxies at local distances of less than 20-30 Mpc and found that the motions followed the (nearly) linear velocity-distance relation, known now as Hubble's law. For decades, the real nature of this phenomenon has remained a mystery, in Sandage's words. After the discovery of dark energy, it was suggested that the dynamics of local expansion flows is dominated by omnipresent dark energy, and it is the dark energy antigravity that is able to introduce the linear velocity-distance relation to the flows. It implies that Hubble's law observed at local distances was in fact the first observational manifestation of dark energy. If this is the case, the commonly accepted criteria of scientific discovery lead to the conclusion: In 1927, Lemaitre discovered dark energy and Hubble confirmed this in 1929.

Optical variability of extragalactic objects used to tie the HIPPARCOS reference frame to an extragalactic system using Hubble space telescope observations

NASA Technical Reports Server (NTRS)

Bozyan, Elizabeth P.; Hemenway, Paul D.; Argue, A. Noel

1990-01-01

Observations of a set of 89 extragalactic objects (EGOs) will be made with the Hubble Space Telescope Fine Guidance Sensors and Planetary Camera in order to link the HIPPARCOS Instrumental System to an extragalactic coordinate system. Most of the sources chosen for observation contain compact radio sources and stellarlike nuclei; 65 percent are optical variables beyond a 0.2 mag limit. To ensure proper exposure times, accurate mean magnitudes are necessary. In many cases, the average magnitudes listed in the literature were not adequate. The literature was searched for all relevant photometric information for the EGOs, and photometric parameters were derived, including mean magnitude, maximum range, and timescale of variability. This paper presents the results of that search and the parameters derived. The results will allow exposure times to be estimated such that an observed magnitude different from the tabular magnitude by 0.5 mag in either direction will not degrade the astrometric centering ability on a Planetary Camera CCD frame.

Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

NASA Astrophysics Data System (ADS)

1999-11-01

Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for

Observing supernova 1987A with the refurbished Hubble Space Telescope.

PubMed

France, Kevin; McCray, Richard; Heng, Kevin; Kirshner, Robert P; Challis, Peter; Bouchet, Patrice; Crotts, Arlin; Dwek, Eli; Fransson, Claes; Garnavich, Peter M; Larsson, Josefin; Lawrence, Stephen S; Lundqvist, Peter; Panagia, Nino; Pun, Chun S J; Smith, Nathan; Sollerman, Jesper; Sonneborn, George; Stocke, John T; Wang, Lifan; Wheeler, J Craig

2010-09-24

Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph failed, we find that the Lyα and Hα lines from shock emission continue to brighten, whereas their maximum velocities continue to decrease. We observe broad, blueshifted Lyα, which we attribute to resonant scattering of photons emitted from hot spots on the equatorial ring. We also detect N v λλ1239, 1243 angstrom line emission, but only to the red of Lyα. The profiles of the N v lines differ markedly from that of Hα, suggesting that the N4+ ions are scattered and accelerated by turbulent electromagnetic fields that isotropize the ions in the collisionless shock.

Levels of maximum end-expiratory carbon monoxide and certain cardiovascular parameters following hubble-bubble smoking.

PubMed

Shafagoj, Yanal A; Mohammed, Faisal I

2002-08-01

The physiological effects of cigarette smoking have been widely studied, however, little is known regarding the effects of smoking hubble-bubble. We examined the acute effects of hubble-bubble smoking on heart rate, systolic, diastolic, and mean arterial blood pressure and maximum end-expiratory carbon monoxide. This study was carried out in the student laboratory, School of Medicine, Department of Physiology, University of Jordan, Amman, Jordan, during the summer of 1999. In 18 healthy habitual hubble-bubble smokers, heart rate, blood pressure, and maximum end-expiratory carbon monoxide was measured before, during and post smoking of one hubble-bubble run (45 minutes). Compared to base line (time zero), at the end of smoking heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, and maximum end-expiratory carbon monoxide were increased 16 2.4 beats per minute, 6.7 2.5 mm Hg, 4.4 1.6 mm Hg, 5.2 1.7 mm Hg, and 14.2 1.8 ppm, (mean standard error of mean, P<.05). Acute short-term active hubble-bubble smoking elicits a modest increase in heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and maximum end-expiratory carbon monoxide in healthy hubble-bubble smokers.

Hubble space telescope: The GO and GTO observing programs, version 3.0

NASA Technical Reports Server (NTRS)

Downes, Ron

1992-01-01

A portion of the observing time with the Hubble Space Telescope (HST) was awarded by NASA to scientists involved in the development of the HST and its instruments. These scientists are the Guaranteed Time Observers (GTO's). Observing time was also awarded to General Observers (GO's) on the basis of the proposal reviews in 1989 and 1991. The majority of the 1989 programs have been completed during 'Cycle 1', while the 1991 programs will be completed during 'Cycle 2', nominally a 12-month period beginning July 1992. This document presents abstracts of these GO and GTO programs, and detailed listings of the specific targets and exposures contained in them. These programs and exposures are protected by NASA policy, as detailed in the HST Call for Proposals (CP), and are not to be duplicated by new programs.

Hubble Tarantula Treasury Project: Unraveling Tarantula's Web. I. Observational Overview and First Results

NASA Technical Reports Server (NTRS)

Sabbi, E.; Anderson, J.; Lennon, D. J.; van der Marel, R. P.; Aloisi, A.; Boyer, Martha L.; Cignoni, M.; De Marchi, G.; De Mink, S. E.; Evans, C. J.;

Hubble 25

NASA Image and Video Library

2015-04-23

If you love Hubble as much as we do you will LOVE this video. Sit back and enjoy 25 mesmerizing years of Hubble images! #Hubble25 You can view all of these images on Flickr here: www.flickr.com/photos/40523828@N07/sets/72157649692430461 Credit NASA Goddard

Hubble Space Telescope

NASA Image and Video Library

2017-12-08

The Hubble Space Telescope in a picture snapped by a Servicing Mission 4 crewmember just after the Space Shuttle Atlantis captured Hubble with its robotic arm on May 13, 2009, beginning the mission to upgrade and repair the telescope. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. Goddard is responsible for HST project management, including mission and science operations, servicing missions, and all associated development activities. To learn more about the Hubble Space Telescope go here: www.nasa.gov/mission_pages/hubble/main/index.html

Hubble's Megamaser Galaxy

NASA Image and Video Library

2017-12-08

Feast your eyes on Hubble's Megamaser galaxy! Phenomena across the Universe emit radiation spanning the entire electromagnetic spectrum — from high-energy gamma rays, which stream out from the most energetic events in the cosmos, to lower-energy microwaves and radio waves. Microwaves, the very same radiation that can heat up your dinner, are produced by a multitude of astrophysical sources, including strong emitters known as masers (microwave lasers), even stronger emitters with the somewhat villainous name of megamasers and the centers of some galaxies. Especially intense and luminous galactic centers are known as active galactic nuclei. They are in turn thought to be driven by the presence of supermassive black holes, which drag surrounding material inwards and spit out bright jets and radiation as they do so. The two galaxies shown here, imaged by the NASA/ESA Hubble Space Telescope, are named MCG+01-38-004 (the upper, red-tinted one) and MCG+01-38-005 (the lower, blue-tinted one). MCG+01-38-005 (also known as NGC 5765B) is a special kind of megamaser; the galaxy’s active galactic nucleus pumps out huge amounts of energy, which stimulates clouds of surrounding water. Water’s constituent atoms of hydrogen and oxygen are able to absorb some of this energy and re-emit it at specific wavelengths, one of which falls within the microwave regime, invisible to Hubble but detectable by microwave telescopes. MCG+01-38-005 is thus known as a water megamaser! Astronomers can use such objects to probe the fundamental properties of the Universe. The microwave emissions from MCG+01-38-005 were used to calculate a refined value for the Hubble constant, a measure of how fast the Universe is expanding. This constant is named after the astronomer whose observations were responsible for the discovery of the expanding Universe and after whom the Hubble Space Telescope was named, Edwin Hubble.

Frequency-based redshift for cosmological observation and Hubble diagram from the 4-D spherical model in comparison with observed supernovae

NASA Astrophysics Data System (ADS)

Nagao, Shigeto

2017-08-01

According to the formerly reported 4-D spherical model of the universe, factors on Hubble diagrams are discussed. The observed redshift is not the prolongation of wavelength from that of the source at the emission but from the wavelength of spectrum of the present atom of the same element. It is equal to the redshift based on the shift of frequency from the time of emission. We demonstrate that the K-correction corresponds to conversion of the light propagated distance (luminosity distance) to the proper distance at present (present distance). Comparison of the graph of the present distance times 1 + z versus the frequency-based redshift with the reported Hubble diagrams from the Supernova Cosmology Project, which were time-dilated by 1 + z and K-corrected, showed an excellent fit for the Present Time (the radius of 4-D sphere) being c.a. 0.7 of its maximum.

Hubble's Cosmic Atlas

NASA Image and Video Library

2017-12-08

Morphologies, masses, and structures - oh, my! This beautiful clump of glowing gas, dark dust and glittering stars is the spiral galaxy NGC 4248, located about 24 million light-years away in the constellation of Canes Venatici (The Hunting Dogs). This image was produced by the NASA/ESA Hubble Space Telescope as it embarked upon compiling the first Hubble ultraviolet “atlas,” for which the telescope targeted 50 nearby star-forming galaxies. The collection spans all kinds of different morphologies, masses, and structures. Studying this sample can help us to piece together the star-formation history of the Universe. By exploring how massive stars form and evolve within such galaxies, astronomers can learn more about how, when, and where star formation occurs, how star clusters change over time, and how the process of forming new stars is related to the properties of both the host galaxy and the surrounding interstellar medium (the gas and dust that fills the space between individual stars). This galaxy was imaged with observations from Hubble’s Wide Field Camera 3. Image credit: ESA/Hubble & NASA

Hubble 2007: Science Year in Review

NASA Technical Reports Server (NTRS)

2008-01-01

This book epitomizes Hubbles continuing years of glorious accomplishments, presenting a sample of the activities, operations and observations, and scientific findings from 2007. Here is our observatory. Here are a few of our talented people. Here is what we have done. NASA plans a final servicing mission to Hubble in 2008. Two powerful new instruments are to be installed, and repairs made. After the astronauts do their wonderful work, Hubble will be more capable than at any time since launch. The science community eagerly anticipates the new opportunities for research offered by a refurbished observatory. While we do not know exactly what new science stories will appear in future editions of this book, we are certain that the frontiers of science will continue to be pushed outward by the forces of human curiosity and cleverness, channeled by the Hubble Space Telescope.

Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope.

PubMed

Nichols, J D; Badman, S V; Baines, K H; Brown, R H; Bunce, E J; Clarke, J T; Cowley, S W H; Crary, F J; Dougherty, M K; Gérard, J-C; Grocott, A; Grodent, D; Kurth, W S; Melin, H; Mitchell, D G; Pryor, W R; Stallard, T S

2014-05-28

We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current.

Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope

PubMed Central

Nichols, J D; Badman, S V; Baines, K H; Brown, R H; Bunce, E J; Clarke, J T; Cowley, S W H; Crary, F J; Dougherty, M K; Gérard, J-C; Grocott, A; Grodent, D; Kurth, W S; Melin, H; Mitchell, D G; Pryor, W R; Stallard, T S

2014-01-01

We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current. PMID:26074636

HUBBLE PINPOINTS WHITE DWARFS IN GLOBULAR CLUSTER

NASA Technical Reports Server (NTRS)

2002-01-01

Peering deep inside a cluster of several hundred thousand stars, NASA's Hubble Space Telescope uncovered the oldest burned-out stars in our Milky Way Galaxy. Located in the globular cluster M4, these small, dying stars - called white dwarfs - are giving astronomers a fresh reading on one of the biggest questions in astronomy: How old is the universe? The ancient white dwarfs in M4 are about 12 to 13 billion years old. After accounting for the time it took the cluster to form after the big bang, astronomers found that the age of the white dwarfs agrees with previous estimates for the universe's age. In the top panel, a ground-based observatory snapped a panoramic view of the entire cluster, which contains several hundred thousand stars within a volume of 10 to 30 light-years across. The Kitt Peak National Observatory's 0.9-meter telescope took this picture in March 1995. The box at left indicates the region observed by the Hubble telescope. The Hubble telescope studied a small region of the cluster. A section of that region is seen in the picture at bottom left. A sampling of an even smaller region is shown at bottom right. This region is only about one light-year across. In this smaller region, Hubble pinpointed a number of faint white dwarfs. The blue circles pinpoint the dwarfs. It took nearly eight days of exposure time over a 67-day period to find these extremely faint stars. Globular clusters are among the oldest clusters of stars in the universe. The faintest and coolest white dwarfs within globular clusters can yield a globular cluster's age. Earlier Hubble observations showed that the first stars formed less than 1 billion years after the universe's birth in the big bang. So, finding the oldest stars puts astronomers within arm's reach of the universe's age. M4 is 7,000 light-years away in the constellation Scorpius. Hubble's Wide Field and Planetary Camera 2 made the observations from January through April 2001. These optical observations were combined to

New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Benecchi, S. D.; Noll, K. S.; Weaver, H. A.; Spencer, J. R.; Stern, S. A.; Buie, M. W.; Parker, A. H.

2014-01-01

We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 epochY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of approx. 0.02 arcsec (approx. 700 km at 44 AU) and delta m less than or equal to 0.5.

Hubble Tracks Jupiter Storms

NASA Technical Reports Server (NTRS)

1995-01-01

NASA's Hubble Space Telescope is following dramatic and rapid changes in Jupiter's turbulent atmosphere that will be critical for targeting observations made by the Galileo space probe when it arrives at the giant planet later this year.

This Hubble image provides a detailed look at a unique cluster of three white oval-shaped storms that lie southwest (below and to the left) of Jupiter's Great Red Spot. The appearance of the clouds, as imaged on February 13, 1995 is considerably different from their appearance only seven months earlier. Hubble shows these features moving closer together as the Great Red Spot is carried westward by the prevailing winds while the white ovals are swept eastward. (This change in appearance is not an effect of last July's comet Shoemaker-Levy 9 collisions with Jupiter.)

The outer two of the white storms formed in the late 1930s. In the centers of these cloud systems the air is rising, carrying fresh ammonia gas upward. New, white ice crystals form when the upwelling gas freezes as it reaches the chilly cloud top level where temperatures are -200 degrees Fahrenheit (- 130 degrees Centigrade).

The intervening white storm center, the ropy structure to the left of the ovals, and the small brown spot have formed in low pressure cells. The white clouds sit above locations where gas is descending to lower, warmer regions. The extent of melting of the white ice exposes varied amounts of Jupiter's ubiquitous brown haze. The stronger the down flow, the less ice, and the browner the region.

A scheduled series of Hubble observations will help target regions of interest for detailed scrutiny by the Galileo spacecraft, which will arrive at Jupiter in early December 1995. Hubble will provide a global view of Jupiter while Galileo will obtain close-up images of structure of the clouds that make up the large storm systems such as the Great Red Spot and white ovals that are seen in this picture.

This color picture is assembled from a

Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially Flat ΛCDM Model, the Deceleration–Acceleration Transition Redshift, and Spatial Curvature

NASA Astrophysics Data System (ADS)

Yu, Hai; Ratra, Bharat; Wang, Fa-Yin

2018-03-01

We compile a complete collection of reliable Hubble parameter H(z) data to redshift z ≤ 2.36 and use them with the Gaussian Process method to determine continuous H(z) functions for various data subsets. From these continuous H(z)'s, summarizing across the data subsets considered, we find H 0 ∼ 67 ± 4 km s‑1 Mpc‑1, more consistent with the recent lower values determined using a variety of techniques. In most data subsets, we see a cosmological deceleration–acceleration transition at 2σ significance, with the data subsets transition redshifts varying over 0.33< {z}da}< 1.0 at 1σ significance. We find that the flat-ΛCDM model is consistent with the H(z) data to a z of 1.5 to 2.0, depending on data subset considered, with 2σ deviations from flat-ΛCDM above this redshift range. Using the continuous H(z) with baryon acoustic oscillation distance-redshift observations, we constrain the current spatial curvature density parameter to be {{{Ω }}}K0=-0.03+/- 0.21, consistent with a flat universe, but the large error bar does not rule out small values of spatial curvature that are now under debate.

Gravitational-wave cosmography with LISA and the Hubble tension

NASA Astrophysics Data System (ADS)

Kyutoku, Koutarou; Seto, Naoki

2017-04-01

We propose that stellar-mass binary black holes like GW150914 will become a tool to explore the local Universe within ˜100 Mpc in the era of the Laser Interferometer Space Antenna (LISA). High calibration accuracy and annual motion of LISA could enable us to localize up to ≈60 binaries more accurately than the error volume of ≈100 Mpc3 without electromagnetic counterparts under moderately optimistic assumptions. This accuracy will give us a fair chance to determine the host object solely by gravitational waves. By combining the luminosity distance extracted from gravitational waves with the cosmological redshift determined from the host, the local value of the Hubble parameter will be determined up to a few % without relying on the empirically constructed distance ladder. Gravitational-wave cosmography would pave the way for resolution of the disputed Hubble tension, where the local and global measurements disagree in the value of the Hubble parameter at 3.4 σ level, which amounts to ≈9 %.

Type Ia supernova Hubble residuals and host-galaxy properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, A. G.; Aldering, G.; Aragon, C.

2014-03-20

Kim et al. introduced a new methodology for determining peak-brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spectrophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is 0.013 ± 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at <<1σ, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement of the Hubble residual step with the host massmore » is 0.045 ± 0.026 mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch parameters: steps at >2σ significance are found in SALT2 Hubble residuals in samples split by the values of their K13 x(1) and x(2) light-curve parameters. x(1) affects the light-curve width and color around peak (similar to the Δm {sub 15} and stretch parameters), and x(2) affects colors, the near-UV light-curve width, and the light-curve decline 20-30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN Ia diversity arising from progenitor stellar evolution.« less

Hubble Supernova Bubble Resembles Holiday Ornament

NASA Image and Video Library

2017-12-08

NASA image release December 14, 2010 A delicate sphere of gas, photographed by NASA's Hubble Space Telescope, floats serenely in the depths of space. The pristine shell, or bubble, is the result of gas that is being shocked by the expanding blast wave from a supernova. Called SNR 0509-67.5 (or SNR 0509 for short), the bubble is the visible remnant of a powerful stellar explosion in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light-years from Earth. Ripples in the shell's surface may be caused by either subtle variations in the density of the ambient interstellar gas, or possibly driven from the interior by pieces of the ejecta. The bubble-shaped shroud of gas is 23 light-years across and is expanding at more than 11 million miles per hour (5,000 kilometers per second). Astronomers have concluded that the explosion was one of an especially energetic and bright variety of supernovae. Known as Type Ia, such supernova events are thought to result from a white dwarf star in a binary system that robs its partner of material, takes on much more mass than it is able to handle, and eventually explodes. Hubble's Advanced Camera for Surveys observed the supernova remnant on Oct. 28, 2006 with a filter that isolates light from glowing hydrogen seen in the expanding shell. These observations were then combined with visible-light images of the surrounding star field that were imaged with Hubble's Wide Field Camera 3 on Nov. 4, 2010. With an age of about 400 years as seen from Earth, the supernova might have been visible to southern hemisphere observers around the year 1600, however, there are no known records of a "new star" in the direction of the LMC near that time. A more recent supernova in the LMC, SN 1987A, did catch the eye of Earth viewers and continues to be studied with ground- and space-based telescopes, including Hubble. For images and more information about SNR 0509, visit: hubblesite.org/news/2010/27 heritage.stsci.edu/2010/27 www.nasa.gov/hubble

HUBBLE SPIES A REALLY COOL STAR

NASA Technical Reports Server (NTRS)

2002-01-01

This is a Hubble Space Telescope picture of one of the least massive and coolest stars even seen (upper right). It is a diminutive companion to the K dwarf star called GL 105A (also known as HD 16160) seen at lower left. The binary pair is located 27 light-years away in the constellation Cetus. Based on the Hubble observation, astronomers calculate that the companion, called GL 105C, is 25,000 times fainter than GL 105A in visible light. If the dim companion were at the distance of our Sun, it would be only four times brighter than the full moon. The Hubble observations confirm the detection of GL 105C last year by David Golimowski and his collaborators at Palomar Observatory in California. Although GL 105C was identified before, the Hubble view allows a more precise measurement of the separation between the binary components. Future Hubble observations of the binary orbit will allow the masses of both stars to be determined accurately. The Palomar group estimates that the companion's mass is 8-9 percent of the Sun's mass, which places it near the theoretical lower limit for stable hydrogen burning. Objects below this limit, called brown dwarfs, still 'shine' -- not by thermonuclear energy, but by the energy released through gravitational contraction. Two pictures, taken with Hubble's Wide Field Planetary Camera 2 (in PC mode) through different filters (in visible and near-infrared light) show that GL 105C is redder, hence cooler than GL 105A. The surface temperature of GL 105C is not precisely known, but may be as low as 2,600 degrees Kelvin (4,200 degrees Fahrenheit). This image was taken in near-infrared light, on January 5, 1995. GL 105C is located 3.4 arc seconds to the west-northwest of the larger GL 105A. (One arc second equals 1/3600 of a degree.) The bright spikes are caused by diffraction of light within the telescope's optical system, and the brighter white bar is an artifact of the CCD camera, which bleeds along a CCD column when a relatively bright

Hubble's diagram and cosmic expansion

PubMed Central

Kirshner, Robert P.

2004-01-01

Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velocities come chiefly from Vesto Melvin Slipher, and the interpretation in terms of the de Sitter effect is out of the mainstream of modern cosmology, this article opened the way to investigation of the expanding, evolving, and accelerating universe that engages today's burgeoning field of cosmology. PMID:14695886

Hubble induced mass after inflation in spectator field models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujita, Tomohiro; Harigaya, Keisuke, E-mail: tomofuji@stanford.edu, E-mail: keisukeh@icrr.u-tokyo.ac.jp

2016-12-01

Spectator field models such as the curvaton scenario and the modulated reheating are attractive scenarios for the generation of the cosmic curvature perturbation, as the constraints on inflation models are relaxed. In this paper, we discuss the effect of Hubble induced masses on the dynamics of spectator fields after inflation. We pay particular attention to the Hubble induced mass by the kinetic energy of an oscillating inflaton, which is generically unsuppressed but often overlooked. In the curvaton scenario, the Hubble induced mass relaxes the constraint on the property of the inflaton and the curvaton, such as the reheating temperature andmore » the inflation scale. We comment on the implication of our discussion for baryogenesis in the curvaton scenario. In the modulated reheating, the predictions of models e.g. the non-gaussianity can be considerably altered. Furthermore, we propose a new model of the modulated reheating utilizing the Hubble induced mass which realizes a wide range of the local non-gaussianity parameter.« less

Hubble illuminates the universe

NASA Technical Reports Server (NTRS)

Maran, Stephen P.

1992-01-01

Latest observations by the Hubble Space Telescope (HST) are described, including the first 'parallel' observations (on January 6, 1992) by the two of the Hubble's instruments of two different targets at the same time. On this date, the faint-object camera made images of the quasar 3C 273 in Virgo, while the wide-field and planetary camera recorded an adjacent field. The new HST images include those of the nucleus and the jet of M85, the giant elliptical galaxy at the heart of the Virgo cluster, and what appears to be a black hole of mass 2.6 billion solar masses in M87, and an image of N66, a planetary nebula in the LMC. Other images yield evidence of 'blue stragglers' in the core of 47 Tucanae, a globular cluster about 16,000 light-years from earth. The Goddard spectrograph recorded the spectrum of the star Capella at very high wavelength resolution, which made it possible to measure deuterium from the Big Bang.

The Far-Field Hubble Constant

NASA Astrophysics Data System (ADS)

Lauer, Tod

1995-07-01

We request deep, near-IR (F814W) WFPC2 images of five nearby Brightest Cluster Galaxies (BCG) to calibrate the BCG Hubble diagram by the Surface Brightness Fluctuation (SBF) method. Lauer & Postman (1992) show that the BCG Hubble diagram measured out to 15,000 km s^-1 is highly linear. Calibration of the Hubble diagram zeropoint by SBF will thus yield an accurate far-field measure of H_0 based on the entire volume within 15,000 km s^-1, thus circumventing any strong biases caused by local peculiar velocity fields. This method of reaching the far field is contrasted with those using distance ratios between Virgo and Coma, or any other limited sample of clusters. HST is required as the ground-based SBF method is limited to <3,000 km s^-1. The high spatial resolution of HST allows precise measurement of the SBF signal at large distances, and allows easy recognition of globular clusters, background galaxies, and dust clouds in the BCG images that must be removed prior to SBF detection. The proposing team developed the SBF method, the first BCG Hubble diagram based on a full-sky, volume-limited BCG sample, played major roles in the calibration of WFPC and WFPC2, and are conducting observations of local galaxies that will validate the SBF zeropoint (through GTO programs). This work uses the SBF method to tie both the Cepheid and Local Group giant-branch distances generated by HST to the large scale Hubble flow, which is most accurately traced by BCGs.

The 1% concordance Hubble constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, C. L.; Larson, D.; Weiland, J. L.

2014-10-20

The determination of the Hubble constant has been a central goal in observational astrophysics for nearly a hundred years. Extraordinary progress has occurred in recent years on two fronts: the cosmic distance ladder measurements at low redshift and cosmic microwave background (CMB) measurements at high redshift. The CMB is used to predict the current expansion rate through a best-fit cosmological model. Complementary progress has been made with baryon acoustic oscillation (BAO) measurements at relatively low redshifts. While BAO data do not independently determine a Hubble constant, they are important for constraints on possible solutions and checks on cosmic consistency. Amore » precise determination of the Hubble constant is of great value, but it is more important to compare the high and low redshift measurements to test our cosmological model. Significant tension would suggest either uncertainties not accounted for in the experimental estimates or the discovery of new physics beyond the standard model of cosmology. In this paper we examine in detail the tension between the CMB, BAO, and cosmic distance ladder data sets. We find that these measurements are consistent within reasonable statistical expectations and we combine them to determine a best-fit Hubble constant of 69.6 ± 0.7 km s{sup –1} Mpc{sup –1}. This value is based upon WMAP9+SPT+ACT+6dFGS+BOSS/DR11+H {sub 0}/Riess; we explore alternate data combinations in the text. The combined data constrain the Hubble constant to 1%, with no compelling evidence for new physics.« less

LRS Bianchi type-I cosmological model with constant deceleration parameter in f(R,T) gravity

NASA Astrophysics Data System (ADS)

Bishi, Binaya K.; Pacif, S. K. J.; Sahoo, P. K.; Singh, G. P.

A spatially homogeneous anisotropic LRS Bianchi type-I cosmological model is studied in f(R,T) gravity with a special form of Hubble's parameter, which leads to constant deceleration parameter. The parameters involved in the considered form of Hubble parameter can be tuned to match, our models with the ΛCDM model. With the present observed value of the deceleration parameter, we have discussed physical and kinematical properties of a specific model. Moreover, we have discussed the cosmological distances for our model.

Hubble Captures Cosmic Ice Sculptures

NASA Image and Video Library

2017-12-08

NASA image release September 16, 2010 Enjoying a frozen treat on a hot summer day can leave a sticky mess as it melts in the Sun and deforms. In the cold vacuum of space, there is no edible ice cream, but there is radiation from massive stars that is carving away at cold molecular clouds, creating bizarre, fantasy-like structures. These one-light-year-tall pillars of cold hydrogen and dust, imaged by the Hubble Space Telescope, are located in the Carina Nebula. Violent stellar winds and powerful radiation from massive stars are sculpting the surrounding nebula. Inside the dense structures, new stars may be born. This image of dust pillars in the Carina Nebula is a composite of 2005 observations taken of the region in hydrogen light (light emitted by hydrogen atoms) along with 2010 observations taken in oxygen light (light emitted by oxygen atoms), both times with Hubble's Advanced Camera for Surveys. The immense Carina Nebula is an estimated 7,500 light-years away in the southern constellation Carina. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C. NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Dismantling Hubble's Legacy?

NASA Astrophysics Data System (ADS)

Way, Michael J.

2014-01-01

Edwin Hubble is famous for a number of discoveries that are well known to amateur and professional astronomers, students and even the general public. The origins of three of the most well-known discoveries are examined: The distances to nearby spiral nebulae, the classification of extragalactic-nebulae and the Hubble constant. In the case of the first two a great deal of supporting evidence was already in place, but little credit was given. The Hubble Constant had already been estimated in 1927 by Georges Lemaitre with roughly the same value that Hubble obtained in 1929 using redshifts provided mostly by Vesto M. Slipher. These earlier estimates were not adopted or were forgotten by the astronomical community for complex scientific, sociological and psychological reasons.

Hubble Spies Spiral Galaxy

NASA Image and Video Library

2017-12-08

Spiral galaxy NGC 3274 is a relatively faint galaxy located over 20 million light-years away in the constellation of Leo (The Lion). This NASA/ESA Hubble Space Telescope image comes courtesy of Hubble's Wide Field Camera 3 (WFC3), whose multi-color vision allows astronomers to study a wide range of targets, from nearby star formation to galaxies in the most remote regions of the cosmos. This image combines observations gathered in five different filters, bringing together ultraviolet, visible and infrared light to show off NGC 3274 in all its glory. NGC 3274 was discovered by Wilhelm Herschel in 1783. The galaxy PGC 213714 is also visible on the upper right of the frame, located much farther away from Earth. Image Credit: ESA/Hubble & NASA, D. Calzetti NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

The Evolution of the Observed Hubble Sequence over the past 6Gyr

NASA Astrophysics Data System (ADS)

Delgado-Serrano, R.; Hammer, F.; Yang, Y. B.; Puech, M.; Flores, H.; Rodrigues, M.

2011-10-01

During the past years we have confronted serious problems of methodology concerning the morphological and kinematic classification of distant galaxies. This has forced us to create a new simple and effective morphological classification methodology, in order to guarantee a morpho-kinematic correlation, make the reproducibility easier and restrict the classification subjectivity. Giving the characteristic of our morphological classification, we have thus been able to apply the same methodology, using equivalent observations, to representative samples of local and distant galaxies. It has allowed us to derive, for the first time, the distant Hubble sequence (~6 Gyr ago), and determine a morphological evolution of galaxies over the past 6 Gyr. Our results strongly suggest that more than half of the present-day spirals had peculiar morphologies, 6 Gyr ago.

A Unique test for Hubble's new Solar Arrays

NASA Astrophysics Data System (ADS)

2000-10-01

In mid-October, a team from the European Space Agency (ESA) and NASA will perform a difficult, never-before-done test on one of the Hubble Space Telescope's new solar array panels. Two of these panels, or arrays, will be installed by astronauts in November 2001, when the Space Shuttle Columbia visits Hubble on a routine service mission. The test will ensure that the new arrays are solid and vibration free before they are installed on orbit. The test will be conducted at ESA's European Space Research and Technology Center (ESTEC) in Noordwijk, The Netherlands. Because of the array's size, the facility's special features, and ESA's longstanding experience with Hubble's solar arrays, ESTEC is the only place in the world the test can be performed. This test is the latest chapter in a longstanding partnership between ESA and NASA on the Hubble Space Telescope. The Large Space Simulator at ESTEC, ESA's world-class test facility, features a huge vacuum chamber containing a bank of extremely bright lights that simulate the Sun's intensity - including sunrise and sunset. By exposing the solar wing to the light and temperature extremes of Hubble's orbit, engineers can verify how the new set of arrays will act in space. Hubble orbits the Earth once every 90 minutes. During each orbit, the telescope experiences 45 minutes of searing sunlight and 45 minutes of frigid darkness. This test will detect any tiny vibrations, or jitters, caused by these dramatic, repeated changes. Even a small amount of jitter can affect Hubble's sensitive instruments and interfere with observations. Hubble's first set of solar arrays experienced mild jitter and was replaced in 1993 with a much more stable pair. Since that time, advances in solar cell technology have led to the development of even more efficient arrays. In 2001, NASA will take advantage of these improvements, by fitting Hubble with a third-generation set of arrays. Though smaller, this new set generates more power than the previous

An independent determination of the local Hubble constant

NASA Astrophysics Data System (ADS)

Fernández Arenas, David; Terlevich, Elena; Terlevich, Roberto; Melnick, Jorge; Chávez, Ricardo; Bresolin, Fabio; Telles, Eduardo; Plionis, Manolis; Basilakos, Spyros

2018-02-01

The relationship between the integrated H β line luminosity and the velocity dispersion of the ionized gas of H II galaxies and giant H II regions represents an exciting standard candle that presently can be used up to redshifts z ˜ 4. Locally it is used to obtain precise measurements of the Hubble constant by combining the slope of the relation obtained from nearby (z ≤ 0.2) H II galaxies with the zero-point determined from giant H II regions belonging to an `anchor sample' of galaxies for which accurate redshift-independent distance moduli are available. We present new data for 36 giant H II regions in 13 galaxies of the anchor sample that includes the megamaser galaxy NGC 4258. Our data are the result of the first 4 yr of observation of our primary sample of 130 giant H II regions in 73 galaxies with Cepheid determined distances. Our best estimate of the Hubble parameter is 71.0 ± 2.8(random) ± 2.1(systematic) km s- 1Mpc- 1. This result is the product of an independent approach and, although at present less precise than the latest SNIa results, it is amenable to substantial improvement.

Hubble Space Telescope Observations of M32: The Color-Magnitude Diagram

NASA Technical Reports Server (NTRS)

Grillmair, C. J.; Lauer, T. R.; Worthey, G.; Faber, S. M.; Freedman, W. L.; Madore, B. F.; Ajhar, E. A.; Baum, W. A.; Holtzman, J. A.; Lynds, C. R.;

Wide-field Hubble Space Telescope Observations of the Globular Cluster System in NGC 1399

NASA Astrophysics Data System (ADS)

Puzia, Thomas H.; Paolillo, Maurizio; Goudfrooij, Paul; Maccarone, Thomas J.; Fabbiano, Giuseppina; Angelini, Lorella

2014-05-01

the literature and split the resulting sample at the median rh value into compact and extended GCs. We find that compact GCs show a significantly smaller line-of-sight velocity dispersion, langσcmprang = 225 ± 25 km s-1, than their extended counterparts, langσextrang = 317 ± 21 km s-1. Considering the weaker statistical correlation in the GC rh color and the GC rh -R gal relations, the more significant GC size-dynamics relation appears to be astrophysically more relevant and hints at the dominant influence of the GC orbit distribution function on the evolution of GC structural parameters. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.

Modeling Hubble Space Telescope flight data by Q-Markov cover identification

NASA Technical Reports Server (NTRS)

Liu, K.; Skelton, R. E.; Sharkey, J. P.

1992-01-01

A state space model for the Hubble Space Telescope under the influence of unknown disturbances in orbit is presented. This model was obtained from flight data by applying the Q-Markov covariance equivalent realization identification algorithm. This state space model guarantees the match of the first Q-Markov parameters and covariance parameters of the Hubble system. The flight data were partitioned into high- and low-frequency components for more efficient Q-Markov cover modeling, to reduce some computational difficulties of the Q-Markov cover algorithm. This identification revealed more than 20 lightly damped modes within the bandwidth of the attitude control system. Comparisons with the analytical (TREETOPS) model are also included.

Interpretation of the Hubble diagram in a nonhomogeneous universe

NASA Astrophysics Data System (ADS)

Fleury, Pierre; Dupuy, Hélène; Uzan, Jean-Philippe

2013-06-01

In the standard cosmological framework, the Hubble diagram is interpreted by assuming that the light emitted by standard candles propagates in a spatially homogeneous and isotropic spacetime. However, the light from “point sources”—such as supernovae—probes the Universe on scales where the homogeneity principle is no longer valid. Inhomogeneities are expected to induce a bias and a dispersion of the Hubble diagram. This is investigated by considering a Swiss-cheese cosmological model, which (1) is an exact solution of the Einstein field equations, (2) is strongly inhomogeneous on small scales, but (3) has the same expansion history as a strictly homogeneous and isotropic universe. By simulating Hubble diagrams in such models, we quantify the influence of inhomogeneities on the measurement of the cosmological parameters. Though significant in general, the effects reduce drastically for a universe dominated by the cosmological constant.

HUBBLE SHOOTS THE MOON

NASA Technical Reports Server (NTRS)

2002-01-01

In a change of venue from peering at the distant universe, NASA's Hubble Space Telescope has taken a look at Earth's closest neighbor in space, the Moon. Hubble was aimed at one of the Moon's most dramatic and photogenic targets, the 58 mile-wide (93 km) impact crater Copernicus. The image was taken while the Space Telescope Imaging Spectrograph (STIS) was aimed at a different part of the moon to measure the colors of sunlight reflected off the Moon. Hubble cannot look at the Sun directly and so must use reflected light to make measurements of the Sun's spectrum. Once calibrated by measuring the Sun's spectrum, the STIS can be used to study how the planets both absorb and reflect sunlight. (upper left) The Moon is so close to Earth that Hubble would need to take a mosaic of 130 pictures to cover the entire disk. This ground-based picture from Lick Observatory shows the area covered in Hubble's photomosaic with the Wide Field Planetary Camera 2.. (center) Hubble's crisp bird's-eye view clearly shows the ray pattern of bright dust ejected out of the crater over one billion years ago, when an asteroid larger than a mile across slammed into the Moon. Hubble can resolve features as small as 600 feet across in the terraced walls of the crater, and the hummock-like blanket of material blasted out by the meteor impact. (lower right) A close-up view of Copernicus' terraced walls. Hubble can resolve features as small as 280 feet across. Credit: John Caldwell (York University, Ontario), Alex Storrs (STScI), and NASA

The Compatibility of Friedmann Cosmological Models with Observed Properties of Gamma-Ray Bursts and a Large Hubble Constant

NASA Technical Reports Server (NTRS)

Horack, John M.; Koshut, Thomas M.; Mallozzi, Robert S.; Emslie, A. Gordon; Meegan, Charles A.

1996-01-01

The distance scale to cosmic gamma-ray bursts (GRB's) is still uncertain by many orders of magnitude; however, one viable scenario places GRB's at cosmological distances, thereby permitting them to be used as tracers of the cosmological expansion over a significant range of redshifts zeta. Also, several recent measurements of the Hubble constant H(sub 0) appearing in the referred literature report values of 70-80 km/s /Mpc. Although there is significant debate regarding these measurements, we proceed here under the assumption that they are evidence of a large value for H(sub 0). This is done in order to investigate the additional constraints on cosmological models that can be obtained under this hypothesis when combined with the age of the universe and the brightness distribution of cosmological gamma-ray bursts. We show that the range of cosmological models that can be consistent with the GRB brightness distribution, a Hubble constant of 70-80 km/s/Mpc, and a minimum age of the universe of 13-15 Gyr is constrained significantly, largely independent of a wide range of assumptions regarding the evolutionary nature of the burst population. Low-density, Lambda greater than 0 cosmological models with deceleration parameter in the range -1 less than q(sub 0) less than 0 and density parameter sigma(sub 0) in the range approximately equals 0.10-0.25(Omega(sub 0) approximately equals 0.2-0.5) are strongly favored.

Hubble's Wide View of 'Mystic Mountain' in Infrared

NASA Image and Video Library

2010-04-23

NASA image release April 22, 2010 This is a NASA Hubble Space Telescope near-infrared-light image of a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby stars in the tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away in the southern constellation Carina. The image marks the 20th anniversary of Hubble's launch and deployment into an orbit around Earth. The image reveals a plethora of stars behind the gaseous veil of the nebula's wall of hydrogen, laced with dust. The foreground pillar becomes semi-transparent because infrared light from background stars penetrates through much of the dust. A few stars inside the pillar also become visible. The false colors are assigned to three different infrared wavelength ranges. Hubble's Wide Field Camera 3 observed the pillar in February and March 2010. Object Names: HH 901, HH 902 Image Type: Astronomical Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) To read learn more about this image go to: www.nasa.gov/mission_pages/hubble/science/hubble20th-img.... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

The Hubble Constant from Supernovae

NASA Astrophysics Data System (ADS)

Saha, Abhijit; Macri, Lucas M.

The decades-long quest to obtain a precise and accurate measurement of the local expansion rate of the universe (the Hubble Constant or H0) has greatly benefited from the use of supernovae (SNe). Starting from humble beginnings (dispersions of ˜ 0.5 mag in the Hubble flow in the late 1960s/early 1970s), the increasingly more sophisticated understanding, classification, and analysis of these events turned type Ia SNe into the premiere choice for a secondary distance indicator by the early 1990s. While some systematic uncertainties specific to SNe and to Cepheid-based distances to the calibrating host galaxies still contribute to the H0 error budget, the major emphasis over the past two decades has been on reducing the statistical uncertainty by obtaining ever-larger samples of distances to SN hosts. Building on early efforts with the first-generation instruments on the Hubble Space Telescope, recent observations with the latest instruments on this facility have reduced the estimated total uncertainty on H0 to 2.4 % and shown a path to reach a 1 % measurement by the end of the decade, aided by Gaia and the James Webb Space Telescope.

Science from a glimpse: Hubble SNAPshot observations of massive galaxy clusters

NASA Astrophysics Data System (ADS)

Repp, A.; Ebeling, H.

2018-06-01

Hubble Space Telescope SNAPshot surveys of 86 X-ray selected galaxy clusters at 0.3 < z < 0.5 from the MACS sample have proven invaluable for the exploration of a wide range of astronomical research topics. We here present an overview of the four MACS SNAPshot surveys conducted from Cycle 14 to Cycle 20 as part of a long-term effort aimed at identifying exceptional cluster targets for in-depth follow up by the extragalactic community. We also release redshifts and X-ray luminosities of all clusters observed as part of this initiative. To illustrate the power of SNAPshot observations of MACS clusters, we explore several aspects of galaxy evolution illuminated by the images obtained for these programmes. We confirm the high lensing efficiency of X-ray selected clusters at z > 0.3. Examining the evolution of the slope of the cluster red sequence, we observe at best a slight decrease with redshift, indicating minimal age contribution since z ˜ 1. Congruent to previous studies' findings, we note that the two BCGs which are significantly bluer (≥5σ) than their clusters' red sequences reside in relaxed clusters and exhibit pronounced internal structure. Thanks to our targets' high X-ray luminosity, the subset of our sample observed with Chandra adds valuable leverage to the X-ray luminosity-optical richness relation, which, albeit with substantial scatter, is now clearly established from groups to extremely massive clusters of galaxies. We conclude that SNAPshot observations of MACS clusters stand to continue to play a vital pathfinder role for astrophysical investigations across the entire electromagnetic spectrum.

Hubble space telescope observations and geometric models of compact multipolar planetary nebulae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsia, Chih-Hao; Chau, Wayne; Zhang, Yong

2014-05-20

We report high angular resolution Hubble Space Telescope observations of 10 compact planetary nebulae (PNs). Many interesting internal structures, including multipolar lobes, arcs, two-dimensional rings, tori, and halos, are revealed for the first time. These results suggest that multipolar structures are common among PNs, and these structures develop early in their evolution. From three-dimensional geometric models, we have determined the intrinsic dimensions of the lobes. Assuming the lobes are the result of interactions between later-developed fast winds and previously ejected asymptotic giant branch winds, the geometric structures of these PNs suggest that there are multiple phases of fast winds separatedmore » by temporal variations and/or directional changes. A scenario of evolution from lobe-dominated to cavity-dominated stages is presented. The results reported here will provide serious constraints on any dynamical models of PNs.« less

Hubble Space Telescope: The Real ‘First Light’ Observation

NASA Astrophysics Data System (ADS)

Benedict, G. F.; McArthur, B.

2014-01-01

To prove that a telescope will meet the design specifications laid down years previously, that it will eventually produce the science envisioned by those designers, they make a ‘first light’ observation, assess it, and pronounce “Here is our new telescope! It works!” That observation is often made with an instrument on the telescope that goes on to make many scientifically productive discoveries. The official Hubble Space Telescope (HST) first light image was secured by the Wide Field Planetary Camera on 5/20/1990, certainly a productive science instrument. The HST Fine Guidance Sensors (FGS), white-light interferometers, have an essential role to play in any scientific observation made with HST. They stabilize HST by locking onto guide stars. The Fine Guidance Sensors (FGS) have on their own produced useful and exciting astrometric scientific results ranging from parallaxes of Galactic Cepheids useful for the cosmic distance scale (Benedict et al. 2007, AJ, 133, 1810) to a demonstration of the degree of coplanarity in an exoplanetary system (McArthur et al. 2010, ApJ, 715, 1203). Hence, we argue that an FGS made the actual first light observation shortly after midnight on 1 May 1990 by successfully locking onto the V=12.97 star GSC 02666-01602. That FGS observation demonstrated light passing through the HST entire optical system and HST tracking. With a little (well, actually quite a lot of) tweaking, scientific results would surely flood forth. However, on May Day 1990 locking success was oddly sporadic. We had a few weeks more to enjoy our blissful ignorance of flapping solar panels and a mis-figured primary mirror, both of which contributed that night to our true first light observation problems. The events of that night and subsequent successful FGS astrometry are thanks to contributions over the years from L. Abramowicz-Reed, A. Bradley*, R. Duncombe, O. Franz, L. Fredrick, P. Hemenway, W. Jefferys, E. Nelan*, P. Shelus, D. Story*, W. van Altena, L

Chandra Independently Determines Hubble Constant

NASA Astrophysics Data System (ADS)

2006-08-01

A critically important number that specifies the expansion rate of the Universe, the so-called Hubble constant, has been independently determined using NASA's Chandra X-ray Observatory. This new value matches recent measurements using other methods and extends their validity to greater distances, thus allowing astronomers to probe earlier epochs in the evolution of the Universe. "The reason this result is so significant is that we need the Hubble constant to tell us the size of the Universe, its age, and how much matter it contains," said Max Bonamente from the University of Alabama in Huntsville and NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., lead author on the paper describing the results. "Astronomers absolutely need to trust this number because we use it for countless calculations." Illustration of Sunyaev-Zeldovich Effect Illustration of Sunyaev-Zeldovich Effect The Hubble constant is calculated by measuring the speed at which objects are moving away from us and dividing by their distance. Most of the previous attempts to determine the Hubble constant have involved using a multi-step, or distance ladder, approach in which the distance to nearby galaxies is used as the basis for determining greater distances. The most common approach has been to use a well-studied type of pulsating star known as a Cepheid variable, in conjunction with more distant supernovae to trace distances across the Universe. Scientists using this method and observations from the Hubble Space Telescope were able to measure the Hubble constant to within 10%. However, only independent checks would give them the confidence they desired, considering that much of our understanding of the Universe hangs in the balance. Chandra X-ray Image of MACS J1149.5+223 Chandra X-ray Image of MACS J1149.5+223 By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion

NASA's Hubble Universe in 3-D

NASA Image and Video Library

2017-12-08

This image depicts a vast canyon of dust and gas in the Orion Nebula from a 3-D computer model based on observations by NASA's Hubble Space Telescope and created by science visualization specialists at the Space Telescope Science Institute (STScI) in Baltimore, Md. A 3-D visualization of this model takes viewers on an amazing four-minute voyage through the 15-light-year-wide canyon. Credit: NASA, G. Bacon, L. Frattare, Z. Levay, and F. Summers (STScI/AURA) Go here to learn more about Hubble 3D: www.nasa.gov/topics/universe/features/hubble_imax_premier... or www.imax.com/hubble/ Take an exhilarating ride through the Orion Nebula, a vast star-making factory 1,500 light-years away. Swoop through Orion's giant canyon of gas and dust. Fly past behemoth stars whose brilliant light illuminates and energizes the entire cloudy region. Zoom by dusty tadpole-shaped objects that are fledgling solar systems. This virtual space journey isn't the latest video game but one of several groundbreaking astronomy visualizations created by specialists at the Space Telescope Science Institute (STScI) in Baltimore, the science operations center for NASA's Hubble Space Telescope. The cinematic space odysseys are part of the new Imax film "Hubble 3D," which opens today at select Imax theaters worldwide. The 43-minute movie chronicles the 20-year life of Hubble and includes highlights from the May 2009 servicing mission to the Earth-orbiting observatory, with footage taken by the astronauts. The giant-screen film showcases some of Hubble's breathtaking iconic pictures, such as the Eagle Nebula's "Pillars of Creation," as well as stunning views taken by the newly installed Wide Field Camera 3. While Hubble pictures of celestial objects are awe-inspiring, they are flat 2-D photographs. For this film, those 2-D images have been converted into 3-D environments, giving the audience the impression they are space travelers taking a tour of Hubble's most popular targets. "A large-format movie is a

Hubble's Slice of Sagittarius

NASA Image and Video Library

2017-12-08

This stunning image, captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), shows part of the sky in the constellation of Sagittarius (The Archer). The region is rendered in exquisite detail — deep red and bright blue stars are scattered across the frame, set against a background of thousands of more distant stars and galaxies. Two features are particularly striking: the colors of the stars, and the dramatic crosses that burst from the centers of the brightest bodies. While some of the colors in this frame have been enhanced and tweaked during the process of creating the image from the observational data, different stars do indeed glow in different colors. Stars differ in color according to their surface temperature: very hot stars are blue or white, while cooler stars are redder. They may be cooler because they are smaller, or because they are very old and have entered the red giant phase, when an old star expands and cools dramatically as its core collapses. The crosses are nothing to do with the stars themselves, and, because Hubble orbits above Earth’s atmosphere, nor are they due to any kind of atmospheric disturbance. They are actually known as diffraction spikes, and are caused by the structure of the telescope itself. Like all big modern telescopes, Hubble uses mirrors to capture light and form images. Its secondary mirror is supported by struts, called telescope spiders, arranged in a cross formation, and they diffract the incoming light. Diffraction is the slight bending of light as it passes near the edge of an object. Every cross in this image is due to a single set of struts within Hubble itself! Whilst the spikes are technically an inaccuracy, many astrophotographers choose to emphasize and celebrate them as a beautiful feature of their images. Image credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science

Hubble Space Telescope Fine Guidance Sensor interferometric observations of the core of 30 doradus

NASA Technical Reports Server (NTRS)

Lattanzi, M. G.; Hershey, J. L.; Burg, R.; Taff, L. G.; Holfeltz, S. T.; Bucciarelli, B.; Evans, I. N.; Gilmozzi, R.; Pringle, J.; Walborn, N. R.

1994-01-01

We present the results of the first high angular resolution observations taken with a Fine Guidance Sensor (FGS) aboard the Hubble Space Telescope (HST) of a star cluster embedded in very bright background. The strong and complex background around the R136 cluster in the 30 Dor nebula does not prevent the FGS from achieving performance close to its angular resolution limit of approximately 0.015 sec per axis with reliable photometry. These FGS observations establish that the central object in R136a is a triple star with the third component delta V = 1.1 mag fainter than the primary star al approximately 0.08 sec way. We estimate from the grid of models of Maeder (1990) that the present mass of al is between 30 and 80 solar masses, with the main-sequence progenitor between 60 and 120 solar masses.

Hubble Against Earth Horizon 1997

NASA Image and Video Library

1997-10-10

The Hubble Space Telescope hovers at the boundary of Earth and space in this picture, taken after Hubble second servicing mission in 1997. Hubble drifts 353 miles (569 km) above the Earth's surface, where it can avoid the atmosphere and clearly see objects in space. http://photojournal.jpl.nasa.gov/catalog/PIA18165

Hubble Space Telescope Observations of Variations in Ganymede's Oxygen Atmosphere and Aurora

NASA Astrophysics Data System (ADS)

Molyneux, P. M.; Nichols, J. D.; Bannister, N. P.; Bunce, E. J.; Clarke, J. T.; Cowley, S. W. H.; Gérard, J.-C.; Grodent, D.; Milan, S. E.; Paty, C.

2018-05-01

We present high-sensitivity Hubble Space Telescope (HST) Cosmic Origins Spectrograph and HST Space Telescope Imaging Spectrograph measurements of atmospheric OI 130.4-nm and OI] 135.6-nm emissions at Ganymede, which exhibit significant spatial and temporal variability. These observations represent the first observations of Ganymede using HST Cosmic Origins Spectrograph and of both the leading and trailing hemispheres within a single HST campaign, minimizing the potential influence of long-term changes in the Jovian plasma sheet or in Ganymede's atmosphere on the comparison of the two hemispheres. The mean disk-averaged OI] 135.6-nm/OI 130.4-nm observed intensity ratio was 2.72 ± 0.57 on the leading hemisphere and 1.42 ± 0.16 on the trailing hemisphere. The observed leading hemisphere ratios are consistent with an O2 atmosphere, but we show that an atomic oxygen component of 10% is required to produce the observed trailing hemisphere ratios. The excess 130.4-nm emission on the trailing hemisphere relative to that expected for an O2 atmosphere was 11 R. The O column density required to produce this excess is determined based on previous estimates of the electron density and temperature at Ganymede and exceeds the limit for an optically thin atmosphere. The implication that the O atmosphere is optically thick may be investigated in future by observing Ganymede as it moves into eclipse or by determining the ratio of the individual components within the 130.4-nm triplet.

Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) Program

NASA Astrophysics Data System (ADS)

Simon, Amy

2017-08-01

Long time base observations of the outer planets are critical in understanding the atmospheric dynamics and evolution of the gas giants. We propose yearly monitoring of each giant planet for the remainder of Hubble's lifetime to provide a lasting legacy of increasingly valuable data for time-domain studies. The Hubble Space Telescope is a unique asset to planetary science, allowing high spatial resolution data with absolute photometric knowledge. For the outer planets, gas/ice giant planets Jupiter, Saturn, Uranus and Neptune, many phenomena happen on timescales of years to decades, and the data we propose are beyond the scope of a typical GO program. Hubble is the only platform that can provide high spatial resolution global studies of cloud coloration, activity, and motion on a consistent time basis to help constrain the underlying mechanics.

Hubble reveals the Ring Nebula’s true shape

NASA Image and Video Library

2017-12-08

Caption: In this composite image, visible-light observations by NASA’s Hubble Space Telescope are combined with infrared data from the ground-based Large Binocular Telescope in Arizona to assemble a dramatic view of the well-known Ring Nebula. Credit: NASA, ESA, C.R. Robert O’Dell (Vanderbilt University), G.J. Ferland (University of Kentucky), W.J. Henney and M. Peimbert (National Autonomous University of Mexico) Credit for Large Binocular Telescope data: David Thompson (University of Arizona) ---- The Ring Nebula's distinctive shape makes it a popular illustration for astronomy books. But new observations by NASA's Hubble Space Telescope of the glowing gas shroud around an old, dying, sun-like star reveal a new twist. "The nebula is not like a bagel, but rather, it's like a jelly doughnut, because it's filled with material in the middle," said C. Robert O'Dell of Vanderbilt University in Nashville, Tenn. He leads a research team that used Hubble and several ground-based telescopes to obtain the best view yet of the iconic nebula. The images show a more complex structure than astronomers once thought and have allowed them to construct the most precise 3-D model of the nebula. "With Hubble's detail, we see a completely different shape than what's been thought about historically for this classic nebula," O'Dell said. "The new Hubble observations show the nebula in much clearer detail, and we see things are not as simple as we previously thought." The Ring Nebula is about 2,000 light-years from Earth and measures roughly 1 light-year across. Located in the constellation Lyra, the nebula is a popular target for amateur astronomers. Read more: 1.usa.gov/14VAOMk NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the

Joint cosmic microwave background and weak lensing analysis: constraints on cosmological parameters.

PubMed

Contaldi, Carlo R; Hoekstra, Henk; Lewis, Antony

2003-06-06

We use cosmic microwave background (CMB) observations together with the red-sequence cluster survey weak lensing results to derive constraints on a range of cosmological parameters. This particular choice of observations is motivated by their robust physical interpretation and complementarity. Our combined analysis, including a weak nucleosynthesis constraint, yields accurate determinations of a number of parameters including the amplitude of fluctuations sigma(8)=0.89+/-0.05 and matter density Omega(m)=0.30+/-0.03. We also find a value for the Hubble parameter of H(0)=70+/-3 km s(-1) Mpc(-1), in good agreement with the Hubble Space Telescope key-project result. We conclude that the combination of CMB and weak lensing data provides some of the most powerful constraints available in cosmology today.

Cosmological test with the QSO Hubble diagram

NASA Astrophysics Data System (ADS)

López-Corredoira, M.; Melia, F.; Lusso, E.; Risaliti, G.

2016-03-01

A Hubble diagram (HD) has recently been constructed in the redshift range 0 ≲ z ≲ 6.5 using a nonlinear relation between the ultraviolet (UV) and X-ray luminosities of quasi stellar objects (QSOs). The Type Ia Supernovae (SN) HD has already provided a high-precision test of cosmological models, but the fact that the QSO distribution extends well beyond the supernova range (z ≲ 1.8), in principle provides us with an important complementary diagnostic whose significantly greater leverage in z can impose tighter constraints on the distance versus redshift relationship. In this paper, we therefore perform an independent test of nine different cosmological models, among which six are expanding, while three are static. Many of these are disfavored by other kinds of observations (including the aforementioned Type Ia SNe). We wish to examine whether the QSO HD confirms or rejects these earlier conclusions. We find that four of these models (Einstein-de Sitter, the Milne universe, the static universe with simple tired light and the static universe with plasma tired light) are excluded at the > 99% C.L. The quasi-steady state model is excluded at > 95% C.L. The remaining four models (ΛCDM/wCDM, the Rh = ct universe, the Friedmann open universe and a static universe with a linear Hubble law) all pass the test. However, only ΛCDM/wCDM and Rh = ct also pass the Alcock-Paczyński (AP) test. The optimized parameters in ΛCDM/wCDM are Ωm = 0.20-0.20+0.24 and wde = -1.2-∞+1.6 (the dark energy equation-of-state). Combined with the AP test, these values become Ωm = 0.38-0.19+0.20 and wde = -0.28-0.40+0.52. But whereas this optimization of parameters in ΛCDM/wCDM creates some tension with their concordance values, the Rh = ct universe has the advantage of fitting the QSO and AP data without any free parameters.

Repairing Hubble Exhibit Reception

NASA Image and Video Library

2014-04-23

Individuals in attendance who had a hand in the development or servicing of the Hubble Space Telescope pose for a group photo at an event unveiling a new exhibit featuring Hubble's Corrective Optics Space Telescope Axial Replacement (COSTAR) and the WFPC2 on Wednesday, April 23, 2014 at the Smithsonian National Air and Space Museum in Washington, DC. COSTAR and WFPC2 were installed in Hubble during the first space shuttle servicing mission in 1993 and returned to Earth on the fifth and final servicing mission in 2009. Photo Credit: (NASA/Joel Kowsky)

Observing Supernova 1987A with the Refurbished Hubble Space Telescope

NASA Technical Reports Server (NTRS)

France, Kevin; McCray, Richard; Heng, Kevin; Kirshner, Robert P.; Challis, Peter; Bouchet, Patrice; Crotts, Arlin; Dwek, Eli; Fransson, Claes; Garnavich, Peter M.;

Observational information for f(T) theories and dark torsion

NASA Astrophysics Data System (ADS)

Bengochea, Gabriel R.

2011-01-01

In the present work we analyze and compare the information coming from different observational data sets in the context of a sort of f(T) theories. We perform a joint analysis with measurements of the most recent type Ia supernovae (SNe Ia), Baryon Acoustic Oscillation (BAO), Cosmic Microwave Background radiation (CMB), Gamma-Ray Bursts data (GRBs) and Hubble parameter observations (OHD) to constraint the only new parameter these theories have. It is shown that when the new combined BAO/CMB parameter is used to put constraints, the result is different from previous works. We also show that when we include Observational Hubble Data (OHD) the simpler ΛCDM model is excluded to one sigma level, leading the effective equation of state of these theories to be of phantom type. Also, analyzing a tension criterion for SNe Ia and other observational sets, we obtain more consistent and better suited data sets to work with these theories.

Hubble Space Telescope observations of comet P/Shoemaker-Levy 9 (1993e)

USGS Publications Warehouse

Weaver, H.A.; Feldman, P.D.; A'Hearn, M.F.; Arpigny, C.; Brown, R.A.; Helin, E.F.; Levy, D.H.; Marsden, B.G.; Meech, K.J.; Larson, S.M.; Noll, K.S.; Scotti, J.V.; Sekanina, Z.; Shoemaker, C.S.; Shoemaker, E.M.; Smith, T.E.; Storrs, A.D.; Yeomans, D.K.; Zellner, B.

1994-01-01

The Hubble Space Telescope observed the fragmented comet P/Shoemaker-Levy 9 (1993e) (P indicates that it is a periodic comet) on 1 July 1993. Approximately 20 individual nuclei and their comae were observed in images taken with the Planetary Camera. After subtraction of the comae light, the 11 brightest nuclei have magnitudes between ~23.7 and 24.8. Assuming that the geometric albedo is 0.04, these magnitudes imply that the nuclear diameters are in the range ~2.5 to 4.3 kilometers. If the density of each nucleus is 1 gram per cubic centimeter, the total energy deposited by the impact of these 11 nuclei into Jupiter's atmosphere next July will be ~4 x 1030 ergs (~108 megatons of TNT). This latter number should be regarded as an upper limit because the nuclear magnitudes probably contain a small residual coma contribution. The Faint Object Spectrograph was used to search for fluorescence from OH, which is usually an excellent indicator of cometary activity. No OH emission was detected, and this can be translated into an upper limit on the water production rate of ~2 x 1027 molecules per second.

New Hubble Servicing Mission to upgrade instruments

NASA Astrophysics Data System (ADS)

2006-10-01

The history of the NASA/ESA Hubble Space Telescope is dominated by the familiar sharp images and amazing discoveries that have had an unprecedented scientific impact on our view of the world and our understanding of the universe. Nevertheless, such important contributions to science and humankind have only been possible as result of regular upgrades and enhancements to Hubble’s instrumentation. Using the Space Shuttle for this fifth Servicing Mission underlines the important role that astronauts have played and continue to play in increasing the Space Telescope’s lifespan and scientific power. Since the loss of Columbia in 2003, the Shuttle has been successfully launched on three missions, confirming that improvements made to it have established the required high level of safety for the spacecraft and its crew. “There is never going to be an end to the science that we can do with a machine like Hubble”, says David Southwood, ESA’s Director of Science. “Hubble is our way of exploring our origins. Everyone should be proud that there is a European element to it and that we all are part of its success at some level.” This Servicing Mission will not just ensure that Hubble can function for perhaps as much as another ten years; it will also increase its capabilities significantly in key areas. This highly visible mission is expected to take place in 2008 and will feature several space walks. As part of the upgrade, two new scientific instruments will be installed: the Cosmic Origins Spectrograph and Wide Field Camera 3. Each has advanced technology sensors that will dramatically improve Hubble’s potential for discovery and enable it to observe faint light from the youngest stars and galaxies in the universe. With such an astounding increase in its science capabilities, this orbital observatory will continue to penetrate the most distant regions of outer space and reveal breathtaking phenomena. “Today, Hubble is producing more science than ever before in

Hot Star Extension to the Hubble Space Telescope Stellar Spectral Library

NASA Astrophysics Data System (ADS)

Khan, Islam; Worthey, Guy

2017-01-01

CCD spectra of 36 stars were obtained from the Space Telescope Imaging Spectrograph (STIS) installed in the Hubble Space Telescope (HST) using three low resolution gratings - G230LB, G430L, and G750L, combined in processing to make single, continuous spectra from 0.2 to 1.0 micrometers. These spectra will be added to the Next Generation Stellar Library (NGSL) after completing the data analysis, reduction, and the required corrections. The stars include normal O-type stars, helium-burning stars, and post-asymptotic giant branch (PAGB) stars. Difficult steps in the data reduction process were removing the cosmic rays from the raw images and defringing of the G750L spectra using fringe flats. Most stars have detectable dust extinction. To aid in analysis, synthetic spectra were generated with various effective temperatures and surface gravities. A five parameter analytic model for the dust extinction correction was adopted. The parameters were varied in order to fit especially the ultraviolet portion of the observed and comparison synthetic spectra. Cross-correlation was used to bring the spectra to a common, final, zero velocity wavelength scale. Some star temperatures obtained from fitting synthetic versus observed spectra vary significantly from literature values. The dust extinction correction parameters also varied for several stars, mostly O stars, indicating variations in dust properties for different lines of sight. Analysis of scattered light effects showed that it was significant only for our two coolest stars.Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.Support for this work was provided by NASA through grant number HST-GO-14141 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Hubble Space Telescope On-orbit Transfer Function Test

NASA Technical Reports Server (NTRS)

Vadlamudi, N.; Blair, M. A.; Clapp, B. R.

1992-01-01

The paper describes the On-orbit Transfer Function Test (TFT) designed for on-orbit vibration testing of the Hubble Space Telescope (HST). The TFT provides means for extracting accurate on-orbit characteristics of HST flexible body dynamics, making it possible to check periodically the state of the vehicle on-orbit and to assess changes in modal parameters.

HUBBLE OBSERVES SPIRAL GAS DISK IN ACTIVE GALAXY

NASA Technical Reports Server (NTRS)

2002-01-01

A NASA Hubble Space Telescope image of a spiral-shaped disk of hot gas in the core of active galaxy M87. HST measurements show the disk is rotating so rapidly it contains a massive black hole at its hub. A black hole is an object that is so massive yet compact nothing can escape its gravitational pull, not even light. The object at the center of M87 fits that description. It weights as much as three billion suns, but is concentrated into a space no larger than our solar system. Now that astronomers have seen the signature of the tremendous gravitational field at the center of M87, it is clear that the region contains only a fraction of the number of stars that would be necessary to create such a powerful attraction. The giant elliptical galaxy M87 is located 50 million light-years away in the constellation Virgo. Earlier observations suggested the black hole was present, but were not decisive. A brilliant jet of high- speed electrons that emits from the nucleus (diagonal line across image) is believed to be produced by the black hole 'engine.' The image was taken with HST's Wide Field Planetary Camera 2 Credit: Holland Ford, Space Telescope Science Institute/Johns Hopkins University; Richard Harms, Applied Research Corp.; Zlatan Tsvetanov, Arthur Davidsen, and Gerard Kriss at Johns Hopkins; Ralph Bohlin and George Hartig at Space Telescope Science Institute; Linda Dressel and Ajay K. Kochhar at Applied Research Corp. in Landover, Md.; and Bruce Margon from the University of Washington in Seattle. NASA PHOTO CAPTION STScI-PR94-23a

Properties of the nuclei and comae of 10 ecliptic comets from Hubble Space Telescope multi-orbit observations

NASA Astrophysics Data System (ADS)

Lamy, P. L.; Toth, I.; Weaver, H. A.; A'Hearn, M. F.; Jorda, L.

2011-04-01

We report on our on-going effort to detect and characterize cometary nuclei with the Hubble Space Telescope (HST). During cycle 9 (2000 July to 2001 June), we performed multi-orbit observations of 10 ecliptic comets with the Wide Field Planetary Camera 2. Nominally, eight contiguous orbits covering a time interval of ˜11 h were devoted to each comet but a few orbits were occasionally lost. In addition to the standard R band, we could additionally observe four of them in the V band and the two brightest ones in the B band. Time series photometry was used to constrain the size, shape and rotational period of the 10 nuclei. Assuming a geometric albedo of 0.04 for the R band, a linear phase law with a coefficient of 0.04 mag deg-1 and an opposition effect similar to that of comet 19P/Borrelly, we determined the following mean values of the effective radii 47P/Ashbrook-Jackson: 2.86±0.08 km, 61P/Shajn-Schaldach: 0.62±0.02 km, 70P/Kojima: 1.83±0.05 km, 74P/Smirnova-Chernykh: 2.23±0.04 km, 76P/West-Kohoutek-Ikemura: 0.30±0.02 km, 82P/Gehrels 3: 0.69±0.02 km, 86P/Wild 3: 0.41±0.03 km, 87P/Bus: 0.270.01 km, 110P/Hartley 3: 2.15±0.04 km and 147P/Kushida-Muramatsu: 0.21±0.01 km. Because of the limited time coverage (˜11 h), the rotational periods could not be accurately determined, multiple solutions were sometime found and three periods were not constrained at all. Our estimates range from ˜5 to ˜32 h. The lower limits for the ratio a/b of the semi-axis of the equivalent spheroids range from 1.10 (70P) to 2.20 (87P). The four nuclei for which we could measure (V-R) are all significantly redder than the Sun, with 86P/Wild 3 (V-R) = 0.86 ± 0.10 appearing as an ultrared object. We finally determined the dust activity parameter Afρ of their coma in the R band, the colour indices and the reflectivity spectra of four of them. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at Space Telescope Science Institute, which is operated by the

Beyond the Hubble Constant

NASA Astrophysics Data System (ADS)

1995-08-01

about the distances to galaxies and thereby about the expansion rate of the Universe. A simple way to determine the distance to a remote galaxy is by measuring its redshift, calculate its velocity from the redshift and divide this by the Hubble constant, H0. For instance, the measured redshift of the parent galaxy of SN 1995K (0.478) yields a velocity of 116,000 km/sec, somewhat more than one-third of the speed of light (300,000 km/sec). From the universal expansion rate, described by the Hubble constant (H0 = 20 km/sec per million lightyears as found by some studies), this velocity would indicate a distance to the supernova and its parent galaxy of about 5,800 million lightyears. The explosion of the supernova would thus have taken place 5,800 million years ago, i.e. about 1,000 million years before the solar system was formed. However, such a simple calculation works only for relatively ``nearby'' objects, perhaps out to some hundred million lightyears. When we look much further into space, we also look far back in time and it is not excluded that the universal expansion rate, i.e. the Hubble constant, may have been different at earlier epochs. This means that unless we know the change of the Hubble constant with time, we cannot determine reliable distances of distant galaxies from their measured redshifts and velocities. At the same time, knowledge about such change or lack of the same will provide unique information about the time elapsed since the Universe began to expand (the ``Big Bang''), that is, the age of the Universe and also its ultimate fate. The Deceleration Parameter q0 Cosmologists are therefore eager to determine not only the current expansion rate (i.e., the Hubble constant, H0) but also its possible change with time (known as the deceleration parameter, q0). Although a highly accurate value of H0 has still not become available, increasing attention is now given to the observational determination of the second parameter, cf. also the Appendix at the

Hubble Source Catalog

NASA Astrophysics Data System (ADS)

Lubow, S.; Budavári, T.

2013-10-01

We have created an initial catalog of objects observed by the WFPC2 and ACS instruments on the Hubble Space Telescope (HST). The catalog is based on observations taken on more than 6000 visits (telescope pointings) of ACS/WFC and more than 25000 visits of WFPC2. The catalog is obtained by cross matching by position in the sky all Hubble Legacy Archive (HLA) Source Extractor source lists for these instruments. The source lists describe properties of source detections within a visit. The calculations are performed on a SQL Server database system. First we collect overlapping images into groups, e.g., Eta Car, and determine nearby (approximately matching) pairs of sources from different images within each group. We then apply a novel algorithm for improving the cross matching of pairs of sources by adjusting the astrometry of the images. Next, we combine pairwise matches into maximal sets of possible multi-source matches. We apply a greedy Bayesian method to split the maximal matches into more reliable matches. We test the accuracy of the matches by comparing the fluxes of the matched sources. The result is a set of information that ties together multiple observations of the same object. A byproduct of the catalog is greatly improved relative astrometry for many of the HST images. We also provide information on nondetections that can be used to determine dropouts. With the catalog, for the first time, one can carry out time domain, multi-wavelength studies across a large set of HST data. The catalog is publicly available. Much more can be done to expand the catalog capabilities.

Hubble Exoplanet Pro/Am Collaboration (Abstract)

NASA Astrophysics Data System (ADS)

Conti, D. M.

2016-06-01

(Abstract only) A collaborative effort is being organized between a world-wide network of amateur astronomers and a Hubble Space Telescope (HST) science team. The purpose of this collaboration is to supplement an HST near-infrared spectroscopy survey of some 15 exoplanets with ground-based observations in the visible range.

The Hubble Space Telescope at 25: Lessons Learned for Future Missions

NASA Astrophysics Data System (ADS)

Wiseman, Jennifer

2015-08-01

This year we celebrate the 25th anniversary of the Hubble Space Telescope mission. Astronomy worldwide has been transformed by the discoveries made with Hubble. At this momentous milestone it is important to reflect on the unique successes of Hubble, and the components of that success, as the astronomical community develops facilities and a vision for future major international efforts in scientific space exploration. First, Hubble was envisioned by pioneering astronomers long before its launch, galvanizing support from astronomers, NASA, and governmental leaders for such an innovative and risky endeavor. Second, the interplay of the astronaut program with scientific exploration was paramount to the success of Hubble, not only with the initial dramatic repair mission, but also for the subsequent five servicing missions that kept the observatory perpetually refreshed. Cooperative missions involving astronauts, engineers, and scientists may be critical for constructing and operating large facilities in space in the future. Third, the scientific discoveries of Hubble involve both incredible successes that were planned from the outset as well as new discoveries and innovative uses of the observatory that could not have been planned in advance. Hubble has been used not only to gauge the expansion rate and age of the universe, but has also been a major player in the recent surprise detection of acceleration in that expansion. Hubble has also been key for studying star formation and now the atmospheres of exoplanets; even water has been detected in exoplanetary systems, something never envisioned for Hubble originally. And the incredible evolutionary picture of galaxies has been unveiled through Hubble observations, now enhanced by the revolutionary uses of gravitational lensing to study both dark matter in the lensing clusters, and extremely distant magnified galaxies. Finally, Hubble’s great success in public outreach has made the discoveries of astronomy easily

Study of the influence of Type Ia supernovae environment on the Hubble diagram

NASA Astrophysics Data System (ADS)

Henne, Vincent

2016-06-01

The observational cosmology with distant Type Ia supernovae as standard candles claims that the Universe is in accelerated expansion, caused by a large fraction of dark energy. In this report we investigated SNe Ia environment, studying the impact of the nature of their host galaxies and their distance to the host galactic center on the Hubble diagram fitting. The supernovae used in the analysis were extracted from Joint-Light-curves-Analysis compilation of high-redshift and nearby supernovae. The analysis are based on the empirical fact that SN Ia luminosities depend on their light curve shapes and colors. No conclusive correlation between SN Ia light curve parameters and galocentric distance were identified. Concerning the host morphology, we showed that the stretch parameter of Type Ia supernovae is correlated with the host galaxy type. The supernovae with lower stretch mainly exploded in elliptical and lenticular galaxies. The studies show that into old star population and low dust environment, supernovae are fainter. We did not find any significant correlation between Type Ia supernovae color and host morphology. We confirm that supernova properties depend on their environment and propose to incorporate a host galaxy term into the Hubble diagram fit in the future cosmological analysis.

Evidence for Type Ia Supernova Diversity from Ultraviolet Observations with the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Wang, Xiaofeng; Wang, Lifan; Filippenko, Alexei; Baron, Eddie; Kromer, Markus; Jack, Dennis; Zhang, Tianmeng; Aldering, Greg; Antilogus, Pierre; Arnett, W. David;

Hubble Spies Big Bang Frontiers

NASA Image and Video Library

2017-12-08

Observations by the NASA/ESA Hubble Space Telescope have taken advantage of gravitational lensing to reveal the largest sample of the faintest and earliest known galaxies in the universe. Some of these galaxies formed just 600 million years after the big bang and are fainter than any other galaxy yet uncovered by Hubble. The team has determined for the first time with some confidence that these small galaxies were vital to creating the universe that we see today. An international team of astronomers, led by Hakim Atek of the Ecole Polytechnique Fédérale de Lausanne, Switzerland, has discovered over 250 tiny galaxies that existed only 600-900 million years after the big bang— one of the largest samples of dwarf galaxies yet to be discovered at these epochs. The light from these galaxies took over 12 billion years to reach the telescope, allowing the astronomers to look back in time when the universe was still very young. Read more: www.nasa.gov/feature/goddard/hubble-spies-big-bang-frontiers Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HUBBLE TRACKS 'PERFECT STORM' ON MARS

NASA Technical Reports Server (NTRS)

2002-01-01

Two dramatically different faces of our Red Planet neighbor appear in these comparison images showing how a global dust storm engulfed Mars with the onset of Martian spring in the Southern Hemisphere. When NASA's Hubble Space Telescope imaged Mars in June, the seeds of the storm were caught brewing in the giant Hellas Basin (oval at 4 o'clock position on disk) and in another storm at the northern polar cap. When Hubble photographed Mars in early September, the storm had already been raging across the planet for nearly two months obscuring all surface features. The fine airborne dust blocks a significant amount of sunlight from reaching the Martian surface. Because the airborne dust is absorbing this sunlight, it heats the upper atmosphere. Seasonal global Mars dust storms have been observed from telescopes for over a century, but this is the biggest storm ever seen in the past several decades. Mars looks gibbous in the right photograph because it is 26 million miles farther from Earth than in the left photo (though the pictures have been scaled to the same angular size), and our viewing angle has changed. The left picture was taken when Mars was near its closest approach to Earth for 2001 (an event called opposition); at that point the disk of Mars was fully illuminated as seen from Earth because Mars was exactly opposite the Sun. Both images are in natural color, taken with Hubble's Wide Field Planetary Camera 2. Credit: NASA, James Bell (Cornell Univ.), Michael Wolff (Space Science Inst.), and the Hubble Heritage Team (STScI/AURA)

Constructing a cosmological model-independent Hubble diagram of type Ia supernovae with cosmic chronometers

NASA Astrophysics Data System (ADS)

Li, Zhengxiang; Gonzalez, J. E.; Yu, Hongwei; Zhu, Zong-Hong; Alcaniz, J. S.

2016-02-01

We apply two methods, i.e., the Gaussian processes and the nonparametric smoothing procedure, to reconstruct the Hubble parameter H (z ) as a function of redshift from 15 measurements of the expansion rate obtained from age estimates of passively evolving galaxies. These reconstructions enable us to derive the luminosity distance to a certain redshift z , calibrate the light-curve fitting parameters accounting for the (unknown) intrinsic magnitude of type Ia supernova (SNe Ia), and construct cosmological model-independent Hubble diagrams of SNe Ia. In order to test the compatibility between the reconstructed functions of H (z ), we perform a statistical analysis considering the latest SNe Ia sample, the so-called joint light-curve compilation. We find that, for the Gaussian processes, the reconstructed functions of Hubble parameter versus redshift, and thus the following analysis on SNe Ia calibrations and cosmological implications, are sensitive to prior mean functions. However, for the nonparametric smoothing method, the reconstructed functions are not dependent on initial guess models, and consistently require high values of H0, which are in excellent agreement with recent measurements of this quantity from Cepheids and other local distance indicators.

Hubble Space Telescope. Update: 18 months in orbit

NASA Technical Reports Server (NTRS)

1990-01-01

In April 1990, Space Shuttle Discovery launched the Hubble Space Telescope (HST). An 18 month in-orbit update of the operations and performance of the HST is presented. Numerous color photographs are shown of objects already observed, and mission plans are presented for future observations by the HST.

Alien aurorae spotted on Uranus by Hubble

NASA Image and Video Library

2017-12-08

This is a composite image of Uranus by Voyager 2 and two different observations made by Hubble — one for the ring and one for the auroras. Ever since Voyager 2 beamed home spectacular images of the planets in the 1980s, planet-lovers have been hooked on auroras on other planets. Auroras are caused by streams of charged particles like electrons that come from various origins such as solar winds, the planetary ionosphere, and moon volcanism. They become caught in powerful magnetic fields and are channeled into the upper atmosphere, where their interactions with gas particles, such as oxygen or nitrogen, set off spectacular bursts of light. The auroras on Jupiter and Saturn are well-studied, but not much is known about the auroras of the giant ice planet Uranus. In 2011, the NASA/ESA Hubble Space Telescope became the first Earth-based telescope to snap an image of the auroras on Uranus. In 2012 and 2014 a team led by an astronomer from Paris Observatory took a second look at the auroras using the ultraviolet capabilities of the Space Telescope Imaging Spectrograph (STIS) installed on Hubble. They tracked the interplanetary shocks caused by two powerful bursts of solar wind traveling from the sun to Uranus, then used Hubble to capture their effect on Uranus’ auroras — and found themselves observing the most intense auroras ever seen on the planet. By watching the auroras over time, they collected the first direct evidence that these powerful shimmering regions rotate with the planet. They also re-discovered Uranus’ long-lost magnetic poles, which were lost shortly after their discovery by Voyager 2 in 1986 due to uncertainties in measurements and the featureless planet surface. Credit: ESA/Hubble & NASA, L. Lamy / Observatoire de Paris NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA�

Hubble Sees Stars and a Stripe in Celestial Fireworks

NASA Image and Video Library

2017-12-08

Release date: July 1, 2008 SN 1006 Supernova Remnant (Hubble) A delicate ribbon of gas floats eerily in our galaxy. A contrail from an alien spaceship? A jet from a black-hole? Actually this image, taken by NASA's Hubble Space Telescope, is a very thin section of a supernova remnant caused by a stellar explosion that occurred more than 1,000 years ago. On or around May 1, 1006 A.D., observers from Africa to Europe to the Far East witnessed and recorded the arrival of light from what is now called SN 1006, a tremendous supernova explosion caused by the final death throes of a white dwarf star nearly 7,000 light-years away. The supernova was probably the brightest star ever seen by humans, and surpassed Venus as the brightest object in the night time sky, only to be surpassed by the moon. It was visible even during the day for weeks, and remained visible to the naked eye for at least two and a half years before fading away. It wasn't until the mid-1960s that radio astronomers first detected a nearly circular ring of material at the recorded position of the supernova. The ring was almost 30 arcminutes across, the same angular diameter as the full moon. The size of the remnant implied that the blast wave from the supernova had expanded at nearly 20 million miles per hour over the nearly 1,000 years since the explosion occurred. In 1976, the first detection of exceedingly faint optical emission of the supernova remnant was reported, but only for a filament located on the northwest edge of the radio ring. A tiny portion of this filament is revealed in detail by the Hubble observation. The twisting ribbon of light seen by Hubble corresponds to locations where the expanding blast wave from the supernova is now sweeping into very tenuous surrounding gas. The hydrogen gas heated by this fast shock wave emits radiation in visible light. Hence, the optical emission provides astronomers with a detailed "snapshot" of the actual position and geometry of the shock front at any

Hubble Takes Mars Portrait Near Close Approach

NASA Image and Video Library

2017-12-08

Mars is looking mighty fine in this portrait nabbed by the Hubble Space Telescope on a near close approach! Read more: go.nasa.gov/1rWYiBT The Hubble Space Telescope is more well known for its picturesque views of nebulae and galaxies, but it's also useful for studying our own planets, including Mars. Hubble imaged Mars on May 12, 2016 - ten days before Mars would be on the exact opposite side of the Earth from the Sun. Bright, frosty polar caps, and clouds above a vivid, rust-colored landscape reveal Mars as a dynamic seasonal planet in this NASA Hubble Space Telescope view taken on May 12, 2016, when Mars was 50 million miles from Earth. The Hubble image reveals details as small as 20 to 30 miles across. The large, dark region at far right is Syrtis Major Planitia, one of the first features identified on the surface of the planet by seventeenth-century observers. Christiaan Huygens used this feature to measure the rotation rate of Mars. (A Martian day is about 24 hours and 37 minutes.) Today we know that Syrtis Major is an ancient, inactive shield volcano. Late-afternoon clouds surround its summit in this view. A large oval feature to the south of Syrtis Major is the bright Hellas Planitia basin. About 1,100 miles across and nearly five miles deep, it was formed about 3.5 billion years ago by an asteroid impact. The orange area in the center of the image is Arabia Terra, a vast upland region in northern Mars that covers about 2,800 miles. The landscape is densely cratered and heavily eroded, indicating that it could be among the oldest terrains on the planet. Dried river canyons (too small to be seen here) wind through the region and empty into the large northern lowlands. Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute) #nasagoddard #mars #hubble #space NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics

The nearest X-ray emitting protostellar jet (HH 154) observed with Hubble

NASA Astrophysics Data System (ADS)

Bonito, R.; Fridlund, C. V. M.; Favata, F.; Micela, G.; Peres, G.; Djupvik, A. A.; Liseau, R.

2008-06-01

Context: The jet coming from the YSO binary L1551 IRS5 is the closest astrophysical jet known. It is therefore a unique laboratory for studies of outflow mechanisms and of the shocks occurring when expanding material hits the ambient medium as well as of how the related processes influence the star- (and planet-) forming process. Aims: The optical data are related to other data covering the spectrum from the optical band to X-rays with goal of understanding the energetics of low-mass star jets, in general, and of this jet in particular. We study the time evolution of the jet, by measuring the proper motions of knots as they progress outwards from the originating source. Methods: The nebulosities associated with the jet(s) from the protostellar binary L1551 IRS5 were imaged in a number of spectral bands using the Hubble Space Telescope. This allows the proper motion to be measured and permits a simple characterization of the physical conditions in different structures. To this end we developed a reproducible method of data analysis, which allows us to define the position and shape of each substructure observed within the protostellar jet. Using this approach, we derive the proper motion of the knots in the jet, as well as their flux variability and shock emission. Results: The time base over which HST observations were carried out is now about ten years. The sub-structures within the jet undergo significant morphological variations: some knots seem to disappear in a few years and collision between different knots, ejected at different epochs and maybe with different speed, may occur. The velocities along the jet vary between ~100 km s-1 and over 400 km s-1, with the highest speed corresponding to the knots at the base of the jet. Conclusions: There are indications that the HH 154 jet has been active relatively recently. Our results suggest the presence of a new shock front at the base of the jet identified with an internal working surface. From the analysis of the

Space environmental effects observed on the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Edelman, Joel E.; Mason, James B.

1995-01-01

The Hubble Space Telescope (HST) Repair Mission of December, 1993, was first and foremost a mission to improve the performance of the observatory. But for a specialized segment of the aerospace industry, the primary interest is in the return to Earth of numerous pieces of the HST hardware, pieces which have been replaced, repaired, improved, or superseded. The returned hardware is of interest because of the information it potentially carries about the effects of exposure to the space environment for three and a half years. Like the LDEF retrieval mission four years ago, the HST repair mission is of interest to many engineering disciplines, including all of the disciplines represented by the LDEF Special Investigation Groups (SIG's). There is particular interest in the evaluation of specific materials and systems in the returned components. Some coated surfaces have been processed with materials which are newer and still in use by, or under consideration for, other spacecraft in a variety of stages of development. Several of the systems are being returned because a specific failure or anomaly has been observed and thus there is, at the outset, a specific investigative trail that needs to be followed. These systems are much more complex than those flown on LDEF and, in two instances, comprised state-of-the-art science instruments. Further, the parts used in these systems generally were characterized more rigorously prior to flight than were those in the LDEF systems, and thus post flight testing may yield more significant results.

Space environmental effects observed on the Hubble Space Telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edelman, J.E.; Mason, J.B.

1995-02-01

The Hubble Space Telescope (HST) Repair Mission of December, 1993, was first and foremost a mission to improve the performance of the observatory. But for a specialized segment of the aerospace industry, the primary interest is in the return to Earth of numerous pieces of the HST hardware, pieces which have been replaced, repaired, improved, or superseded. The returned hardware is of interest because of the information it potentially carries about the effects of exposure to the space environment for three and a half years. Like the LDEF retrieval mission four years ago, the HST repair mission is of interestmore » to many engineering disciplines, including all of the disciplines represented by the LDEF Special Investigation Groups (SIG`s). There is particular interest in the evaluation of specific materials and systems in the returned components. Some coated surfaces have been processed with materials which are newer and still in use by, or under consideration for, other spacecraft in a variety of stages of development. Several of the systems are being returned because a specific failure or anomaly has been observed and thus there is, at the outset, a specific investigative trail that needs to be followed. These systems are much more complex than those flown on LDEF and, in two instances, comprised state-of-the-art science instruments. Further, the parts used in these systems generally were characterized more rigorously prior to flight than were those in the LDEF systems, and thus post flight testing may yield more significant results.« less

Hubble Observes Glowing, Fiery Shells of Gas

NASA Image and Video Library

2017-12-08

It may look like something from "The Lord of the Rings," but this fiery swirl is actually a planetary nebula known as ESO 456-67. Set against a backdrop of bright stars, the rust-colored object lies in the constellation of Sagittarius (The Archer), in the southern sky. In this image of ESO 456-67, it is possible to see the various layers of material expelled by the central star. Each appears in a different hue - red, orange, yellow, and green-tinted bands of gas are visible, with clear patches of space at the heart of the nebula. It is not fully understood how planetary nebulae form such a wide variety of shapes and structures; some appear to be spherical, some elliptical, others shoot material in waves from their polar regions, some look like hourglasses or figures of eight, and others resemble large, messy stellar explosions - to name but a few. Image Credit: ESA/Hubble and NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble (HST) hardware is inspected in PHSF

NASA Technical Reports Server (NTRS)

1999-01-01

In the Payload Hazardous Servicing Facility, part of the servicing equipment for the third Hubble Space Telescope Servicing Mission (SM-3A), STS-103, is given a black light inspection. The hardware is undergoing final testing and integration of payload elements. Mission STS-103 is a 'call-up' due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. The scheduled launch date in October is under review.

The structure of the inner arcsecond of R Aquarii observed with the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Burgarella, Denis; Paresce, Francesco

1992-01-01

The inner arcsec of R Aquarii has been observed with the Faint Object Camera on the Hubble Space Telescope. A simple and reliable linear deconvolution method is used to resolve the two features, designated C1 and C2 from radio observations, into several condensations. C1 is composed of four objects, designated C1a, C1b located at 0.099 arcsec from C1a, C3 at 0.162 arcsec from C1a, and C4 at 0.137 arcsec from C1a. The source C3, detected at 2 cm in the radio and in H-alpha, might be the V = 6-11 Mira variable. The nature of feature C4 is still unknown. Features C1a and C1b have not been resolved by another instrument, and it might be possible that the hot star is one of the two or a nearby nondetected object.

A gravitational-wave standard siren measurement of the Hubble constant.

PubMed

2017-11-02

On 17 August 2017, the Advanced LIGO and Virgo detectors observed the gravitational-wave event GW170817-a strong signal from the merger of a binary neutron-star system. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source. This sky region was subsequently observed by optical astronomy facilities, resulting in the identification of an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first 'multi-messenger' astronomical observation. Such observations enable GW170817 to be used as a 'standard siren' (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic 'distance ladder': the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. This value is consistent with existing measurements, while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision.

A gravitational-wave standard siren measurement of the Hubble constant

NASA Astrophysics Data System (ADS)

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X.; Ramirez-Ruiz, E.; Rest, A.; Rojas-Bravo, C.; Shappee, B. J.; Siebert, M. R.; Simon, J. D.; Ulloa, N.; Annis, J.; Soares-Santos, M.; Brout, D.; Scolnic, D.; Diehl, H. T.; Frieman, J.; Berger, E.; Alexander, K. D.; Allam, S.; Balbinot, E.; Blanchard, P.; Butler, R. E.; Chornock, R.; Cook, E. R.; Cowperthwaite, P.; Drlica-Wagner, A.; Drout, M. R.; Durret, F.; Eftekhari, T.; Finley, D. A.; Fong, W.; Fryer, C. L.; García-Bellido, J.; Gill, M. S. S.; Gruendl, R. A.; Hanna, C.; Hartley, W.; Herner, K.; Huterer, D.; Kasen, D.; Kessler, R.; Li, T. S.; Lin, H.; Lopes, P. A. A.; Lourenço, A. C. C.; Margutti, R.; Marriner, J.; Marshall, J. L.; Matheson, T.; Medina, G. E.; Metzger, B. D.; Muñoz, R. R.; Muir, J.; Nicholl, M.; Nugent, P.; Palmese, A.; Paz-Chinchón, F.; Quataert, E.; Sako, M.; Sauseda, M.; Schlegel, D. J.; Secco, L. F.; Smith, N.; Sobreira, F.; Stebbins, A.; Villar, V. A.; Vivas, A. K.; Wester, W.; Williams, P. K. G.; Yanny, B.; Zenteno, A.; Abbott, T. M. C.; Abdalla, F. B.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Bridle, S. L.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Castander, F. J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; Depoy, D. L.; Desai, S.; Dietrich, J. P.; Estrada, J.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruen, D.; Gutierrez, G.; Hartley, W. G.; Honscheid, K.; Jain, B.; James, D. J.; Jeltema, T.; Johnson, M. W. G.; Kent, S.; Krause, E.; Kron, R.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lahav, O.; Lima, M.; Maia, M. A. G.; March, M.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nord, B.; Ogando, R. L. C.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Suchyta, E.; Tarle, G.; Thomas, D.; Thomas, R. C.; Troxel, M. A.; Tucker, D. L.; Vikram, V.; Walker, A. R.; Weller, J.; Zhang, Y.; Haislip, J. B.; Kouprianov, V. V.; Reichart, D. E.; Tartaglia, L.; Sand, D. J.; Valenti, S.; Yang, S.; Arcavi, Iair; Hosseinzadeh, Griffin; Howell, D. Andrew; McCully, Curtis; Poznanski, Dovi; Vasylyev, Sergiy; Tanvir, N. R.; Levan, A. J.; Hjorth, J.; Cano, Z.; Copperwheat, C.; de Ugarte-Postigo, A.; Evans, P. A.; Fynbo, J. P. U.; González-Fernández, C.; Greiner, J.; Irwin, M.; Lyman, J.; Mandel, I.; McMahon, R.; Milvang-Jensen, B.; O'Brien, P.; Osborne, J. P.; Perley, D. A.; Pian, E.; Palazzi, E.; Rol, E.; Rosetti, S.; Rosswog, S.; Rowlinson, A.; Schulze, S.; Steeghs, D. T. H.; Thöne, C. C.; Ulaczyk, K.; Watson, D.; Wiersema, K.; Lipunov, V. M.; Gorbovskoy, E.; Kornilov, V. G.; Tyurina, N.; Balanutsa, P.; Vlasenko, D.; Gorbunov, I.; Podesta, R.; Levato, H.; Saffe, C.; Buckley, D. A. H.; Budnev, N. M.; Gress, O.; Yurkov, V.; Rebolo, R.; Serra-Ricart, M.

2017-11-01

On 17 August 2017, the Advanced LIGO and Virgo detectors observed the gravitational-wave event GW170817—a strong signal from the merger of a binary neutron-star system. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source. This sky region was subsequently observed by optical astronomy facilities, resulting in the identification of an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first ‘multi-messenger’ astronomical observation. Such observations enable GW170817 to be used as a ‘standard siren’ (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic ‘distance ladder’: the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. This value is consistent with existing measurements, while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision.

The Carnegie Hubble Program

NASA Technical Reports Server (NTRS)

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Vicky; Mnso, Andy; Persson, S. E.; Rigby, Jane; Sturch, Laura; Stetson, Peter

2011-01-01

We present an overview of and preliminary results from an ongoing comprehensive program that has a goal of determining the Hubble constant to a systematic accuracy of 2%. As part of this program, we are currently obtaining 3.6 micron data using the Infrared Array Camera (IRAC) on Spitzer, and the program is designed to include JWST in the future. We demonstrate that the mid-infrared period-luminosity relation for Cepheids at 3.6 microns is the most accurate means of measuring Cepheid distances to date. At 3.6 microns, it is possible to minimize the known remaining systematic uncertainties in the Cepheid extragalactic distance scale. We discuss the advantages of 3.6 micron observations in minimizing systematic effects in the Cepheid calibration of the Hubble constant including the absolute zero point, extinction corrections, and the effects of metallicity on the colors and magnitudes of Cepheids. We are undertaking three independent tests of the sensitivity of the mid-IR Cepheid Leavitt Law to metallicity, which when combined will allow a robust constraint on the effect. Finally, we are providing a new mid-IR Tully-Fisher relation for spiral galaxies.

HUBBLE SEES MINI-COMET FRAGMENTS FROM COMET LINEAR

NASA Technical Reports Server (NTRS)

2002-01-01

[lower right] In one stunning Hubble picture the fate of the mysteriously vanished solid nucleus of Comet LINEAR has been settled. The Hubble picture shows that the comet nucleus has been reduced to a shower of glowing 'mini-comets' resembling the fiery fragments from an exploding aerial firework. This is the first time astronomers have ever gotten a close-up look at what may be the smallest building blocks of cometary nuclei, the icy solid pieces called 'cometesimals', which are thought to be less than 100 feet across. The farthest fragment to the left, which is now very faint, may be the remains of the parent nucleus that fragmented into the cluster of smaller pieces to the right. The comet broke apart around July 26, when it made its closest approach to the Sun. The picture was taken with Hubble's Wide Field Planetary Camera 2 on August 5, 2000, when the comet was at a distance of 64 million miles (102 million kilometers) from Earth. Credit: NASA, Harold Weaver (the Johns Hopkins University), and the HST Comet LINEAR Investigation Team [upper left] A ground-based telescopic view (2.2-meter telescope) of Comet LINEAR taken on August 5, at nearly the same time as the Hubble observations. The comet appears as a diffuse elongated cloud of debris without any visible nucleus. Based on these images, some astronomers had concluded that the ices in the nucleus had completely vaporized, leaving behind a loose swarm of dust. Hubble's resolution was needed to pinpoint the remaining nuclei (inset box shows HST field of view as shown in lower right). Credit: University of Hawaii

Hubble Sees 'Island Universe' in the Coma Cluster

NASA Image and Video Library

2017-12-08

NASA image release August 10, 2010 A long-exposure Hubble Space Telescope image shows a majestic face-on spiral galaxy located deep within the Coma Cluster of galaxies, which lies 320 million light-years away in the northern constellation Coma Berenices. The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes. The high resolution of Hubble's cameras, paired with considerably long exposures, made it possible to observe these faint details. NGC 4911 and other spirals near the center of the cluster are being transformed by the gravitational tug of their neighbors. In the case of NGC 4911, wispy arcs of the galaxy's outer spiral arms are being pulled and distorted by forces from a companion galaxy (NGC 4911A), to the upper right. The resultant stripped material will eventually be dispersed throughout the core of the Coma Cluster, where it will fuel the intergalactic populations of stars and star clusters. The Coma Cluster is home to almost 1,000 galaxies, making it one of the densest collections of galaxies in the nearby universe. It continues to transform galaxies at the present epoch, due to the interactions of close-proximity galaxy systems within the dense cluster. Vigorous star formation is triggered in such collisions. Galaxies in this cluster are so densely packed that they undergo frequent interactions and collisions. When galaxies of nearly equal masses merge, they form elliptical galaxies. Merging is more likely to occur in the center of the cluster where the density of galaxies is higher, giving rise to more elliptical galaxies. This natural-color Hubble image, which combines data obtained in 2006, 2007, and 2009 from the Wide Field Planetary Camera 2 and the

Hubble Catches Stellar Exodus in Action

NASA Image and Video Library

2015-05-14

Using NASA’s Hubble Space Telescope, astronomers have captured for the first time snapshots of fledging white dwarf stars beginning their slow-paced, 40-million-year migration from the crowded center of an ancient star cluster to the less populated suburbs. White dwarfs are the burned-out relics of stars that rapidly lose mass, cool down and shut off their nuclear furnaces. As these glowing carcasses age and shed weight, their orbits begin to expand outward from the star cluster’s packed downtown. This migration is caused by a gravitational tussle among stars inside the cluster. Globular star clusters sort out stars according to their mass, governed by a gravitational billiard ball game where lower mass stars rob momentum from more massive stars. The result is that heavier stars slow down and sink to the cluster's core, while lighter stars pick up speed and move across the cluster to the edge. This process is known as "mass segregation." Until these Hubble observations, astronomers had never definitively seen the dynamical conveyor belt in action. Astronomers used Hubble to watch the white-dwarf exodus in the globular star cluster 47 Tucanae, a dense swarm of hundreds of thousands of stars in our Milky Way galaxy. The cluster resides 16,700 light-years away in the southern constellation Tucana. Read more: www.nasa.gov/feature/goddard/hubble-catches-stellar-exodu... Credits: NASA, ESA, and H. Richer and J. Heyl (University of British Columbia, Vancouver, Canada); acknowledgement: J. Mack (STScI) and G. Piotto (University of Padova, Italy) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Space Telescope observations of Europa in and out of eclipse

USGS Publications Warehouse

Sparks, W.B.; McGrath, M.; Hand, K.; Ford, H.C.; Geissler, P.; Hough, J.H.; Turner, E.L.; Chyba, C.F.; Carlson, R.; Turnbull, M.

2010-01-01

Europa is a prime target for astrobiology and has been prioritized as the next target for a National Aeronautics and Space Administration flagship mission. It is important, therefore, that we advance our understanding of Europa, its ocean and physical environment as much as possible. Here, we describe observations of Europa obtained during its orbital eclipse by Jupiter using the Hubble Space Telescope. We obtained Advanced Camera for Surveys Solar Blind Channel far ultraviolet low-resolution spectra that show oxygen line emission both in and out of eclipse. We also used the Wide-Field and Planetary Camera-2 and searched for broad-band optical emission from fluorescence of the surface material, arising from the very high level of incident energetic particle radiation on ices and potentially organic substances. The high-energy particle radiation at the surface of Europa is extremely intense and is responsible for the production of a tenuous oxygen atmosphere and associated FUV line emission. Approximately 50% of the oxygen emission lasts at least a few hours into the eclipse. We discuss the detection limits of the optical emission, which allow us to estimate the fraction of incident energy reradiated at optical wavelengths, through electron-excited emission, Cherenkov radiation in the ice and fluorescent processes. ?? 2010 Cambridge University Press.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

2000-07-01

This is a color Hubble Space Telescope (HST) heritage image of supernova remnant N49, a neighboring galaxy, that was taken with Hubble's Wide Field Planetary Camera 2. Color filters were used to sample light emitted by sulfur, oxygen, and hydrogen. The color image was superimposed on a black and white image of stars in the same field also taken with Hubble. Resembling a fireworks display, these delicate filaments are actually sheets of debris from a stellar explosion.

Carnegie Hubble Program: A Mid-Infrared Calibration of the Hubble Constant

NASA Technical Reports Server (NTRS)

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Victoria; Burns, Chris; Monson, Andy; Persson, S. Eric; Seibert, Mark; Rigby, Jane

2012-01-01

Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 micrometers with the Spitzer Space Telescope, we have obtained a new, high-accuracy calibration of the Hubble constant. We have established the mid-IR zero point of the Leavitt law (the Cepheid period-luminosity relation) using time-averaged 3.6 micrometers data for 10 high-metallicity, MilkyWay Cepheids having independently measured trigonometric parallaxes. We have adopted the slope of the PL relation using time-averaged 3.6micrometers data for 80 long-period Large Magellanic Cloud (LMC) Cepheids falling in the period range 0.8 < log(P) < 1.8.We find a new reddening-corrected distance to the LMC of 18.477 +/- 0.033 (systematic) mag. We re-examine the systematic uncertainties in H(sub 0), also taking into account new data over the past decade. In combination with the new Spitzer calibration, the systematic uncertainty in H(sub 0) over that obtained by the Hubble Space Telescope Key Project has decreased by over a factor of three. Applying the Spitzer calibration to the Key Project sample, we find a value of H(sub 0) = 74.3 with a systematic uncertainty of +/-2.1 (systematic) kilometers per second Mpc(sup -1), corresponding to a 2.8% systematic uncertainty in the Hubble constant. This result, in combination with WMAP7measurements of the cosmic microwave background anisotropies and assuming a flat universe, yields a value of the equation of state for dark energy, w(sub 0) = -1.09 +/- 0.10. Alternatively, relaxing the constraints on flatness and the numbers of relativistic species, and combining our results with those of WMAP7, Type Ia supernovae and baryon acoustic oscillations yield w(sub 0) = -1.08 +/- 0.10 and a value of N(sub eff) = 4.13 +/- 0.67, mildly consistent with the existence of a fourth neutrino species.

Hubble Space Telescope Observations of Active Asteroid 324P/La Sagra

NASA Astrophysics Data System (ADS)

Jewitt, David; Agarwal, Jessica; Weaver, Harold; Mutchler, Max; Li, Jing; Larson, Stephen

2016-09-01

Hubble Space Telescope observations of active asteroid 324P/La Sagra near perihelion show continued mass loss consistent with the sublimation of near-surface ice. Isophotes of the coma measured from a vantage point below the orbital plane are best matched by steady emission of particles having a nominal size of a ˜ 100 μm. The inferred rate of mass loss, dM d /dt ˜ 0.2 kg s-1, can be supplied by sublimation of water ice in thermal equilibrium with sunlight from an area as small as 930 m2, corresponding to about 0.2% of the nucleus surface. Observations taken from a vantage point only 0.°6 from the orbital plane of 324P set a limit to the velocity of ejection of dust in the direction perpendicular to the plane, V ⊥ < 1 m s-1. Short-term photometric variations of the near-nucleus region, if related to rotation of the underlying nucleus, rule-out periods ≤3.8 hr and suggest that rotation probably does not play a central role in driving the observed mass loss. We estimate that, in the previous orbit, 324P lost about 4 × 107 kg in dust particles, corresponding to 6 × 10-5 of the mass of a 550 m spherical nucleus of assumed density ρ = 1000 kg m-3. If continued, mass loss at this rate would limit the lifetime of 324P to ˜1.6 × 104 orbits (about 105 years). To survive for the 100-400 Myr timescales corresponding to dynamical and collisional stability requires a duty cycle of 2 × 10-4 ≤ f d ≤ 8 × 10-4. Unless its time in orbit is overestimated by many orders of magnitude, 324P is revealed as a briefly active member of a vast population of otherwise dormant ice-containing asteroids.

Hubble's Next Generation Spectral Library

NASA Astrophysics Data System (ADS)

Heap, Sara R.; Lindler, D.

2008-03-01

Spectroscopic surveys of galaxies at z 1 or more bring the rest-frame ultraviolet into view of large, ground-based telescopes. This spectral region is rich in diagnostics, but these diagnostics have not yet been calibrated in terms of the properties of the responsible stellar population(s). Such calibrations are now possible with Hubble's Next Generation Spectral Library (NGSL). This library contains UV-optical spectra (0.2-1.0 microns) of 378 stars having a wide range in temperature, luminosity, and metallicity. We have derived the basic stellar parameters from the optical spectral region (0.35 - 1.0 microns) and are using them to calibrate UV spectral diagnostic indices and colors.

Hubble Images of Comet Hale-Bopp

NASA Technical Reports Server (NTRS)

1998-01-01

This is a series of Hubble Space Telescope observations of the region around the nucleus of Hale-Bopp, taken on eight different dates since September 1995. They chronicle changes in the evolution of the nucleus as it moves ever closer to, and is warmed by, the sun.

The first picture in the sequence, seen at upper left shows a strong dust outburst on the comet that occurred when it was beyond the orbit of Jupiter. Images in the Fall of 1996 show multiple jets that are presumably connected to the activation of multiple vents on the surface of the nucleus.

In these false color images, taken with the Wide Field and Planetary Camera 2, the faintest regions are black, the brightest regions are white, and intermediate intensities are represented by different levels of red. All images are processed at the same spatial scale of 280 miles per pixel (470 kilometers), so the solid nucleus, no larger than 25 miles across, is far below Hubble's resolution.

The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

David Leckrone, senior project scientist for Hubble at NASA's Goddard Space Flight Center in Greenbelt, Md. discusses newly released images from NASA's Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

Hubble Tarantula Treasury Project V. The Star Cluster Hodge 301: The Old Face of 30 Doradus

NASA Astrophysics Data System (ADS)

Cignoni, M.; Sabbi, E.; van der Marel, R. P.; Lennon, D. J.; Tosi, M.; Grebel, E. K.; Gallagher, J. S., III; Aloisi, A.; de Marchi, G.; Gouliermis, D. A.; Larsen, S.; Panagia, N.; Smith, L. J.

2016-12-01

Based on color-magnitude diagrams (CMDs) from the Hubble Space Telescope Hubble Tarantula Treasury Project (HTTP) survey, we present the star formation history of Hodge 301, the oldest star cluster in the Tarantula Nebula. The HTTP photometry extends faint enough to reach, for the first time, the cluster pre-main sequence (PMS) turn-on, where the PMS joins the main sequence. Using the location of this feature, along with synthetic CMDs generated with the latest PARSEC models, we find that Hodge 301 is older than previously thought, with an age between 26.5 and 31.5 Myr. From this age, we also estimate that between 38 and 61 Type II supernovae exploded in the region. The same age is derived from the main sequence turn-off, whereas the age derived from the post-main sequence stars is younger and between 20 and 25 Myr. Other relevant parameters are a total stellar mass of ≈8800 ± 800 M ⊙ and average reddening E(B - V) ≈ 0.22-0.24 mag, with a differential reddening δE(B - V) ≈ 0.04 mag. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA Inc., under NASA contract NAS 5-26555.

HUBBLE'S PLANETARY NEBULA GALLERY

NASA Technical Reports Server (NTRS)

2002-01-01

[Top left] - IC 3568 lies in the constellation Camelopardalis at a distance of about 9,000 light-years, and has a diameter of about 0.4 light-years (or about 800 times the diameter of our solar system). It is an example of a round planetary nebula. Note the bright inner shell and fainter, smooth, circular outer envelope. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Top center] - NGC 6826's eye-like appearance is marred by two sets of blood-red 'fliers' that lie horizontally across the image. The surrounding faint green 'white' of the eye is believed to be gas that made up almost half of the star's mass for most of its life. The hot remnant star (in the center of the green oval) drives a fast wind into older material, forming a hot interior bubble which pushes the older gas ahead of it to form a bright rim. (The star is one of the brightest stars in any planetary.) NGC 6826 is 2,200 light- years away in the constellation Cygnus. The Hubble telescope observation was taken Jan. 27, 1996 with the Wide Field and Planetary Camera 2. Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy) and NASA [Top right ] - NGC 3918 is in the constellation Centaurus and is about 3,000 light-years from us. Its diameter is about 0.3 light-year. It shows a roughly spherical outer envelope but an elongated inner balloon inflated by a fast wind from the hot central star, which is starting to break out of the spherical envelope at the top and bottom of the image. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Bottom left] - Hubble 5 is a striking example of a 'butterfly' or bipolar (two-lobed) nebula. The heat generated by fast winds causes

Hubble Sees Recurring Plume Erupting From Europa

NASA Image and Video Library

2017-04-13

These composite images show a suspected plume of material erupting two years apart from the same location on Jupiter's icy moon Europa. The images bolster evidence that the plumes are a real phenomenon, flaring up intermittently in the same region on the satellite. Both plumes, photographed in ultraviolet light by NASA's Hubble's Space Telescope Imaging Spectrograph, were seen in silhouette as the moon passed in front of Jupiter. The newly imaged plume, shown at right, rises about 62 miles (100 kilometers) above Europa's frozen surface. The image was taken Feb. 22, 2016. The plume in the image at left, observed by Hubble on March 17, 2014, originates from the same location. It is estimated to be about 30 miles (50 kilometers) high. The snapshot of Europa, superimposed on the Hubble image, was assembled from data from NASA's Galileo mission to Jupiter. The plumes correspond to the location of an unusually warm spot on the moon's icy crust, seen in the late 1990s by the Galileo spacecraft (see PIA21444). Researchers speculate that this might be circumstantial evidence for water venting from the moon's subsurface. The material could be associated with the global ocean that is believed to be present beneath the frozen crust. https://photojournal.jpl.nasa.gov/catalog/PIA21443

The hubble constant.

PubMed

Huchra, J P

1992-04-17

The Hubble constant is the constant of proportionality between recession velocity and distance in the expanding universe. It is a fundamental property of cosmology that sets both the scale and the expansion age of the universe. It is determined by measurement of galaxy The Hubble constant is the constant of proportionality between recession velocity and development of new techniques for the measurements of galaxy distances, both calibration uncertainties and debates over systematic errors remain. Current determinations still range over nearly a factor of 2; the higher values favored by most local measurements are not consistent with many theories of the origin of large-scale structure and stellar evolution.

Hubble Captures Vivid Auroras in Jupiter’s Atmosphere

NASA Image and Video Library

2017-12-08

Astronomers are using the NASA/ESA Hubble Space Telescope to study auroras — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the solar system, Jupiter. This observation program is supported by measurements made by NASA’s Juno spacecraft, currently on its way to Jupiter. Jupiter, the largest planet in the solar system, is best known for its colorful storms, the most famous being the Great Red Spot. Now astronomers have focused on another beautiful feature of the planet, using Hubble's ultraviolet capabilities. The extraordinary vivid glows shown in the new observations are known as auroras. They are created when high-energy particles enter a planet’s atmosphere near its magnetic poles and collide with atoms of gas. As well as producing beautiful images, this program aims to determine how various components of Jupiter’s auroras respond to different conditions in the solar wind, a stream of charged particles ejected from the sun. This observation program is perfectly timed as NASA’s Juno spacecraft is currently in the solar wind near Jupiter and will enter the orbit of the planet in early July 2016. While Hubble is observing and measuring the auroras on Jupiter, Juno is measuring the properties of the solar wind itself; a perfect collaboration between a telescope and a space probe. “These auroras are very dramatic and among the most active I have ever seen”, said Jonathan Nichols from the University of Leicester, U.K., and principal investigator of the study. “It almost seems as if Jupiter is throwing a firework party for the imminent arrival of Juno.” Read more: go.nasa.gov/294QswK Credits: NASA, ESA, and J. Nichols (University of Leicester)

Hubble Captures Vivid Auroras in Jupiter’s Atmosphere

NASA Image and Video Library

2016-06-30

Astronomers are using the NASA/ESA Hubble Space Telescope to study auroras — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the solar system, Jupiter. This observation program is supported by measurements made by NASA’s Juno spacecraft, currently on its way to Jupiter. Jupiter, the largest planet in the solar system, is best known for its colorful storms, the most famous being the Great Red Spot. Now astronomers have focused on another beautiful feature of the planet, using Hubble's ultraviolet capabilities. The extraordinary vivid glows shown in the new observations are known as auroras. They are created when high-energy particles enter a planet’s atmosphere near its magnetic poles and collide with atoms of gas. As well as producing beautiful images, this program aims to determine how various components of Jupiter’s auroras respond to different conditions in the solar wind, a stream of charged particles ejected from the sun. This observation program is perfectly timed as NASA’s Juno spacecraft is currently in the solar wind near Jupiter and will enter the orbit of the planet in early July 2016. While Hubble is observing and measuring the auroras on Jupiter, Juno is measuring the properties of the solar wind itself; a perfect collaboration between a telescope and a space probe. “These auroras are very dramatic and among the most active I have ever seen”, said Jonathan Nichols from the University of Leicester, U.K., and principal investigator of the study. “It almost seems as if Jupiter is throwing a firework party for the imminent arrival of Juno.” Credits: NASA, ESA, and J. Nichols (University of Leicester)

Near-UV Sources in the Hubble Ultra Deep Field: The Catalog

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.; Voyrer, Elysse; de Mello, Duilia F.; Siana, Brian; Quirk, Cori; Teplitz, Harry I.

2009-01-01

The catalog from the first high resolution U-band image of the Hubble Ultra Deep Field, taken with Hubble s Wide Field Planetary Camera 2 through the F300W filter, is presented. We detect 96 U-band objects and compare and combine this catalog with a Great Observatories Origins Deep Survey (GOODS) B-selected catalog that provides B, V, i, and z photometry, spectral types, and photometric redshifts. We have also obtained Far-Ultraviolet (FUV, 1614 Angstroms) data with Hubble s Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) and with Galaxy Evolution Explorer (GALEX). We detected 31 sources with ACS/SBC, 28 with GALEX/FUV, and 45 with GALEX/NUV. The methods of observations, image processing, object identification, catalog preparation, and catalog matching are presented.

A gravitational-wave standard siren measurement of the Hubble constant

DOE PAGES

Abbott, B. P.; Abbott, R.; Abbott, T. D.; ...

2017-10-16

On 17 August 2017, the Advanced LIGO and Virgo detectors observed the gravitational-wave event GW170817—a strong signal from the merger of a binary neutron-star system. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO–Virgo-derived location of the gravitational-wave source. This sky region was subsequently observed by optical astronomy facilities, resulting in the identificationof an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first ‘multi-messenger’ astronomical observation. Such observationsmore » enable GW170817 to be used as a ‘standard siren’ (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic ‘distance ladder’: the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. Furthermore, this value is consistent with existing measurements, while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision.« less

A gravitational-wave standard siren measurement of the Hubble constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbott, B. P.; Abbott, R.; Abbott, T. D.

On 17 August 2017, the Advanced LIGO and Virgo detectors observed the gravitational-wave event GW170817—a strong signal from the merger of a binary neutron-star system. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO–Virgo-derived location of the gravitational-wave source. This sky region was subsequently observed by optical astronomy facilities, resulting in the identificationof an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first ‘multi-messenger’ astronomical observation. Such observationsmore » enable GW170817 to be used as a ‘standard siren’ (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic ‘distance ladder’: the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. Furthermore, this value is consistent with existing measurements, while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision.« less

Hubble Eyes Galactic Refurbishment

NASA Image and Video Library

2015-04-30

The smudge of stars at the center of this NASA/ESA Hubble Space Telescope image is a galaxy known as UGC 5797. UGC 5797 is an emission line galaxy, meaning that it is currently undergoing active star formation. The result is a stellar population that is constantly being refurbished as massive bright blue stars form. Galaxies with prolific star formation are not only veiled in a blue tint, but are key to the continuation of a stellar cycle. In this image UGC 5797 appears in front of a background of spiral galaxies. Spiral galaxies have copious amounts of dust and gas — the main ingredient for stars — and therefore often also belong to the class of emission line galaxies. Spiral galaxies have disk-like shapes that drastically vary in appearance depending on the angle at which they are observed. The collection of spiral galaxies in this frame exhibits this attribute acutely: Some are viewed face-on, revealing the structure of the spiral arms, while the two in the bottom left are seen edge-on, appearing as plain streaks in the sky. There are many spiral galaxies, with varying colors and at different angles, sprinkled across this image — just take a look. Credit: ESA/Hubble & NASA, Acknowledgement: Luca Limatola

Calibration of the Hubble Space Telescope polarimetric modes

NASA Technical Reports Server (NTRS)

Lupie, O. L.; Stockman, H. S.

1988-01-01

Stellar and galactic polarimetry from space is an unexplored observational regime and one which holds exciting promise for answering many fundamental astrophysical questions. The Hubble Space Telescope will be the first space observatory to provide a variety of polarimetric modes to astronomers including spectral, imaging, and single-aperture UV polarimetry. As part of the calibration program for these modes, the Space Telescope Science Institute has initiated a ground-based program to define faint standard fields and solicited community support to establish a temporal baseline for these potential standard targets. In this paper, the polarimetric capabilities of the Hubble Space Telescope, the philosophy and complications of in-flight calibration, and the status and direction of the standard targets program are discussed.

Observational constraint on dynamical evolution of dark energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, Yungui; Cai, Rong-Gen; Chen, Yun

2010-01-01

We use the Constitution supernova, the baryon acoustic oscillation, the cosmic microwave background, and the Hubble parameter data to analyze the evolution property of dark energy. We obtain different results when we fit different baryon acoustic oscillation data combined with the Constitution supernova data to the Chevallier-Polarski-Linder model. We find that the difference stems from the different values of Ω{sub m0}. We also fit the observational data to the model independent piecewise constant parametrization. Four redshift bins with boundaries at z = 0.22, 0.53, 0.85 and 1.8 were chosen for the piecewise constant parametrization of the equation of state parametermore » w(z) of dark energy. We find no significant evidence for evolving w(z). With the addition of the Hubble parameter, the constraint on the equation of state parameter at high redshift is improved by 70%. The marginalization of the nuisance parameter connected to the supernova distance modulus is discussed.« less

A Hubble Sky Full of Stars

NASA Image and Video Library

2017-12-08

So Coldplay isn't the only one to see a sky full of stars, these are 22K light-years away Located approximately 22,000 light-years away in the constellation of Musca (The Fly), this tightly packed collection of stars — known as a globular cluster — goes by the name of NGC 4833. This NASA/ESA Hubble Space Telescope image shows the dazzling stellar group in all its glory. NGC 4833 is one of the over 150 globular clusters known to reside within the Milky Way. These objects are thought to contain some of the oldest stars in our galaxy. Studying these ancient cosmic clusters can help astronomers to unravel how a galaxy formed and evolved, and give an idea of the galaxy’s age. Globular clusters are responsible for some of the most striking sights in the cosmos, with hundreds of thousands of stars congregating in the same region of space. Hubble has observed many of these clusters during its time in orbit around our planet, each as breathtaking as the last. bit.ly/2b85p36 Image credit: ESA/Hubble and NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Catches Stellar Exodus in Action

NASA Image and Video Library

2015-05-14

Using NASA’s Hubble Space Telescope, astronomers have captured for the first time snapshots of fledging white dwarf stars beginning their slow-paced, 40-million-year migration from the crowded center of an ancient star cluster to the less populated suburbs. White dwarfs are the burned-out relics of stars that rapidly lose mass, cool down and shut off their nuclear furnaces. As these glowing carcasses age and shed weight, their orbits begin to expand outward from the star cluster’s packed downtown. This migration is caused by a gravitational tussle among stars inside the cluster. Globular star clusters sort out stars according to their mass, governed by a gravitational billiard ball game where lower mass stars rob momentum from more massive stars. The result is that heavier stars slow down and sink to the cluster's core, while lighter stars pick up speed and move across the cluster to the edge. This process is known as "mass segregation." Until these Hubble observations, astronomers had never definitively seen the dynamical conveyor belt in action. Astronomers used Hubble to watch the white-dwarf exodus in the globular star cluster 47 Tucanae, a dense swarm of hundreds of thousands of stars in our Milky Way galaxy. The cluster resides 16,700 light-years away in the southern constellation Tucana. Credits: NASA, ESA, and H. Richer and J. Heyl (University of British Columbia, Vancouver, Canada); acknowledgement: J. Mack (STScI) and G. Piotto (University of Padova, Italy)

Hubble Captures Spectacular "Landscape" in the Carina Nebula

NASA Image and Video Library

2017-12-08

NASA image release April 22, 2010 NASA's Hubble Space Telescope captured this billowing cloud of cold interstellar gas and dust rising from a tempestuous stellar nursery located in the Carina Nebula, 7,500 light-years away in the southern constellation Carina. This pillar of dust and gas serves as an incubator for new stars and is teeming with new star-forming activity. Hot, young stars erode and sculpt the clouds into this fantasy landscape by sending out thick stellar winds and scorching ultraviolet radiation. The low-density regions of the nebula are shredded while the denser parts resist erosion and remain as thick pillars. In the dark, cold interiors of these columns new stars continue to form. In the process of star formation, a disk around the proto-star slowly accretes onto the star's surface. Part of the material is ejected along jets perpendicular to the accretion disk. The jets have speeds of several hundreds of miles per second. As these jets plow into the surround nebula, they create small, glowing patches of nebulosity, called Herbig-Haro (HH) objects. Long streamers of gas can be seen shooting in opposite directions off the pedestal on the upper right-hand side of the image. Another pair of jets is visible in a peak near the top-center of the image. These jets (known as HH 901 and HH 902, respectively) are common signatures of the births of new stars. This image celebrates the 20th anniversary of Hubble's launch and deployment into an orbit around Earth. Hubble's Wide Field Camera 3 observed the pillar on Feb. 1-2, 2010. The colors in this composite image correspond to the glow of oxygen (blue), hydrogen and nitrogen (green), and sulfur (red). Object Names: HH 901, HH 902 Image Type: Astronomical Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) To read learn more about this image go to: www.nasa.gov/mission_pages/hubble/science/hubble20th-img.... NASA Goddard Space Flight Center is home to the nation's largest organization

Venus Cloud Tops Viewed by Hubble

NASA Image and Video Library

1999-05-18

Venus Cloud Tops Viewed by Hubble. This is a NASA Hubble Space Telescope ultraviolet-light image of the planet Venus, taken on January 24 1995, when Venus was at a distance of 70.6 million miles 113.6 million kilometers from Earth.

The nature of the redshift and directly observed quasar statistics.

PubMed

Segal, I E; Nicoll, J F; Wu, P; Zhou, Z

1991-07-01

The nature of the cosmic redshift is one of the most fundamental questions in modern science. Hubble's discovery of the apparent Expansion of the Universe is derived from observations on a small number of galaxies at very low redshifts. Today, quasar redshifts have a range more than 1000 times greater than those in Hubble's sample, and represent more than 100 times as many objects. A recent comprehensive compilation of published measurements provides the basis for a study indicating that quasar observations are not in good agreement with the original predictions of the Expanding Universe theory, but are well fit by the predictions of an alternative theory having fewer adjustable parameters.

Hubble Space Telescope Observations of the HD 202628 Debris Disk

NASA Technical Reports Server (NTRS)

Krist, John E.; Stapelfeldt, Karl R.; Bryden, Geoffrey; Plavchan, Peter

2012-01-01

A ring-shaped debris disk around the G2V star HD 202628 (d = 24.4 pc) was imaged in scattered light at visible wavelengths using the coronagraphic mode of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The ring is inclined by approx.64deg from face-on, based on the apparent major/minor axis ratio, with the major axis aligned along PA = 130deg. It has inner and outer radii (> 50% maximum surface brightness) of 139 AU and 193 AU in the northwest ansae and 161 AU and 223 AU in the southeast ((Delta)r/r approx. = 0.4). The maximum visible radial extent is approx. 254 AU. With a mean surface brightnesses of V approx. = 24 mag arcsec.(sup -2), this is the faintest debris disk observed to date in reflected light. The center of the ring appears offset from the star by approx.28 AU (deprojected). An ellipse fit to the inner edge has an eccentricity of 0.18 and a = 158 AU. This offset, along with the relatively sharp inner edge of the ring, suggests the influence of a planetary-mass companion. There is a strong similarity with the debris ring around Fomalhaut, though HD 202628 is a more mature star with an estimated age of about 2 Gyr. We also provide surface brightness limits for nine other stars in our study with strong Spitzer excesses around which no debris disks were detected in scattered light (HD 377, HD 7590, HD 38858, HD 45184, HD 73350, HD 135599, HD 145229, HD 187897, and HD 201219).

Hubble Space Telescope Observations of the HD 202628 Debris Disk

NASA Astrophysics Data System (ADS)

Krist, John E.; Stapelfeldt, Karl R.; Bryden, Geoffrey; Plavchan, Peter

2012-08-01

A ring-shaped debris disk around the G2V star HD 202628 (d = 24.4 pc) was imaged in scattered light at visible wavelengths using the coronagraphic mode of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The ring is inclined by ~64° from face-on, based on the apparent major/minor axis ratio, with the major axis aligned along P.A. = 130°. It has inner and outer radii (>50% maximum surface brightness) of 139 AU and 193 AU in the northwest ansae and 161 AU and 223 AU in the southeast (Δr/r ≈ 0.4). The maximum visible radial extent is ~254 AU. With mean surface brightness of V ≈ 24 mag arcsec-2, this is the faintest debris disk observed to date in reflected light. The center of the ring appears offset from the star by ~28 AU (deprojected). An ellipse fit to the inner edge has an eccentricity of 0.18 and a = 158 AU. This offset, along with the relatively sharp inner edge of the ring, suggests the influence of a planetary-mass companion. There is a strong similarity with the debris ring around Fomalhaut, though HD 202628 is a more mature star with an estimated age of about 2 Gyr. We also provide surface brightness limits for nine other stars in our study with strong Spitzer excesses around which no debris disks were detected in scattered light (HD 377, HD 7590, HD 38858, HD 45184, HD 73350, HD 135599, HD 145229, HD 187897, and HD 201219).

Hubble Witnesses an Asteroid Mysteriously Disintegrating

NASA Image and Video Library

2014-03-06

Though fragile comet nuclei have been seen falling apart as they near the Sun, nothing like the slow breakup of an asteroid has ever before been observed in the asteroid belt. A series of Hubble Space Telescope images shows that the fragments are drifting away from each other at a leisurely one mile per hour. This makes it unlikely that the asteroid is disintegrating because of a collision with another asteroid. A plausible explanation is that the asteroid is crumbling due to a subtle effect of sunlight. This causes the rotation rate to slowly increase until centrifugal force pulls the asteroid apart. The asteroid's remnant debris, weighing in at 200,000 tons, will in the future provide a rich source of meteoroids. Hubble Observation of P/2013 R3 - November 15, 2013 Credit: NASA, ESA, and D. Jewitt (University of California, Los Angeles) Read more: 1.usa.gov/1ig2E0x NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble 2006: Science Year in Review

NASA Technical Reports Server (NTRS)

Brown, R.

2007-01-01

The 10 science articles selected for this years annual science report exemplify the range of Hubble research from the Solar System, across our Milky Way, and on to distant galaxies. The objects of study include a new feature on Jupiter, binaries in the Kuiper Belt, Cepheid variable stars, the Orion Nebula, distant transiting planets, lensing galaxies, active galactic nuclei, red-and-dead galaxies, and galactic outflows and jets. Each narrative strives to construct the readers understanding of the topics and issues, and to place the latest research in historical, as well as scientific, context. These essays reveal trends in the practice of astronomy. More powerful computers are permitting astronomers to study ever larger data sets, enabling the discovery of subtle effects and rare objects. (Two investigations created mosaic images that are among the largest produced to date.) Multiwavelength data sets from ground-based telescopes, as well as other great observatories Spitzer and Chandraare increasingly important for holistic interpretations of Hubble results. This yearbook also presents profiles of 12 individuals who work with Hubble, or Hubble data, on a daily basis. They are representative of the many students, scientists, engineers, and other professions who are proudly associated with Hubble. Their stories collectively communicate the excitement and reward of careers related to space science and technology.

In Defense of an Accelerating Universe: Model Insensitivity of the Hubble Diagram

NASA Astrophysics Data System (ADS)

Ringermacher, Harry I.; Mead, Lawrence R.

2018-01-01

A recently published paper by Nielsen, Guffanti & Sarkar (. Sci. Rep. 6, 35596, Oct. 2016) argues that the evidence for cosmic acceleration is marginal and that a coasting universe - the “Milne Universe” - fits the same supernovae data in a Hubble diagram nearly as well. Other papers have since jumped on the bandwagon. The Milne Universe has negative spatial curvature, but is Riemann-flat. Nevertheless, we confirm that the Milne model fits the data just as well as LCDM. We show that this unexpected result points to a weakness in the Hubble diagram rather than to a failure in LCDM. It seems the Hubble diagram is insensitive to spatial curvature. To be specific, the spatial curvature dependences of the comoving radius in the luminosity distance nearly exactly cancel the energy density differences. That is, r(LCDM) = sinh[r(Milne)]. By transforming the distance modulus vs. redshift data to scale factor vs. cosmological time data, for each curvature, k = {+1, 0, -1}, the curvature dependence of the data is effectively separated thus permitting a more precise fit of the Omega parameters to the scale factor data to decide the correct model. Here we present the data and both models in a scale factor vs. cosmological time plot. The difference of the means of the k = 0 and k =-1 data separate at a 2-sigma confidence level. The LCDM fit to the k = 0 data are consistent with an accelerating universe to 99% confidence. The Milne universe fits the k =-1 data to no better than about 70% confidence. This is consistent with independent CMB and BAO observations supporting a flat universe.

Measuring the Value of the Hubble Constant “à la Refsdal”

NASA Astrophysics Data System (ADS)

Grillo, C.; Rosati, P.; Suyu, S. H.; Balestra, I.; Caminha, G. B.; Halkola, A.; Kelly, P. L.; Lombardi, M.; Mercurio, A.; Rodney, S. A.; Treu, T.

2018-06-01

Realizing Refsdal’s original idea from 1964, we present estimates of the Hubble constant that are complementary to, and potentially competitive with, those of other cosmological probes. We use the observed positions of 89 multiple images, with extensive spectroscopic information, from 28 background sources and the measured time delays between the images S1–S4 and SX of supernova “Refsdal” (z = 1.489), which were obtained thanks to Hubble Space Telescope deep imaging and Multi Unit Spectroscopic Explorer data. We extend the strong-lensing modeling of the Hubble Frontier Fields galaxy cluster MACS J1149.5+2223 (z = 0.542), published by Grillo et al. (2016), and explore different ΛCDM models. Taking advantage of the lensing information associated to the presence of very close pairs of multiple images at various redshifts, and to the extended surface brightness distribution of the SN Refsdal host, we can reconstruct the total mass-density profile of the cluster very precisely. The combined dependence of the multiple-image positions and time delays on the cosmological parameters allows us to infer the values of H 0 and Ωm with relative (1σ) statistical errors of, respectively, 6% (7%) and 31% (26%) in flat (general) cosmological models, assuming a conservative 3% uncertainty on the final time delay of image SX and, remarkably, no priors from other cosmological experiments. Our best estimate of H 0, based on the model described in this work, will be presented when the final time-delay measurement becomes available. Our results show that it is possible to utilize time delays in lens galaxy clusters as an important alternative tool for measuring the expansion rate and the geometry of the universe.

Hubble Sees Pinwheel of Star Birth

NASA Image and Video Library

2017-12-08

NASA image release October 19, 2010 Though the universe is chock full of spiral-shaped galaxies, no two look exactly the same. This face-on spiral galaxy, called NGC 3982, is striking for its rich tapestry of star birth, along with its winding arms. The arms are lined with pink star-forming regions of glowing hydrogen, newborn blue star clusters, and obscuring dust lanes that provide the raw material for future generations of stars. The bright nucleus is home to an older population of stars, which grow ever more densely packed toward the center. NGC 3982 is located about 68 million light-years away in the constellation Ursa Major. The galaxy spans about 30,000 light-years, one-third of the size of our Milky Way galaxy. This color image is composed of exposures taken by the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), the Advanced Camera for Surveys (ACS), and the Wide Field Camera 3 (WFC3). The observations were taken between March 2000 and August 2009. The rich color range comes from the fact that the galaxy was photographed invisible and near-infrared light. Also used was a filter that isolates hydrogen emission that emanates from bright star-forming regions dotting the spiral arms. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgment: A. Riess (STScI) NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us

Monitoring Mars with the Hubble Space Telescope: 1990-1991 observations

NASA Technical Reports Server (NTRS)

James, Philip B.; Clancy, R. Todd; Lee, Steven W.; Martin, Leonard J.; Singer, Robert B.; Smith, ED; Kahn, Ralph A.; Zurek, Richard W.

1994-01-01

Images of Mars obtained using the Planetary Camera on the Hubble Space Telescope during 1990 and 1991 are described and analyzed. Multispectral images of Mars record the martian season between L(sub s) = 348 deg and 60 deg corresponding to late winter and spring in the northern hemisphere. The wavelengths of these observations varied between 230 nm in the ultraviolet and 890 nm in the near infrared. We use these images to discuss atmospheric and polar phenomena, to constrain the aerosols and ozone in the martian atmosphere, and to compare surface albedo features within this data set as well as with previous observations. Two methods are used to constrain the opacity of the martian atmosphere: comparisons of ultraviolet images with atmospheric scattering models and examination of contrast changes of surface features observed at visible wavelengths. Our observations are consistent with a Mars which was quite different from the planet when it was viewed by Viking; we estimate an upper limit of 0.1 for equatorial dust opacity near vernal equinox, compared to values of 0.4 to 0.5 measured in Chryse by Viking Lander 1. Later, at L(sub s) = 60 deg, and upper limit of 0.2 was found for dust in the southern hemisphere. Except for suggestions of local dust activity near the north polar cap in late spring, there was no visual evidence of dust storms on the planet. The Hartley band of ozone is within the F230W filter bandpass, and the 230W/336W ratio is therefore sensitive to ozone. High latitude ozone is observed at a concentration similar to that observed by Mariner 9; a seasonal dependence in ozone concentration was observed with concentration decreasing at northern arctic latitudes and increasing at southern midlatitudes as L(sub s) increases from 350 deg to 60 deg. Despite the difference in dust loading, the behavior of condensate clouds and the recession of the north polar cap are consistent with those observed during Viking years. Late winter images of the north polar

Hubble Spies a UFO

NASA Image and Video Library

2017-12-08

The Hubble Space Telescope has spotted a UFO — well, the UFO Galaxy, to be precise. NGC 2683 is a spiral galaxy seen almost edge-on, giving it the shape of a classic science fiction spaceship. This is why the astronomers at the Astronaut Memorial Planetarium and Observatory gave it this attention-grabbing nickname. While a bird’s eye view lets us see the detailed structure of a galaxy (such as this Hubble image of a barred spiral), a side-on view has its own perks. In particular, it gives astronomers a great opportunity to see the delicate dusty lanes of the spiral arms silhouetted against the golden haze of the galaxy’s core. In addition, brilliant clusters of young blue stars shine scattered throughout the disc, mapping the galaxy’s star-forming regions. Perhaps surprisingly, side-on views of galaxies like this one do not prevent astronomers from deducing their structures. Studies of the properties of the light coming from NGC 2683 suggest that this is a barred spiral galaxy, even though the angle we see it at does not let us see this directly. NGC 2683, discovered on 5 February 1788 by the famous astronomer William Herschel, lies in the Northern constellation of Lynx. A constellation named not because of its resemblance to the feline animal, but because it is fairly faint, requiring the “sensitive eyes of a cat” to discern it. And when you manage to get a look at it, you’ll find treasures like this, making it well worth the effort. This image is produced from two adjacent fields observed in visible and infrared light by Hubble’s Advanced Camera for Surveys. A narrow strip which appears slightly blurred and crosses most the image horizontally is a result of a gap between Hubble’s detectors. This strip has been patched using images from observations of the galaxy made by ground-based telescopes, which show significantly less detail. The field of view is approximately 6.5 by 3.3 arcminutes. Credit: ESA/Hubble & NASA NASA image use policy. NASA

Hubble Sees a Legion of Galaxies

NASA Image and Video Library

2017-12-08

Peering deep into the early universe, this picturesque parallel field observation from the NASA/ESA Hubble Space Telescope reveals thousands of colorful galaxies swimming in the inky blackness of space. A few foreground stars from our own galaxy, the Milky Way, are also visible. In October 2013 Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) began observing this portion of sky as part of the Frontier Fields program. This spectacular skyscape was captured during the study of the giant galaxy cluster Abell 2744, otherwise known as Pandora’s Box. While one of Hubble’s cameras concentrated on Abell 2744, the other camera viewed this adjacent patch of sky near to the cluster. Containing countless galaxies of various ages, shapes and sizes, this parallel field observation is nearly as deep as the Hubble Ultra-Deep Field. In addition to showcasing the stunning beauty of the deep universe in incredible detail, this parallel field — when compared to other deep fields — will help astronomers understand how similar the universe looks in different directions. Image credit: NASA, ESA and the HST Frontier Fields team (STScI), NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble's Necklace

NASA Image and Video Library

2017-12-08

Image released 11 Aug 2011. The "Necklace Nebula" is located 15,000 light-years away in the constellation Sagitta (the Arrow). In this composite image, taken on July 2, 2011, Hubble's Wide Field Camera 3 captured the glow of hydrogen (blue), oxygen (green), and nitrogen (red). The object, aptly named the Necklace Nebula, is a recently discovered planetary nebula, the glowing remains of an ordinary, Sun-like star. The nebula consists of a bright ring, measuring 12 trillion miles wide, dotted with dense, bright knots of gas that resemble diamonds in a necklace. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble's Glittering Frisbee Galaxy

NASA Image and Video Library

2017-12-08

This image from Hubble’s Wide Field Camera 3 (WFC3) shows a section of NGC 1448, a spiral galaxy located about 50 million light-years from Earth in the little-known constellation of Horologium (The Pendulum Clock). We tend to think of spiral galaxies as massive and roughly circular celestial bodies, so this glittering oval does not immediately appear to fit the visual bill. What’s going on? Imagine a spiral galaxy as a circular frisbee spinning gently in space. When we see it face on, our observations reveal a spectacular amount of detail and structure — a great example from Hubble is the telescope’s view of Messier 51, otherwise known as the Whirlpool Galaxy. However, the NGC 1448 frisbee is very nearly edge-on with respect to Earth, giving it an appearance that is more oval than circular. The spiral arms, which curve out from NGC 1448’s dense core, can just about be seen. Although spiral galaxies might appear static with their picturesque shapes frozen in space, this is very far from the truth. The stars in these dramatic spiral configurations are constantly moving as they orbit around the galaxy’s core, with those on the inside making the orbit faster than those sitting further out. This makes the formation and continued existence of a spiral galaxy’s arms something of a cosmic puzzle, because the arms wrapped around the spinning core should become wound tighter and tighter as time goes on — but this is not what we see. This is known as the winding problem. Credit: ESA/Hubble & NASA #nasagoddard #space #science #Hubble #star NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

ASASSN-15LH: A SUPERLUMINOUS ULTRAVIOLET REBRIGHTENING OBSERVED BY SWIFT AND HUBBLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Peter J.; Yang, Yi; Wang, Lifan

2016-09-01

We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope , all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greatermore » than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Ly α absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs.« less

Hubble Captures Detailed Image of Uranus Atmosphere

NASA Image and Video Library

1998-08-02

NASA Hubble Space Telescope peered deep into Uranus atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus atmosphere.

Updated reduced CMB data and constraints on cosmological parameters

NASA Astrophysics Data System (ADS)

Cai, Rong-Gen; Guo, Zong-Kuan; Tang, Bo

2015-07-01

We obtain the reduced CMB data {lA, R, z∗} from WMAP9, WMAP9+BKP, Planck+WP and Planck+WP+BKP for the ΛCDM and wCDM models with or without spatial curvature. We then use these reduced CMB data in combination with low-redshift observations to put constraints on cosmological parameters. We find that including BKP results in a higher value of the Hubble constant especially when the equation of state (EOS) of dark energy and curvature are allowed to vary. For the ΛCDM model with curvature, the estimate of the Hubble constant with Planck+WP+Lensing is inconsistent with the one derived from Planck+WP+BKP at about 1.2σ confidence level (CL).

The Hubble Catalog of Variables

NASA Astrophysics Data System (ADS)

Gavras, P.; Bonanos, A. Z.; Bellas-Velidis, I.; Charmandaris, V.; Georgantopoulos, I.; Hatzidimitriou, D.; Kakaletris, G.; Karampelas, A.; Laskaris, N.; Lennon, D. J.; Moretti, M. I.; Pouliasis, E.; Sokolovsky, K.; Spetsieri, Z. T.; Tsinganos, K.; Whitmore, B. C.; Yang, M.

2017-06-01

The Hubble Catalog of Variables (HCV) is a 3 year ESA funded project that aims to develop a set of algorithms to identify variables among the sources included in the Hubble Source Catalog (HSC) and produce the HCV. We will process all HSC sources with more than a predefined number of measurements in a single filter/instrument combination and compute a range of lightcurve features to determine the variability status of each source. At the end of the project, the first release of the Hubble Catalog of Variables will be made available at the Mikulski Archive for Space Telescopes (MAST) and the ESA Science Archives. The variability detection pipeline will be implemented at the Space Telescope Science Institute (STScI) so that updated versions of the HCV may be created following the future releases of the HSC.

M Dwarfs from Hubble Space Telescope Star Counts. IV.

NASA Astrophysics Data System (ADS)

Zheng, Zheng; Flynn, Chris; Gould, Andrew; Bahcall, John N.; Salim, Samir

2001-07-01

We study a sample of about 1400 disk M dwarfs that are found in 148 fields observed with the Wide Field Camera 2 (WFC2) on the Hubble Space Telescope and 162 fields observed with pre-repair Planetary Camera 1 (PC1), of which 95 of the WFC2 fields are newly analyzed. The method of maximum likelihood is applied to derive the luminosity function and the Galactic disk parameters. At first, we use a local color-magnitude relation and a locally determined mass-luminosity relation in our analysis. The results are consistent with those of previous work but with considerably reduced statistical errors. These small statistical errors motivate us to investigate the systematic uncertainties. Considering the metallicity gradient above the Galactic plane, we introduce a modified color-magnitude relation that is a function of Galactic height. The resultant M dwarf luminosity function has a shape similar to that derived using the local color-magnitude relation but with a higher peak value. The peak occurs at MV~12, and the luminosity function drops sharply toward MV~14. We then apply a height-dependent mass-luminosity function interpolated from theoretical models with different metallicities to calculate the mass function. Unlike the mass function obtained using local relations, which has a power-law index α=0.47, the one derived from the height-dependent relations tends to be flat (α=-0.10). The resultant local surface density of disk M dwarfs (12.2+/-1.6 Msolar pc-2) is somewhat smaller than the one obtained using local relations (14.3+/-1.3 Msolar pc-2). Our measurement favors a short disk scale length, H=2.75+/-0.16 (statistical)+/-0.25 (systematic) kpc. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Observational tests of non-adiabatic Chaplygin gas

NASA Astrophysics Data System (ADS)

Carneiro, S.; Pigozzo, C.

2014-10-01

In a previous paper [1] it was shown that any dark sector model can be mapped into a non-adiabatic fluid formed by two interacting components, one with zero pressure and the other with equation-of-state parameter ω = -1. It was also shown that the latter does not cluster and, hence, the former is identified as the observed clustering matter. This guarantees that the dark matter power spectrum does not suffer from oscillations or instabilities. It applies in particular to the generalised Chaplygin gas, which was shown to be equivalent to interacting models at both background and perturbation levels. In the present paper we test the non-adiabatic Chaplygin gas against the Hubble diagram of type Ia supernovae, the position of the first acoustic peak in the anisotropy spectrum of the cosmic microwave background and the linear power spectrum of large scale structures. We consider two different compilations of SNe Ia, namely the Constitution and SDSS samples, both calibrated with the MLCS2k2 fitter, and for the power spectrum we use the 2dFGRS catalogue. The model parameters to be adjusted are the present Hubble parameter, the present matter density and the Chaplygin gas parameter α. The joint analysis best fit gives α ≈ - 0.5, which corresponds to a constant-rate energy flux from dark energy to dark matter, with the dark energy density decaying linearly with the Hubble parameter. The ΛCDM model, equivalent to α = 0, stands outside the 3σ confidence interval.

Observational tests of non-adiabatic Chaplygin gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carneiro, S.; Pigozzo, C., E-mail: saulo.carneiro@pq.cnpq.br, E-mail: cpigozzo@ufba.br

2014-10-01

In a previous paper [1] it was shown that any dark sector model can be mapped into a non-adiabatic fluid formed by two interacting components, one with zero pressure and the other with equation-of-state parameter ω = -1. It was also shown that the latter does not cluster and, hence, the former is identified as the observed clustering matter. This guarantees that the dark matter power spectrum does not suffer from oscillations or instabilities. It applies in particular to the generalised Chaplygin gas, which was shown to be equivalent to interacting models at both background and perturbation levels. In the present papermore » we test the non-adiabatic Chaplygin gas against the Hubble diagram of type Ia supernovae, the position of the first acoustic peak in the anisotropy spectrum of the cosmic microwave background and the linear power spectrum of large scale structures. We consider two different compilations of SNe Ia, namely the Constitution and SDSS samples, both calibrated with the MLCS2k2 fitter, and for the power spectrum we use the 2dFGRS catalogue. The model parameters to be adjusted are the present Hubble parameter, the present matter density and the Chaplygin gas parameter α. The joint analysis best fit gives α ≈ - 0.5, which corresponds to a constant-rate energy flux from dark energy to dark matter, with the dark energy density decaying linearly with the Hubble parameter. The ΛCDM model, equivalent to α = 0, stands outside the 3σ confidence interval.« less

Hubble Sees Spiral in Serpens

NASA Image and Video Library

2017-12-08

This new NASA/ESA Hubble Space Telescope image shows a beautiful spiral galaxy known as PGC 54493, located in the constellation of Serpens (The Serpent). This galaxy is part of a galaxy cluster that has been studied by astronomers exploring an intriguing phenomenon known as weak gravitational lensing. This effect, caused by the uneven distribution of matter (including dark matter) throughout the Universe, has been explored via surveys such as the Hubble Medium Deep Survey. Dark matter is one of the great mysteries in cosmology. It behaves very differently from ordinary matter as it does not emit or absorb light or other forms of electromagnetic energy — hence the term "dark." Even though we cannot observe dark matter directly, we know it exists. One prominent piece of evidence for the existence of this mysterious matter is known as the "galaxy rotation problem." Galaxies rotate at such speeds and in such a way that ordinary matter alone — the stuff we see — would not be able to hold them together. The amount of mass that is "missing" visibly is dark matter, which is thought to make up some 27 percent of the total contents of the Universe, with dark energy and normal matter making up the rest. PGC 55493 has been studied in connection with an effect known as cosmic shearing. This is a weak gravitational lensing effect that creates tiny distortions in images of distant galaxies. European Space Agency ESA/Hubble & NASA, Acknowledgement: Judy Schmidt NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Servicing Mission Press Conference

NASA Image and Video Library

2009-04-22

Ed Weiler, Associate Administrator, Science Mission Directorate at NASA Headquarters, seated second from left, speaks during a press conference on the upcoming Hubble Space Telescope servicing mission as David Leckrone, Hubble Project Scientist, Preston Burch and Mike Klenlen, seated right, look on, Thursday, April 23, 2009, at NASA Headquarters in Washington. J.D. Harrington, Public Affairs officer for the Science Mission Directorate looks on at left. Photo Credit: (NASA/Paul. E. Alers)

Hubble Revisits a Globular Cluster’s Age

NASA Image and Video Library

2014-08-13

This new NASA/ESA Hubble Space Telescope image shows the globular cluster IC 4499. Globular clusters are big balls of old stars that orbit around their host galaxy. It has long been believed that all the stars within a globular cluster form at the about same time, a property which can be used to determine the cluster's age. For more massive globulars however, detailed observations have shown that this is not entirely true — there is evidence that they instead consist of multiple populations of stars born at different times. One of the driving forces behind this behavior is thought to be gravity: more massive globulars manage to grab more gas and dust, which can then be transformed into new stars. IC 4499 is a somewhat special case. Its mass lies somewhere between low-mass globulars, which show a single generation build-up, and the more complex and massive globulars which can contain more than one generation of stars. By studying objects like IC 4499 astronomers can therefore explore how mass affects a cluster's contents. Astronomers found no sign of multiple generations of stars in IC 4499 — supporting the idea that less massive clusters in general only consist of a single stellar generation. Hubble observations of IC 4499 have also helped to pinpoint the cluster's age: observations of this cluster from the 1990s suggested a puzzlingly young age when compared to other globular clusters within the Milky Way. However, since those first estimates new Hubble data have been obtained and it has been found to be much more likely that IC 4499 is actually roughly the same age as other Milky Way clusters at approximately 12 billion years old. Credit: ESA and NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the

Hubble (HST) hardware is unwrapped in the PHSF

NASA Technical Reports Server (NTRS)

1999-01-01

In the Payload Hazardous Servicing Facility (PHSF), a worker begins to open the protective covering over a part of payload flight hardware for the third Hubble Space Telescope Servicing Mission (SM-3A). The hardware will undergo final testing and integration of payload elements in the PHSF. Mission STS-103 is a 'call-up' mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-103 is currently targeted for Oct. 14 but the date is under review.

HUBBLE'S TOP TEN GRAVITATIONAL LENSES

NASA Technical Reports Server (NTRS)

2002-01-01

The NASA Hubble Space Telescope serendipitous survey of the sky has uncovered exotic patterns, rings, arcs and crosses that are all optical mirages produced by a gravitational lens, nature's equivalent of having giant magnifying glass in space. Shown are the top 10 lens candidates uncovered in the deepest 100 Hubble fields. Hubble's sensitivity and high resolution allow it to see faint and distant lenses that cannot be detected with ground-based telescopes whose images are blurred by Earth's atmosphere. [Top Left] - HST 01248+0351 is a lensed pair on either side of the edge-on disk lensing galaxy. [Top Center] - HST 01247+0352 is another pair of bluer lensed source images around the red spherical elliptical lensing galaxy. Two much fainter images can be seen near the detection limit which might make this a quadruple system. [Top Right] - HST 15433+5352 is a very good lens candidate with a bluer lensed source in the form of an extended arc about the redder elliptical lensing galaxy. [Middle Far Left] - HST 16302+8230 could be an 'Einstein ring' and the most intriguing lens candidate. It has been nicknamed the 'the London Underground' since it resembles that logo. [Middle Near Left] - HST 14176+5226 is the first, and brightest lens system discovered in 1995 with the Hubble telescope. This lens candidate has now been confirmed spectroscopically using large ground-based telescopes. The elliptical lensing galaxy is located 7 billion light-years away, and the lensed quasar is about 11 billion light-years distant. [Middle Near Right] - HST 12531-2914 is the second quadruple lens candidate discovered with Hubble. It is similar to the first, but appears smaller and fainter. [Middle Far Right] - HST 14164+5215 is a pair of bluish lensed images symmetrically placed around a brighter, redder galaxy. [Bottom Left] - HST 16309+8230 is an edge-on disk-like galaxy (blue arc) which has been significantly distorted by the redder lensing elliptical galaxy. [Bottom Center] - HST 12368

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2007-01-01

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts 2x3, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z>lO, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (<50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth- Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems.

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan F.; Barbier, L. M.; Barthelmy, S. D.; Cummings, J. R.; Fenimore, E. E.; Gehrels, N.; Hullinger, D. D.; Markwardt, C. B.; Palmer, D. M.; Parsons, A. M.;

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2007-01-01

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z>6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z>10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (<50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth- Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems.

Constraining Galaxy Evolution With Hubble's Next Generation Spectral Library

NASA Astrophysics Data System (ADS)

Heap, S.; Lindler, D. J.

2009-03-01

We present Hubble's Next Generation Spectral Library, a library of UV-optical spectra (0.2-1.0 μ) of 378 stars. We show that the mid-UV spectrum can be used to constrain the ages and metallicities of high-redshift galaxies presently being observed with large, ground-based telescopes.

Correcting Hubble Vision.

ERIC Educational Resources Information Center

Shaw, John M.; Sheahen, Thomas P.

1994-01-01

Describes the theory behind the workings of the Hubble Space Telescope, the spherical aberration in the primary mirror that caused a reduction in image quality, and the corrective device that compensated for the error. (JRH)

Hubble Sees a Star ‘Inflating’ a Giant Bubble

NASA Image and Video Library

2017-12-08

light in the bubble near the star, while the cooler pillars are yellow from the combined light of hydrogen and nitrogen. The pillars are similar to the iconic columns in the “Pillars of Creation” Eagle Nebula. As seen with the structures in the Eagle Nebula, the Bubble Nebula pillars are being illuminated by the strong ultraviolet radiation from the brilliant star inside the bubble. The Bubble Nebula was discovered in 1787 by William Herschel, a prominent British astronomer. It is being formed by a proto-typical Wolf-Rayet star, BD +60º2522, an extremely bright, massive, and short-lived star that has lost most of its outer hydrogen and is now fusing helium into heavier elements. The star is about four million years old, and in 10 million to 20 million years, it will likely detonate as a supernova. Hubble’s Wide Field Camera-3 imaged the nebula in visible light with unprecedented clarity in February 2016. The colors correspond to blue for oxygen, green for hydrogen, and red for nitrogen. This information will help astronomers understand the geometry and dynamics of this complex system. The Bubble Nebula is one of only a handful of astronomical objects that have been observed with several different instruments onboard Hubble. Hubble also imaged it with the Wide Field Planetary Camera (WFPC) in September 1992, and with Wide Field Planetary Camera-2 (WFPC2) in April 1999. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Hubble Sees Material Ejected From Comet Hale-Bopp

NASA Technical Reports Server (NTRS)

1995-01-01

These NASA Hubble Space Telescope pictures of comet Hale-Bopp show a remarkable 'pinwheel' pattern and a blob of free-flying debris near the nucleus. The bright clump of light along the spiral (above the nucleus, which is near the center of the frame) may be a piece of the comet's icy crust that was ejected into space by a combination of ice evaporation and the comet's rotation, and which then disintegrated into a bright cloud of particles.

Although the 'blob' is about 3.5 times fainter than the brightest portion at the nucleus, the lump appears brighter because it covers a larger area. The debris follows a spiral pattern outward because the solid nucleus is rotating like a lawn sprinkler, completing a single rotation about once per week.

Ground-based observations conducted over the past two months have documented at least two separate episodes of jet and pinwheel formation and fading. By coincidence, the first Hubble images of Hale-Bopp, taken on September 26, 1995, immediately followed one of these outbursts and allow researchers to examine it at unprecedented detail. For the first time they see a clear separation between the nucleus and some of the debris being shed. By putting together information from the Hubble images and those taken during the recent outburst using the 82 cm telescope of the Teide Observatory (Tenerife, Canary Islands, Spain), astronomers find that the debris is moving away from the nucleus at a speed (projected on the sky) of about 68 miles per hour (109 kilometers per hour).

The Hubble observations will be used to determine if Hale-Bopp is really a giant comet or rather a more moderate-sized object whose current activity is driven by outgassing from a very volatile ice which will 'burn out' over the next year. Comet Hale-Bopp was discovered on July 23, 1995 by amateur astronomers Alan Hale and Thomas Bopp. Though this comet is still well outside the orbit of Jupiter (almost 600 million miles, or one billion kilometers from Earth

European astronaut selected for the third Hubble Space Telescope

NASA Astrophysics Data System (ADS)

1998-08-01

The STS-104 crew will rendezvous with the orbiting Hubble Space Telescope, which is the size of a city bus, capture it using the Shuttle's Canadian robot arm and secure it in Columbia's payload bay. Then, working in teams of two, the four astronauts will leave the Shuttle's pressurised cabin and venture into the payload bay, performing a variety of tasks that will improve the productivity and reliability of the telescope. The four astronauts will perform a series of six "extravehicular" activities in the open space environment. Such activities are commonly called spacewalks, but this term does little justice to the considerable physical and mental efforts that astronauts need to make in doing the very demanding work involved. The Shuttle commander and pilot for this flight have not yet been appointed, but the four designated mission specialists begin training for the STS-104 mission immediately. "The ambitious nature of this mission, with its six spacewalks, made it important for the payload crew to begin training as early as possible," said David C. Leestma, NASA Director of Flight Crew Operations at the Johnson Space Center in Houston, to which Claude Nicollier is on resident assignment from ESA's European Astronaut Centre in Cologne, Germany, the home base of the European astronaut corps. The Hubble Space Telescope was launched into orbit in April 1990. It is one of the most capable optical telescopes available to astronomers today, producing images and spectral observations at the forefront of astronomy. The European Space Agency contributed a 15 share to the development of Hubble. One of the five scientific instruments on board, the Faint Object Camera, was built by a European industrial consortium made up of British Aerospace, Dornier and Matra under a contract with the European Space Agency. The solar arrays which provide Hubble with electrical power were manufactured by British Aerospace and Dornier. In its eight years of operation, the telescope has not

Hubble Space Telescope,Spitzer Space Telescope

NASA Image and Video Library

2018-01-11

This image showcases both the visible and infrared visualizations of the Orion Nebula. This view from a movie sequence looks down the 'valley' leading to the star cluster at the far end. The left side of the image shows the visible-light visualization, which fades to the infrared-light visualization on the right. These two contrasting models derive from observations by the Hubble and Spitzer space telescopes. An animation is available at https://photojournal.jpl.nasa.gov/catalog/PIA22089

Hubble Hotbed of Vigorous Star Formation

NASA Image and Video Library

2017-12-08

This galaxy is currently a hotbed of vigorous star formation. NGC 1569 is a starburst galaxy, meaning that — as the name suggests — it is bursting at the seams with stars, and is currently producing them at a rate far higher than that observed in most other galaxies. For almost 100 million years, NGC 1569 has pumped out stars more than 100 times faster than the Milky Way! As a result, this glittering galaxy is home to super star clusters, three of which are visible in this image — one of the two bright clusters is actually the superposition of two massive clusters. Each containing more than a million stars, these brilliant blue clusters reside within a large cavity of gas carved out by multiple supernovae, the energetic remnants of massive stars. In 2008, Hubble observed the galaxy's cluttered core and sparsely populated outer fringes. By pinpointing individual red giant stars, Hubble’s Advanced Camera for Surveys enabled astronomers to calculate a new — and much more precise — estimate for NGC 1569’s distance. This revealed that the galaxy is actually one and a half times farther away than previously thought, and a member of the IC 342 galaxy group. Astronomers suspect that the IC 342 cosmic congregation is responsible for the star-forming frenzy observed in NGC 1569. Gravitational interactions between this galactic group are believed to be compressing the gas within NGC 1569. As it is compressed, the gas collapses, heats up and forms new stars. Image credit: ESA/Hubble & NASA, Aloisi, Ford; Acknowledgement: Judy Schmidt

Hubble gets revitalised in new Servicing Mission for more and better science!

NASA Astrophysics Data System (ADS)

2002-02-01

European astronomers look forward to use the new camera and perform new science building on the great breakthroughs they have already achieved." ACS is going to replace the Faint Object Camera, or FOC, built by ESA. The FOC, which has functioned perfectly since the beginning, has been a key instrument to get the best out of the unprecedented imaging capability of Hubble. The FOC was a "state-of-the art" instrument in the 80s, but the field of digital imaging has progressed so much in the past 20 years that, having fulfilled its scientific goals, this ESA flagship on Hubble is chivalrously giving way to newer technology. However, the story of FOC is not over yet: experts will still learn from it, as it will be brought back to Earth and inspected, to study the effects on the hardware of the long duration exposure in space. Hubble is expected to continue to explore the sky during the next decade, after which its work will be taken over by its successor, the powerful ESA/NASA/CSA(*) Next Generation Space Telescope. NGST's main focus will be observations of the faint infrared light from the first stars and galaxies in the Universe. Notes for editors The Hubble Space Telescope is a project of international co-operation between ESA and NASA. It was launched in 1990. The partnership agreement between ESA and NASA was signed on 7 October 1977; as a result of this agreement European astronomers have guaranteed access to more than 20% of Hubble's observing time. Astronauts have already paid visits to Hubble in 1993, '97, '99 and now, in the spring of 2002, it is time for the fourth Servicing Mission (named Servicing Mission 3B), planned for launch on 28th February. Originally planned as one mission, the third Servicing Mission was split into two parts (Servicing Mission 3A and 3B) because of the sheer number of tasks to be carried out and the urgency with which Hubble's gyroscopes had to be replaced in late '99. In addition to the new solar panels and the ACS camera, astronauts will

HUBBLE PROBES THE VIOLENT BIRTH OF STARS IN GALAXY NGC 253 [Left

NASA Technical Reports Server (NTRS)

2002-01-01

An image of the spiral galaxy NGC 253, taken with a ground-based telescope. The galaxy is located about 8 million light-years away in the constellation Sculptor. Credit: Jay Gallagher (University of Wisconsin-Madison), Alan Watson (Lowell Observatory, Flagstaff, AZ), and NASA [Right] This NASA Hubble Space Telescope image of the core of the nearest starburst spiral galaxy, NGC 253, reveals violent star formation within a region 1,000 light-years across. A starburst galaxy has an exceptionally high rate of star birth, first identified by its excess of infrared radiation from warm dust. Hubble's high resolution allows astronomers to quantify complex structures in the starburst core of the galaxy for the first time, including luminous star clusters, dust lanes which trace regions of dense gas and filaments of glowing gas. Hubble identifies several regions of intense star formation, which include a bright, super-compact star cluster. These observations confirm that stars are often born in dense clusters within starbursts, and that dense gas coexists with and obscures the starburst core. This image was taken with Hubble's Wide Field Planetary Camera 2 (in PC mode). Credit: Carnegie Institution of Washington

Differential cosmic expansion and the Hubble flow anisotropy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolejko, Krzysztof; Nazer, M. Ahsan; Wiltshire, David L., E-mail: bolejko@physics.usyd.edu.au, E-mail: ahsan.nazer@canterbury.ac.nz, E-mail: david.wiltshire@canterbury.ac.nz

2016-06-01

The Universe on scales 10–100 h {sup −1}Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters to the above average expansion rate of voids. In this paper we characterize Hubble expansion anisotropies in the COMPOSITE sample of 4534 galaxies and clusters. We concentrate on the dipole and quadrupole in the rest frame of the Local Group. These both have statistically significant amplitudes. These anisotropies, and their redshift dependence, cannot be explained solely by a boost of the Local Groupmore » in the Friedmann-Lemaitre-Robertson-Walker (FLRW) model which expands isotropically in the rest frame of the cosmic microwave background (CMB) radiation. We simulate the local expansion of the Universe with inhomogeneous Szekeres solutions, which match the standard FLRW model on ∼> 100 h {sup −1}Mpc scales but exhibit nonkinematic relativistic differential expansion on small scales. We restrict models to be consistent with observed CMB temperature anisotropies, while simultaneously fitting the redshift variation of the Hubble expansion dipole. We include features to account for both the Local Void and the 'Great Attractor'. While this naturally accounts for the Hubble expansion and CMB dipoles, the simulated quadrupoles are smaller than observed. Further refinement to incorporate additional structures may improve this. This would enable a test of the hypothesis that some large angle CMB anomalies result from failing to treat the relativistic differential expansion of the background geometry; a natural feature of solutions to Einstein's equations not included in the current standard model of cosmology.« less

Frame-dependence of higher-order inflationary observables in scalar-tensor theories

NASA Astrophysics Data System (ADS)

Karam, Alexandros; Pappas, Thomas; Tamvakis, Kyriakos

2017-09-01

In the context of scalar-tensor theories of gravity we compute the third-order corrected spectral indices in the slow-roll approximation. The calculation is carried out by employing the Green's function method for scalar and tensor perturbations in both the Einstein and Jordan frames. Then, using the interrelations between the Hubble slow-roll parameters in the two frames we find that the frames are equivalent up to third order. Since the Hubble slow-roll parameters are related to the potential slow-roll parameters, we express the observables in terms of the latter which are manifestly invariant. Nevertheless, the same inflaton excursion leads to different predictions in the two frames since the definition of the number of e -folds differs. To illustrate this effect we consider a nonminimal inflationary model and find that the difference in the predictions grows with the nonminimal coupling, and it can actually be larger than the difference between the first and third order results for the observables. Finally, we demonstrate the effect of various end-of-inflation conditions on the observables. These effects will become important for the analyses of inflationary models in view of the improved sensitivity of future experiments.

Hubble's Little Sombrero

NASA Image and Video Library

2015-02-06

Galaxies can take many shapes and be oriented any way relative to us in the sky. This can make it hard to figure out their actual morphology, as a galaxy can look very different from different viewpoints. A special case is when we are lucky enough to observe a spiral galaxy directly from its edge, providing us with a spectacular view like the one seen in this picture of the week. This is NGC 7814, also known as the “Little Sombrero.” Its larger namesake, the Sombrero Galaxy, is another stunning example of an edge-on galaxy — in fact, the “Little Sombrero” is about the same size as its bright namesake at about 60,000 light-years across, but as it lies farther away, and so appears smaller in the sky. NGC 7814 has a bright central bulge and a bright halo of glowing gas extending outwards into space. The dusty spiral arms appear as dark streaks. They consist of dusty material that absorbs and blocks light from the galactic center behind it. The field of view of this NASA/ESA Hubble Space Telescope image would be very impressive even without NGC 7814 in front; nearly all the objects seen in this image are galaxies as well. Credit: ESA/Hubble & NASA Acknowledgement: Josh Barrington NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Provides Clear Images of Saturn's Aurora

NASA Technical Reports Server (NTRS)

1998-01-01

This is the first image of Saturn's ultraviolet aurora taken by the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope in October 1997, when Saturn was a distance of 810 million miles (1.3 billion kilometers) from Earth. The new instrument, used as a camera, provides more than ten times the sensitivity of previous Hubble instruments in the ultraviolet. STIS images reveal exquisite detail never before seen in the spectacular auroral curtains of light that encircle Saturn's north and south poles and rise more than a thousand miles above the cloud tops.

Saturn's auroral displays are caused by an energetic wind from the Sun that sweeps over the planet, much like the Earths aurora that is occasionally seen in the nighttime sky and similar to the phenomenon that causes fluorescent lamps to glow. But unlike the Earth, Saturn's aurora is only seen in ultraviolet light that is invisible from the Earths surface, hence the aurora can only be observed from space. New Hubble images reveal ripples and overall patterns that evolve slowly, appearing generally fixed in our view and independent of planet rotation. At the same time, the curtains show local brightening that often follow the rotation of the planet and exhibit rapid variations on time scales of minutes. These variations and regularities indicate that the aurora is primarily shaped and powered by a continual tug-of-war between Saturn's magnetic field and the flow of charged particles from the Sun.

Study of the aurora on Saturn had its beginnings just seventeen years ago. The Pioneer 11 spacecraft observed a far-ultraviolet brightening on Saturn's poles in 1979. The Saturn flybys of the Voyager 1 and 2 spacecraft in the early 1980s provided a basic description of the aurora and mapped for the first time planets enormous magnetic field that guides energetic electrons into the atmosphere near the north and south poles.

The first images of Saturn's aurora were provided in 1994-5 by the

Morphology and time variation of the Jovian Far UV aurora: Hubble Space Telescope observations

NASA Technical Reports Server (NTRS)

Gerard, Jean-Claude; Dols, Vincent; Paresce, Francesco; Prange, Renee

1993-01-01

High spatial resolution images of the north polar region of Jupiter have been obtained with the Faint Object Camera (FOC) on board the Hubble Space Telescope (HST). The first set of two images collected 87 min apart in February 1992 shows a bright (approximately or equal to 180 kR) emission superimposed on the background in rotation with the planet. Both Ly alpha images show common regions of enhanced emission but differences are also observed, possibly due to temporal variations. The second group of images obtained on June 23 and 26, 1992 isolates a spectral region near 153 nm dominated by the H2 Lyman bands and continuum. Both pictures exhibit a narrow arc structure fitting the L = 30 magnetotail field line footprint in the morning sector and a broader diffuse aurora in the afternoon. They show no indication of an evening twilight enhancement. Although the central meridian longitudes were similar, significant differences are seen in the two exposures, especially in the region of diffuse emission, and interpreted as signatures of temporal variations. The total power radiated in the H2 bands is approximately or equal to 2 x 10(exp 12) W, in agreement with previous UV spectrometer observations. The high local H2 emission rates (approximately 450 kR) imply a particle precipitation carrying an energy flux of about 5 x 10(exp -2) W/sq m.

HUBBLE FINDS MANY BRIGHT CLOUDS ON URANUS

NASA Technical Reports Server (NTRS)

2002-01-01

A recent Hubble Space Telescope view reveals Uranus surrounded by its four major rings and by 10 of its 17 known satellites. This false-color image was generated by Erich Karkoschka using data taken on August 8, 1998, with Hubble's Near Infrared Camera and Multi-Object Spectrometer. Hubble recently found about 20 clouds - nearly as many clouds on Uranus as the previous total in the history of modern observations. The orange-colored clouds near the prominent bright band circle the planet at more than 300 mph (500 km/h), according to team member Heidi Hammel (MIT). One of the clouds on the right-hand side is brighter than any other cloud ever seen on Uranus. The colors in the image indicate altitude. Team member Mark Marley (New Mexico State University) reports that green and blue regions show where the atmosphere is clear and sunlight can penetrate deep into Uranus. In yellow and grey regions the sunlight reflects from a higher haze or cloud layer. Orange and red colors indicate very high clouds, such as cirrus clouds on Earth. The Hubble image is one of the first images revealing the precession of the brightest ring with respect to a previous image [LINK to PRC97-36a]. Precession makes the fainter part of the ring (currently on the upper right-hand side) slide around Uranus once every nine months. The fading is caused by ring particles crowding and hiding each other on one side of their eight-hour orbit around Uranus. The blue, green and red components of this false-color image correspond to exposures taken at near-infrared wavelengths of 0.9, 1.1, and 1.7 micrometers. Thus, regions on Uranus appearing blue, for example, reflect more sunlight at 0.9 micrometer than at the longer wavelengths. Apparent colors on Uranus are caused by absorption of methane gas in its atmosphere, an effect comparable to absorption in our atmosphere which can make distant clouds appear red. Credit: Erich Karkoschka (University of Arizona) and NASA

HUBBLE SPACE TELESCOPE OBSERVATIONS OF ACTIVE ASTEROID 324P/La SAGRA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jewitt, David; Li, Jing; Agarwal, Jessica

Hubble Space Telescope observations of active asteroid 324P/La Sagra near perihelion show continued mass loss consistent with the sublimation of near-surface ice. Isophotes of the coma measured from a vantage point below the orbital plane are best matched by steady emission of particles having a nominal size  of  a  ∼ 100 μ m. The inferred rate of mass loss, dM{sub d} / dt  ∼ 0.2 kg s{sup −1}, can be supplied by sublimation of water ice in thermal equilibrium with sunlight from an area as small as 930 m{sup 2}, corresponding to about 0.2% of the nucleus surface. Observations taken from amore » vantage point only 0.°6 from the orbital plane of 324P set a limit to the velocity of ejection of dust in the direction perpendicular to the plane, V {sub ⊥} < 1 m s{sup −1}. Short-term photometric variations of the near-nucleus region, if related to rotation of the underlying nucleus, rule-out periods ≤3.8 hr and suggest that rotation probably does not play a central role in driving the observed mass loss. We estimate that, in the previous orbit, 324P lost about 4 × 10{sup 7} kg in dust particles, corresponding to 6 × 10{sup −5} of the mass of a 550 m spherical nucleus of assumed density ρ  = 1000 kg m{sup −3}. If continued, mass loss at this rate would limit the lifetime of 324P to ∼1.6 × 10{sup 4} orbits (about 10{sup 5} years). To survive for the 100–400 Myr timescales corresponding to dynamical and collisional stability requires a duty cycle of 2 × 10{sup −4} ≤  f{sub d}  ≤ 8 × 10{sup −4}. Unless its time in orbit is overestimated by many orders of magnitude, 324P is revealed as a briefly active member of a vast population of otherwise dormant ice-containing asteroids.« less

Two ESA astronauts named to early Hubble Space Telescope servicing mission

NASA Astrophysics Data System (ADS)

1999-03-01

Space Telescope, launched in 1990, is one of the most powerful optical telescopes available to astronomers today, producing images and spectral observations at the forefront of astronomy. ESA contributed a 15 share to the development of Hubble and European astronomers receive in return a guaranteed 15 share of observing time (and 20 on average in practice).

Hubble IMAX Premier

NASA Image and Video Library

2010-03-09

Dr. Ed Weiler, left, is interviewed by Miles O'Brien prior to the World Premiere of "Hubble 3D", screened at the Smithsonian's Air and Space Museum Tuesday evening, March 9, 2010, in Washington. Photo Credit: (NASA/Paul E. Alers)

Hubble (HST) hardware is uncrated in the PHSF

NASA Technical Reports Server (NTRS)

1999-01-01

In the Payload Hazardous Servicing Facility (PHSF), a crane lifts equipment for mission STS-103 out of its shipping container to move it to a workstand. The equipment is the first part of payload flight hardware for the third Hubble Space Telescope Servicing Mission (SM-3A). The hardware will undergo final testing and integration of payload elements in the PHSF. Mission STS-103 is a 'call-up' mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-103 is currently targeted for Oct. 14 but the date is under review.

Hubble (HST) hardware is uncrated in the PHSF

NASA Technical Reports Server (NTRS)

1999-01-01

In the Payload Hazardous Servicing Facility (PHSF), a crane lifts equipment for mission STS-103 out of its shipping container. The equipment is the first part of payload flight hardware for the third Hubble Space Telescope Servicing Mission (SM-3A). The hardware will undergo final testing and integration of payload elements in the PHSF. Mission STS-103 is a 'call-up' mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-103 is currently targeted for Oct. 14 but the date is under review.

HUBBLE VIEWS DISTANT GALAXIES THROUGH A COSMIC LENS

NASA Technical Reports Server (NTRS)

2002-01-01

This NASA Hubble Space Telescope image of the rich galaxy cluster, Abell 2218, is a spectacular example of gravitational lensing. The arc-like pattern spread across the picture like a spider web is an illusion caused by the gravitational field of the cluster. The cluster is so massive and compact that light rays passing through it are deflected by its enormous gravitational field, much as an optical lens bends light to form an image. The process magnifies, brightens and distorts images of objects that lie far beyond the cluster. This provides a powerful 'zoom lens' for viewing galaxies that are so far away they could not normally be observed with the largest available telescopes. Hubble's high resolution reveals numerous arcs which are difficult to detect with ground-based telescopes because they appear to be so thin. The arcs are the distorted images of a very distant galaxy population extending 5-10 times farther than the lensing cluster. This population existed when the universe was just one quarter of its present age. The arcs provide a direct glimpse of how star forming regions are distributed in remote galaxies, and other clues to the early evoution of galaxies. Hubble also reveals multiple imaging, a rarer lensing event that happens when the distortion is large enough to produce more than one image of the same galaxy. Abell 2218 has an unprecedented total of seven multiple systems. The abundance of lensing features in Abell 2218 has been used to make a detailed map of the distribution of matter in the cluster's center. From this, distances can be calculated for a sample of 120 faint arclets found on the Hubble image. These arclets represent galaxies that are 50 times fainter than objects that can be seen with ground-based telescopes. Studies of remote galaxies viewed through well-studied lenses like Abell 2218 promise to reveal the nature of normal galaxies at much earlier epochs than was previously possible. The technique is a powerful combination of Hubble

Long range science scheduling for the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Miller, Glenn; Johnston, Mark

1991-01-01

Observations with NASA's Hubble Space Telescope (HST) are scheduled with the assistance of a long-range scheduling system (SPIKE) that was developed using artificial intelligence techniques. In earlier papers, the system architecture and the constraint representation and propagation mechanisms were described. The development of high-level automated scheduling tools, including tools based on constraint satisfaction techniques and neural networks is described. The performance of these tools in scheduling HST observations is discussed.

Version 1 of the Hubble Source Catalog

DOE PAGES

Whitmore, Bradley C.; Allam, Sahar S.; Budavari, Tamas; ...

2016-05-11

The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160 thousand HST exposures. Source lists from Data Release 8 of the Hubble Legacy Archive are matched using an algorithm developed by Budavari & Lubow (2012). The mean photometric accuracy for the catalog as a whole is better than 0.10 mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10 mas, with a value for the mode (i.e., most common value) of 2.3 mas. The absolute astrometric accuracy is better thanmore » $$\\sim$$0.1 arcsec for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. Here, we provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog.« less

Hubble Finds New Dark Spot on Neptune

NASA Technical Reports Server (NTRS)

1995-01-01

NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet.

The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared.

Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere.

Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere.

The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops.

The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

Maintaining an expert system for the Hubble Space Telescope ground support

NASA Technical Reports Server (NTRS)

Lindenmayer, Kelly; Vick, Shon; Rosenthal, Don

1987-01-01

The transformation portion of the Hubble Space Telescope (HST) Proposal Entry Processor System converts astronomer-oriented description of a scientific observing program into a detailed description of the parameters needed for planning and scheduling. The transformation system is one of a very few rulebased expert systems that has ever entered an operational phase. The day to day operations of the system and its rulebase are no longer the responsibility of the original developer. As a result, software engineering properties of the rulebased approach become more important. Maintenance issues associated with the coupling of rules within a rulebased system are discussed and a method is offered for partitioning a rulebase so that the amount of knowledge needed to modify the rulebase is minimized. This method is also used to develop a measure of the coupling strength of the rulebase.

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2009-01-01

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z greater than 6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z greater than 10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (less than 50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth-Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems, and discuss recent progress in constructing the observatory.

Jovian Hotspots in the NEB in the Visible and Near-IR from Hubble and Ground-Based IR Observations

NASA Astrophysics Data System (ADS)

Wittal, Matthew Michael; Orton, Glenn; Sinclair, James; Wong, Michael; Simon, Amy; Irwin, Patrick; Braude, Ashwin

2018-01-01

In order to better understand the composition and behavior of Jupiter's atmosphere, radiating regions in the infrared known as ‘hotspots’ are compared with darker spots in the visible at the same locations within the Northern Equatorial Band (NEB). Hubble images taken in across the visible and into the near-infrared (between 275 nm and 889 nm) are compared with 5.1 µm images taken using the Subaru telescope and other ground-based observations. The connection between these regions has been known for some time, and comparison between them at these wavelengths showed a general correlation between dimness in the visible and brightness in the infrared, but this was not the case in all observed locations. The origins and cause of these hotspots remains unclear, but because of their quasi-stable nature and reoccurrence at roughly 30-degree longitudes suggests a relationship with Rossby Waves. Continuous spectra from Multi Unite Spectroscopic Explorer (MUSE) also shows that measured values from the near-infrared fit well with observations, and hints at the composition of the discolored region through the use of NEMESIS software cross-correlation.

HUBBLE FINDS NEW DARK SPOT ON NEPTUNE

NASA Technical Reports Server (NTRS)

2002-01-01

NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet. The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared. Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere. Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere. The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops. Credit: H. Hammel (Massachusetts Institute of Technology) and NASA

Hubble Space Telescope/NICMOS Observations of I Zw 18: A Population of Old Asymptotic Giant Branch Stars Revealed.

PubMed

Östlin

2000-06-01

I present the first results from a Hubble Space Telescope/NICMOS imaging study of the most metal-poor blue compact dwarf galaxy, I Zw 18. The near-infrared color-magnitude diagram (CMD) is dominated by two populations, one 10-20 Myr population of red supergiants and one 0.1-5 Gyr population of asymptotic giant branch stars. Stars older than 1 Gyr are required to explain the observed CMD at the adopted distance of 12.6 Mpc, showing that I Zw 18 is not a young galaxy. The results hold also if the distance to I Zw 18 is significantly larger. This rules out the possibility that I Zw 18 is a truly young galaxy formed recently in the local universe.

Hubble Watches the Red Planet as Mars Global Surveyor Begins Aerobraking

NASA Technical Reports Server (NTRS)

1997-01-01

[RIGHT] This NASA Hubble Space Telescope picture of Mars was taken on Sept. 12, one day after the arrival of the Mars Global Surveyor (MGS) spacecraft and only five hours before the beginning of autumn in the Martian northern hemisphere. (Mars is tilted on its axis like Earth, so it has similar seasonal changes, including an autumnal equinox when the Sun crosses Mars' equator from the northern to the southern hemisphere).

This Hubble picture was taken in support of the MGS mission. Hubble is monitoring the Martian weather conditions during the early phases of MGS aerobraking; in particular, the detection of large dust storms are important inputs into the atmospheric models used by the MGS mission to plan aerobraking operations.

Though a dusty haze fills the giant Hellas impact basin south of the dark fin-shaped feature Syrtis Major, the dust appears to be localized within Hellas. Unless the region covered expands significantly, the dust will not be of concern for MGS aerobraking.

Other early signs of seasonal transitions on Mars are apparent in the Hubble picture. The northern polar ice cap is blanketed under a polar hood of clouds that typically start forming in late northern summer. As fall progresses, sunlight will dwindle in the north polar region and the seasonal polar cap of frozen carbon dioxide will start condensing onto the surface under these clouds.

Hubble observations will continue until October 13, as MGS carefully uses the drag of the Martian atmosphere to circularize its orbit about the Red Planet. After mid-October, Mars will be too close to the Sun, in angular separation, for Hubble to safely view.

The image is a composite of three separately filtered colored images taken with the Wide Field Planetary Camera 2 (WFPC2). Resolution is 35 miles (57 kilometers) per pixel (picture element). The Pathfinder landing site near Ares Valles is about 2200 miles (3600 kilometers) west of the center of this image, so was not visible during this

Hubble's Cosmology: From a Finite Expanding Universe to a Static Endless Universe

NASA Astrophysics Data System (ADS)

Assis, A. K. T.; Neves, M. C. D.; Soares, D. S. L.

2009-12-01

We analyze the views of Edwin Hubble (1889-1953) as regards the large scale structure of the universe. In 1929 he initially accepted a finite expanding universe in order to explain the redshifts of distant galaxies. Later on he turned to an infinite stationary universe and a new principle of nature in order to explain the same phenomena. Initially, he was impressed by the agreement of his redshift-distance relation with one of the predictions of de Sitter's cosmological model, namely, the so-called "de Sitter effect'', the phenomenon of the scattering of material particles, leading to an expanding universe. A number of observational evidences, though, made him highly skeptical with such a scenario. They were better accounted for by an infinite static universe. The evidences he found were: (i) the huge values he was getting for the "recession'' velocities of the nebulae (1,800 km s-1 in 1929 up to 42,000 km s-1 in 1942, leading to v/c = 1/7), with the redshifts interpreted as velocity-shifts. All other known real velocities of large astronomical bodies are much smaller than these. (ii) The "number effect'' test, which is the running of nebulae luminosity with redshift. Hubble found that a static universe is, within the observational uncertainties, slightly favored. The test is equivalent to the modern "Tolman effect,'' for galaxy surface brightnesses, whose results are still a matter of dispute. (iii) The smallness of the size and the age of the curved expanding universe, implied by the expansion rate that he had determined, and, (iv) the fact that a uniform distribution of galaxies on large scales is more easily obtained from galaxy counts, when a static and flat model is considered. In an expanding and closed universe, Hubble found that homogeneity was only obtained at the cost of a large curvature. We show, by quoting his works, that Hubble remained cautiously against the big bang until the end of his life, contrary to the statements of many modern authors. In

From Hubble's NGSL to Absolute Fluxes

NASA Technical Reports Server (NTRS)

Heap, Sara R.; Lindler, Don

2012-01-01

Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.

Hubble Sees 'Ghost Light' From Dead Galaxies

NASA Image and Video Library

2014-10-30

NASA’s Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies that were gravitationally ripped apart several billion years ago. The mayhem happened 4 billion light-years away, inside an immense collection of nearly 500 galaxies nicknamed “Pandora’s Cluster,” also known as Abell 2744. The scattered stars are no longer bound to any one galaxy, and drift freely between galaxies in the cluster. By observing the light from the orphaned stars, Hubble astronomers have assembled forensic evidence that suggests as many as six galaxies were torn to pieces inside the cluster over a stretch of 6 billion years. Read more: 1.usa.gov/1yK2Ucp Credit: NASA/ESA/IAC/HFF Team, STScI NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

A Decade of Hubble Space Telescope Science

NASA Astrophysics Data System (ADS)

Livio, Mario; Noll, Keith; Stiavelli, Massimo

2003-06-01

1. HST studies of Mars J. F. Bell; 2. HST images of Jupiter's UV aurora J. T. Clarke; 3. Star formation J. Bally; 4. SN1987A: the birth of a supernova remnant R. McCray; 5. Globular clusters: the view from HST W. E. Harris; 6. Ultraviolet absorption line studies of the Galactic interstellar medium with the Goddard High Resolution Spectrograph B. D. Savage; 7. HST's view of the center of the Milky Way galaxy M. J. Rieke; 8. Stellar populations in dwarf galaxies: a review of the contribution of HST to our understanding of the nearby universe E. Tolstoy; 9. The formation of star clusters B. C. Whitmore; 10. Starburst galaxies observed with the Hubble Space Telescope C. Leitherer; 11. Supermassive black holes F. D. Macchetto; 12. The HST Key Project to measure the Hubble Constant W. L. Freedman, R. C. Kennicutt, J. R. Mould and B. F. Madore; 13. Ho from Type Ia Supernovae G. A. Tammann, A. Sandage and A. Saha; 14. Strong gravitational lensing: cosmology from angels and redshifts A. Tyson.

Hubble Views a Dwarf Galaxy

NASA Image and Video Library

2017-12-08

The constellation of Ursa Major (The Great Bear) is home to Messier 101, the Pinwheel Galaxy. Messier 101 is one of the biggest and brightest spiral galaxies in the night sky. Like the Milky Way, Messier 101 is not alone, with smaller dwarf galaxies in its neighborhood. NGC 5477, one of these dwarf galaxies in the Messier 101 group, is the subject of this image from the NASA/ESA Hubble Space Telescope. Without obvious structure, but with visible signs of ongoing star birth, NGC 5477 looks much like an typical dwarf irregular galaxy. The bright nebulae that extend across much of the galaxy are clouds of glowing hydrogen gas in which new stars are forming. These glow pinkish red in real life, although the selection of green and infrared filters through which this image was taken makes them appear almost white. The observations were taken as part of a project to measure accurate distances to a range of galaxies within about 30 million light-years from Earth, by studying the brightness of red giant stars. In addition to NGC 5477, the image includes numerous galaxies in the background, including some that are visible right through NGC 5477. This serves as a reminder that galaxies, far from being solid, opaque objects, are actually largely made up of the empty space between their stars. This image is a combination of exposures taken through green and infrared filters using Hubble's Advanced Camera for Surveys. The field of view is approximately 3.3 by 3.3 arcminutes. ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

First Hubble Space Telescope observations of the brightest stars in the Virgo galaxy M100 = NGC 4321

NASA Technical Reports Server (NTRS)

Freedman, Wendy L.; Madore, Barry F.; Stetson, Peter B.; Hughes, Shaun M. G.; Holtzman, Jon A.; Mould, Jeremy R.; Trauger, John T.; Gallagher, John S., III; Ballester, Gilda E.; Burrows, Christopher J.

1994-01-01

As part of both the Early Release Observations from the Hubble Space Telescope (HST) and the Key Project on the Extragalactic Distance Scale, we have obtained multiwavelength BVR Wide Field/Planetary Camera-2 (WFPC2) images for the face-on Virgo cluster spiral galaxy M100 = NGC 4321. We report here preliminary results from those observations, in the form of a color-magnitude diagram for approximately 11,500 stars down to V approximately 27 mag and a luminosity function for the brightest blue stars which is found to have a slope of 0.7, in excellent agreement with previous results obtained for significantly nearer galaxies. With the increased resolution now available using WFPC2, the number of galaxies in which we can directly measure Population I stars and thereby quantify the recent evolution, as well as test stellar evolution theory, has dramatically increased by at least a factor of 100. Finally, we find that the stars are present in M100 at the colors and luminosities expected for the brightest Cepheid variables in galaxies.

The UV Spectrum of the Ultracool Dwarf LSR J1835+3259 Observed with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Saur, Joachim; Fischer, Christian; Wennmacher, Alexandre; Feldman, Paul; Roth, Lorenz; Strobel, D.; Reiners, Ansgar

2018-01-01

An interesting question about ultracool dwarfs is whether their emission is purely internally driven or partially powered by external processes similar to auroral emission known from planetary bodies of the solar system. Here we present Hubble Space Telescope observations of the energy fluxes of the M8.5 ultracool dwarf LSR J1835+3259 throughout the UV. The dwarf’s UV emission is generally weaker compared to younger-type M-dwarfs. We detect the Mg II doublet at 2800 A and constrain an average flux throughout the Near-UV. In the Far-UV without Lyman alpha, the ultracool dwarf is extremely faint with an energy output of at least a factor of 1000 smaller than expected from auroral emission physically similar to that on Jupiter. We also detect the red wing of the Lyman alpha emission. Our overall finding is that the observed UV spectrum of LSR J1835+3259 resembles the spectrum of M-dwarf stars much closer than the spectrum expected from Jupiter-like auroral processes.

The UV Spectrum of the Ultracool Dwarf LSR J1835+3259 Observed with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Saur, Joachim; Fischer, Christian; Wennmacher, Alexandre; Feldman, Paul D.; Roth, Lorenz; Strobel, Darrell F.; Reiners, Ansgar

2018-05-01

An interesting question about ultracool dwarfs recently raised in the literature is whether their emission is purely internally driven or partially powered by external processes similar to planetary aurora known from the solar system. In this work, we present Hubble Space Telescope observations of the energy fluxes of the M8.5 ultracool dwarf LSR J1835+3259 throughout the ultraviolet (UV). The obtained spectra reveal that the object is generally UV-fainter compared with other earlier-type dwarfs. We detect the Mg II doublet at 2800 Å and constrain an average flux throughout the near-UV. In the far-UV without Lyα, the ultracool dwarf is extremely faint with an energy output at least a factor of 250 smaller as expected from auroral emission physically similar to that on Jupiter. We also detect the red wing of the Lyα emission. Our overall finding is that the observed UV spectrum of LSR J1835+3259 resembles the spectrum of mid/late-type M-dwarf stars relatively well, but it is distinct from a spectrum expected from Jupiter-like auroral processes.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1997-01-02

What look like giant twisters are spotted by the Hubble Space Telescope (HST). These images are, in actuality, pillars of gases that are in the process of the formation of a new star. These pillars can be billions of miles in length and may have been forming for millions of years. This one formation is located in the Lagoon Nebula and was captured by the Hubble's wide field planetary camera-2 (WFPC-2).

HUBBLE PROVIDES THE FIRST IMAGES OF SATURN'S AURORA (Top)

NASA Technical Reports Server (NTRS)

2002-01-01

This is the first image ever taken of bright aurorae at Saturn's northern and southern poles, as seen in far ultraviolet light by the Wide Field and Planetary Camera 2 aboard NASA's Hubble Space Telescope. Hubble resolves a luminous, circular band centered on the north pole, where an enormous auroral curtain rises as far as 1,200 miles (2,000 kilometers) above the cloudtops. This curtain changed rapidly in brightness and extent over the two hour period of our HST observations, though the brightest emissions remained at a position fixed in sun angle, near 'dawn' in the north auroral band. The image was taken on October 9, 1994, when Saturn was at a distance of 831 million miles (1.3 billion kilometers) from Earth. The aurora is produced as trapped charged particles precipitating from the magnetosphere collide with atmospheric gases -- molecular and atomic hydrogen in Saturn's case. As a result of the bombardment, Saturn's gases glow at far-ultraviolet wavelengths (110-160 nanometers) which are absorbed by the Earth's atmosphere, and so can only be observed from space-based telescopes. Saturn's magnetic field is nearly perfectly aligned with the planet's rotation, giving the auroral 'ring' its symmetry centered on the pole. (The southern aurora is faintly visible in this view despite the fact that Saturn's northern pole is now tilted slightly toward Earth.) The Hubble images demonstrate our capability to record from the Earth the auroral brightness and distribution about Saturn's poles, which will ultimately complement the in situ measurements of Saturn's magnetic field and charged particles to be made by the NASA/ESA Cassini spacecraft near the turn of the century. Study of the aurora on Saturn had its beginnings a few decades ago. The Pioneer 11 probe observed a far-ultraviolet brightening on Saturn's poles in 1979. Beginning in 1980, a series of spectroscopic observations by the International Ultraviolet Explorer (IUE) have sporadically detected emissions from

NASA's Hubble Celebrates 21st Anniversary with "Rose" of Galaxies

NASA Image and Video Library

2017-12-08

NASA image release April 20, 2011 To see a video of this image go here: www.flickr.com/photos/gsfc/5637796622 To celebrate the 21st anniversary of the Hubble Space Telescope's deployment into space, astronomers at the Space Telescope Science Institute in Baltimore, Md., pointed Hubble's eye at an especially photogenic pair of interacting galaxies called Arp 273. The larger of the spiral galaxies, known as UGC 1810, has a disk that is distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. This image is a composite of Hubble Wide Field Camera 3 data taken on December 17, 2010, with three separate filters that allow a broad range of wavelengths covering the ultraviolet, blue, and red portions of the spectrum. Hubble was launched April 24, 1990, aboard Discovery's STS-31 mission. Hubble discoveries revolutionized nearly all areas of current astronomical research from planetary science to cosmology. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) To read more about this image go here: www.nasa.gov/mission_pages/hubble/science/hubble-rose.html NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Hubble Space Telescope Planetary Camera observations of Arp 220

NASA Technical Reports Server (NTRS)

Shaya, Edward J.; Dowling, Daniel M.; Currie, Douglas G.; Faber, S. M.; Groth, Edward J.

1994-01-01

Planetary Camera images of peculiar galaxy Arp 220 taken with V, R, and I band filters reveal a very luminous object near the position of the western radio continuum source, assumed to be the major nucleus, ans seven lesser objects within 2 sec of this position. The most luminous object is formally coincident with the radio source to within the errors of Hubble Space Telescope (HST) pointing accuracy, but we have found an alternate, more compelling alignment of maps in which the eastern radio source coincides with one of the lesser objects and the OH radio sources reside near the surfaces of other optical objects. The proposed centering places the most luminous object 150 pc (0.4 sec) away from the western radio source. We explore the possibilities that the objects are either holes in the dense dust distribution, dusty clouds reflecting a hidden bright nucleus, or associations of bright young stars. We favor the interpretation that at least the brightest two objects are massive young star associations with luminosities 10(exp 9) to 10(exp 11) solar luminosity, but highly extinguished by intervening dust. These massive associations should fall into the nucleus on a time scale of 10(exp 8) yr. About 10% of the enigmatic far-IR flux arises from the observed objects. In addition, if the diffuse starlight out to a radius of 8 sec is dominated by stars with typical ages of order 10(exp 8) yr (the time since the alleged merger of two galaxies), as indicated by the blue colors at larger radius, then the lower limit to the reradiation of diffuse starlight contributes 3 x 10(exp 11) solar luminosity to the far-infrared flux, or greater than or equal to 25% of the total far-IR flux. Three additional bright objects (M(sub V) approximately equals -13) located about 6 sec from the core are likely young globular clusters, but any of these could be recently exploded supernovae instead. The expected supernovae rate, if the dominant energy source is young stars, is about one per

NASA's Hubble Shows Jupiter's Great Red Spot is Smaller than Ever

NASA Image and Video Library

2014-05-15

An image of Jupiter's Great Red Spot taken in 2014 with Hubble's WFC3 camera. The spot has a diameter here of 16 000km. -- Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger than Earth -- has shrunk to its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across. Astronomers have followed this downsizing since the 1930s. Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle. Read more: 1.usa.gov/1mvuo0R Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's Hubble Shows Jupiter's Great Red Spot is Smaller than Ever

NASA Image and Video Library

2014-05-15

This full-disc image of Jupiter was taken on 21 April 2014 with Hubble's Wide Field Camera 3 (WFC3). -- Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger than Earth -- has shrunk to its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across. Astronomers have followed this downsizing since the 1930s. Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle. Read more: 1.usa.gov/1mvuo0R Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

New Constraints on ΩM, ΩΛ, and w from an Independent Set of 11 High-Redshift Supernovae Observed with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Knop, R. A.; Aldering, G.; Amanullah, R.; Astier, P.; Blanc, G.; Burns, M. S.; Conley, A.; Deustua, S. E.; Doi, M.; Ellis, R.; Fabbro, S.; Folatelli, G.; Fruchter, A. S.; Garavini, G.; Garmond, S.; Garton, K.; Gibbons, R.; Goldhaber, G.; Goobar, A.; Groom, D. E.; Hardin, D.; Hook, I.; Howell, D. A.; Kim, A. G.; Lee, B. C.; Lidman, C.; Mendez, J.; Nobili, S.; Nugent, P. E.; Pain, R.; Panagia, N.; Pennypacker, C. R.; Perlmutter, S.; Quimby, R.; Raux, J.; Regnault, N.; Ruiz-Lapuente, P.; Sainton, G.; Schaefer, B.; Schahmaneche, K.; Smith, E.; Spadafora, A. L.; Stanishev, V.; Sullivan, M.; Walton, N. A.; Wang, L.; Wood-Vasey, W. M.; Yasuda, N.

2003-11-01

We report measurements of ΩM, ΩΛ, and w from 11 supernovae (SNe) at z=0.36-0.86 with high-quality light curves measured using WFPC2 on the Hubble Space Telescope (HST). This is an independent set of high-redshift SNe that confirms previous SN evidence for an accelerating universe. The high-quality light curves available from photometry on WFPC2 make it possible for these 11 SNe alone to provide measurements of the cosmological parameters comparable in statistical weight to the previous results. Combined with earlier Supernova Cosmology Project data, the new SNe yield a measurement of the mass density ΩM=0.25+0.07-0.06(statistical)+/-0.04 (identified systematics), or equivalently, a cosmological constant of ΩΛ=0.75+0.06-0.07(statistical)+/-0.04 (identified systematics), under the assumptions of a flat universe and that the dark energy equation-of-state parameter has a constant value w=-1. When the SN results are combined with independent flat-universe measurements of ΩM from cosmic microwave background and galaxy redshift distortion data, they provide a measurement of w=-1.05+0.15-0.20(statistical)+/-0.09 (identified systematic), if w is assumed to be constant in time. In addition to high-precision light-curve measurements, the new data offer greatly improved color measurements of the high-redshift SNe and hence improved host galaxy extinction estimates. These extinction measurements show no anomalous negative E(B-V) at high redshift. The precision of the measurements is such that it is possible to perform a host galaxy extinction correction directly for individual SNe without any assumptions or priors on the parent E(B-V) distribution. Our cosmological fits using full extinction corrections confirm that dark energy is required with P(ΩΛ>0)>0.99, a result consistent with previous and current SN analyses that rely on the identification of a low-extinction subset or prior assumptions concerning the intrinsic extinction distribution. Based in part on

Hubble and the Language of Images

NASA Astrophysics Data System (ADS)

Levay, Z. G.

2005-12-01

Images released from the Hubble Space Telescope have been very highly regarded by the astronomy-attentive public for at least a decade. Due in large part to these images, Hubble has become an iconic figure, even among the general public. This iconic status is both a boon and a burden for those who produce the stream of images fl owing from this telescope. While the benefits of attention are fairly obvious, the negative aspects are less visible. One of the most persistent challenges is the need to continue to deliver images that "top" those released before. In part this can be accomplished because of Hubble's upgraded instrumentation. But it can also be a source of pressure that could, if left unchecked, erode ethical boundaries in our communication with the public. These pressures are magnified in an atmosphere of uncertainty with regard to the future of the mission.

Hubble Captures Volcanic Eruption Plume From Io

NASA Technical Reports Server (NTRS)

1997-01-01

The Hubble Space Telescope has snapped a picture of a 400-km-high (250-mile-high) plume of gas and dust from a volcanic eruption on Io, Jupiter's large innermost moon.

Io was passing in front of Jupiter when this image was taken by the Wide Field and Planetary Camera 2 in July 1996. The plume appears as an orange patch just off the edge of Io in the eight o'clock position, against the blue background of Jupiter's clouds. Io's volcanic eruptions blasts material hundreds of kilometers into space in giant plumes of gas and dust. In this image, material must have been blown out of the volcano at more than 2,000 mph to form a plume of this size, which is the largest yet seen on Io.

Until now, these plumes have only been seen by spacecraft near Jupiter, and their detection from the Earth-orbiting Hubble Space Telescope opens up new opportunities for long-term studies of these remarkable phenomena.

The plume seen here is from Pele, one of Io's most powerful volcanos. Pele's eruptions have been seen before. In March 1979, the Voyager 1 spacecraft recorded a 300-km-high eruption cloud from Pele. But the volcano was inactive when the Voyager 2 spacecraft flew by Jupiter in July 1979. This Hubble observation is the first glimpse of a Pele eruption plume since the Voyager expeditions.

Io's volcanic plumes are much taller than those produced by terrestrial volcanos because of a combination of factors. The moon's thin atmosphere offers no resistance to the expanding volcanic gases; its weak gravity (one-sixth that of Earth) allows material to climb higher before falling; and its biggest volcanos are more powerful than most of Earth's volcanos.

This image is a contrast-enhanced composite of an ultraviolet image (2600 Angstrom wavelength), shown in blue, and a violet image (4100 Angstrom wavelength), shown in orange. The orange color probably occurs because of the absorption and/or scattering of ultraviolet light in the plume. This light from Jupiter passes through

Hubble reveals heart of Lagoon Nebula

NASA Image and Video Library

2010-09-22

astronomers’ theories about star formation in such hydrogen-rich regions. The Lagoon Nebula is faintly visible to the naked eye on dark nights as a small patch of grey in the heart of the Milky Way. Without a telescope, the nebula looks underwhelming because human eyes are unable to distinguish clearly between colours at low light levels. Charles Messier, the 18th century French astronomer, observed the nebula and included it in his famous astronomical catalogue, from which the nebula’s alternative name comes. But his relatively small refracting telescope would only have hinted at the dramatic structures and colours now visible thanks to Hubble. The Hubble Space Telescope is a project of international cooperation between ESA and NASA. Image credit: NASA, ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram To learn more about the Hubble Space Telescope go here: www.nasa.gov/mission_pages/hubble/main/index.html

Comparative analysis of the effects of hubble-bubble (Sheesha) and cigarette smoking on respiratory and metabolic parameters in hubble-bubble and cigarette smokers.

PubMed

Al Mutairi, Sana S; Shihab-Eldeen, Aida A; Mojiminiyi, Olusegun A; Anwar, Alia Aisha

2006-07-01

Hazard of smoking tobacco is believed to be minimized by smoking hubble-bubble (HB) instead of cigarettes. Our aims were to (i) develop an assay for estimating nicotine and cotinine; and (ii) evaluate the effect of smoking on respiratory and metabolic parameters in cigarette and HB smokers. Urine samples were collected from 152 volunteer smokers (75 cigarette and 77 HB) as well as from 16 healthy controls. We optimized an HPLC method for the determination of nicotine and cotinine. Subjects were asked to complete a chronic respiratory symptoms questionnaire and to undergo spirometry. Fasting blood samples were collected for the determination of their lipid profile. The intra-assay coefficients of variation for nicotine and cotinine were 16.6% and 6.6%, respectively. The mean of cotinine in cigarette smokers (1321.4 ng/mL) was significantly (P = 0.008) higher than the mean cotinine (677.6 ng/mL) in HB smokers. The mean nicotine level in cigarette smokers (1487.3 ng/mL) was significantly (P < 0.0001) higher than the mean nicotine (440.5 ng/mL) in HB smoker. The urinary cotinine and nicotine levels of the control subjects were lower than the detection levels of the assay. The mean high-density lipoprotein cholesterol was lower in cigarette smokers (0.99 mmol/L) compared with HB smoker smokers (1.02 mmol/L) but this was not significant (P = 0.28). Spirometric values were comparable among the three groups but the chronic respiratory symptoms in the smoking groups appeared at an earlier age in the HB smokers compared with the cigarettes smokers (P < 0.05). Smoking HB does not reduce the risk of tobacco exposure and it's potentially harmful metabolites on health.

Hubble Legacy Archive And The Public

NASA Astrophysics Data System (ADS)

Harris, Jessica; Whitmore, B.; Eisenhamer, B.; Bishop, M.; Knisely, L.

2012-01-01

The Hubble Legacy Archive (HLA) at the Space Telescope Science Institute (STScI) hosts the Image of the Month (IOTM) Series. The HLA is a joint project of STScI, the Space Telescope European Coordinating Facility (ST-ECF), and the Canadian Astronomy Data Centre (CADC). The HLA is designed optimize science from the Hubble Space Telescope by providing online enhanced Hubble products and advanced browsing capabilities. The IOTM's are created for astronomers and the public to highlight various features within HLA, such as the "Interactive Display", "Footprint” and "Inventory” features to name a few. We have been working with the Office of Public Outreach (OPO) to create a standards based educational module for middle school to high school students of the IOTM: Rings and the Moons of Uranus. The set of Uranus activities are highlighted by a movie that displays the orbit of five of Uranus’ largest satellites. We made the movie based on eight visits of Uranus from 2000-06-16 to 2000-06-18, using the PC chip on the Wide Field Planetary Camera 2 (WFPC2) and filter F850LP (proposal ID: 8680). Students will be engaged in activities that will allow them to "discover” the rings and satellites around Uranus, calculate the orbit of the satellites, and introduces students to analyze real data from Hubble.

NASA Hubble Sees Comet ISON Intact

NASA Image and Video Library

2013-10-09

This image from NASA Hubble Space Telescope of the sunward plunging comet ISON suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the sun warms it. In this NASA Hubble Space Telescope image taken on October 9, 2013 the comet's solid nucleus is unresolved because it is so small. If the nucleus broke apart then Hubble would have likely seen evidence for multiple fragments. Moreover, the coma or head surrounding the comet's nucleus is symmetric and smooth. This would probably not be the case if clusters of smaller fragments were flying along. What's more, a polar jet of dust first seen in Hubble images taken in April is no longer visible and may have turned off. This color composite image was assembled using two filters. The comet's coma appears cyan, a greenish-blue color due to gas, while the tail is reddish due to dust streaming off the nucleus. The tail forms as dust particles are pushed away from the nucleus by the pressure of sunlight. The comet was inside Mars' orbit and 177 million miles from Earth when photographed. Comet ISON is predicted to make its closest approach to Earth on 26 December, at a distance of 39.9 million miles. http://photojournal.jpl.nasa.gov/catalog/PIA18153

HUBBLE WATCHES THE RED PLANET AS MARS GLOBAL SURVEYOR BEGINS AEROBRAKING

NASA Technical Reports Server (NTRS)

2002-01-01

his NASA Hubble Space Telescope picture of Mars was taken on Sept. 12, one day after the arrival of the Mars Global Surveyor (MGS) spacecraft and only five hours before the beginning of autumn in the Martian northern hemisphere. (Mars is tilted on its axis like Earth, so it has similar seasonal changes, including an autumnal equinox when the Sun crosses Mars' equator from the northern to the southern hemisphere). This Hubble picture was taken in support of the MGS mission. Hubble is monitoring the Martian weather conditions during the early phases of MGS aerobraking; in particular, the detection of large dust storms are important inputs into the atmospheric models used by the MGS mission to plan aerobraking operations. Though a dusty haze fills the giant Hellas impact basin south of the dark fin-shaped feature Syrtis Major, the dust appears to be localized within Hellas. Unless the region covered expands significantly, the dust will not be of concern for MGS aerobraking. Other early signs of seasonal transitions on Mars are apparent in the Hubble picture. The northern polar ice cap is blanketed under a polar hood of clouds that typically start forming in late northern summer. As fall progresses, sunlight will dwindle in the north polar region and the seasonal polar cap of frozen carbon dioxide will start condensing onto the surface under these clouds. Hubble observations will continue until October 13, as MGS carefully uses the drag of the Martian atmosphere to circularize its orbit about the Red Planet. After mid-October, Mars will be too close to the Sun, in angular separation, for Hubble to safely view. The image is a composite of three separately filtered colored images taken with the Wide Field Planetary Camera 2 (WFPC2). Resolution is 35 miles (57 kilometers) per pixel (picture element). The Pathfinder landing site near Ares Valles is about 2200 miles (3600 kilometers) west of the center of this image, so was not visible during this observation. Mars was 158

HUBBLE PHOTOGRAPHS WARPED GALAXY AS CAMERA PASSES MILESTONE

NASA Technical Reports Server (NTRS)

2002-01-01

NASA's Hubble Space Telescope has captured an image of an unusual edge-on galaxy, revealing remarkable details of its warped dusty disk and showing how colliding galaxies spawn the formation of new generations of stars. The dust and spiral arms of normal spiral galaxies, like our own Milky Way, appear flat when viewed edge-on. This month's Hubble Heritage image of ESO 510-G13 shows a galaxy that, by contrast, has an unusual twisted disk structure, first seen in ground-based photographs obtained at the European Southern Observatory (ESO) in Chile. ESO 510-G13 lies in the southern constellation Hydra, roughly 150 million light-years from Earth. Details of the structure of ESO 510-G13 are visible because the interstellar dust clouds that trace its disk are silhouetted from behind by light from the galaxy's bright, smooth central bulge. The strong warping of the disk indicates that ESO 510-G13 has recently undergone a collision with a nearby galaxy and is in the process of swallowing it. Gravitational forces distort the structures of the galaxies as their stars, gas, and dust merge together in a process that takes millions of years. Eventually the disturbances will die out, and ESO 510-G13 will become a normal-appearing single galaxy. In the outer regions of ESO 510-G13, especially on the right-hand side of the image, we see that the twisted disk contains not only dark dust, but also bright clouds of blue stars. This shows that hot, young stars are being formed in the disk. Astronomers believe that the formation of new stars may be triggered by collisions between galaxies, as their interstellar clouds smash together and are compressed. The Heritage Team used Hubble's Wide Field Planetary Camera 2 (WFPC2) to observe ESO 510-G13 in April 2001. Pictures obtained through blue, green, and red filters were combined to make this color-composite image, which emphasizes the contrast between the dusty spiral arms, the bright bulge, and the blue star-forming regions. During the

Hubble Witnesses an Asteroid Mysteriously Disintegrating

NASA Image and Video Library

2014-03-06

This series of images shows the asteroid P/2013 R3 breaking apart, as viewed by the NASA/ESA Hubble Space Telescope in 2013. This is the first time that such a body has been seen to undergo this kind of break-up. The Hubble observations showed that there are ten distinct objects, each with comet-like dust tails, embedded within the asteroid's dusty envelope. The four largest rocky fragments are up to 200 metres in radius, about twice the length of a football pitch. The date increases from left to right, with frames from 29 October 2013, 15 November 2013, 13 December 2013, and 14 January 2014 respectively, showing how the clumps of debris material move around. The 14 January 2014 frame was not included in the science paper and is additional data. Credit: NASA, ESA, D. Jewitt (UCLA) Read more: 1.usa.gov/1ig2E0x NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HUBBLE UNVEILS A GALAXY IN LIVING COLOR

NASA Technical Reports Server (NTRS)

2002-01-01

collaboration. 'The clusters are either completely hidden, enshrouded in their birth clouds, or almost completely exposed.' The scientists believe that stellar winds and powerful radiation from the bright, newly born stars have cleared away the original natal dust cloud in a fast and efficient 'cleansing' process. Aaron Barth, a co-investigator on the team, adds: 'It is remarkable how similar the properties of this starburst are to those of other nearby starbursts that have been studied in detail with Hubble.' This similarity gives the astronomers the hope that, by understanding the processes occurring in nearby galaxies, they can better interpret observations of very distant and faint starburst galaxies. Such distant galaxies formed the first generations of stars, when the universe was a fraction of its current age. Circumstellar star-forming rings are common in the universe. Such rings within barred spiral galaxies may in fact comprise the most numerous class of nearby starburst regions. Astronomers generally believe that the giant bar funnels the gas to the inner ring, where stars are formed within numerous star clusters. Studies like this one emphasize the need to observe at many different wavelengths to get the full picture of the processes taking place.

Hubble Captures Celestial Fireworks Within the Large Magellanic Cloud

NASA Technical Reports Server (NTRS)

2000-01-01

This is a color Hubble Space Telescope (HST) heritage image of supernova remnant N49, a neighboring galaxy, that was taken with Hubble's Wide Field Planetary Camera 2. Color filters were used to sample light emitted by sulfur, oxygen, and hydrogen. The color image was superimposed on a black and white image of stars in the same field also taken with Hubble. Resembling a fireworks display, these delicate filaments are actually sheets of debris from a stellar explosion.

Hubble Sees a Bizarre Cosmic Rarity

NASA Image and Video Library

2013-12-06

This new Hubble image shows a peculiar galaxy known as NGC 660, located around 45 million light-years away from us. NGC 660 is classified as a "polar ring galaxy," meaning that it has a belt of gas and stars around its center that it ripped from a near neighbor during a clash about one billion years ago.The first polar ring galaxy was observed in 1978 and only around a dozen more have been discovered since then, making them something of a cosmic rarity. Unfortunately, NGC 660’s polar ring cannot be seen in this image, but the image has plenty of other features that make it of interest to astronomers – its central bulge is strangely off-kilter and, perhaps more intriguingly, it is thought to harbor exceptionally large amounts of dark matter. In addition, in late 2012 astronomers observed a massive outburst emanating from NGC 660 that was around ten times as bright as a supernova explosion. This burst was thought to be caused by a massive jet shooting out of the supermassive black hole at the center of the galaxy. Credit: Hubble/NASA/European Space Agency NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HubbleSite: News

Science.gov Websites

HubbleSite Toggle navigation Home News Images Videos Blogs Explore Discoveries Astronomy Technology stars, and yet, star formation is still a vexing question in astronomy. To piece together a more with this form. Inbox Astronomy Subscribe Sign up to receive the latest news, images, and discoveries

The 2008 Passage of Jupiter's Great Red Spot and Oval BA as Observed from Hubble/WFPC2

NASA Technical Reports Server (NTRS)

Simon-Miller, Amy A.; Chanover, N. J.; Orton, G. S.; Tsavaris, I.

2008-01-01

Hubble Space Telescope data of the passage of Jupiter's Great Red Spot (GRS) and Oval BA were acquired on May 15, June 28 (near closest approach), and July 8. Wind fields were measured from Wide Field Planetary Camera 2 (WFPC2) data with 10-hour separations before and after closest approach, and within the GRS with 40-minute separations on all three dates. Color information was also derived using 8 narrowband WFPC2 filters from 343 to 673-nm on all three dates. We will present the results of principal components and wind analyses and discuss unique features seen in this data set. In addition, we will highlight any changes observed in the GRS, Oval BA and their surroundings as a result of the passage, including the movement of a smaller red anticyclone from west of the GRS, around its southern periphery, and to the east of the GRS.

NASA Hubble Space Telescope (HST) Research Project Capstone Even

NASA Image and Video Library

2014-05-05

John Grunsfeld, NASA Associate Administrator for the Science Mission Directorate, speaks to students from Mapletown Jr/Sr High School and Margaret Bell Middle School about his experiences on the final space shuttle servicing mission to the Hubble Space Telescope during the NASA Hubble Space Telescope (HST) Research Project Capstone Event in the James E. Webb Auditorium at NASA Headquarters on Monday, May 5, 2014. Grunsfeld flew on three of the five servicing missions to the Hubble Space Telescope. Photo Credit: (NASA/Joel Kowsky)

Hubble Spies Spectacular Sombrero

NASA Image and Video Library

2005-05-05

Lying at the southern edge of the rich Virgo cluster of galaxies, Messier 104, also called the Sombrero galaxy, is one of the most famous objects in the sky in this image from NASA Hubble Space Telescope.

Hubble Space Telescope observations of cool white dwarf stars: Detection of new species of heavy elements

NASA Technical Reports Server (NTRS)

Shipman, Harry; Barnhill, Maurice; Provencal, Judi; Roby, Scott; Bues, Irmela; Cordova, France; Hammond, Gordon; Hintzen, Paul; Koester, Detlev; Liebert, James

1995-01-01

Observations of cool white dwarf stars with the Hubble Space Telescope (HST) has uncovered a number of spectral features from previouslly unobserved species. In this paper we present the data on four cool white dwarfs. We present identifications, equivalent width measurements, and brief summaries of the significance of our findings. The four stars observed are GD 40 (DBZ3, G 74-7 (DAZ), L 745-46A (DZ), and LDS 749B (DBA). Many additional species of heavey elements were detected in GD 40 and G 74-7. In L 745-46A, while the detections are limited to Fe 1, Fe II, and Mg II, the quality of the Mg II h and K line profiles should permit a test of the line broadening theories, which are so crucial to abundance determinations. The clear detection of Mg II h and k in LDS 749 B should, once an abundance determination is made, provide a clear test of the hypothesis that the DBA stars are the result of accretion from the interstellar medium. This star contains no other clear features other than a tantalizing hint of C II 1335 with a P Cygni profile, and some expected He 1 lines.

HUBBLE CAPTURES MERGER BETWEEN QUASAR AND GALAXY

NASA Technical Reports Server (NTRS)

2002-01-01

This NASA Hubble Space Telescope image shows evidence fo r a merger between a quasar and a companion galaxy. This surprising result might require theorists to rethink their explanations for the nature of quasars, the most energetic objects in the universe. The bright central object is the quasar itself, located several billion light-years away. The two wisps on the (left) of the bright central object are remnants of a bright galaxy that have been disrupted by the mutual gravitational attraction between the quasar and the companion galaxy. This provides clear evidence for a merger between the two objects. Since their discovery in 1963, quasars (quasi-stellar objects) have been enigmatic because they emit prodigious amounts of energy from a very compact source. The most widely accepted model is that a quasar is powered by a supermassive black hole in the core of a galaxy. These new observations proved a challenge for theorists as no current models predict the complex quasar interactions unveiled by Hubble. The image was taken with the Wide Field Planetary Camera-2. Credit: John Bahcall, Institute for Advanced Study, NASA.

Hubble Space Telescope and James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Straughn, Amber

2011-01-01

Over the past 20 years the Hubble Space Telescope has revolutionized our understanding of the Universe. Most recently, the complete refurbishment of Hubble in 2009 has given new life to the telescope and the new science instruments have already produced ground breaking science results, revealing some of the most distant galaxy candidates ever discovered. Despite the remarkable advances in astrophysics that Hubble has provided, the new questions that have arisen demand a new space telescope with new technologies and capabilities. I will present the exciting new technology development and science goals of NASA's James Webb Space Telescope, which is currently being built and tested and will be launched this decade.

Hubble's deepest view ever of the Universe unveils earliest galaxies

NASA Astrophysics Data System (ADS)

2004-03-01

Hubble sees galaxies galore hi-res Size hi-res: 446 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble sees galaxies galore Galaxies, galaxies everywhere - as far as the NASA/ESA Hubble Space Telescope can see. This view of nearly 10,000 galaxies is the deepest visible-light image of the cosmos. Called the Hubble Ultra Deep Field, this galaxy-studded view represents a ‘deep’ core sample of the universe, cutting across billions of light-years. Hubble reveals galactic drama hi-res Size hi-res: 879 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. Here three galaxies just below centre are enmeshed in battle, their shapes distorted by the brutal encounter. Hubble reveals galactic drama hi-res Size hi-res: 886 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. Here three galaxies just below centre are enmeshed in battle, their shapes distorted by the brutal encounter. Hubble reveals galactic drama hi-res Size hi-res: 892 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. The galaxies in this panel were plucked from a harvest of nearly 10,000 galaxies in the Ultra Deep Field, the deepest visible-light image of the cosmos. This historic new view is actually made up by two separate images taken by Hubble's Advanced Camera for Surveys (ACS) and the Near Infrared Camera and

Hubble Watches Star Clusters on a Collision Course

NASA Image and Video Library

2012-08-16

Image release August 16, 2012 Astronomers using data from NASA's Hubble Space Telescope have caught two clusters full of massive stars that may be in the early stages of merging. The 30 Doradus Nebula is 170,000 light-years from Earth. What at first was thought to be only one cluster in the core of the massive star-forming region 30 Doradus has been found to be a composite of two clusters that differ in age by about one million years. The entire 30 Doradus complex has been an active star-forming region for 25 million years, and it is currently unknown how much longer this region can continue creating new stars. Smaller systems that merge into larger ones could help to explain the origin of some of the largest known star clusters. The Hubble observations, made with the Wide Field Camera 3, were taken Oct. 20-27, 2009. The blue color is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen. To read more about this image go to: www.nasa.gov/mission_pages/hubble/science/cluster-collisi... Image Credit: NASA, ESA, and E. Sabbi (ESA/STScI) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Views the Whirling Disk of NGC 4526

NASA Image and Video Library

2014-10-24

This neat little galaxy is known as NGC 4526. Its dark lanes of dust and bright diffuse glow make the galaxy appear to hang like a halo in the emptiness of space in this image from the NASA/ESA Hubble Space Telescope. Although this image paints a picture of serenity, the galaxy is anything but. It is one of the brightest lenticular galaxies known, a category that lies somewhere between spirals and ellipticals. It has hosted two known supernova explosions, one in 1969 and another in 1994, and is known to have a colossal supermassive black hole at its center that has the mass of 450 million suns. NGC 4526 is part of the Virgo cluster of galaxies. Ground-based observations of galaxies in this cluster have revealed that a quarter of these galaxies seem to have rapidly rotating disks of gas at their centers. The most spectacular of these is this galaxy, NGC 4526, and its spinning disk of gas, dust, and stars reaches out uniquely far from its heart, spanning some seven percent of the galaxy's entire radius. This disk is moving incredibly fast, spinning at more than 250 kilometers per second. The dynamics of this quickly whirling region were actually used to infer the mass of NGC 4526’s central black hole — a technique that had not been used before to constrain a galaxy’s central black hole. This image was taken with Hubble's Wide Field and Planetary Camera 2 and the Advanced Camera for Surveys. Credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt

Constraints on a generalized deceleration parameter from cosmic chronometers

NASA Astrophysics Data System (ADS)

Mamon, Abdulla Al

2018-04-01

In this paper, we have proposed a generalized parametrization for the deceleration parameter q in order to study the evolutionary history of the universe. We have shown that the proposed model can reproduce three well known q-parametrized models for some specific values of the model parameter α. We have used the latest compilation of the Hubble parameter measurements obtained from the cosmic chronometer (CC) method (in combination with the local value of the Hubble constant H0) and the Type Ia supernova (SNIa) data to place constraints on the parameters of the model for different values of α. We have found that the resulting constraints on the deceleration parameter and the dark energy equation of state support the ΛCDM model within 1σ confidence level at the present epoch.

Hubble Space Telescope Parallel Observations Supporting the Kepler Mission

NASA Astrophysics Data System (ADS)

Caldwell, J.; Borucki, W.

1999-09-01

Kepler will detect Earth-like planets by monitoring 100,000 stars over four years for planetary transits. The required photometric precision is one part in 100.000. It is expected that if such ``Earths" are common, about 200 will be detected. In order to achieve the necessary precision, Kepler will be intentionally unfocussed, spreading the light of a single star over an area of 25 pixels. This will minimize the effect of space-craft jitter on photon counting. However, it will also allow the possibility of confusion with background objects which may be in the line of sight to a Kepler target. The greatest concern is that there may be a distant eclipsing binary star which could introduce a photometric signature that is similar to a planetary transit. For the brightest stars in Kepler's intended magnitude range, which is 9 to 14 mv, this will not be serious, because the profiles are different: eclipses have a ``V" shape, transits are flat-bottomed, and Kepler will differentiate the two. However, in this magnitude range, the number of stars per magnitude doubles at each fainter magnitude. More than half of Kepler's discoveries will be in the magnitude which is the faintest in which the precision of the photometry will be able to reveal a transit. That is, most of the discoveries will be low signal to noise events, in which the reality of a small decrease in the light from the region of the target star is certain, but the details of the decrease are not. Hubble Space Telescope images indicate there will be, on average, 0.5 background objects in the magnitude range that could be a problem for Kepler in the 25 pixel blur region of Kepler's optics. Approximately half of the stars will be binaries. The probability that a binary will be eclipsing is the same as that a planetary orbit will be transitting. In order to reduce the chance of a misidentification, various strategies can be used. Rather than integrating the signal over the 25 pixels and returning only the sum, the

The effect of interacting dark energy on local measurements of the Hubble constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odderskov, Io; Baldi, Marco; Amendola, Luca, E-mail: isho07@phys.au.dk, E-mail: marco.baldi5@unibo.it, E-mail: l.amendola@thphys.uni-heidelberg.de

2016-05-01

In the current state of cosmology, where cosmological parameters are being measured to percent accuracy, it is essential to understand all sources of error to high precision. In this paper we present the results of a study of the local variations in the Hubble constant measured at the distance scale of the Coma Cluster, and test the validity of correcting for the peculiar velocities predicted by gravitational instability theory. The study is based on N-body simulations, and includes models featuring a coupling between dark energy and dark matter, as well as two ΛCDM simulations with different values of σ{sub 8}.more » It is found that the variance in the local flows is significantly larger in the coupled models, which increases the uncertainty in the local measurements of the Hubble constant in these scenarios. By comparing the results from the different simulations, it is found that most of the effect is caused by the higher value of σ{sub 8} in the coupled cosmologies, though this cannot account for all of the additional variance. Given the discrepancy between different estimates of the Hubble constant in the universe today, cosmological models causing a greater cosmic variance is something that we should be aware of.« less

Version 1 of the Hubble Source Catalog

NASA Astrophysics Data System (ADS)

Whitmore, Bradley C.; Allam, Sahar S.; Budavári, Tamás; Casertano, Stefano; Downes, Ronald A.; Donaldson, Thomas; Fall, S. Michael; Lubow, Stephen H.; Quick, Lee; Strolger, Louis-Gregory; Wallace, Geoff; White, Richard L.

2016-06-01

The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope (HST) by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive (HLA) into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160,000 HST exposures. Source lists from Data Release 8 of the HLA are matched using an algorithm developed by Budavári & Lubow. The mean photometric accuracy for the catalog as a whole is better than 0.10 mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10 mas, with a value for the mode (I.e., most common value) of 2.3 mas. The absolute astrometric accuracy is better than 0''\\hspace{-0.5em}. 1 for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. We provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog.

HUBBLE'S DEEPEST VIEW OF THE UNIVERSE

NASA Technical Reports Server (NTRS)

2002-01-01

[Left] A NASA Hubble Space Telescope view of the faintest galaxies ever seen in the universe, taken in infrared light with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The picture contains over 300 galaxies having spiral, elliptical and irregular shapes. Though most of these galaxies were first seen in 1995 when Hubble was used to take a visible-light deep exposure of the same field, NICMOS uncovers many new objects. Most of these objects are too small and faint to be apparent in the full field NICMOS view. Some of the reddest and faintest of the newly detected objects may be over 12 billion light-years away, as derived from a standard model of the universe. However, a powerful new generation of telescopes will be needed to confirm the suspected distances of these objects. The field of view is 2 million light-years across, at its maximum. Yet, on a cosmic scale, it represents only a thin pencil beam look across the universe. The area of sky is merely 1/100th the apparent diameter on the full moon. [Right] Two close-up NICMOS views of candidate objects which may be over 12 billion light-years away. Each candidate is centered in the frame. The reddish color may mean all of the starlight has been stretched to infrared wavelengths by the universe's expansion. Alternative explanations are that the objects are closer to us, but the light has been reddened by dust scattering. A new generation of telescopes will be needed to make follow-up observations capable of establishing true distance. The image was taken in January 1998 and required an exposure time of 36 hours to detect objects down to 30th magnitude. Hubble was aimed in the direction of the constellation Ursa Major, in a region just above the handle of the Big Dipper. The color corresponds to blue (0.45 microns), green (1.1 microns) and red (1.6 microns). Credit: Rodger I. Thompson (University of Arizona), and NASA

Hubble View of Neptune

NASA Image and Video Library

1998-08-02

These NASA Hubble Space Telescope views of the blue-green planet Neptune provide three snapshots of changing weather conditions. The images were taken in 1994 on 3 separate days when Neptune was 2.8 billion miles 4.5 billion kilometers from Earth.

Wide-Field Hubble Space Telescope Observations of the Globular Cluster System in NGC 1399*

NASA Technical Reports Server (NTRS)

Puzia, Thomas H.; Paolillo, Maurizio; Goudfrooij, Paul; Maccarone, Thomas J.; Fabbiano, Giuseppina; Angelini, Lorella

2014-01-01

We present a comprehensive high spatial resolution imaging study of globular clusters (GCs) in NGC 1399, thecentral giant elliptical cD galaxy in the Fornax galaxy cluster, conducted with the Advanced Camera for Surveys(ACS) aboard theHubble Space Telescope(HST).Using a novel technique to construct drizzled point-spreadfunction libraries for HSTACS data, we accurately determine the fidelity of GC structural parameter measurementsfrom detailed artificial star cluster experiments and show the superior robustness of the GC half-light radius,rh,compared with other GC structural parameters, such as King core and tidal radius. The measurement ofrhfor themajor fraction of the NGC 1399 GC system reveals a trend of increasingrhversus galactocentric distance,Rgal,out to about 10 kpc and a flat relation beyond. This trend is very similar for blue and red GCs, which are found tohave a mean size ratio ofrh,redrh,blue0.820.11 at all galactocentric radii from the core regions of the galaxyout to40 kpc. This suggests that the size difference between blue and red GCs is due to internal mechanismsrelated to the evolution of their constituent stellar populations. Modeling the mass density profile of NGC 1399shows that additional external dynamical mechanisms are required to limit the GC size in the galaxy halo regionstorh2 pc. We suggest that this may be realized by an exotic GC orbit distribution function, an extended darkmatter halo, andor tidal stress induced by the increased stochasticity in the dwarf halo substructure at largergalactocentric distances. We compare our results with the GCrhdistribution functions in various galaxies and findthat the fraction of extended GCs withrh5 pc is systematically larger in late-type galaxies compared with GCsystems in early-type galaxies. This is likely due to the dynamically more violent evolution of early-type galaxies.We match our GCrhmeasurements with radial velocity data from the literature and split the resulting sample at

Hubble Solves Mystery on Source of Supernova in Nearby Galaxy

NASA Image and Video Library

2017-12-08

NASA image release January 11, 2012 Using NASA's Hubble Space Telescope, astronomers have solved a longstanding mystery on the type of star, or so-called progenitor, that caused a supernova in a nearby galaxy. The finding yields new observational data for pinpointing one of several scenarios that could trigger such outbursts. Based on previous observations from ground-based telescopes, astronomers knew that a kind of supernova called a Type Ia created a remnant named SNR 0509-67.5, which lies 170,000 light-years away in the Large Magellanic Cloud galaxy. The type of system that leads to this kind of supernova explosion has long been a high importance problem with various proposed solutions but no decisive answer. All these solutions involve a white dwarf star that somehow increases in mass to the highest limit. Astronomers failed to find any companion star near the center of the remnant, and this rules out all but one solution, so the only remaining possibility is that this one Type Ia supernova came from a pair of white dwarfs in close orbit. To read more go to: www.nasa.gov/mission_pages/hubble/science/supernova-sourc... Image Credit: NASA, ESA, CXC, SAO, the Hubble Heritage Team (STScI/AURA), and J. Hughes (Rutgers University) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Space Telescope studies of low-redshift Type Ia supernovae: evolution with redshift and ultraviolet spectral trends

NASA Astrophysics Data System (ADS)

Maguire, K.; Sullivan, M.; Ellis, R. S.; Nugent, P. E.; Howell, D. A.; Gal-Yam, A.; Cooke, J.; Mazzali, P.; Pan, Y.-C.; Dilday, B.; Thomas, R. C.; Arcavi, I.; Ben-Ami, S.; Bersier, D.; Bianco, F. B.; Fulton, B. J.; Hook, I.; Horesh, A.; Hsiao, E.; James, P. A.; Podsiadlowski, P.; Walker, E. S.; Yaron, O.; Kasliwal, M. M.; Laher, R. R.; Law, N. M.; Ofek, E. O.; Poznanski, D.; Surace, J.

2012-11-01

We present an analysis of the maximum light, near-ultraviolet (NUV; 2900 < λ < 5500 Å) spectra of 32 low-redshift (0.001 < z < 0.08) Type Ia supernovae (SNe Ia), obtained with the Hubble Space Telescope (HST) using the Space Telescope Imaging Spectrograph. We combine this spectroscopic sample with high-quality gri light curves obtained with robotic telescopes to measure SN Ia photometric parameters, such as stretch (light-curve width), optical colour and brightness (Hubble residual). By comparing our new data to a comparable sample of SNe Ia at intermediate redshift (0.4 < z < 0.9), we detect modest spectral evolution (3σ), in the sense that our mean low-redshift NUV spectrum has a depressed flux compared to its intermediate-redshift counterpart. We also see a strongly increased dispersion about the mean with decreasing wavelength, confirming the results of earlier surveys. We show that these trends are consistent with changes in metallicity as predicted by contemporary SN Ia spectral models. We also examine the properties of various NUV spectral diagnostics in the individual SN spectra. We find a general correlation between SN stretch and the velocity (or position) of many NUV spectral features. In particular, we observe that higher stretch SNe have larger Ca II H&K velocities, which also correlate with host galaxy stellar mass. This latter trend is probably driven by the well-established correlation between stretch and host galaxy stellar mass. We find no significant trends between UV spectral features and optical colour. Mean spectra constructed according to whether the SN has a positive or negative Hubble residual show very little difference at NUV wavelengths, indicating that the NUV evolution and variation we identify does not directly correlate with Hubble diagram residuals. Our work confirms and strengthens earlier conclusions regarding the complex behaviour of SNe Ia in the NUV spectral region, but suggests the correlations we find are more useful in

HUBBLE SPIES HUGE CLUSTERS OF STARS FORMED

NASA Technical Reports Server (NTRS)

2002-01-01

BY ANCIENT ENCOUNTER This stunningly beautiful image [right] taken with the NASA Hubble Space Telescope shows the heart of the prototypical starburst galaxy M82. The ongoing violent star formation due to an ancient encounter with its large galactic neighbor, M81, gives this galaxy its disturbed appearance. The smaller picture at upper left shows the entire galaxy. The image was taken in December 1994 by the Kitt Peak National Observatory's 0.9-meter telescope. Hubble's view is represented by the white outline in the center. In the Hubble image, taken by the Wide Field and Planetary Camera 2, the huge lanes of dust that crisscross M82's disk are another telltale sign of the flurry of star formation. Below the center and to the right, a strong galactic wind is spewing knotty filaments of hydrogen and nitrogen gas. More than 100 super star clusters -- very bright, compact groupings of about 100,000 stars -- are seen in this detailed Hubble picture as white dots sprinkled throughout M82's central region. The dark region just above the center of the picture is a huge dust cloud. A collaboration of European and American scientists used these clusters to date the ancient interaction between M82 and M81. About 600 million years ago, a region called 'M82 B' (the bright area just below and to the left of the central dust cloud) exploded with new stars. Scientists have discovered that this ancient starburst was triggered by the violent encounter with M81. M82 is a bright (eighth magnitude), nearby (12 million light-years from Earth) galaxy in the constellation Ursa Major (the Great Bear). The Hubble picture was taken Sept. 15, 1997. The natural-color composite was constructed from three Wide Field and Planetary Camera 2 exposures, which were combined in chromatic order: 4,250 seconds through a blue filter (428 nm); 2,800 seconds through a green filter (520 nm); and 2,200 seconds through a red (820 nm) filter. Credits for Hubble image: NASA, ESA, R. de Grijs (Institute of

BEAUTY IN THE EYE OF HUBBLE

NASA Technical Reports Server (NTRS)

2002-01-01

A dying star, IC 4406, dubbed the 'Retina Nebula' is revealed in this month's Hubble Heritage image. Like many other so-called planetary nebulae, IC 4406 exhibits a high degree of symmetry; the left and right halves of the Hubble image are nearly mirror images of the other. If we could fly around IC4406 in a starship, we would see that the gas and dust form a vast donut of material streaming outward from the dying star. From Earth, we are viewing the donut from the side. This side view allows us to see the intricate tendrils of dust that have been compared to the eye's retina. In other planetary nebulae, like the Ring Nebula (NGC 6720), we view the donut from the top. The donut of material confines the intense radiation coming from the remnant of the dying star. Gas on the inside of the donut is ionized by light from the central star and glows. Light from oxygen atoms is rendered blue in this image; hydrogen is shown as green, and nitrogen as red. The range of color in the final image shows the differences in concentration of these three gases in the nebula. Unseen in the Hubble image is a larger zone of neutral gas that is not emitting visible light, but which can be seen by radio telescopes. One of the most interesting features of IC 4406 is the irregular lattice of dark lanes that criss-cross the center of the nebula. These lanes are about 160 astronomical units wide (1 astronomical unit is the distance between the Earth and Sun). They are located right at the boundary between the hot glowing gas that produces the visual light imaged here and the neutral gas seen with radio telescopes. We see the lanes in silhouette because they have a density of dust and gas that is a thousand times higher than the rest of the nebula. The dust lanes are like a rather open mesh veil that has been wrapped around the bright donut. The fate of these dense knots of material is unknown. Will they survive the nebula's expansion and become dark denizens of the space between the stars

HUBBLE SEES A VAST 'CITY' OF STARS

NASA Technical Reports Server (NTRS)

2002-01-01

In these pictures, a 'city' of a million stars glitters like a New York City skyline. The images capture the globular cluster 47 Tucanae, located 15,000 light-years from Earth in the southern constellation Tucana. Using NASA's Hubble Space Telescope, astronomers went hunting in this large city for planetary companions: bloated gaseous planets that snuggle close to their parent stars, completing an orbit in a quick three to five days. To their surprise, they found none. This finding suggests that the cluster's environment is too hostile for breeding planets or that it lacks the necessary elements for making them. The picture at left, taken by a terrestrial telescope, shows most of the cluster, a tightly packed group of middle-aged stars held together by mutual gravitational attraction. The box near the center represents the Hubble telescope's view. The image at right shows the Hubble telescope's close-up look at a swarm of 35,000 stars near the cluster's central region. The stars are tightly packed together: They're much closer together than our Sun and its closest stars. The picture, taken by the Wide Field and Planetary Camera 2, depicts the stars' natural colors and tells scientists about their composition and age. For example, the red stars denote bright red giants nearing the end of their lives; the more common yellow stars are similar to our middle-aged Sun. Most of the stars in the cluster are believed to have formed about 10 billion years ago. The bright, blue stars -- thought to be remnants of stellar collisions and mergers -- provide a few rejuvenated, energetic stars in an otherwise old system. The Hubble picture was taken in July 1999. Credits for Hubble image: NASA and Ron Gilliland (Space Telescope Science Institute) Credits for ground-based image: David Malin, c Anglo-Australian Observatory

Hubble tracks down a galaxy cluster's dark matter

NASA Astrophysics Data System (ADS)

2003-07-01

Unique mass map hi-res Size hi-res: 495 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Unique mass map This is a mass map of galaxy cluster Cl0024+1654 derived from an extensive Hubble Space Telescope campaign. The colour image is made from two images: a dark-matter map (the blue part of the image) and a 'luminous-matter' map determined from the galaxies in the cluster (the red part of the image). They were constructed by feeding Hubble and ground-based observations into advanced mathematical mass-mapping models. The map shows that dark matter is present where the galaxies clump together. The mass of the galaxies is shown in red, the mass of the dark matter in blue. The dark matter behaves like a 'glue', holding the cluster together. The dark-matter distribution in the cluster is not spherical. A secondary concentration of dark-matter mass is shown in blue to the upper right of the main concentration. Sky around galaxy cluster Cl0024+1654 hi-res Size hi-res: 3742 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Sky around galaxy cluster Cl0024+1654 This is a 2.5-degree field around galaxy cluster Cl0024+1654. The cluster galaxies are visible in the centre of the image in yellow. The image is a colour composite constructed from three Digitized Sky Survey 2 images: Blue (shown in blue), Red (shown in green), and Infrared (shown in red). HST observes shapes of more than 7000 faint background galaxies hi-res Size hi-res: 5593 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Hubble observes shapes of more than 7000 faint background galaxies Five days of observations produced the altogether 39 Hubble Wide Field and Planetary Camera 2 (WFPC2) images required to map the mass of the galaxy cluster Cl0024+1654. Each WFPC2 image has a size of about 1/150 the diameter of the full Moon. In

Observational constraints on extended Chaplygin gas cosmologies

NASA Astrophysics Data System (ADS)

Paul, B. C.; Thakur, P.; Saha, A.

2017-08-01

We investigate cosmological models with extended Chaplygin gas (ECG) as a candidate for dark energy and determine the equation of state parameters using observed data namely, observed Hubble data, baryon acoustic oscillation data and cosmic microwave background shift data. Cosmological models are investigated considering cosmic fluid which is an extension of Chaplygin gas, however, it reduces to modified Chaplygin gas (MCG) and also to generalized Chaplygin gas (GCG) in special cases. It is found that in the case of MCG and GCG, the best-fit values of all the parameters are positive. The distance modulus agrees quite well with the experimental Union2 data. The speed of sound obtained in the model is small, necessary for structure formation. We also determine the observational constraints on the constants of the ECG equation.

Hubble Sees A Smiling Lens

NASA Image and Video Library

2015-02-10

In the center of this image, taken with the NASA/ESA Hubble Space Telescope, is the galaxy cluster SDSS J1038+4849 — and it seems to be smiling. You can make out its two orange eyes and white button nose. In the case of this “happy face”, the two eyes are very bright galaxies and the misleading smile lines are actually arcs caused by an effect known as strong gravitational lensing. Galaxy clusters are the most massive structures in the Universe and exert such a powerful gravitational pull that they warp the spacetime around them and act as cosmic lenses which can magnify, distort and bend the light behind them. This phenomenon, crucial to many of Hubble’s discoveries, can be explained by Einstein’s theory of general relativity. In this special case of gravitational lensing, a ring — known as an Einstein Ring — is produced from this bending of light, a consequence of the exact and symmetrical alignment of the source, lens and observer and resulting in the ring-like structure we see here. Hubble has provided astronomers with the tools to probe these massive galaxies and model their lensing effects, allowing us to peer further into the early Universe than ever before. This object was studied by Hubble’s Wide Field and Planetary Camera 2 (WFPC2) and Wide Field Camera 3 (WFC3) as part of a survey of strong lenses. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt. Image Credit: NASA/ESA

Hubble On Its Way

NASA Image and Video Library

2009-05-21

This still image of the Hubble Space Telescope was captured by an STS-125 crew member as the two spacecraft continue their relative separation. During the week five spacewalks were performed to complete the final servicing mission for the orbital observatory. Photo credit: NASA May 19, 2009

Hubble Feathers the Peacock

NASA Image and Video Library

2014-09-19

This picture, taken by the NASA/ESA Hubble Space Telescope WFPC2, shows a galaxy known as NGC 6872 in the constellation of Pavo The Peacock. Its unusual shape is caused by its interactions with the smaller galaxy that can be seen just above NGC 6872.

Short term effect of hubble-bubble smoking on voice.

PubMed

Hamdan, A-L; Sibai, A; Mahfoud, L; Oubari, D; Ashkar, J; Fuleihan, N

2011-05-01

To investigate the short term effect of hubble-bubble smoking on voice. Prospective study. Eighteen non-dysphonic subjects (seven men and 11 women) with a history of hubble-bubble smoking and no history of cigarette smoking underwent acoustic analysis and laryngeal video-stroboscopic examination before and 30 minutes after hubble-bubble smoking. On laryngeal video-stroboscopy, none of the subjects had vocal fold erythema either before or after smoking. Five patients had mild vocal fold oedema both before and after smoking. After smoking, there was a slight increase in the number of subjects with thick mucus between the vocal folds (six, vs four before smoking) and with vocal fold vessel dilation (two, vs one before smoking). Acoustic analysis indicated a drop in habitual pitch, fundamental frequency and voice turbulence index after smoking, and an increase in noise-to-harmonics ratio. Even 30 minutes of hubble-bubble smoking can cause a drop in vocal pitch and an increase in laryngeal secretions and vocal fold vasodilation.

The Hubble Legacy Archive ACS grism data

NASA Astrophysics Data System (ADS)

Kümmel, M.; Rosati, P.; Fosbury, R.; Haase, J.; Hook, R. N.; Kuntschner, H.; Lombardi, M.; Micol, A.; Nilsson, K. K.; Stoehr, F.; Walsh, J. R.

2011-06-01

A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00 μm, with a dispersion of 40 Å/pixel and a resolution of ~80 Å for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47 919 datasets (65% of the total number of extracted spectra) for 32 149 unique objects, with a median iAB-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. This release is part of the continuing effort to enhance the content of the Hubble Legacy Archive (HLA) with highly processed data products which significantly facilitate the scientific exploitation of the Hubble data. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2 - 4.6. Almost all redshift determinations outside of the GOODS fields are new. The scope of science projects

Hubble Monitors Supernova In Nearby Galaxy M82

NASA Image and Video Library

2014-02-26

This is a Hubble Space Telescope composite image of a supernova explosion designated SN 2014J in the galaxy M82. At a distance of approximately 11.5 million light-years from Earth it is the closest supernova of its type discovered in the past few decades. The explosion is categorized as a Type Ia supernova, which is theorized to be triggered in binary systems consisting of a white dwarf and another star — which could be a second white dwarf, a star like our sun, or a giant star. Astronomers using a ground-based telescope discovered the explosion on January 21, 2014. This Hubble photograph was taken on January 31, as the supernova approached its peak brightness. The Hubble data are expected to help astronomers refine distance measurements to Type Ia supernovae. In addition, the observations could yield insights into what kind of stars were involved in the explosion. Hubble’s ultraviolet-light sensitivity will allow astronomers to probe the environment around the site of the supernova explosion and in the interstellar medium of the host galaxy. Because of their consistent peak brightness, Type Ia supernovae are among the best tools to measure distances in the universe. They were fundamental to the 1998 discovery of the mysterious acceleration of the expanding universe. A hypothesized repulsive force, called dark energy, is thought to cause the acceleration. Among the other major NASA space-based observatories used in the M82 viewing campaign are Spitzer Space Telescope, Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array (NuSTAR), Fermi Gamma-ray Space Telescope, Swift Gamma Ray Burst Explorer, and the Stratospheric Observatory for Infrared Astronomy (SOFIA). Image Credit: NASA, ESA, A. Goobar (Stockholm University), and the Hubble Heritage Team (STScI/AURA) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics

Hubble Watches Super Star Create Holiday Light Show

NASA Image and Video Library

2017-12-08

This festive NASA Hubble Space Telescope image resembles a holiday wreath made of sparkling lights. The bright southern hemisphere star RS Puppis, at the center of the image, is swaddled in a gossamer cocoon of reflective dust illuminated by the glittering star. The super star is ten times more massive than our sun and 200 times larger. RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of so-called Cepheid variable stars. Its average intrinsic brightness is 15,000 times greater than our sun’s luminosity. The nebula flickers in brightness as pulses of light from the Cepheid propagate outwards. Hubble took a series of photos of light flashes rippling across the nebula in a phenomenon known as a "light echo." Even though light travels through space fast enough to span the gap between Earth and the moon in a little over a second, the nebula is so large that reflected light can actually be photographed traversing the nebula. By observing the fluctuation of light in RS Puppis itself, as well as recording the faint reflections of light pulses moving across the nebula, astronomers are able to measure these light echoes and pin down a very accurate distance. The distance to RS Puppis has been narrowed down to 6,500 light-years (with a margin of error of only one percent). The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C. Acknowledgment: H. Bond (STScI and Pennsylvania State University) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics

An Inverse Square Law Variation for Hubble's Constant

NASA Astrophysics Data System (ADS)

Day, Orville W., Jr.

1999-11-01

The solution to Einstein's gravitational field equations is examined, using a Robertson-Walker metric with positive curvature, when Hubble's parameter, H_0, is taken to be a constant divided by R^2. R is the cosmic scale factor for the universe treated as a three-dimensional hypersphere in a four-dimensional Euclidean space. This solution produces a self-energy of the universe, W^(0)_self, proportional to the square of the total mass, times the universal gravitational constant divided by the cosmic scale factor, R. This result is totally analogous to the self-energy of the electromagnetic field of a charged particle, W^(0)_self = ke^2/2r, where the total charge e is squared, k is the universal electric constant and r is the scale factor, usually identified as the radius of the particle. It is shown that this choice for H0 leads to physically meaningful results for the average mass density and pressure, and a deacceleration parameter q_0=1.

Hubble (HST) hardware arrives at KSC for servicing mission, STS-103

NASA Technical Reports Server (NTRS)

1999-01-01

A shipping container with payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A) sits on a flatbed trailer for transfer to the Payload Hazardous Servicing Facility where it will undergo final testing and integration of payload elements. Mission STS-103 is a 'call-up' mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review.

Hubble Frontier Fields: systematic errors in strong lensing models of galaxy clusters - implications for cosmography

NASA Astrophysics Data System (ADS)

Acebron, Ana; Jullo, Eric; Limousin, Marceau; Tilquin, André; Giocoli, Carlo; Jauzac, Mathilde; Mahler, Guillaume; Richard, Johan

2017-09-01

Strong gravitational lensing by galaxy clusters is a fundamental tool to study dark matter and constrain the geometry of the Universe. Recently, the Hubble Space Telescope Frontier Fields programme has allowed a significant improvement of mass and magnification measurements but lensing models still have a residual root mean square between 0.2 arcsec and few arcseconds, not yet completely understood. Systematic errors have to be better understood and treated in order to use strong lensing clusters as reliable cosmological probes. We have analysed two simulated Hubble-Frontier-Fields-like clusters from the Hubble Frontier Fields Comparison Challenge, Ares and Hera. We use several estimators (relative bias on magnification, density profiles, ellipticity and orientation) to quantify the goodness of our reconstructions by comparing our multiple models, optimized with the parametric software lenstool, with the input models. We have quantified the impact of systematic errors arising, first, from the choice of different density profiles and configurations and, secondly, from the availability of constraints (spectroscopic or photometric redshifts, redshift ranges of the background sources) in the parametric modelling of strong lensing galaxy clusters and therefore on the retrieval of cosmological parameters. We find that substructures in the outskirts have a significant impact on the position of the multiple images, yielding tighter cosmological contours. The need for wide-field imaging around massive clusters is thus reinforced. We show that competitive cosmological constraints can be obtained also with complex multimodal clusters and that photometric redshifts improve the constraints on cosmological parameters when considering a narrow range of (spectroscopic) redshifts for the sources.

Hubble Sees Galaxies Spiraling around Leo

NASA Image and Video Library

2014-04-18

Shown here is a spiral galaxy known as NGC 3455, which lies some 65 million light-years away from us in the constellation of Leo (the Lion). Galaxies are classified into different types according to their structure and appearance. This classification system is known as the Hubble Sequence, named after its creator Edwin Hubble. In this image released 14, April, 2014, NGC 3455 is known as a type SB galaxy — a barred spiral. Barred spiral galaxies account for approximately two thirds of all spirals. Galaxies of this type appear to have a bar of stars slicing through the bulge of stars at their center. The SB classification is further sub-divided by the appearance of a galaxy's pinwheeling spiral arms; SBa types have more tightly wound arms, whereas SBc types have looser ones. SBb types, such as NGC 3455, lie in between. NGC 3455 is part of a pair of galaxies — its partner, NGC 3454, lies out of frame. This cosmic duo belong to a group known as the NGC 3370 group, which is in turn one of the Leo II groups, a large collection of galaxies scattered some 30 million light-years to the right of the Virgo cluster. This image is from Hubble's Advanced Camera for Surveys. Credit: ESA/Hubble & NASA, Acknowledgement: Nick Rose NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Simultaneous Chandra X ray, Hubble Space Telescope Ultraviolet, and Ulysses Radio Observations of Jupiter's Aurora

NASA Technical Reports Server (NTRS)

Elsner, R. F.; Lugaz, N.; Waite, J. H., Jr.; Cravens, T. E.; Gladstone, G. R.; Ford, P.; Grodent, D.; Bhardwaj. A.; MacDowall, R. J.; Desch, M. D. 8;

Dark energy equation of state parameter and its evolution at low redshift

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathi, Ashutosh; Sangwan, Archana; Jassal, H.K., E-mail: ashutosh_tripathi@fudan.edu.cn, E-mail: archanakumari@iisermohali.ac.in, E-mail: hkjassal@iisermohali.ac.in

In this paper, we constrain dark energy models using a compendium of observations at low redshifts. We consider the dark energy as a barotropic fluid, with the equation of state a constant as well the case where dark energy equation of state is a function of time. The observations considered here are Supernova Type Ia data, Baryon Acoustic Oscillation data and Hubble parameter measurements. We compare constraints obtained from these data and also do a combined analysis. The combined observational constraints put strong limits on variation of dark energy density with redshift. For varying dark energy models, the range ofmore » parameters preferred by the supernova type Ia data is in tension with the other low redshift distance measurements.« less

HUBBLE SPIES BROWN DWARFS IN NEARBY STELLAR NURSERY

NASA Technical Reports Server (NTRS)

2002-01-01

Probing deep within a neighborhood stellar nursery, NASA's Hubble Space Telescope uncovered a swarm of newborn brown dwarfs. The orbiting observatory's near-infrared camera revealed about 50 of these objects throughout the Orion Nebula's Trapezium cluster [image at right], about 1,500 light-years from Earth. Appearing like glistening precious stones surrounding a setting of sparkling diamonds, more than 300 fledgling stars and brown dwarfs surround the brightest, most massive stars [center of picture] in Hubble's view of the Trapezium cluster's central region. All of the celestial objects in the Trapezium were born together in this hotbed of star formation. The cluster is named for the trapezoidal alignment of those central massive stars. Brown dwarfs are gaseous objects with masses so low that their cores never become hot enough to fuse hydrogen, the thermonuclear fuel stars like the Sun need to shine steadily. Instead, these gaseous objects fade and cool as they grow older. Brown dwarfs around the age of the Sun (5 billion years old) are very cool and dim, and therefore are difficult for telescopes to find. The brown dwarfs discovered in the Trapezium, however, are youngsters (1 million years old). So they're still hot and bright, and easier to see. This finding, along with observations from ground-based telescopes, is further evidence that brown dwarfs, once considered exotic objects, are nearly as abundant as stars. The image and results appear in the Sept. 20 issue of the Astrophysical Journal. The brown dwarfs are too dim to be seen in a visible-light image taken by the Hubble telescope's Wide Field and Planetary Camera 2 [picture at left]. This view also doesn't show the assemblage of infant stars seen in the near-infrared image. That's because the young stars are embedded in dense clouds of dust and gas. The Hubble telescope's near-infrared camera, the Near Infrared Camera and Multi-Object Spectrometer, penetrated those clouds to capture a view of those

Hubble Space Telescope: SRM/QA observations and lessons learned

NASA Technical Reports Server (NTRS)

Rodney, George A.

1990-01-01

The Hubble Space Telescope (HST) Optical Systems Board of Investigation was established on July 2, 1990 to review, analyze, and evaluate the facts and circumstances regarding the manufacture, development, and testing of the HST Optical Telescope Assembly (OTA). Specifically, the board was tasked to ascertain what caused the spherical aberration and how it escaped notice until on-orbit operation. The error that caused the on-orbit spherical aberration in the primary mirror was traced to the assembly process of the Reflective Null Corrector, one of the three Null Correctors developed as special test equipment (STE) to measure and test the primary mirror. Therefore, the safety, reliability, maintainability, and quality assurance (SRM&QA) investigation covers the events and the overall product assurance environment during the manufacturing phase of the primary mirror and Null Correctors (from 1978 through 1981). The SRM&QA issues that were identified during the HST investigation are summarized. The crucial product assurance requirements (including nonconformance processing) for the HST are examined. The history of Quality Assurance (QA) practices at Perkin-Elmer (P-E) for the period under investigation are reviewed. The importance of the information management function is discussed relative to data retention/control issues. Metrology and other critical technical issues also are discussed. The SRM&QA lessons learned from the investigation are presented along with specific recommendations. Appendix A provides the MSFC SRM&QA report. Appendix B provides supplemental reference materials. Appendix C presents the findings of the independent optical consultants, Optical Research Associates (ORA). Appendix D provides further details of the fault-tree analysis portion of the investigation process.

Hubble Uncovers a Galaxy Pair Coming in from the Wilderness

NASA Image and Video Library

2017-12-08

NASA’s Hubble Space Telescope uncovered two tiny dwarf galaxies that have wandered from a vast cosmic wilderness into a nearby “big city” packed with galaxies. After being idle for billions of years, they are ready to party by starting a firestorm of star birth. Hubble captured the glow of new stars in these small, ancient galaxies, called Pisces A and Pisces B. Observations suggests the galaxies are late bloomers because they have spent most of their existence in the Local Void, a region of the universe sparsely populated with galaxies. The Local Void is roughly 150 million light-years across. Credits: NASA, ESA, and E. Tollerud (STScI) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Sees a Silver Needle in the Sky

NASA Image and Video Library

2014-08-22

This stunning new image from the NASA/ESA Hubble Space Telescope shows part of the sky in the constellation of Canes Venatici (The Hunting Dogs). Although this region of the sky is not home to any stellar heavyweights, being mostly filled with stars of average brightness, it does contain five Messier objects and numerous intriguing galaxies — including NGC 5195, a small barred spiral galaxy considered to be one of the most beautiful galaxies visible, and its nearby interacting partner the Whirlpool Galaxy (heic0506a). The quirky Sunflower Galaxy is another notable galaxy in this constellation, and is one of the largest and brightest edge-on galaxies in our skies. Joining this host of characters is spiral galaxy NGC 4244, nicknamed the Silver Needle Galaxy, shown in this new image from Hubble. This galaxy spans some 65,000 light-years and lies around 13.5 million light-years away. It appears as a wafer-thin streak across the sky, with loosely wound spiral arms hidden from view as we observe the galaxy from the side. It is part of a group of galaxies known as the M94 Group. Numerous bright clumps of gas can be seen scattered across its length, along with dark dust lanes surrounding the galaxy’s core. NGC 4244 also has a bright star cluster at its center. Although we can make out the galaxy’s bright central region and star-spattered arms, we cannot see any more intricate structure due to the galaxy’s position; from Earth, we see it stretched out as a flattened streak across the sky. A number of different observations were pieced together to form this mosaic, and gaps in Hubble’s coverage have been filled in using ground-based data. The Hubble observations were taken as part of the Galaxy Halos, Outer disks, Substructure, Thick disks and Star clusters (GHOSTS) survey, which is scanning nearby galaxies to explore how they and their stars formed to get a more complete view of the history of the Universe. European Space Agency Credit: NASA & ESA, Acknowledgement

Dismantling Hubble's Legacy?

NASA Technical Reports Server (NTRS)

Way, Michael Joseph

2013-01-01

Edwin Hubble is famous for a number of discoveries that are well known to amateur and professional astronomers, students and the general public. The origins of these discoveries are examined and it is demonstrated that, in each case, a great deal of supporting evidence was already in place. In some cases the discoveries had either already been made, or competing versions were not adopted for complex scientific and sociological reasons.

Observational constraints on generalized Proca theories

NASA Astrophysics Data System (ADS)

De Felice, Antonio; Heisenberg, Lavinia; Tsujikawa, Shinji

2017-06-01

In a model of the late-time cosmic acceleration within the framework of generalized Proca theories, there exists a de Sitter attractor preceded by the dark energy equation of state wDE=-1 -s , where s is a positive constant. We run the Markov-chain-Monte Carlo code to confront the model with the observational data of the cosmic microwave background (CMB), baryon acoustic oscillations, supernovae type Ia, and local measurements of the Hubble expansion rate for the background cosmological solutions and obtain the bound s =0.254-0.097+0.118 at 95% confidence level (C.L.). Existence of the additional parameter s to those in the Λ -cold-dark-matter (Λ CDM ) model allows to reduce tensions of the Hubble constant H0 between the CMB and the low-redshift measurements. Including the cosmic growth data of redshift-space distortions in the galaxy power spectrum and taking into account no-ghost and stability conditions of cosmological perturbations, we find that the bound on s is shifted to s =0.1 6-0.08+0.08 (95% C.L.) and hence the model with s >0 is still favored over the Λ CDM model. Apart from the quantities s ,H0 and the today's matter density parameter Ωm 0, the constraints on other model parameters associated with perturbations are less stringent, reflecting the fact that there are different sets of parameters that give rise to a similar cosmic expansion and growth history.

A Scientific Revolution: the Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2011-01-01

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the most important astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

A Scientific Revolution: The Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan

2011-01-01

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the most important astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

A Scientific Revolution: The Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2009-01-01

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss the top 10 astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

A Scientific Revolution: the Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2012-01-01

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the most important astronomical discoveries of the last IO years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

Hubble Probes Comet 103P/Hartley 2 in Preparation for DIXI flyby

NASA Image and Video Library

2017-12-08

NASA image release October 5, 2010 Hubble Space Telescope observations of comet 103P/Hartley 2, taken on September 25, are helping in the planning for a November 4 flyby of the comet by NASA's Deep Impact eXtended Investigation (DIXI) spacecraft. Analysis of the new Hubble data shows that the nucleus has a diameter of approximately 0.93 miles (1.5 km), which is consistent with previous estimates. The comet is in a highly active state, as it approaches the Sun. The Hubble data show that the coma is remarkably uniform, with no evidence for the types of outgassing jets seen from most "Jupiter Family" comets, of which Hartley 2 is a member. Jets can be produced when the dust emanates from a few specific icy regions, while most of the surface is covered with relatively inert, meteoritic-like material. In stark contrast, the activity from Hartley 2's nucleus appears to be more uniformly distributed over its entire surface, perhaps indicating a relatively "young" surface that hasn't yet been crusted over. Hubble's spectrographs - the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS) -- are expected to provide unique information about the comet's chemical composition that might not be obtainable any other way, including measurements by DIXI. The Hubble team is specifically searching for emissions from carbon monoxide (CO) and diatomic sulfur (S2). These molecules have been seen in other comets but have not yet been detected in 103P/Hartley 2. 103P/Hartley has an orbital period of 6.46 years. It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit in Siding Spring, Australia. The comet will pass within 11 million miles of Earth (about 45 times the distance to the Moon) on October 20. During that time the comet may be visible to the naked eye as a 5th magnitude "fuzzy star" in the constellation Auriga. Credit: NASA, ESA, and H. Weaver (The Johns Hopkins University/Applied Physics Lab) The Hubble Space Telescope is a

Hubble Frontier Field Abell 2744

NASA Image and Video Library

2014-01-07

This long-exposure image from NASA Hubble Space Telescope of massive galaxy cluster Abell 2744 is the deepest ever made of any cluster of galaxies. Shown in the foreground is Abell 2744, located in the constellation Sculptor.

HUBBLE SPACE TELESCOPE AND GROUND-BASED OBSERVATIONS OF V455 ANDROMEDAE POST-OUTBURST

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szkody, Paula; Mukadam, Anjum S.; Brown, Justin

2013-09-20

Hubble Space Telescope spectra obtained in 2010 and 2011, 3 and 4 yr after the large amplitude dwarf nova outburst of V455 And, were combined with optical photometry and spectra to study the cooling of the white dwarf, its spin, and possible pulsation periods after the outburst. The modeling of the ultraviolet (UV) spectra shows that the white dwarf temperature remains ∼600 K hotter than its quiescent value at 3 yr post-outburst, and still a few hundred degrees hotter at 4 yr post-outburst. The white dwarf spin at 67.6 s and its second harmonic at 33.8 s are visible inmore » the optical within a month of outburst and are obvious in the later UV observations in the shortest wavelength continuum and the UV emission lines, indicating an origin in high-temperature regions near the accretion curtains. The UV light curves folded on the spin period show a double-humped modulation consistent with two-pole accretion. The optical photometry 2 yr after outburst shows a group of frequencies present at shorter periods (250-263 s) than the periods ascribed to pulsation at quiescence, and these gradually shift toward the quiescent frequencies (300-360 s) as time progresses past outburst. The most surprising result is that the frequencies near this period in the UV data are only prominent in the emission lines, not the UV continuum, implying an origin away from the white dwarf photosphere. Thus, the connection of this group of periods with non-radial pulsations of the white dwarf remains elusive.« less

Hubble Space Telescope Eclipse Observations of the Nova Like Cataclysmic Variable UX Ursae Majoris

NASA Technical Reports Server (NTRS)

Knigge, Christian; Long, Knox S.; Wade, Richard A.; Baptista, Raymundo; Horne, Keith; Hubeny, Ivan; Rutten, Rene G. M.

1998-01-01

We present and analyze Hubble Space Telescope observations of the eclipsing nova-like cataclysmic variable UX UMa obtained with the Faint Object Spectrograph. Two eclipses each were observed with the G160L grating (covering the ultraviolet waveband) in 1994 August and with the PRISM (covering the near-ultraviolet to near-infrared) in November of the same year. The system was about 50% brighter in November than in August, which, if due to a change in the accretion rate, indicates a fairly substantial increase in Mass accretion by about 50%. The eclipse light curves are qualitatively consistent with the gradual occultation of an accretion disk with a radially decreasing temperature distribution. The light curves also exhibit asymmetries about mideclipse that are likely due to a bright spot at the disk edge. Bright-spot spectra have been constructed by differencing the mean spectra observed at pre- and posteclipse orbital phases. These difference spectra contain ultraviolet absorption lines and show the Balmer jump in emission. This suggests that part of the bright spot may be optically thin in the continuum and vertically extended enough to veil the inner disk and/or the outflow from UX UMa in some spectral lines. Model disk spectra constructed as ensembles of stellar atmospheres provide poor descriptions of the observed posteclipse spectra, despite the fact that UX UMa's light should be dominated by the disk at this time. Suitably scaled single temperature model stellar atmospheres with T(sub eff) approximately equals 12,500-14,500 K actually provide a better match to both the ultraviolet and optical posteclipse spectra. Evidently, great care must be taken in attempts to derive accretion rates from comparisons of disk models to observations. One way to reconcile disk models with the observed posteclipse spectra is to postulate the presence of a significant amount of optically thin material in the system. Such an optically thin component might be associated with the

Hubble Sees a Galactic Sunflower

NASA Image and Video Library

2017-12-08

The arrangement of the spiral arms in the galaxy Messier 63, seen here in an image from the NASA/ESA Hubble Space Telescope, recall the pattern at the center of a sunflower. So the nickname for this cosmic object — the Sunflower Galaxy — is no coincidence. Discovered by Pierre Mechain in 1779, the galaxy later made it as the 63rd entry into fellow French astronomer Charles Messier’s famous catalogue, published in 1781. The two astronomers spotted the Sunflower Galaxy’s glow in the small, northern constellation Canes Venatici (the Hunting Dogs). We now know this galaxy is about 27 million light-years away and belongs to the M51 Group — a group of galaxies, named after its brightest member, Messier 51, another spiral-shaped galaxy dubbed the Whirlpool Galaxy. Galactic arms, sunflowers and whirlpools are only a few examples of nature’s apparent preference for spirals. For galaxies like Messier 63 the winding arms shine bright because of the presence of recently formed, blue–white giant stars and clusters, readily seen in this Hubble image. Image credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Portrait of the Double

NASA Image and Video Library

1998-03-28

This is the clearest view yet of the distant planet Pluto and its moon, Charon, as revealed by NASA Hubble Space Telescope. The image was taken by the European Space Agency Faint Object Camera on February 21, 1994.

The Hubble Spectroscopic Legacy Archive

NASA Astrophysics Data System (ADS)

Peeples, Molly S.; Tumlinson, Jason; Fox, Andrew; Aloisi, Alessandra; Ayres, Thomas R.; Danforth, Charles; Fleming, Scott W.; Jenkins, Edward B.; Jedrzejewski, Robert I.; Keeney, Brian A.; Oliveira, Cristina M.

2016-01-01

With no future space ultraviolet instruments currently planned, the data from the UV spectrographs aboard the Hubble Space Telescope have a legacy value beyond their initial science goals. The Hubble Spectroscopic Legacy Archive will provide to the community new science-grade combined spectra for all publicly available data obtained by the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS). These data will be packaged into "smart archives" according to target type and scientific themes to facilitate the construction of archival samples for common science uses. A new "quick look" capability will make the data easy for users to quickly access, assess the quality of, and download for archival science starting in Cycle 24, with the first generation of these products for the FUV modes of COS available online via MAST in early 2016.

Hubble Goes to the eXtreme to Assemble Farthest-Ever View of the Universe

NASA Image and Video Library

2017-12-08

NASA image release September 25, 2012 Like photographers assembling a portfolio of best shots, astronomers have assembled a new, improved portrait of mankind's deepest-ever view of the universe. Called the eXtreme Deep Field, or XDF, the photo was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a patch of sky at the center of the original Hubble Ultra Deep Field. The XDF is a small fraction of the angular diameter of the full moon. The Hubble Ultra Deep Field is an image of a small area of space in the constellation Fornax, created using Hubble Space Telescope data from 2003 and 2004. By collecting faint light over many hours of observation, it revealed thousands of galaxies, both nearby and very distant, making it the deepest image of the universe ever taken at that time. The new full-color XDF image is even more sensitive, and contains about 5,500 galaxies even within its smaller field of view. The faintest galaxies are one ten-billionth the brightness of what the human eye can see. To read more go to:http://www.nasa.gov/mission_pages/hubble/science/xdf.html Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Catches a Galaxy Duo by the "Hare"

NASA Image and Video Library

2017-12-08

This image from the NASA/ESA Hubble Space Telescope shows the unusual galaxy IRAS 06076-2139, found in the constellation Lepus (The Hare). Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) instruments observed the galaxy from a distance of 500 million light-years. This particular object stands out from the crowd by actually being composed of two separate galaxies rushing past each other at about 2 million kilometers (1,243,000 miles) per hour. This speed is most likely too fast for them to merge and form a single galaxy. However, because of their small separation of only about 20,000 light-years, the galaxies will distort one another through the force of gravity while passing each other, changing their structures on a grand scale. Such galactic interactions are a common sight for Hubble, and have long been a field of study for astronomers. The intriguing behaviors of interacting galaxies take many forms; galactic cannibalism, galaxy harassment and even galaxy collisions. The Milky Way itself will eventually fall victim to the latter, merging with the Andromeda Galaxy in about 4.5 billion years. The fate of our galaxy shouldn’t be alarming though: while galaxies are populated by billions of stars, the distances between individual stars are so large that hardly any stellar collisions will occur. Credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble the Rotation of Uranus

NASA Image and Video Library

1998-08-02

These three NASA Hubble Space Telescope images of the planet Uranus reveal the motion of a pair of bright clouds in the planet southern hemisphere, and a high altitude haze that forms a cap above the planet south pole.

Finding our Origins with the Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2009-01-01

NASA is planning a successor to the Hubble Space Telescope designed to study the origins of galaxies, stars, planets and life in the universe. In this talk, Dr. Gardner will discuss the origin and evolution of galaxies, beginning with the Big Bang and tracing what we have learned with Hubble through to the present day. He will show that results from studies with Hubble have led to plans for its successor, the James Webb Space Telescope. Webb is scheduled to launch in 2014, and is designed to find the first galaxies that formed in the distant past and to penetrate the dusty clouds of gas where stars are still forming today. He will compare Webb to Hubble, and discuss recent progress in the construction of the observatory.

Finding our Origins with the Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan

2008-01-01

NASA is planning a successor to the Hubble Space Telescope designed to study the origins of galaxies, stars, planets and life in the universe. In this talk, Dr. Gardner will discuss the origin and evolution of galaxies, beginning with the Big Bang and tracing what we have learned with Hubble through to the present day. He will show that results from studies with Hubble have led to plans for its successor, the James Webb Space Telescope. Webb is scheduled to launch in 2013, and is designed to find the first galaxies that formed in the distant past and to penetrate the dusty clouds of gas where stars are still forming today. He will compare Webb to Hubble, and discuss recent progress in the construction of the observatory.

HUBBLE AND KECK TELESCOPE OBSERVATIONS OF ACTIVE ASTEROID 288P/300163 (2006 VW139)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarwal, Jessica; Jewitt, David; Weaver, Harold

We present Hubble Space Telescope (HST) and Keck 10 m telescope observations of active asteroid 288P/300163 (2006 VW139) taken to examine ejected dust. The nucleus is a C-type object with absolute magnitude H{sub V} = 17.0 ± 0.1 and estimated diameter ∼2.6 km (for assumed visual geometric albedo p{sub V} = 0.04). Variations in the brightness of the nucleus at the 10%–15% level are significant in both 2011 December and 2012 October but we possess too few data to distinguish variations caused by activity from those caused by rotation. The dust scattering cross-section in 2011 December is ∼40 km{sup 2},more » corresponding to a dust mass ∼9 × 10{sup 6} kg (88 μm mean particle radius assumed). The FWHM of the debris sheet varies from ∼100 km near the nucleus to ∼1000 km 30″ (40,000 km) east of it. Dust dynamical models indicate ejection speeds between 0.06 and 0.3 m s{sup −1}, particle sizes between 10 and 300 μm and an inverse square-root relation between particle size and velocity. Overall, the data are most simply explained by prolonged, low velocity ejection of dust, starting in or before 2011 July and continuing until at least 2011 October. These properties are consistent with the sublimation of near-surface ice aided by centrifugal forces. The high spatial resolution of our HST images (52 km pixel{sup −1}) reveals details that remained hidden in previous ground-based observations, such as the extraordinarily small vertical extent of the dust sheet, ejection speeds well below the nucleus escape speed, and the possibility of a binary nucleus.« less

Interactive, Collaborative Science via the 'Net: Live from the Hubble Space Telescope.

ERIC Educational Resources Information Center

Federman, Alan N.; Edwards, Sheri

1997-01-01

As a part of the Passport to Knowledge Project "Live from the Hubble Space Telescope," over 60 schools collaborated by making weather observations that were displayed via the Internet during the week of April 15-19, 1996. Describes the weather activity, technical information, and the experiences of participating students in grades 5/6 at…

Hubble Space Telescope Wide Field Planetary Camera 2 Observations of Neptune

NASA Technical Reports Server (NTRS)

1995-01-01

Two groups have recently used the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC 2) to acquire new high-resolution images of the planet Neptune. Members of the WFPC-2 Science Team, lead by John Trauger, acquired the first series of images on 27 through 29 June 1994. These were the highest resolution images of Neptune taken since the Voyager-2 flyby in August of 1989. A more comprehensive program is currently being conducted by Heidi Hammel and Wes Lockwood. These two sets of observations are providing a wealth of new information about the structure, composition, and meteorology of this distant planet's atmosphere.

Neptune is currently the most distant planet from the sun, with an orbital radius of 4.5 billion kilometers (2.8 billion miles, or 30 Astronomical Units). Even though its diameter is about four times that of the Earth (49,420 vs. 12,742 km), ground-based telescopes reveal a tiny blue disk that subtends less than 1/1200 of a degree (2.3 arc-seconds). Neptune has therefore been a particularly challenging object to study from the ground because its disk is badly blurred by the Earth's atmosphere. In spite of this, ground-based astronomers had learned a great deal about this planet since its position was first predicted by John C. Adams and Urbain Leverrier in 1845. For example, they had determined that Neptune was composed primarily of hydrogen and helium gas, and that its blue color caused by the presence of trace amounts of the gas methane, which absorbs red light. They had also detected bright cloud features whose brightness changed with time, and tracked these clouds to infer a rotation period between 17 and 22 hours.

When the Voyager-2 spacecraft flew past the Neptune in 1989, its instruments revealed a surprising array of meteorological phenomena, including strong winds, bright, high-altitude clouds, and two large dark spots attributed to long-lived giant storm systems. These bright clouds and dark spots were tracked as they

Hubble (HST) hardware arrives at KSC for servicing mission, STS-103

NASA Technical Reports Server (NTRS)

1999-01-01

A shipping container with payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A) is transferred onto a transporter from the C-5 air cargo plane that brought it to KSC. The hardware will be taken to the Payload Hazardous Servicing Facility for final testing and integration of payload elements. Mission STS-103 is a 'call-up' mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review.

Hubble (HST) hardware is moved to a workstand in the PHSF

NASA Technical Reports Server (NTRS)

1999-01-01

In the Payload Hazardous Servicing Facility (PHSF), workers check the placement of equipment, part of mission STS-103, onto a workstand. The equipment is the first part of payload flight hardware for the third Hubble Space Telescope Servicing Mission (SM-3A). The hardware will undergo final testing and integration of payload elements in the PHSF. Mission STS-103 is a 'call-up' mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-103 is currently targeted for Oct. 14 but the date is under review.

Hubble's View of Little Blue Dots

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2018-02-01

The recent discovery of a new type of tiny, star-forming galaxy is the latest in a zoo of detections shedding light on our early universe. What can we learn from the unique little blue dots found in archival Hubble data?Peas, Berries, and DotsGreen pea galaxies identified by citizen scientists with Galaxy Zoo. [Richard Nowell Carolin Cardamone]As telescope capabilities improve and we develop increasingly deeper large-scale surveys of our universe, we continue to learn more about small, faraway galaxies. In recent years, increasing sensitivity first enabled the detection of green peas luminous, compact, low-mass (10 billion solar masses; compare this to the Milky Ways 1 trillion solar masses!) galaxies with high rates of star formation.Not long thereafter, we discovered galaxies that form stars similarly rapidly, but are even smaller only 330 million solar masses, spanning less than 3,000 light-years in size. These tiny powerhouses were termed blueberries for their distinctive color.Now, scientists Debra and Bruce Elmegreen (of Vassar College and IBM Research Division, respectively) report the discovery of galaxies that have even higher star formation rates and even lower masses: little blue dots.Exploring Tiny Star FactoriesThe Elmegreens discovered these unique galaxies by exploring archival Hubble data. The Hubble Frontier Fields data consist of deep images of six distant galaxy clusters and the parallel fields next to them. It was in the archival data for two Frontier Field Parallels, those for clusters Abell 2744 and MAS J0416.1-2403, that the authors noticed several galaxies that stand out as tiny, bright, blue objects that are nearly point sources.Top: a few examples of the little blue dots recently identified in two Hubble Frontier Field Parallels. Bottom: stacked images for three different groups of little blue dots. [Elmegreen Elmegreen 2017]The authors performed a search through the two Frontier Field Parallels, discovering a total of 55 little blue dots

HUBBLE HERITAGE PROJECT'S FIRST ANNIVERSARY(NGC 2261)

NASA Technical Reports Server (NTRS)

2002-01-01

NGC 2346, in contrast to the first two young objects, is a so-called 'planetary nebula,' which is ejected from Sun-like stars which are near the ends of their lives. NGC 2346 is remarkable because its central star is known to be actually a very close pair of stars, orbiting each other every 16 days. It is believed that the binary star was originally more widely separated. However, when one component of the binary evolved, expanded in size, and became a red-giant star, it literally swallowed its companion star. The companion star then spiralled downwards inside the red giant, and in the process spewed out gas into a ring around the binary system. Later on, when the hot core of the red giant was exposed, it developed a faster stellar wind, which emerged perpendicularly to the ring and inflated two huge 'bubbles.' This two-stage process is believed to have resulted in the butterfly-like shape of the nebula. NGC 2346 lies about 2,000 light-years away from us, and is about one-third of a light-year in size. The Hubble Heritage team made this image from observations of NGC 2346 acquired by Massimo Stiavelli (STScI), Inge Heyer (STScI), and collaborators. Image Credit: NASA/The Hubble Heritage Team (AURA/STScI).

Replacement vs. Renovation: The Reincarnation of Hubble Middle School

ERIC Educational Resources Information Center

Ogurek, Douglas J.

2010-01-01

At the original Hubble Middle School, neither the views (a congested Roosevelt Road and glimpses of downtown Wheaton) nor the century-old facility that offered them was very inspiring. Built at the start of the 20th century, the 250,000-square-foot building was converted from Wheaton Central High School to Hubble Middle School in the early 1980s.…

Figure of merit and different combinations of observational data sets

NASA Astrophysics Data System (ADS)

Su, Qiping; Tuo, Zhong-Liang; Cai, Rong-Gen

2011-11-01

To constrain cosmological parameters, one often makes a joint analysis with different combinations of observational data sets. In this paper we take the figure of merit (FoM) for Dark Energy Task Force fiducial model (Chevallier-Polarski-Linder model) to estimate goodness of different combinations of data sets, which include 11 widely used observational data sets (type Ia supernovae, observational hubble parameter, baryon acoustic oscillation, cosmic microwave background, x-ray cluster baryon mass fraction, and gamma-ray bursts). We analyze different combinations and make a comparison for two types of combinations based on two types of basic combinations, which are often adopted in the literature. We find two sets of combinations, which have a strong ability to constrain the dark energy parameters: one has the largest FoM, and the other contains less observational data with a relatively large FoM and a simple fitting procedure.

Finding our Origins with the Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2007-01-01

NASA is planning a successor to the Hubble Space Telescope designed to study the origins of galaxies, stars, planets and life in the universe. In this talk, Dr. Gardner will discuss the origin and evolution of galaxies, beginning with the Big Bang and tracing what we have learned with Hubble through to the present day. He will show that results from studies with Hubble have led to plans for its successor, the James Webb Space Telescope. Webb is scheduled to launch in 201 3, and is designed to find the first galaxies that formed in the distant past and to penetrate the dusty clouds of gas where stars are still forming today. He will compare Webb to Hubble, and discuss recent progress in the construction of the observatory.

NASA's Hubble Sees A New Supernova Remnant Light Up

NASA Image and Video Library

2011-06-10

NASA image release June 10, 2011 Astronomers using NASA's Hubble Space Telescope are witnessing the unprecedented transition of a supernova to a supernova remnant, where light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth in February 1987. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years. The supernova's close proximity to Earth has allowed astronomers to study it in detail as it evolves. Now, the supernova debris, which has faded over the years, is brightening. This means that a different power source has begun to light the debris. The debris of SN 1987A is beginning to impact the surrounding ring, creating powerful shock waves that generate X-rays observed with NASA's Chandra X-ray Observatory. Those X-rays are illuminating the supernova debris and shock heating is making it glow in visible light. The results are being reported in the June 9, 2011, issue of the journal Nature by a team including Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics (CfA), who leads a long-term study of SN 1987A with Hubble. Since its launch in 1990, the Hubble telescope has provided a continuous record of the changes in SN 1987A. Credit: NASA, ESA, and P. Challis (Harvard-Smithsonian Center for Astrophysics) NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook Find us on Instagram

Hubble Case Studies of Transiting Giant Exoplanets

NASA Astrophysics Data System (ADS)

Wilkins, Ashlee N.; Deming, Drake; Barker, Adrian; Benneke, Björn; Delrez, Laetitia; Gillon, Michaël; Hamilton, Douglas P.; Jehin, Emmanuel; Knutson, Heather; Lewis, Nikole K.; Madhusudhan, Nikku; Mandell, Avi; McCullough, Peter R.; Wakeford, Hannah R.

2017-01-01

The study of planets around other stars has entered a science-rich era of characterization, in which detailed information about individual planets can be inferred from observations beyond mere detection, which only yields bulk properties like mass or radius. Characterization probes more revealing quantities such as chemical abundances, albedo, and temperature/pressure profiles, which allow us to address larger questions of planet formation mechanisms, planetary evolution, and, eventually, habitability and presence of biosignature gases. The primary method for characterization of close-in planets is transit spectroscopy. This dissertation talk will focus on transiting exoplanet case studies with the Hubble Space Telescope’ Wide-Field Camera-3 (WFC-3) as a tool of exoplanet characterization in a near-infrared band dominated by strong water features. I will first present a characterization the WFC-3 systematic effects that must be mitigated to extract the incredibly small (tens to 200 parts per million) signals, and then a study of four transiting giant planets (HATS-7b, HAT-p-3b, HD 149026b, and WASP-18b) in transmission, and two (WASP-18b and CoRoT-2b) in eclipse. Finally, I will discuss the role of transit timing monitoring of WASP-18b with HST and other observatories as another clue to its evolution as a close-in, massive planet. The five planets range from Neptune-class to Super-Jupiter-class in size/mass. Though these planets may be relatively rare, their observability represents a unique opportunity to probe planet formation and evolution, as well as atmospheric structures in a high-irradiation environment. These observations also yield insights into aerosols (i.e. clouds/hazes) in the atmosphere; clouds and/or hazes should significantly impact atmospheric chemistry and observational signatures, and we as a community must get a better handle on the phenomenon of aerosols in advance of the next generation of space observatories, including JWST and WFIRST

New Hubble Observations of Supernova 1987A Trace Shock Wave

NASA Image and Video Library

2017-12-08

Image release September 2, 2010 ABOUT THIS IMAGE: This image shows the entire region around supernova 1987A. The most prominent feature in the image is a ring with dozens of bright spots. A shock wave of material unleashed by the stellar blast is slamming into regions along the ring's inner regions, heating them up, and causing them to glow. The ring, about a light-year across, was probably shed by the star about 20,000 years before it exploded. An international team of astronomers using the Hubble Space Telescope reports a significant brightening of the emissions from Supernova 1987A. The results, which appear in this week's Science magazine, are consistent with theoretical predictions about how supernovae interact with their immediate galactic environment. The team observed the supernova remnant in optical, ultraviolet, and near-infrared light. They studied the interaction between the ejecta from the stellar explosion and a glowing 6-trillion-mile-diameter ring of gas encircling the supernova remnant. The gas ring was probably shed some 20,000 years before the supernova exploded. Shock waves resulting from the impact of the ejecta onto the ring have brightened 30 to 40 pearl-like "hot spots" in the ring. These blobs likely will grow and merge together in the coming years to form a continuous, glowing circle. "We are seeing the effect a supernova can have in the surrounding galaxy, including how the energy deposited by these stellar explosions changes the dynamics and chemistry of the environment," said University of Colorado at Boulder Research Associate Kevin France of the Center for Astrophysics and Space Astronomy. "We can use these new data to understand how supernova processes regulate the evolution of galaxies." Discovered in 1987, Supernova 1987A is the closest exploding star to Earth to be detected since 1604 and it resides in the nearby Large Magellanic Cloud, a dwarf galaxy adjacent to our own Milky Way Galaxy. Credit: NASA, ESA, K. France (University

Hubble Sees Turquoise-Tinted Plumes in Large Magellanic Cloud

NASA Image and Video Library

2017-12-08

The brightly glowing plumes seen in this image are reminiscent of an underwater scene, with turquoise-tinted currents and nebulous strands reaching out into the surroundings. However, this is no ocean. This image actually shows part of the Large Magellanic Cloud (LMC), a small nearby galaxy that orbits our galaxy, the Milky Way, and appears as a blurred blob in our skies. The NASA/European Space Agency (ESA) Hubble Space Telescope has peeked many times into this galaxy, releasing stunning images of the whirling clouds of gas and sparkling stars (opo9944a, heic1301, potw1408a). This image shows part of the Tarantula Nebula's outskirts. This famously beautiful nebula, located within the LMC, is a frequent target for Hubble (heic1206, heic1402). In most images of the LMC the color is completely different to that seen here. This is because, in this new image, a different set of filters was used. The customary R filter, which selects the red light, was replaced by a filter letting through the near-infrared light. In traditional images, the hydrogen gas appears pink because it shines most brightly in the red. Here however, other less prominent emission lines dominate in the blue and green filters. This data is part of the Archival Pure Parallel Project (APPP), a project that gathered together and processed over 1,000 images taken using Hubble’s Wide Field Planetary Camera 2, obtained in parallel with other Hubble instruments. Much of the data in the project could be used to study a wide range of astronomical topics, including gravitational lensing and cosmic shear, exploring distant star-forming galaxies, supplementing observations in other wavelength ranges with optical data, and examining star populations from stellar heavyweights all the way down to solar-mass stars. Image Credit: ESA/Hubble & NASA: acknowledgement: Josh Barrington NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science

HUBBLE FINDS A BARE BLACK HOLE POURING OUT LIGHT

NASA Technical Reports Server (NTRS)

2002-01-01

NASA's Hubble Space Telescope has provided a never-before-seen view of a warped disk flooded with a torrent of ultraviolet light from hot gas trapped around a suspected massive black hole. [Right] This composite image of the core of the galaxy was constructed by combining a visible light image taken with Hubble's Wide Field Planetary Camera 2 (WFPC2), with a separate image taken in ultraviolet light with the Faint Object Camera (FOC). While the visible light image shows a dark dust disk, the ultraviolet image (color-coded blue) shows a bright feature along one side of the disk. Because Hubble sees ultraviolet light reflected from only one side of the disk, astronomers conclude the disk must be warped like the brim of a hat. The bright white spot at the image's center is light from the vicinity of the black hole which is illuminating the disk. [Left] A ground-based telescopic view of the core of the elliptical galaxy NGC 6251. The inset box shows Hubble Space Telescope's field of view. The galaxy is 300 million light-years away in the constellation Ursa Minor. Photo Credit: Philippe Crane (European Southern Observatory), and NASA

NASA's Hubble Shows Jupiter's Great Red Spot is Smaller than Ever

NASA Image and Video Library

2014-05-15

In this comparison image the photo at the top was taken by Hubble's Wide Field Planetary Camera 2 in 1995 and shows the spot at a diameter of just under 21 000km; the second down shows a 2009 WFC3 photo of the spot at a diameter of just under 18 000km; and the lowest shows the newest image from WFC3 taken in 2014 with the spot at its smallest yet, with diameter of just 16 000km. -- Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger than Earth -- has shrunk to its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across. Astronomers have followed this downsizing since the 1930s. Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle. Read more: 1.usa.gov/1mvuo0R Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble's new view of the cosmos

PubMed

Villard, R

1996-05-01

Since the December 1993 repair of NASA's Hubble Space Telescope's (HST) optics by the crew of the Space Shuttle Endeavour, the rapid-fire scientific achievements have brought a new era of discovery to the field of astronomy. Hubble has confirmed some astronomical theories, challenged others, and often come up with complete surprises. Some images are so unexpected that astronomers have to develop new theories to explain what they are seeing. The HST has detected galaxies out to the visible horizon of the cosmos, and has made an attempt at pinning down the universe's expansion rate. Both of these key research areas should ultimately yield answers to age-old questions: What has happened since the beginning of time, and will the universe go on forever?

Delivering Hubble Discoveries to the Classroom

NASA Astrophysics Data System (ADS)

Eisenhamer, B.; Villard, R.; Weaver, D.; Cordes, K.; Knisely, L.

2013-04-01

Today's classrooms are significantly influenced by current news events, delivered instantly into the classroom via the Internet. Educators are challenged daily to transform these events into student learning opportunities. In the case of space science, current news events may be the only chance for educators and students to explore the marvels of the Universe. Inspired by these circumstances, the education and news teams developed the Star Witness News science content reading series. These online news stories (also available in downloadable PDF format) mirror the content of Hubble press releases and are designed for upper elementary and middle school level readers to enjoy. Educators can use Star Witness News stories to reinforce students' reading skills while exposing students to the latest Hubble discoveries.

An analysis of the Hubble Space Telescope fine guidance sensor fine lock mode

NASA Technical Reports Server (NTRS)

Taff, L. G.

1991-01-01

There are two guiding modes of the Hubble Space Telescope (HST) used for the acquisition of astronomical data by one of its six scientific instruments. The more precise one is called Fine Lock. Command and control problems in the onboard electronics has limited Fine Lock to brighter stars, V less than 13.0 mag, instead of fulfilling its goal of V = 14.5 mag. Consequently, the less precise guiding mode of Coarse Track (approximately 40 milli-arc seconds) has to be used fairly frequently. Indeed, almost half of the scientific observations to have been made with the HST will be compromised. The only realistic or extensive simulations of the Fine Lock guidance mode are reported. The theoretical analysis underlying the Monte Carlo experiments and the numerical computations clearly show both that the control electronics are severely under-engineered and how to adjust the various control parameters to successfully extend Fine Lock guiding performance back to V = 14.0 mag and sometimes beyond.

A TYPE Ia SUPERNOVA AT REDSHIFT 1.55 IN HUBBLE SPACE TELESCOPE INFRARED OBSERVATIONS FROM CANDELS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodney, Steven A.; Riess, Adam G.; Jones, David O.

2012-02-10

We report the discovery of a Type Ia supernova (SN Ia) at redshift z = 1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble Ultra Deep Field and followed as part of the CANDELS+CLASH Supernova project, comprising the SN search components from those two HST multi-cycle treasury programs. This is the highest redshift SN Ia with direct spectroscopic evidence for classification. It is also the first SN Ia at z > 1 found and followed in the infrared, providing amore » full light curve in rest-frame optical bands. The classification and redshift are securely defined from a combination of multi-band and multi-epoch photometry of the SN, ground-based spectroscopy of the host galaxy, and WFC3-IR grism spectroscopy of both the SN and host. This object is the first of a projected sample at z > 1.5 that will be discovered by the CANDELS and CLASH programs. The full CANDELS+CLASH SN Ia sample will enable unique tests for evolutionary effects that could arise due to differences in SN Ia progenitor systems as a function of redshift. This high-z sample will also allow measurement of the SN Ia rate out to z Almost-Equal-To 2, providing a complementary constraint on SN Ia progenitor models.« less

HUBBLE SPACE TELESCOPE OBSERVATIONS OF DUSTY FILAMENTS IN HERCULES A: EVIDENCE FOR ENTRAINMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Dea, C. P.; Kharb, P.; Baum, S. A.

2013-07-01

We present U-, V-, and I-band images of the host galaxy of Hercules A (3C 348) obtained with HST/WFC3/UVIS. We find a network of dusty filaments which are more complex and extended than seen in earlier Hubble Space Telescope (HST) observations. The filaments are associated with a faint blue continuum light (possibly from young stars) and faint H{alpha} emission. It seems likely that the cold gas and dust has been stripped from a companion galaxy now seen as a secondary nucleus. There are dusty filaments aligned with the base of the jets on both eastern and western sides of themore » galaxy. The morphology of the filaments is different on the two sides-the western filaments are fairly straight, while the eastern filaments are mainly in two loop-like structures. We suggest that despite the difference in morphologies, both sets of filaments have been entrained in a slow-moving boundary layer outside the relativistic flow. As suggested by Fabian et al., magnetic fields in the filaments may stabilize them against disruption. We consider a speculative scenario to explain the relation between the radio source and the shock and cavities in the hot intracluster medium seen in the Chandra data. We suggest that the radio source originally ({approx}60 Myr ago) propagated along a position angle of {approx}35 Degree-Sign where it created the shock and cavities. The radio source axis changed to its current orientation ({approx}100 Degree-Sign ) possibly due to a supermassive black hole merger and began its current epoch of activity about 20 Myr ago.« less

Temperatures and Altitudes of Jupiter's Ultraviolet Aurora Inferred from GHRS Observations with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Kim, Y. H.; Fox, J. L.; Caldwell, John J.

1997-07-01

We observed the jovian UV auroral regions with the Goddard high resolution spectrograph (GHRS) on board the Hubble Space Telescope (HST) on Apr. 29, May 2, and June 10, 1995. Observations of target areas were made in pairs in the two wavelength ranges 1257-1293 Å and 1587-1621 Å. Spectra in the long wavelength range are dominated by emissions of the H2Lyman band system and show well separated rotational features, which we have used to determine the temperatures of the auroral emission regions. Spectra in the short wavelength range are mostly due to emission in the H2Lyman and Werner band systems, but their intensities are reduced by hydrocarbon absorption. The brightest spectral pair was observed toward an area with longitude 155° and jovicentric latitude 58° when the central meridian longitudes (CMLs) were 191° and 203°. This area was found to be bright in our previous HST observations in 1993 and in HST faint object camera images. Assuming that electron impact excitation is the major source of the jovian aurora, we estimate total emission rates in the Lyman band system of about 270 and 46 kR for the long and short wavelength spectra of the pair, respectively. The attenuation of emission rate in the short wavelength spectrum implies a methane column density of about 3 × 1016cm-2, and a temperature of about 450 K is inferred from the long wavelength spectrum of the brightest pair. For all six pairs of observed spectra, we estimate methane column densities in the range (1-7) × 1016cm-2, which, when compared to a standard mid-latitude model, corresponds to a pressure range from a few μbar to a few tens of μbar. The temperatures derived are in the range 400-850 K with a possible tendency toward lower temperatures for higher methane column densities. This tendency and the uncertainty in the temperatures derived may indicate that the temperatures increases rapidly with altitude around the methane homopause in the auroral regions.

Hubble Space Telescope-Concept

NASA Technical Reports Server (NTRS)

1986-01-01

This is an artist's concept of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

Hubble Spies Spooky Shadow on Jupiter's Giant Eye

NASA Image and Video Library

2014-10-28

This trick that the planet is looking back at you is actually a Hubble treat: An eerie, close-up view of Jupiter, the biggest planet in our solar system. Hubble was monitoring changes in Jupiter’s immense Great Red Spot (GRS) storm on April 21, 2014, when the shadow of the Jovian moon, Ganymede, swept across the center of the storm. This gave the giant planet the uncanny appearance of having a pupil in the center of a 10,000 mile-diameter “eye.” For a moment, Jupiter “stared” back at Hubble like a one-eyed giant Cyclops. Credit: NASA, ESA, and A. Simon (Goddard Space Flight Center) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Sees an Ancient Globular Cluster

NASA Image and Video Library

2017-12-08

This image captures the stunning NGC 6535, a globular cluster 22,000 light-years away in the constellation of Serpens (The Serpent) that measures one light-year across. Globular clusters are tightly bound groups of stars which orbit galaxies. The large mass in the rich stellar centre of the globular cluster pulls the stars inward to form a ball of stars. The word globulus, from which these clusters take their name, is Latin for small sphere. Globular clusters are generally very ancient objects formed around the same time as their host galaxy. To date, no new star formation has been observed within a globular cluster, which explains the abundance of aging yellow stars in this image, most of them containing very few heavy elements. NGC 6535 was first discovered in 1852 by English astronomer John Russell Hind. The cluster would have appeared to Hind as a small, faint smudge through his telescope. Now, over 160 years later, instruments like the Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) on the NASA/ European Space Agency (ESA) Hubble Space Telescope allow us to marvel at the cluster and its contents in greater detail. Credit: ESA/Hubble & NASA, Acknowledgement: Gilles Chapdelaine NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Astronomers celebrate a year of new Hubble results

NASA Astrophysics Data System (ADS)

1995-02-01

"We are beginning to understand that because of these observations we are going to have to change the way we look at the Universe," said ESA's Dr Duccio Macchetto, Associate Director for Science Programs at the Space Telescope Science Institute (STScI), Baltimore, Maryland, USA. The European Space Agency plays a major role in the Hubble Space Telescope programme. The Agency provided one of the telescope's four major instruments, called the Faint Object Camera, and two sets of electricity-generating solar arrays. In addition, 15 ESA scientific and technical staff work at the STScI. In return for this contribution, European astronomers are entitled to 15 percent of the telescope's observing time, although currently they account for 20 percent of all observations. "This is a testimony to the quality of the European science community", said Dr Roger Bonnet, Director of Science at ESA. "We are only guaranteed 15 percent of the telescope's use, but consistently receive much more than that." Astronomers from universities, observatories and research institutes across Europe lead more than 60 investigations planned for the telescope's fifth observing cycle, which begins this summer. Many more Europeans contribute to teams led by other astronomers. Looking back to the very start of time European astronomer Dr Peter Jakobsen used ESA's Faint Object Camera to confirm that helium was present in the early Universe. Astronomers had long predicted that 90 percent of the newly born Universe consisted of hydrogen, with helium making up the remainder. Before the refurbished Hubble came along, it was easy to detect the hydrogen, but the primordial helium remained elusive. The ultraviolet capabilities of the telescope, combined with the improvement in spatial resolution following the repair, made it possible for Dr Jakobsen to obtain an image of a quasar close to the edge of the known Universe. A spectral analysis of this picture revealed the quasar's light, which took 13 billion years

Kalman filter data assimilation: targeting observations and parameter estimation.

PubMed

Bellsky, Thomas; Kostelich, Eric J; Mahalov, Alex

2014-06-01

This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly located observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.

Starry-Eyed Hubble Celebrates 20 Years of Awe and Discovery

NASA Image and Video Library

2017-12-08

NASA image release April 22, 2010 This brand new Hubble photo is of a small portion of one of the largest seen star-birth regions in the galaxy, the Carina Nebula. Towers of cool hydrogen laced with dust rise from the wall of the nebula. The scene is reminiscent of Hubble's classic "Pillars of Creation" photo from 1995, but is even more striking in appearance. The image captures the top of a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars. The pillar is also being pushed apart from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks like arrows sailing through the air. Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) To read learn more about this image go to: www.nasa.gov/mission_pages/hubble/science/hubble20th-img.... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble's View of Comet Siding Spring

NASA Image and Video Library

2017-12-08

MARCH 27, 2014: Comet Siding Spring is plunging toward the Sun along a roughly 1-million-year orbit. The comet, discovered in 2013, was within the radius of Jupiter's orbit when the Hubble Space Telescope photographed it on March 11, 2014. Hubble resolves two jets of dust coming from the solid icy nucleus. These persistent jets were first seen in Hubble pictures taken on Oct. 29, 2013. The feature should allow astronomers to measure the direction of the nucleus's pole, and hence, rotation axis. The comet will make its closest approach to our Sun on Oct. 25, 2014, at a distance of 130 million miles, well outside Earth's orbit. On its inbound leg, Comet Siding Spring will pass within 84,000 miles of Mars on Oct. 19, 2014, which is less than half the Moon's distance from Earth. The comet is not expected to become bright enough to be seen by the naked eye. Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HUBBLE IDENTIFIES SOURCE OF ULTRAVIOLET LIGHT IN AN OLD GALAXY

NASA Technical Reports Server (NTRS)

2002-01-01

Hubble Space Telescope's exquisite resolution has allowed astronomers to resolve, for the first time, hot blue stars deep inside an elliptical galaxy. The swarm of nearly 8,000 blue stars resembles a blizzard of snowflakes near the core (lower right) of the neighboring galaxy M32, located 2.5 million light-years away in the constellation Andromeda. Hubble confirms that the ultraviolet light comes from a population of extremely hot helium-burning stars at a late stage in their lives. Unlike the Sun, which burns hydrogen into helium, these old stars exhausted their central hydrogen long ago, and now burn helium into heavier elements. The observations, taken in October 1998, were made with the camera mode of the Space Telescope Imaging Spectrograph (STIS) in ultraviolet light. The STIS field of view is only a small portion of the entire galaxy, which is 20 times wider on the sky. For reference, the full moon is 70 times wider than the STIS field-of-view. The bright center of the galaxy was placed on the right side of the image, allowing fainter stars to be seen on the left side of the image. These results are to be published in the March 1, 2000 issue of The Astrophysical Journal. Thirty years ago, the first ultraviolet observations of elliptical galaxies showed that they were surprisingly bright when viewed in ultraviolet light. Before those pioneering UV observations, old groups of stars were assumed to be relatively cool and thus extremely faint in the ultraviolet. Over the years since the initial discovery of this unexpected ultraviolet light, indirect evidence has accumulated that it originates in a population of old, but hot, helium-burning stars. Now Hubble provides the first direct visual evidence. Nearby elliptical galaxies are thought to be relatively simple galaxies comprised of old stars. Because they are among the brightest objects in the Universe, this simplicity makes them useful for tracing the evolution of stars and galaxies. Credits: NASA and Thomas

HUBBLE AND KECK DISCOVER GALAXY BUILDING BLOCK

NASA Technical Reports Server (NTRS)

2002-01-01

This NASA Hubble Space Telescope image shows a very small, faint galaxy 'building block' newly discovered by a unique collaboration between ground- and space-based telescopes. Hubble and the 10-meter Keck Telescopes in Hawaii joined forces, using a galaxy cluster which acts as gravitational lens to detect what scientists believe is one of the smallest very distant objects ever found. The galaxy cluster Abell 2218 was used by a team of European and American astronomers led by Richard Ellis (Caltech) in their systematic search for intrinsically faint distant star-forming systems. Without help from Abell 2218's exceptional magnifying power to make objects appear about 30 times brighter, the galaxy building block would have been undetectable. In the image to the right, the object is seen distorted into two nearly identical, very red 'images' by the gravitational lens. The image pair represents the magnified result of a single background object gravitationally lensed by Abell 2218 and viewed at a distance of 13.4 billion light-years. The intriguing object contains only one million stars, far fewer than a mature galaxy, and scientists believe it is very young. Such young star-forming systems of low mass at early cosmic times are likely to be the objects from which present-day galaxies have formed. In the image to the left, the full overview of the galaxy cluster Abell 2218 is seen. This image was taken by Hubble in 1999 at the completion of Hubble Servicing Mission 3A. Credit: NASA, ESA, Richard Ellis (Caltech) and Jean-Paul Kneib (Observatoire Midi-Pyrenees, France) Acknowledgment: NASA, A. Fruchter and the ERO Team (STScI and ST-ECF)

Hubble Eyes a Powerful Galaxy

NASA Image and Video Library

2017-06-30

Not all galaxies have the luxury of possessing a simple moniker or quirky nickname. This impressive galaxy imaged by the NASA/ESA Hubble Space Telescope is one of the unlucky ones, and goes by a name that looks more like a password for a computer: 2XMM J143450.5+033843. Such a name may seem like a random jumble of numbers and letters, but like all galactic epithets it has a distinct meaning. This galaxy, for example, was detected and observed as part of the second X-ray sky survey performed by ESA’s XMM-Newton Observatory. Its celestial coordinates form the rest of the bulky name, following the “J”: a right ascension value of 14h (hours) 34m (minutes) 50.5s (seconds). This can be likened to terrestrial longitude. It also has a declination of +03d (degrees) 38m (minutes) 43s (seconds). Declination can be likened to terrestrial latitude. The other fuzzy object in the frame was named in the same way — it is a bright galaxy named 2XMM J143448.3+033749. 2XMM J143450.5+033843 lies nearly 400 million light-years away from Earth. It is a Seyfert galaxy that is dominated by something known as an Active Galactic Nucleus — its core is thought to contain a supermassive black hole that is emitting huge amounts of radiation, pouring energetic X-rays out into the Universe. Photo credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble confirms cosmic acceleration with weak lensing

NASA Image and Video Library

2017-12-08

NASA/ESA Hubble Release Date: March 25, 2010 This image shows a smoothed reconstruction of the total (mostly dark) matter distribution in the COSMOS field, created from data taken by the NASA/ESA Hubble Space Telescope and ground-based telescopes. It was inferred from the weak gravitational lensing distortions that are imprinted onto the shapes of background galaxies. The colour coding indicates the distance of the foreground mass concentrations as gathered from the weak lensing effect. Structures shown in white, cyan, and green are typically closer to us than those indicated in orange and red. To improve the resolution of the map, data from galaxies both with and without redshift information were used. The new study presents the most comprehensive analysis of data from the COSMOS survey. The researchers have, for the first time ever, used Hubble and the natural "weak lenses" in space to characterise the accelerated expansion of the Universe. Credit: NASA, ESA, P. Simon (University of Bonn) and T. Schrabback (Leiden Observatory) To learn more abou this image go to: www.spacetelescope.org/news/html/heic1005.html For more information about Goddard Space Flight Center go here: www.nasa.gov/centers/goddard/home/index.html

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

NASA Associate Administrator of the Science Mission Directorate Dr. Edward J. Weiler discusses newly released images from NASA's Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

Hubble Helps Find Smallest Known Galaxy Containing a Supermassive Black Hole

NASA Image and Video Library

2017-12-08

This is an illustration of a supermassive black hole, weighing as much as 21 million suns, located in the middle of the ultradense galaxy M60-UCD1. The dwarf galaxy is so dense that millions of stars fill the sky as seen by an imaginary visitor. Because no light can escape from the black hole, it appears simply in silhouette against the starry background. The black hole's intense gravitational field warps the light of the background stars to form ring-like images just outside the dark edges of the black hole's event horizon. Combined observations by the Hubble Space Telescope and Gemini North telescope determined the presence of the black hole inside such a small and dense galaxy. More info: Astronomers using data from NASA’s Hubble Space Telescope and ground observation have found an unlikely object in an improbable place -- a monster black hole lurking inside one of the tiniest galaxies ever known. The black hole is five times the mass of the one at the center of our Milky Way galaxy. It is inside one of the densest galaxies known to date -- the M60-UCD1 dwarf galaxy that crams 140 million stars within a diameter of about 300 light-years, which is only 1/500th of our galaxy’s diameter. If you lived inside this dwarf galaxy, the night sky would dazzle with at least 1 million stars visible to the naked eye. Our nighttime sky as seen from Earth’s surface shows 4,000 stars. The finding implies there are many other compact galaxies in the universe that contain supermassive black holes. The observation also suggests dwarf galaxies may actually be the stripped remnants of larger galaxies that were torn apart during collisions with other galaxies rather than small islands of stars born in isolation. “We don’t know of any other way you could make a black hole so big in an object this small,” said University of Utah astronomer Anil Seth, lead author of an international study of the dwarf galaxy published in Thursday’s issue of the journal Nature. Seth�

HUBBLE: ON THE ASTEROID TRAIL

NASA Technical Reports Server (NTRS)

2002-01-01

Astronomers Karl Stapelfeldt and Robin Evans have tracked down about 100 small asteroids by hunting through more than 28,000 archival images taken by the Hubble Space Telescope's Wide Field and Planetary Camera 2. Here is a sample of what they have found: four archival images that show the curved trails left by asteroids. [Top left]: Hubble captured a bright asteroid, with a visual magnitude of 18.7, roaming in the constellation Centaurus. Background stars are shown in white, while the asteroid trail is depicted in blue at top center. The trail has a length of 19 arc seconds. This asteroid has a diameter of one and one-quarter miles (2 kilometers), and was located 87 million miles from Earth and 156 million miles from the sun. Numerous orange and blue specks in this image and the following two images were created by cosmic rays, energetic subatomic particles that struck the camera's detector. [Top right]: Here is an asteroid with a visual magnitude of 21.8 passing a galaxy in the constellation Leo. The trail is seen in two consecutive exposures, the first shown in blue and the second in red. This asteroid has a diameter of half a mile (0.8 kilometers), and was located 188 million miles from Earth and 233 million miles from the sun. [Lower left]: This asteroid in the constellation Taurus has a visual magnitude of 23, and is one of the faintest seen so far in the Hubble archive. It moves from upper right to lower left in two consecutive exposures; the first trail is shown in blue and the second in red. Because of the asteroid's relatively straight trail, astronomers could not accurately determine its distance. The estimated diameter is half a mile (0.8 kilometers) at an Earth distance of 205 million miles and a sun distance of 298 million miles. [Lower right]: This is a broken asteroid trail crossing the outer regions of galaxy NGC 4548 in Coma Berenices. Five trail segments (shown in white) were extracted from individual exposures and added to a cleaned color image

The Hubble Spectroscopic Legacy Archive

NASA Astrophysics Data System (ADS)

Peeples, M.; Tumlinson, J.; Fox, A.; Aloisi, A.; Fleming, S.; Jedrzejewski, R.; Oliveira, C.; Ayres, T.; Danforth, C.; Keeney, B.; Jenkins, E.

2017-04-01

With no future space ultraviolet instruments currently planned, the data from the UV spectrographs aboard the Hubble Space Telescope have a legacy value beyond their initial science goals. The goal of the Hubble Spectroscopic Legacy Archive(HSLA) is to provide to the community new science-grade combined spectra for all publicly available data obtained by the Cosmic Origins Spectrograph (COS)and the Space Telescope Imaging Spectrograph (STIS). These data are packaged into "smart archives" according to target type and scientific themes to facilitate the construction of archival samples for common science uses. A new "quick look" capability makes the data easy for users to quickly access, assess the quality of,and download for archival science. The first generation of these products for the far-ultraviolet (FUV) modes of COS was made available online via the Mikulski Archive for Space Telescopes (MAST) in early 2016 and updated in early 2017; future releases will include COS/NUV and STIS/UV data.

HUBBLE'S NEW IMPROVED OPTICS PROBE THE CORE OF A DISTANT GALAXY

NASA Technical Reports Server (NTRS)

2002-01-01

This comparison image of the core of the galaxy M100 shows the dramatic improvement in Hubble Space Telescope's view of the universe. The new image was taken with the second generation Wide Field and Planetary Camera (WFPC-2) which was installed during the STS-61 Hubble Servicing Mission. The picture beautifully demonstrates that the corrective optics incorporated within the WFPC-2 compensate fully for optical aberration in Hubble's primary mirror. The new camera will allow Hubble to probe the universe with unprecedented clarity and sensitivity, and to fulfill many of the most important scientific objectives for which the telescope was originally built. [ Right ] The core of the grand design spiral galaxy M100, as imaged by Hubble Space Telescope's Wide Field Planetary Camera 2 in its high resolution channel. The WFPC-2 contains modified optics that correct for Hubble's previously blurry vision, allowing the telescope for the first time to cleanly resolve faint structure as small as 30 light-years across in a galaxy which is tens of millions of light years away. The image was taken on December 31, 1993. [Left ] For comparison, a picture taken with the WFPC-1 camera in wide field mode, on November 27, 1993, just a few days prior to the STS-61 servicing mission. The effects of optical aberration in HST's 2.4-meter primary mirror blur starlight, smear out fine detail, and limit the telescope's ability to see faint structure. Both Hubble images are 'raw;' they have not been subject to computer image reconstruction techniques commonly used in aberrated images made before the servicing mission. TARGET INFORMATION: M100 The galaxy M100 (100th object in the Messier Catalog of non-stellar objects) is one of the brightest members of the Virgo Cluster of galaxies. The galaxy is in the spring constellation Coma Berenices and can be seen through a moderate-sized amateur telescope. M100 is spiral shaped, like our Milky Way, and tilted nearly face-on as seen from earth. The

Three Axis Control of the Hubble Space Telescope Using Two Reaction Wheels and Magnetic Torquer Bars for Science Observations

NASA Technical Reports Server (NTRS)

Hur-Diaz, Sun; Wirzburger, John; Smith, Dan

2008-01-01

The Hubble Space Telescope (HST) is renowned for its superb pointing accuracy of less than 10 milli-arcseconds absolute pointing error. To accomplish this, the HST relies on its complement of four reaction wheel assemblies (RWAs) for attitude control and four magnetic torquer bars (MTBs) for momentum management. As with most satellites with reaction wheel control, the fourth RWA provides for fault tolerance to maintain three-axis pointing capability should a failure occur and a wheel is lost from operations. If an additional failure is encountered, the ability to maintain three-axis pointing is jeopardized. In order to prepare for this potential situation, HST Pointing Control Subsystem (PCS) Team developed a Two Reaction Wheel Science (TRS) control mode. This mode utilizes two RWAs and four magnetic torquer bars to achieve three-axis stabilization and pointing accuracy necessary for a continued science observing program. This paper presents the design of the TRS mode and operational considerations necessary to protect the spacecraft while allowing for a substantial science program.

Kalman filter data assimilation: Targeting observations and parameter estimation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellsky, Thomas, E-mail: bellskyt@asu.edu; Kostelich, Eric J.; Mahalov, Alex

2014-06-15

This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly locatedmore » observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.« less

History of Hubble Space Telescope (HST)

NASA Image and Video Library

2004-02-08

This photo, captured by the NASA Hubble Space Telescope's (HST) Advanced Camera for Surveys, is Hubble's latest view of an expanding halo of light around the distant star V838 Monocerotis, or V Mon, caused by an unusual stellar outburst that occurred back in January 2002. A burst of light from the bizarre star is spreading into space and reflecting off of surrounding circumstellar dust. As different parts are sequentially illuminated, the appearance of the dust changes. This effect is referred to as a "light echo". Located about 20,000 light-years away in the winter constellation Monoceros (the Unicorn), the star brightened to more than 600,000 times our Sun's luminosity. The light echo gives the illusion of contracting, until it finally disappears by the end of the decade.

The Hubble flow of plateau inflation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coone, Dries; Roest, Diederik; Vennin, Vincent, E-mail: a.a.coone@rug.nl, E-mail: d.roest@rug.nl, E-mail: vincent.vennin@port.ac.uk

2015-11-01

In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard ''horizon flow'' procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau inflation, which suggests the use of Padé approximants instead. We propose a novel method that provides analytic solutions of the flow equations for a given parametrization of the Hubble function. This method is illustrated in the Taylor and Padé cases, for low order expansions. We then present the results of a full numerical treatment scanning larger ordermore » expansions, and compare these parametrizations in terms of convergence, prior dependence, predictivity and compatibility with the data. Finally, we highlight the implications for potential reconstruction methods.« less

Near-infrared Detection of WD 0806-661 B with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Luhman, K. L.; Morley, C. V.; Burgasser, A. J.; Esplin, T. L.; Bochanski, J. J.

2014-10-01

WD 0806-661 B is one of the coldest known brown dwarfs (T eff = 300-345 K) based on previous mid-infrared photometry from the Spitzer Space Telescope. In addition, it is a benchmark for testing theoretical models of brown dwarfs because its age and distance are well constrained via its primary star (2 ± 0.5 Gyr, 19.2 ± 0.6 pc). We present the first near-infrared detection of this object, which has been achieved through F110W imaging (~Y + J) with the Wide Field Camera 3 on board the Hubble Space Telescope. We measure a Vega magnitude of m 110 = 25.70 ± 0.08, which implies J ~ 25.0. When combined with the Spitzer photometry, our estimate of J helps to better define the empirical sequence of the coldest brown dwarfs in M 4.5 versus J - [4.5]. The positions of WD 0806-661 B and other Y dwarfs in that diagram are best matched by the cloudy models of Burrows et al. and the cloudless models of Saumon et al., both of which employ chemical equilibrium. The calculations by Morley et al. for 50% cloud coverage differ only modestly from the data. Spectroscopy would enable a more stringent test of the models, but based on our F110W measurement, such observations are currently possible only with Hubble, and would require at least ~10 orbits to reach a signal-to-noise ratio of ~5. Based on observations made with the NASA/ESA Hubble Space Telescope through program 12815, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, and observations with the ESO Telescopes at Paranal Observatory under programs ID 089.C-0428 and ID 089.C-0597.

HUBBLE WATCHES STAR TEAR APART ITS NEIGHBORHOOD

NASA Technical Reports Server (NTRS)

2002-01-01

,000 years. Then the stellar wind collided with the material around the star and swept it up into a thin shell. That shell broke apart into the network of bright clumps seen in the image. The present-day strong wind of the Wolf-Rayet star has only now caught up with the outer edge of the shell, and is stripping away matter as it flows past [the tongue-shaped material in the upper right of the Hubble image]. The stellar wind continues moving outside the shell, slamming into more material and creating a shock wave. This powerful force produces an extremely hot, glowing skin [seen in blue], which envelops the bright nebula. A shock wave is analogous to the sonic boom produced by a jet plane that exceeds the speed of sound; in a cosmic setting, this boom is seen rather than heard. The outer material is too thin to see in the image until the shock wave hits it. The cosmic collision and subsequent shock wave implies that a large amount of matter resides outside the visible shell. The discovery of this material may explain the discrepancy between the mass of the entire shell (four solar masses) and the amount of matter the star lost when it was a red super-giant (15 solar masses). The nebula's short-term fate is less spectacular. As the stellar wind muscles past the clumps of material, the pressure around them drops. A decrease in pressure means that the clumps expand, leading to a steady decline in brightness and fading perhaps to invisibility. Later, the shell may be compressed and begin glowing again, this time as the powerful blast wave of the Wolf-Rayet star completely destroys itself in a powerful supernova explosion. The nebula resides in the constellation Cygnus, 4,700 light-years from Earth. If the nebula were visible to the naked eye, it would appear in the sky as an ellipse one-quarter the size of the full moon. The observations were taken in June 1995 with the Wide Field and Planetary Camera 2. Scientists selected the colors in this composite image to correspond with

HUBBLE SPACE TELESCOPE CAPTURES FIRST DIRECT IMAGE OF A STAR

NASA Technical Reports Server (NTRS)

2002-01-01

This is the first direct image of a star other than the Sun, made with NASA's Hubble Space Telescope. Called Alpha Orionis, or Betelgeuse, it is a red supergiant star marking the shoulder of the winter constellation Orion the Hunter (diagram at right). The Hubble image reveals a huge ultraviolet atmosphere with a mysterious hot spot on the stellar behemoth's surface. The enormous bright spot, more than ten times the diameter of Earth, is at least 2,000 Kelvin degrees hotter than the surface of the star. The image suggests that a totally new physical phenomenon may be affecting the atmospheres of some stars. Follow-up observations will be needed to help astronomers understand whether the spot is linked to oscillations previously detected in the giant star, or whether it moves systematically across the star's surface under the grip of powerful magnetic fields. The observations were made by Andrea Dupree of the Harvard- Smithsonian Center for Astrophysics in Cambridge, MA, and Ronald Gilliland of the Space Telescope Science Institute in Baltimore, MD, who announced their discovery today at the 187th meeting of the American Astronomical Society in San Antonio, Texas. The image was taken in ultraviolet light with the Faint Object Camera on March 3, 1995. Hubble can resolve the star even though the apparent size is 20,000 times smaller than the width of the full Moon -- roughly equivalent to being able to resolve a car's headlights at a distance of 6,000 miles. Betelgeuse is so huge that, if it replaced the Sun at the center of our Solar System, its outer atmosphere would extend past the orbit of Jupiter (scale at lower left). Credit: Andrea Dupree (Harvard-Smithsonian CfA), Ronald Gilliland (STScI), NASA and ESA Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

Heidi Hammel, senior research scientist at the Space Science Institute in Boulder, Colorado discusses newly released images from NASA's Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

Estimability of geodetic parameters from space VLBI observables

NASA Technical Reports Server (NTRS)

Adam, Jozsef

1990-01-01

The feasibility of space very long base interferometry (VLBI) observables for geodesy and geodynamics is investigated. A brief review of space VLBI systems from the point of view of potential geodetic application is given. A selected notational convention is used to jointly treat the VLBI observables of different types of baselines within a combined ground/space VLBI network. The basic equations of the space VLBI observables appropriate for convariance analysis are derived and included. The corresponding equations for the ground-to-ground baseline VLBI observables are also given for a comparison. The simplified expression of the mathematical models for both space VLBI observables (time delay and delay rate) include the ground station coordinates, the satellite orbital elements, the earth rotation parameters, the radio source coordinates, and clock parameters. The observation equations with these parameters were examined in order to determine which of them are separable or nonseparable. Singularity problems arising from coordinate system definition and critical configuration are studied. Linear dependencies between partials are analytically derived. The mathematical models for ground-space baseline VLBI observables were tested with simulation data in the frame of some numerical experiments. Singularity due to datum defect is confirmed.

Hubble Space Telescope photometry of the central regions of Virgo Cluster elliptical galaxies. 1: Observations, discussion, and conclusions

NASA Technical Reports Server (NTRS)

Jaffe, Walter; Ford, Holland C.; O'Connell, Robert W.; Bosch, Frank C. Van Den; Ferrarese, Laura

1994-01-01

Using the Hubble Space Telescope we have observed at 10 pc resolution the nuclei of a luminosity-limited sample of 14 E and E/SO galaxies in the Virgo Cluster with magnitudes B(sub T) = 9.4 to 13.4. In this paper we present the images, and discuss the results of the detailed analysis of the surface photometry given in two companion papers. We find that the nuclear and near-nuclear morphologies confirm and strengthen the previously recognized dichotomy of 'E' galaxies into 'true' and 'disky' subtypes. The latter, usually classified E4 or later, often show a bright nuclear disk of radius approximately 100 pc. Essentially all early-type galaxies with -18 greater than M(sub B) greater than -20 are disky. Most true E galaxies are classified E4 or earlier. Most galaxies of both types show dust in the nuclear regions, the most remarkable example being a compact dust disk in NGC 4261. Other than dust, no anomalies were detected in the centers of the three galaxies in our sample which show clear kinematic evidence for a decoupled component.

Hubble Finds Misbehaving Spiral

NASA Image and Video Library

2016-01-29

Despite its unassuming appearance, the edge-on spiral galaxy captured in the left half of this NASA/ESA Hubble Space Telescope image is actually quite remarkable. Located about one billion light-years away in the constellation of Eridanus, this striking galaxy — known as LO95 0313-192 — has a spiral shape similar to that of the Milky Way. It has a large central bulge, and arms speckled with brightly glowing gas mottled by thick lanes of dark dust. Its companion, sitting in the right of the frame, is known rather unpoetically as [LOY2001] J031549.8-190623. Jets, outbursts of superheated gas moving at close to the speed of light, have long been associated with the cores of giant elliptical galaxies, and galaxies in the process of merging. However, in an unexpected discovery, astronomers found LO95 0313-192, even though it is a spiral galaxy, to have intense radio jets spewing out from its center. The galaxy appears to have two more regions that are also strongly emitting in the radio part of the spectrum, making it even rarer still. The discovery of these giant jets in 2003 — not visible in this image, but indicated in this earlier Hubble composite — has been followed by the unearthing of a further three spiral galaxies containing radio-emitting jets in recent years. This growing class of unusual spirals continues to raise significant questions about how jets are produced within galaxies, and how they are thrown out into the cosmos. Image credit: ESA/Hubble & NASA; acknowledgement, Judy Schmidt NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Updated observational constraints on quintessence dark energy models

NASA Astrophysics Data System (ADS)

Durrive, Jean-Baptiste; Ooba, Junpei; Ichiki, Kiyotomo; Sugiyama, Naoshi

2018-02-01

The recent GW170817 measurement favors the simplest dark energy models, such as a single scalar field. Quintessence models can be classified in two classes, freezing and thawing, depending on whether the equation of state decreases towards -1 or departs from it. In this paper, we put observational constraints on the parameters governing the equations of state of tracking freezing, scaling freezing, and thawing models using updated data, from the Planck 2015 release, joint light-curve analysis, and baryonic acoustic oscillations. Because of the current tensions on the value of the Hubble parameter H0, unlike previous authors, we let this parameter vary, which modifies significantly the results. Finally, we also derive constraints on neutrino masses in each of these scenarios.

Listening to galaxies tuning at z ~ 2.5-3.0: The first strikes of the Hubble fork

NASA Astrophysics Data System (ADS)

Talia, M.; Cimatti, A.; Mignoli, M.; Pozzetti, L.; Renzini, A.; Kurk, J.; Halliday, C.

2014-02-01

Aims: We investigate the morphological properties of 494 galaxies selected from the Galaxy Mass Assembly ultra-deep Spectroscopic Survey (GMASS) at z > 1, primarily in their optical rest frame, using Hubble Space Telescope (HST) infrared images, from the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). Methods: The morphological analysis of Wield Field Camera (WFC3) H160 band images was performed using two different methods: a visual classification identifying traditional Hubble types, and a quantitative analysis using parameters that describe structural properties, such as the concentration of light and the rotational asymmetry. The two classifications are compared. We then analysed how apparent morphologies correlate with the physical properties of galaxies. Results: The fractions of both elliptical and disk galaxies decrease between redshifts z ~ 1 to z ~ 3, while at z > 3 the galaxy population is dominated by irregular galaxies. The quantitative morphological analysis shows that, at 1 < z < 3, morphological parameters are not as effective in distinguishing the different morphological Hubble types as they are at low redshift. No significant morphological k-correction was found to be required for the Hubble type classification, with some exceptions. In general, different morphological types occupy the two peaks of the (U - B)rest colour bimodality of galaxies: most irregulars occupy the blue peak, while ellipticals are mainly found in the red peak, though with some level of contamination. Disks are more evenly distributed than either irregulars and ellipticals. We find that the position of a galaxy in a UVJ diagram is related to its morphological type: the "quiescent" region of the plot is mainly occupied by ellipticals and, to a lesser extent, by disks. We find that only ~33% of all morphological ellipticals in our sample are red and passively evolving galaxies, a percentage that is consistent with previous results obtained at z < 1. Blue

Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results

NASA Technical Reports Server (NTRS)

Hinshaw, G.; Larson, D.; Komatsu, E.; Spergel, D. N.; Bennett, C. L.; Dunkley, J.; Nolta, M. R.; Halpern, M.; Hill, R. S.; Odegard, N.;

NASA Hubble Space Telescope (HST) Research Project Capstone Even

NASA Image and Video Library

2014-05-05

Students and faculty from Mapletown Jr/Sr High School and Margaret Bell Middle School listen as John Grunsfeld, NASA Associate Administrator for the Science Mission Directorate, speaks about his experiences on the final space shuttle servicing mission to the Hubble Space Telescope during the NASA Hubble Space Telescope (HST) Research Project Capstone Event in the James E. Webb Auditorium at NASA Headquarters on Monday, May 5, 2014. Photo Credit: (NASA/Joel Kowsky)

HUBBLE'S PANORAMIC PORTRAIT OF A VAST STAR-FORMING REGION

NASA Technical Reports Server (NTRS)

2002-01-01

NASA's Hubble Space Telescope has snapped a panoramic portrait of a vast, sculpted landscape of gas and dust where thousands of stars are being born. This fertile star-forming region, called the 30 Doradus Nebula, has a sparkling stellar centerpiece: the most spectacular cluster of massive stars in our cosmic neighborhood of about 25 galaxies. The mosaic picture shows that ultraviolet radiation and high-speed material unleashed by the stars in the cluster, called R136 [the large blue blob left of center], are weaving a tapestry of creation and destruction, triggering the collapse of looming gas and dust clouds and forming pillar-like structures that are incubators for nascent stars. The photo offers an unprecedented, detailed view of the entire inner region of 30 Doradus, measuring 200 light-years wide by 150 light-years high. The nebula resides in the Large Magellanic Cloud (a satellite galaxy of the Milky Way), 170,000 light-years from Earth. Nebulas like 30 Doradus are the 'signposts' of recent star birth. High-energy ultraviolet radiation from the young, hot, massive stars in R136 causes the surrounding gaseous material to glow. Previous Hubble telescope observations showed that R136 contains several dozen of the most massive stars known, each about 100 times the mass of the Sun and about 10 times as hot. These stellar behemoths all formed at the same time about 2 million years ago. The stars in R136 are producing intense 'stellar winds' (streams of material traveling at several million miles an hour), which are wreaking havoc on the gas and dust in the surrounding neighborhood. The winds are pushing the gas away from the cluster and compressing the inner regions of the surrounding gas and dust clouds [the pinkish material]. The intense pressure is triggering the collapse of parts of the clouds, producing a new generation of star formation around the central cluster. The new stellar nursery is about 30 to 50 light-years from R136. Most of the stars in the

Hubble Captures Detailed Image of Uranus' Atmosphere

NASA Technical Reports Server (NTRS)

1996-01-01

Hubble Space Telescope has peered deep into Uranus' atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus' atmosphere.

Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail.

The infrared image allows astronomers to probe the structure of Uranus' atmosphere, which consists of mostly hydrogen with traces of methane. The red around the planet's edge represents a very thin haze at a high altitude. The haze is so thin that it can only be seen by looking at the edges of the disk, and is similar to looking at the edge of a soap bubble. The yellow near the bottom of Uranus is another hazy layer. The deepest layer, the blue near the top of Uranus, shows a clearer atmosphere.

Image processing has been used to brighten the rings around Uranus so that astronomers can study their structure. In reality, the rings are as dark as black lava or charcoal.

This false color picture was assembled from several exposures taken July 3, 1995 by the Wide Field Planetary Camera-2.

The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

Hubble's Blue Bubble

NASA Image and Video Library

2017-12-08

A large blue bubble with a bright star in the center on a black background filled with stars Sparkling at the center of this beautiful NASA/ESA Hubble Space Telescope image is a Wolf–Rayet star known as WR 31a, located about 30,000 light-years away in the constellation of Carina (The Keel). The distinctive blue bubble appearing to encircle WR 31a is a Wolf–Rayet nebula — an interstellar cloud of dust, hydrogen, helium and other gases. Created when speedy stellar winds interact with the outer layers of hydrogen ejected by Wolf–Rayet stars, these nebulae are frequently ring-shaped or spherical. The bubble — estimated to have formed around 20,000 years ago — is expanding at a rate of around 220,000 kilometers (136,700 miles) per hour! Unfortunately, the lifecycle of a Wolf–Rayet star is only a few hundred thousand years — the blink of an eye in cosmic terms. Despite beginning life with a mass at least 20 times that of the sun, Wolf–Rayet stars typically lose half their mass in less than 100,000 years. And WR 31a is no exception to this case. It will, therefore, eventually end its life as a spectacular supernova, and the stellar material expelled from its explosion will later nourish a new generation of stars and planets. Image credi: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt

Hubble Peers at a Distinctly Disorganized Dwarf Galaxy

NASA Image and Video Library

2017-12-08

Despite being less famous than their elliptical and spiral galactic cousins, irregular dwarf galaxies, such as the one captured in this NASA/ESA Hubble Space Telescope image, are actually one of the most common types of galaxy in the universe. Known as UGC 4459, this dwarf galaxy is located approximately 11 million light-years away in the constellation of Ursa Major (The Great Bear), a constellation that is also home to the Pinwheel Galaxy (M101), the Owl Nebula (M97), Messier 81, Messier 82 and several other galaxies all part of the M81 group. UGC 4459’s diffused and disorganized appearance is characteristic of an irregular dwarf galaxy. Lacking a distinctive structure or shape, irregular dwarf galaxies are often chaotic in appearance, with neither a nuclear bulge — a huge, tightly packed central group of stars — nor any trace of spiral arms — regions of stars extending from the center of the galaxy. Astronomers suspect that some irregular dwarf galaxies were once spiral or elliptical galaxies, but were later deformed by the gravitational pull of nearby objects. Rich with young blue stars and older red stars, UGC 4459 has a stellar population of several billion. Though seemingly impressive, this is small when compared to the 200 to 400 billion stars in the Milky Way! Observations with Hubble have shown that because of their low masses of dwarf galaxies like UGC 4459, star formation is very low compared to larger galaxies. Only very little of their original gas has been turned into stars. Thus, these small galaxies are interesting to study to better understand primordial environments and the star formation process. Image Credit: ESA/Hubble and NASA; Acknowledgement: Judy Schmidt NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific

Hubble Space Telescope observations of Orion Nebula, Helix Nebula, and NGC 6822

NASA Technical Reports Server (NTRS)

Spitzer, Lyman; Fitzpatrick, Ed

1999-01-01

This grant covered the major part of the work of the Principal Investigator and his collaborators as a Guaranteed Time Observer on the Hubble Space Telescope. The work done naturally divided itself into two portions the first being study of nebular objects and the second investigation of the interstellar medium between stars. The latter investigation was pursued through a contract with Princeton University, with Professor Lyman Spitzer as the supervising astronomer, assisted by Dr. Ed Fitzpatrick. Following the abrupt death of Professor Spitzer, his responsibilities were shifted to Dr. Fitzpatrick. When Dr. Fitzpatrick relocated to Villanova University the concluding work on that portion of this grant was concluded under a direct service arrangement. This program has been highly successful and the resulting publications in scientific journals are listed below. To the scientist, this is the bottom line, so that I shall simply try to describe the general nature of what was accomplished. There were three nebular programs conducted, one on the Orion Nebula, the second on the Helix Nebula, and the third on NGC 6822. The largest program was that on the Orion Nebula. This involved both HST observations and supporting groundbased observations obtained with a variety of instruments, including the Coude Feed Telescope at the Kitt Peak National observatory in Arizona, the Cerro Tololo observatory in Chile, and the Keck Observatory on Mauna Kea, Hawaii. Moreover, considerable theoretical modeling was done and all of the data analysis was performed at the Rice University in Houston, except for the PI's period of sabbatical leave (6-96 through 7-97) when he was based at the Max Planck Institute for Astronomy in Heidelberg, Germany. The Orion Nebula program was the most productive part, resulting in numerous papers, but more important in the discovery of a new class of objects, for which we coined the name "proplyds". The proplyds are protoplanetary disks surrounding very young

Creation of the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

O'Dell, C. R.

2009-08-01

The Hubble Space Telescope has been the most successful space astronomy project to date, producing images that put the public in awe and images and spectra that have produced many scientific discoveries. It is the natural culmination of a dream envisioned when rocket flight into space was first projected and a goal set for the US space program soon after NASA was created. The design and construction period lasted almost two decades and its operations have already lasted almost as long. The capabilities of the observatory have evolved and expanded with periodic upgrading of its instrumentation, thus realizing the advantages of its unique design. The success of this long-lived observatory is closely tied to the availability of the Space Shuttle and the end of the Shuttle program means that the end of the Hubble program will follow before long.

The evolution of C/O in dwarf galaxies from Hubble Space Telescope FOS observations

NASA Technical Reports Server (NTRS)

Garnett, D. R.; Skillman, E. D.; Dufour, R. J.; Peimbert, M.; Torres-Peimbert, S.; Terlevich, R.; Terlevich, E.; Shields, G. A.

1995-01-01

We present UV observations of seven H II regions in low-luminosity dwarf irregular galaxies and the Magellanic Clouds obtained with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST) in order to measure the C/O abundance ratio in the interstellar medium (ISM) of those galaxies. We measure both O III 1666 A and C III 1909 A in our spectra, enabling us to determine C(+2)/O(+2) with relatively small uncertainties. The results from our HST observations show a continuous increase in C/O with increasing O/H, consistent with a power law having an index of 0.43 +/- 0.09 over the range -4.7 to -3.6 in log (O/H). One possible interpretation of this trend is that the most metal-poor galaxies are the youngest and dominated by the products of early enrichment by massive stars, while more metal-rich galaxies show increasing, delayed contributions of carbon from intermediate-mass stars. Our results also suggest that it may not be appropiate to combine abundances in irregular galaxies with those in spiral galaxies to study the evolution of chemical abundances. Our measured C/O ratios in the most metal-poor galaxies are consistent with predictions of nucleosynthesis from massive stars for Weaver & Woosley's best estimate for the 12C(alpha, gamma) 16O nuclear reaction rate, assuming negligible contanmination from carbon produced in intermediate-mass stars in these galaxies. We detect a weak N III 1750 A multiplet in SMC N88A and obtain interesting upper limits for two other objects. Our 2 sigma uppr limits on the 1750 A feature indicate that the N(+2)/O(+2) ratios in these objects are not significantly larger than the N(+)/O(+) ratios measured from optical spectra. This behavior is consistent with predictions of photionization models, although better detections of N III are needed to confirm the results.

Mass-sheet degeneracy, power-law models and external convergence: Impact on the determination of the Hubble constant from gravitational lensing

NASA Astrophysics Data System (ADS)

Schneider, Peter; Sluse, Dominique

2013-11-01

The light travel time differences in strong gravitational lensing systems allows an independent determination of the Hubble constant. This method has been successfully applied to several lens systems. The formally most precise measurements are, however, in tension with the recent determination of H0 from the Planck satellite for a spatially flat six-parameters ΛCDM cosmology. We reconsider the uncertainties of the method, concerning the mass profile of the lens galaxies, and show that the formal precision relies on the assumption that the mass profile is a perfect power law. Simple analytical arguments and numerical experiments reveal that mass-sheet like transformations yield significant freedom in choosing the mass profile, even when exquisite Einstein rings are observed. Furthermore, the characterization of the environment of the lens does not break that degeneracy which is not physically linked to extrinsic convergence. We present an illustrative example where the multiple imaging properties of a composite (baryons + dark matter) lens can be extremely well reproduced by a power-law model having the same velocity dispersion, but with predictions for the Hubble constant that deviate by ~20%. Hence we conclude that the impact of degeneracies between parametrized models have been underestimated in current H0 measurements from lensing, and need to be carefully reconsidered.

Effect of correlated observation error on parameters, predictions, and uncertainty

USGS Publications Warehouse

Tiedeman, Claire; Green, Christopher T.

2013-01-01

Correlations among observation errors are typically omitted when calculating observation weights for model calibration by inverse methods. We explore the effects of omitting these correlations on estimates of parameters, predictions, and uncertainties. First, we develop a new analytical expression for the difference in parameter variance estimated with and without error correlations for a simple one-parameter two-observation inverse model. Results indicate that omitting error correlations from both the weight matrix and the variance calculation can either increase or decrease the parameter variance, depending on the values of error correlation (ρ) and the ratio of dimensionless scaled sensitivities (rdss). For small ρ, the difference in variance is always small, but for large ρ, the difference varies widely depending on the sign and magnitude of rdss. Next, we consider a groundwater reactive transport model of denitrification with four parameters and correlated geochemical observation errors that are computed by an error-propagation approach that is new for hydrogeologic studies. We compare parameter estimates, predictions, and uncertainties obtained with and without the error correlations. Omitting the correlations modestly to substantially changes parameter estimates, and causes both increases and decreases of parameter variances, consistent with the analytical expression. Differences in predictions for the models calibrated with and without error correlations can be greater than parameter differences when both are considered relative to their respective confidence intervals. These results indicate that including observation error correlations in weighting for nonlinear regression can have important effects on parameter estimates, predictions, and their respective uncertainties.

An Occultation by Saturn's Rings on 1991 October 2-3 October 2-3 Observed with the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Bosh, A. S.; Cooke, M. L.; Bless, R. C.; Nelson, M. J.; Percival, J. W.; Taylor, M. J.; Dolan, J. F.; Robinson, E. L.; Van Citters, G. W.

1993-01-01

An occultation of the star GSC 6323-01396 (V = 11.9) by Saturn's rings was observed with the High-Speed Photometer on the Hubble Space Telescope (HST) on 1991 October 2-3. This occultation occurred when Saturn was near a stationary point, so the apparent motion of Saturn relative to the star was dominated by the HST orbital motion (8 km/s). Data were recorded simultaneously at effective wavelengths of 3200 and 7500 A, with an integration time of 0.15 s. Fifteen segments of occultation data, totaling 6.8 h, were recorded in 13 successive orbits during the 20.0 h interval from UTC 1991 October 2, 19:35 until UTC 1991 October 3, 15:35. Occultations by 43 different features throughout the classical rings were unambiguously identified in the light curve, with a second occultation by 24 of them occurring due to spacecraft orbital parallax during this extremely slow event. Occultation times for features currently presumed circular were measured and employed in a geometrical model for the rings. This model, relating the observed occultation times to feature radii and longitudes, is presented here and is used in a least-squares fit for the pole direction and radius scale of Saturn's ring system.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1998-01-01

This photograph is a Hubble Space Telescope (HST) image of a sky full of glittering jewels. The HST peered into the Sagittarius star cloud, a narrow dust free region, providing this spectacular glimpse of a treasure chest full of stars.

Hubble Captures View of Mystic Mountain

NASA Image and Video Library

2010-04-22

NASA Hubble Space Telescope captures the chaotic activity atop a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars in a tempestuous stellar nursery called the Carina Nebula.

Hubble's Last Look at Comet ISON Before Perihelion

NASA Image and Video Library

2013-11-22

As of mid-November, ISON is officially upon us. Using Hubble, we've taken our closest look yet at the innermost region of the comet, where geysers of sublimating ice are fueling a spectacular tail. Made from observations on November 2nd, the image combines pictures of ISON taken through blue and red filters. As we expect, the round coma around ISON's nucleus is blue and the tail has a redder hue. Ice and gas in the coma reflect blue light from the Sun, while dust grains in the tail reflect more red light than blue light. This is the most color separation we've seen so far in ISON -- that's because the comet, nearer than ever to the Sun, is brighter and more structured than ever before. We've certainly come a long way since Hubble started observing Comet ISON, way back in April. Of course, our eight-month retrospective pales in comparison with ISON's own journey, which started some 10,000 years ago in the Oort cloud. ISON will come closest to the Sun on November 28, a point in its orbit known as perihelion. What's remarkable here is that the entire ISON, this awesome, shimmery space tadpole, is being produced from a dusty ball of ice estimated to be a few kilometers in diameter. Compared to ISON's full extent, Hubble's latest image is tiny. It only shows the very base of the tail. Yet even in this closest closeup we've ever had, a single pixel spans 24 km across the comet. Now that Comet ISON is close, amateur astromers rule the day. But Hubble observations, including this latest image, are still providing key insights into the science and spectacle of a comet we hope will continue to impress. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) -------- More details on Comet ISON: Comet ISON began its trip from the Oort cloud region of our solar system and is now travelling toward the sun. The comet will reach its closest approach to the sun on Thanksgiving Day -- 28 Nov 2013 -- skimming just 730,000 miles above the sun's surface. If it comes around the sun

Critical points of the cosmic velocity field and the uncertainties in the value of the Hubble constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Hao; Naselsky, Pavel; Mohayaee, Roya, E-mail: liuhao@nbi.dk, E-mail: roya@iap.fr, E-mail: naselsky@nbi.dk

2016-06-01

The existence of critical points for the peculiar velocity field is a natural feature of the correlated vector field. These points appear at the junctions of velocity domains with different orientations of their averaged velocity vectors. Since peculiar velocities are the important cause of the scatter in the Hubble expansion rate, we propose that a more precise determination of the Hubble constant can be made by restricting analysis to a subsample of observational data containing only the zones around the critical points of the peculiar velocity field, associated with voids and saddle points. On large-scales the critical points, where themore » first derivative of the gravitational potential vanishes, can easily be identified using the density field and classified by the behavior of the Hessian of the gravitational potential. We use high-resolution N-body simulations to show that these regions are stable in time and hence are excellent tracers of the initial conditions. Furthermore, we show that the variance of the Hubble flow can be substantially minimized by restricting observations to the subsample of such regions of vanishing velocity instead of aiming at increasing the statistics by averaging indiscriminately using the full data sets, as is the common approach.« less

HUBBLE REVEALS THE HEART OF THE WHIRLPOOL GALAXY

NASA Technical Reports Server (NTRS)

2002-01-01

New images from NASA's Hubble Space Telescope are helping researchers view in unprecedented detail the spiral arms and dust clouds of a nearby galaxy, which are the birth sites of massive and luminous stars. The Whirlpool galaxy, M51, has been one of the most photogenic galaxies in amateur and professional astronomy. Easily photographed and viewed by smaller telescopes, this celestial beauty is studied extensively in a range of wavelengths by large ground- and space-based observatories. This Hubble composite image shows visible starlight as well as light from the emission of glowing hydrogen, which is associated with the most luminous young stars in the spiral arms. M51, also known as NGC 5194, is having a close encounter with a nearby companion galaxy, NGC 5195, just off the upper edge of this image. The companion's gravitational pull is triggering star formation in the main galaxy, as seen in brilliant detail by numerous, luminous clusters of young and energetic stars. The bright clusters are highlighted in red by their associated emission from glowing hydrogen gas. This Wide Field Planetary Camera 2 image enables a research group, led by Nick Scoville (Caltech), to clearly define the structure of both the cold dust clouds and the hot hydrogen and link individual clusters to their parent dust clouds. Team members include M. Polletta (U. Geneva); S. Ewald and S. Stolovy (Caltech); R. Thompson and M. Rieke (U. of Arizona). Intricate structure is also seen for the first time in the dust clouds. Along the spiral arms, dust 'spurs' are seen branching out almost perpendicular to the main spiral arms. The regularity and large number of these features suggests to astronomers that previous models of 'two-arm' spiral galaxies may need to be revisited. The new images also reveal a dust disk in the nucleus, which may provide fuel for a nuclear black hole. The team is also studying this galaxy at near-infrared wavelengths with the NICMOS instrument onboard Hubble. At these

Hubble's Hockey Stick Galaxy

NASA Image and Video Library

2017-12-08

The star of this NASA/ESA Hubble Space Telescope image is a galaxy known as NGC 4656, located in the constellation of Canes Venatici (The Hunting Dogs). However, it also has a somewhat more interesting and intriguing name: the Hockey Stick Galaxy! The reason for this is a little unclear from this partial view, which shows the bright central region, but the galaxy is actually shaped like an elongated, warped stick, stretching out through space until it curls around at one end to form a striking imitation of a celestial hockey stick. This unusual shape is thought to be due to an interaction between NGC 4656 and a couple of near neighbors, NGC 4631 (otherwise known as The Whale Galaxy) and NGC 4627 (a small elliptical). Galactic interactions can completely reshape a celestial object, shifting and warping its constituent gas, stars, and dust into bizarre and beautiful configurations. Credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Views Two Galaxies Merging

NASA Image and Video Library

2017-12-08

This image, taken with the Wide Field Planetary Camera 2 on board the NASA/ESA Hubble Space Telescope, shows the galaxy NGC 6052, located around 230 million light-years away in the constellation of Hercules. It would be reasonable to think of this as a single abnormal galaxy, and it was originally classified as such. However, it is in fact a “new” galaxy in the process of forming. Two separate galaxies have been gradually drawn together, attracted by gravity, and have collided. We now see them merging into a single structure. As the merging process continues, individual stars are thrown out of their original orbits and placed onto entirely new paths, some very distant from the region of the collision itself. Since the stars produce the light we see, the “galaxy” now appears to have a highly chaotic shape. Eventually, this new galaxy will settle down into a stable shape, which may not resemble either of the two original galaxies. Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt

Coordinated Hubble Space Telescope and Venus Express Observations of Venus' upper cloud deck

NASA Astrophysics Data System (ADS)

Jessup, Kandis Lea; Marcq, Emmanuel; Mills, Franklin; Mahieux, Arnaud; Limaye, Sanjay; Wilson, Colin; Allen, Mark; Bertaux, Jean-Loup; Markiewicz, Wojciech; Roman, Tony; Vandaele, Ann-Carine; Wilquet, Valerie; Yung, Yuk

2015-09-01

Hubble Space Telescope Imaging Spectrograph (HST/STIS) UV observations of Venus' upper cloud tops were obtained between 20N and 40S latitude on December 28, 2010; January 22, 2011 and January 27, 2011 in coordination with the Venus Express (VEx) mission. The high spectral (0.27 nm) and spatial (40-60 km/pixel) resolution HST/STIS data provide the first direct and simultaneous record of the latitude and local time distribution of Venus' 70-80 km SO and SO2 (SOx) gas density on Venus' morning quadrant. These data were obtained simultaneously with (a) VEx/SOIR occultation and/or ground-based James Clerk Maxwell Telescope sub-mm observations that record respectively, Venus' near-terminator SO2 and dayside SOx vertical profiles between ∼75 and 100 km; and (b) 0.36 μm VEx/VMC images of Venus' cloud-tops. Updating the (Marcq, E. et al. [2011]. Icarus 211, 58-69) radiative transfer model SO2 gas column densities of ∼2-10 μm-atm and ∼0.4-1.8 μm-atm are retrieved from the December 2010 and January 2011 HST observations, respectively on Venus' dayside (i.e., at solar zenith angles (SZA) < 60°); SO gas column densities of 0.1-0.11 μm-atm, 0.03-0.31 μm-atm and 0.01-0.13 μm-atm are also retrieved from the respective December 28, 2010, January 22, 2011 and January 27, 2011 HST observations. A decline in the observed low-latitude 0.24 and 0.36 μm cloud top brightness paralleled the declining SOx gas densities. On December 28, 2010 SO2 VMR values ∼280-290 ppb are retrieved between 74 and 81 km from the HST and SOIR data obtained near Venus' morning terminator (at SZAs equal to 70° and 90°, respectively); these values are 10× higher than the HST-retrieved January 2011 near terminator values. Thus, the cloud top SO2 gas abundance declined at all local times between the three HST observing dates. On all dates the average dayside SO2/SO ratio inferred from HST between 70 and 80 km is higher than that inferred from the sub-mm the JCMT data above 84 km confirming that

A 2.4% Determination of the Local Value of the Hubble Constant

NASA Astrophysics Data System (ADS)

Riess, Adam G.; Macri, Lucas M.; Hoffmann, Samantha L.; Scolnic, Dan; Casertano, Stefano; Filippenko, Alexei V.; Tucker, Brad E.; Reid, Mark J.; Jones, David O.; Silverman, Jeffrey M.; Chornock, Ryan; Challis, Peter; Yuan, Wenlong; Brown, Peter J.; Foley, Ryan J.

2016-07-01

We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%. The bulk of this improvement comes from new near-infrared (NIR) observations of Cepheid variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these in turn leverage the magnitude-redshift relation based on ˜300 SNe Ia at z < 0.15. All 19 hosts as well as the megamaser system NGC 4258 have been observed with WFC3 in the optical and NIR, thus nullifying cross-instrument zeropoint errors in the relative distance estimates from Cepheids. Other noteworthy improvements include a 33% reduction in the systematic uncertainty in the maser distance to NGC 4258, a larger sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of Cepheids in M31, and new HST-based trigonometric parallaxes for Milky Way (MW) Cepheids. We consider four geometric distance calibrations of Cepheids: (I) megamasers in NGC 4258, (II) 8 DEBs in the LMC, (III) 15 MW Cepheids with parallaxes measured with HST/FGS, HST/WFC3 spatial scanning and/or Hipparcos, and (IV) 2 DEBs in M31. The Hubble constant from each is 72.25 ± 2.51, 72.04 ± 2.67, 76.18 ± 2.37, and 74.50 ± 3.27 km s-1 Mpc-1, respectively. Our best estimate of H 0 = 73.24 ± 1.74 km s-1 Mpc-1 combines the anchors NGC 4258, MW, and LMC, yielding a 2.4% determination (all quoted uncertainties include fully propagated statistical and systematic components). This value is 3.4σ higher than 66.93 ± 0.62 km s-1 Mpc-1 predicted by ΛCDM with 3 neutrino flavors having a mass of 0.06 eV and the new Planck data, but the discrepancy reduces to 2.1σ relative to the prediction of 69.3 ± 0.7 km s-1 Mpc-1 based on the comparably precise combination of WMAP

Near-infrared and ultraviolet spectrophotometry of the young planetary nebula Hubble 12

NASA Technical Reports Server (NTRS)

Rudy, Richard J.; Rossano, George S.; Erwin, Peter; Puetter, R. C.; Feibelman, Walter A.

1993-01-01

The young planetary nebula Hubble 12 is observed using near-IR and UV spectrophotometry. The brightness of the O I lines, which is greater than in any other planetary nebula yet measured, indicates that fluorescent excitation by stellar continuum is the principal mechanism generating these lines. Extinction, electron density, and electron temperature are determined using infrared measurements combined with UV data and published optical observations. The range in extinction, density, and temperature implies that, within the ionized region, pockets of emission with distinctly different conditions exist. Logarithmic abundances for helium, oxygen, and sulfur are presented.

Hubble Spies Spooky Shadow on Jupiter's Giant Eye (color)

NASA Image and Video Library

2014-10-28

This trick that the planet is looking back at you is actually a Hubble treat: An eerie, close-up view of Jupiter, the biggest planet in our solar system. Hubble was monitoring changes in Jupiter’s immense Great Red Spot (GRS) storm on April 21, 2014, when the shadow of the Jovian moon, Ganymede, swept across the center of the storm. This gave the giant planet the uncanny appearance of having a pupil in the center of a 10,000 mile-diameter “eye.” For a moment, Jupiter “stared” back at Hubble like a one-eyed giant Cyclops. Credit: NASA, ESA, and A. Simon (Goddard Space Flight Center) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

NASA Associate Administrator of the Science Mission Directorate Dr. Edward J. Weiler listens to a reporters question during a press conference where NASA released images from NASA's Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

Hubble Space Telescope: Fine guidance sensors instrument handbook. Version 2.1

NASA Technical Reports Server (NTRS)

Taff, Larry (Editor)

1990-01-01

The Fine Guidance Sensors (FGS) are a system of photomultiplier tubes and white light amplitude interferometers (Koester's prism) which are used for the fine guidance of the Hubble Space Telescope (HST). The purpose of the handbook is to provide information to a potential user of the FGS so that he may explore the feasibility of performing various observations. A brief overview is given of how the FGS works, along with an explanation of the instrument in some detail. The procedure for estimating exposure times is explained. The observing modes are described. Some details needed to specify the exposures and observation requirements on the proposal forms are explained. Data reduction procedures are outlined.

Dark energy in the environments of the Local Group, the M 81 group, and the CenA group: the normalized Hubble diagram

NASA Astrophysics Data System (ADS)

Teerikorpi, P.; Chernin, A. D.; Karachentsev, I. D.; Valtonen, M. J.

2008-05-01

Context: Type Ia supernova observations on scales of thousands of Mpc show that the global expansion of the universe is accelerated by antigravity produced by the enigmatic dark energy contributing 3/4 of the total energy of the universe. Aims: Does antigravity act on small scales as well as large? As a continuation of our efforts to answer this crucial question we combine high accuracy observations of the galaxy flows around the Local Group and the nearby M 81 and CenA groups to observe the effect of the dark energy density on local scales of a few Mpc. Methods: We use an analytical model to describe non-uniform static space-time regions around galaxy groups. In this context it is useful to present the Hubble flow in a normalized Hubble diagram V/Hv Rv vs. r/R_v, where the vacuum Hubble constant Hv depends only on the cosmological vacuum density and the zero-gravity distance Rv depends on the vacuum density and on the mass of the galaxy group. We have prepared the normalized Hubble diagrams for the LG, M 81 and CenA group environments for different values of the assumed vacuum energy density, using a total of about 150 galaxies, for almost all of which the distances have been measured by the HST. Results: The normalized Hubble diagram, where we identify dynamically different regions, is in agreement with the standard vacuum density (Ωv = 0.77~h_70-2), the out-flow of galaxies clearly being controlled by the minimum energy condition imposed by the central mass plus the vacuum density. A high vacuum density 1.6~h_70-2 violates the minimum energy limit, while a low density 0.1~h_70-2 leaves the start of the Hubble flow around 1-2 Mpc with the slope close to the global value obscure. We also consider the subtle relation of the zero-gravity radius Rv to the zero-velocity distance R0 appearing in the usual retarded expansion around a mass M: in a vacuum-dominated flat universe R0 ≈ 0.76 R_v. Conclusions: The normalized Hubble diagram appears to be a good way to

Hubble and ESO's VLT provide unique 3D views of remote galaxies

NASA Astrophysics Data System (ADS)

2009-03-01

Astronomers have obtained exceptional 3D views of distant galaxies, seen when the Universe was half its current age, by combining the twin strengths of the NASA/ESA Hubble Space Telescope's acute eye, and the capacity of ESO's Very Large Telescope to probe the motions of gas in tiny objects. By looking at this unique "history book" of our Universe, at an epoch when the Sun and the Earth did not yet exist, scientists hope to solve the puzzle of how galaxies formed in the remote past. ESO PR Photo 10a/09 A 3D view of remote galaxies ESO PR Photo 10b/09 Measuring motions in 3 distant galaxies ESO PR Video 10a/09 Galaxies in collision For decades, distant galaxies that emitted their light six billion years ago were no more than small specks of light on the sky. With the launch of the Hubble Space Telescope in the early 1990s, astronomers were able to scrutinise the structure of distant galaxies in some detail for the first time. Under the superb skies of Paranal, the VLT's FLAMES/GIRAFFE spectrograph (ESO 13/02) -- which obtains simultaneous spectra from small areas of extended objects -- can now also resolve the motions of the gas in these distant galaxies (ESO 10/06). "This unique combination of Hubble and the VLT allows us to model distant galaxies almost as nicely as we can close ones," says François Hammer, who led the team. "In effect, FLAMES/GIRAFFE now allows us to measure the velocity of the gas at various locations in these objects. This means that we can see how the gas is moving, which provides us with a three-dimensional view of galaxies halfway across the Universe." The team has undertaken the Herculean task of reconstituting the history of about one hundred remote galaxies that have been observed with both Hubble and GIRAFFE on the VLT. The first results are coming in and have already provided useful insights for three galaxies. In one galaxy, GIRAFFE revealed a region full of ionised gas, that is, hot gas composed of atoms that have been stripped of

Reflective correctors for the Hubble Space Telescope axial instruments

NASA Technical Reports Server (NTRS)

Bottema, Murk

1993-01-01

Reflective correctors to compensate the spherical aberration in the Hubble Space Telescope are placed in front of three of the axial scientific instruments (a camera and two spectrographs) during the first scheduled refurbishment mission. The five correctors required are deployed from a new module that replaces the fourth axial instrument. Each corrector consists of a field mirror and an aspherical, aberration-correcting reimaging mirror. In the camera the angular resolution capability is restored, be it in reduced fields, and in the spectrographs the potential for observations in crowded areas is regained along with effective light collection at the slits.

Hubble Space Telescope NiH2 six battery test

NASA Technical Reports Server (NTRS)

Whitt, Thomas H.; Lanier, J. Roy

1991-01-01

The primary objectives of the test are: (1) to get a better understanding of the operating characteristics of the NiH2 batteries in the Hubble Space Telescope (HST) Electric Power Subsystem (EPS) by simulating every aspect of the expected operating environment; (2) to determine the optimum charge level and charge scheme for the NiH2 batteries in the HST EPS; (3) to predict the performance of the actual HST EPS; (4) to observe the aging characteristics of the batteries; and (5) to test different EPS anomalies before experiencing the anomalies on the actual HST.

Hubble Space Telescope Thermal Blanket Repair Design and Implementation

NASA Technical Reports Server (NTRS)

Ousley, Wes; Skladany, Joseph; Dell, Lawrence

2000-01-01

Substantial damage to the outer layer of Hubble Space Telescope (HST) thermal blankets was observed during the February 1997 servicing mission. After six years in LEO, many areas of the aluminized Teflon(R) outer blanket layer had significant cracks, and some material was peeled away to expose inner layers to solar flux. After the mission, the failure mechanism was determined, and repair materials and priorities were selected for follow-on missions. This paper focuses on the thermal, mechanical, and EVA design requirements for the blanket repair, the creative solutions developed for these unique problems, hardware development, and testing.

Hubble peers inside a celestial geode

NASA Astrophysics Data System (ADS)

2004-08-01

celestial geode hi-res Size hi-res: 148 Kb Credits: ESA/NASA, Yäel Nazé (University of Liège, Belgium) and You-Hua Chu (University of Illinois, Urbana, USA) Hubble peers inside a celestial geode In this unusual image, the NASA/ESA Hubble Space Telescope captures a rare view of the celestial equivalent of a geode - a gas cavity carved by the stellar wind and intense ultraviolet radiation from a young hot star. Real geodes are handball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter ‘celestial geode’ the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior. Low resolution version (JPG format) 148 Kb High resolution version (TIFF format) 1929 Kb Acknowledgment: This image was created with the help of the ESA/ESO/NASA Photoshop FITS Liberator. Real geodes are handball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter ‘celestial geode’ the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior. The object, called N44F, is being inflated by a torrent of fast-moving particles (what astronomers call a 'stellar wind') from an exceptionally hot star (the bright star just below the centre of the bubble) once buried inside a cold dense cloud. Compared with our Sun (which is losing mass through the so-called 'solar wind'), the central star in N44F is ejecting more than a 100 million times more mass per second and the hurricane of particles moves much faster at 7 million km per hour

ISOCAM observations of the Hubble Deep Field reduced with the PRETI method

NASA Astrophysics Data System (ADS)

Aussel, H.; Cesarsky, C. J.; Elbaz, D.; Starck, J. L.

1999-02-01

We have developed a new ISOCAM data reduction technique based on wavelet analysis, especially designed for the detection of faint sources in mid-infrared surveys. This method, the Pattern REcognition Technique for Isocam data (PRETI) has been used to reduce the observations of the Hubble Deep Field (HDF) and flanking fields with ISOCAM at 6.75 (LW2) and 15 mu m (LW3) (Rowan-Robinson et al. \\cite{RowanRobinson}). Simulations of ISOCAM data allow us to test the photometric accuracy and completeness of the reduction. According to these simulations, the PRETI source list is 95% complete in the 15 mu m band at 200 mu Jy and in the 6.75 mu m band at 65 mu Jy, using detection thresholds which minimize the number of false detections. We detect 49 objects in the ISO-HDF at high confidence secure level, 42 in the LW3 filter, 3 in the LW2 filter, and 4 in both filters. An additional, less secure, list of 100 sources is presented, of which 89 are detected at 15 mu m only, 7 at 6.75 mu m only and 4 in both filters. All ISO-HDF objects detected in the HDF itself have optical or infrared counterparts, except for one from the additional list. All except one of the radio sources detected in the field by Fomalont et al. (\\cite{Fomalont}) are detected with ISOCAM. Using a precise correction for the field of view distortion of ISOCAM allows us to separate blended sources. This, together with the fact that PRETI allows to correct data on the tail of cosmic rays glitches, lead us to produce deeper source lists than previous authors. Our list of bright sources agree with those of Désert et al. (\\cite{IAS}) in both filters, and with those of Goldschmidt et al. (\\cite{Goldschmidt}) in the LW3 filter, with systematic difference in photometry. Number counts derived from our results show an excess by a factor of 10 with respect to the prediction of a no evolution model (Franceschini \\cite{Franceschini98}) in the LW3 band. On the contrary, the number of sources in the LW2 band is

Mothers of Invention: Hubble Engineers Push Robotic 'Evolution' to Save Telescope, Enable New Exploration

NASA Technical Reports Server (NTRS)

Morring, Frank, Jr.

2004-01-01

Robotic technology being developed out of necessity to keep the Hubble Space Telescope operating could also lead to new levels of man-machine team-work in deep-space exploration down the road-if it survives the near-term scramble for funding. Engineers here who have devoted their NASA careers to the concept of humans servicing the telescope in orbit are planning modifications to International Space Station (ISS) robots that would leave the humans on the ground. The work. forced by post-Columbia flight rules that killed a planned shuttle-servicing mission to Hubble, marks another step in the evolution of robot-partners for human space explorers. "Hubble has always been a pathfider for this agency," says Mike Weiss. Hubble deputy program manager technical. "When the space station was flown and assembled, Hubble was the pathfinder. not just for modularity, but for operations, for assembly techniques. Exploration is the next step. Things we're going to do on Hubble are going to be applied to exploration. It's not just putting a robot in space. It's operating a robot in space. It's adapting that robot to what needs to be done the next time you're up there."

NASA Hubble Sees Sparring Antennae Galaxies

NASA Image and Video Library

2013-11-15

The NASA/ESA Hubble Space Telescope has snapped the best ever image of the Antennae Galaxies. Hubble has released images of these stunning galaxies twice before, once using observations from its Wide Field and Planetary Camera 2 (WFPC2) in 1997, and again in 2006 from the Advanced Camera for Surveys (ACS). Each of Hubble’s images of the Antennae Galaxies has been better than the last, due to upgrades made during the famous servicing missions, the last of which took place in 2009. The galaxies — also known as NGC 4038 and NGC 4039 — are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years sparring with one another. This clash is so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. In wide-field images of the pair the reason for their name becomes clear — far-flung stars and streamers of gas stretch out into space, creating long tidal tails reminiscent of antennae. This new image of the Antennae Galaxies shows obvious signs of chaos. Clouds of gas are seen in bright pink and red, surrounding the bright flashes of blue star-forming regions — some of which are partially obscured by dark patches of dust. The rate of star formation is so high that the Antennae Galaxies are said to be in a state of starburst, a period in which all of the gas within the galaxies is being used to form stars. This cannot last forever and neither can the separate galaxies; eventually the nuclei will coalesce, and the galaxies will begin their retirement together as one large elliptical galaxy. This image uses visible and near-infrared observations from Hubble’s Wide Field Camera 3 (WFC3), along with some of the previously-released observations from Hubble’s Advanced Camera for Surveys (ACS). Credit: NASA/European Space Agency NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors

HUBBLE CAPTURES DETAILED IMAGE OF URANUS' ATMOSPHERE

NASA Technical Reports Server (NTRS)

2002-01-01

Hubble Space Telescope has peered deep into Uranus' atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus' atmosphere. Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail. The infrared image allows astronomers to probe the structure of Uranus' atmosphere, which consists of mostly hydrogen with traces of methane. The red around the planet's edge represents a very thin haze at a high altitude. The haze is so thin that it can only be seen by looking at the edges of the disk, and is similar to looking at the edge of a soap bubble. The yellow near the bottom of Uranus is another hazy layer. The deepest layer, the blue near the top of Uranus, shows a clearer atmosphere. Image processing has been used to brighten the rings around Uranus so that astronomers can study their structure. In reality, the rings are as dark as black lava or charcoal. This false color picture was assembled from several exposures taken July 3, 1995 by the Wide Field Planetary Camera-2. CREDIT: Erich Karkoschka (University of Arizona Lunar and Planetary Lab) and NASA

Discovery of Associated Absorption Lines in an X-Ray Warm Absorber: Hubble Space Telescope Faint Object Spectrograph Observations of MR 2251-178

NASA Technical Reports Server (NTRS)

Monier, Eric M.; Mathur, Smita; Wilkes, Belinda; Elvis, Martin

2001-01-01

The presence of a 'warm absorber' was first suggested to explain spectral variability in an X-ray spectrum of the radio-quiet quasi-stellar object (QSO) MR 2251-178. A unified picture, in which X-ray warm absorbers and 'intrinsic' UV absorbers are the same, offers the opportunity to probe the nuclear environment of active galactic nuclei. To test this scenario and understand the physical properties of the absorber, we obtained a UV spectrum of MR 2251-178 with the Faint Object Spectrograph on board the Hubble Space Telescope (HST). The HST spectrum clearly shows absorption due to Lyalpha, N v, and C IV, blueshifted by 300 km s(exp -1) from the emission redshift of the QSO. The rarity of both X-ray and UV absorbers in radio-quiet QSOs suggests these absorbers are physically related, if not identical. Assuming the unified scenario, we place constraints on the physical parameters of the absorber and conclude the mass outflow rate is essentially the same as the accretion rate in MR 2251-178.

The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators

NASA Astrophysics Data System (ADS)

Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Bono, Giuseppe; Carlson, Erika K.; Clementini, Gisella; Durbin, Meredith J.; Garofalo, Alessia; Hatt, Dylan; Jang, In Sung; Kollmeier, Juna A.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark; Sturch, Laura; Yang, Soung-Chul

2016-12-01

We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This alternative distance ladder can be applied to galaxies of any Hubble type, of any inclination, and, using old stars in low-density environments, is robust to the degenerate effects of metallicity and interstellar extinction. Given the relatively small number of SNe Ia host galaxies with independently measured distances, these properties provide a great systematic advantage in the measurement of H 0 via the distance ladder. Initially, the accuracy of our value of H 0 will be set by the five Galactic RR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensor parallaxes. With Gaia, both the RR Lyrae zero-point and TRGB method will be independently calibrated, the former with at least an order of magnitude more calibrators and the latter directly through parallax measurement of tip red giants. As the first end-to-end “distance ladder” completely independent of both Cepheid variables and the Large Magellanic Cloud, this path to H 0 will allow for the high-precision comparison at each rung of the traditional distance ladder that is necessary to understand tensions between this and other routes to H 0. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #13472 and #13691.

Higgs field and cosmological parameters in the fractal quantum system

NASA Astrophysics Data System (ADS)

Abramov, Valeriy

2017-10-01

For the fractal model of the Universe the relations of cosmological parameters and the Higgs field are established. Estimates of the critical density, the expansion and speed-up parameters of the Universe (the Hubble constant and the cosmological redshift); temperature and anisotropy of the cosmic microwave background radiation were performed.

Selections from 2017: Hubble Survey Explores Distant Galaxies

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-12-01

Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.CANDELS Multi-Wavelength Catalogs: Source Identification and Photometry in the CANDELS COSMOSSurvey FieldPublished January2017Main takeaway:A publication led byHooshang Nayyeri(UC Irvine and UC Riverside) early this year details acatalog of sources built using the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey(CANDELS), a survey carried out by cameras on board the Hubble Space Telescope. The catalogliststhe properties of 38,000 distant galaxies visiblewithin the COSMOS field, a two-square-degree equatorial field explored in depthto answer cosmological questions.Why its interesting:Illustration showing the three-dimensional map of the dark matter distribution in theCOSMOS field. [Adapted from NASA/ESA/R. Massey(California Institute of Technology)]The depth and resolution of the CANDELS observations areuseful for addressingseveral major science goals, including the following:Studying the most distant objects in the universe at the epoch of reionization in the cosmic dawn.Understanding galaxy formation and evolution during the peak epoch of star formation in the cosmic high noon.Studying star formation from deep ultravioletobservations and studying cosmology from supernova observations.Why CANDELS is a major endeavor:CANDELS isthe largest multi-cycle treasury program ever approved on the Hubble Space Telescope using over 900 orbits between 2010 and 2013 withtwo cameras on board the spacecraftto study galaxy formation and evolution throughout cosmic time. The CANDELS images are all publicly available, and the new catalogrepresents an enormous source of information about distant objectsin our universe.CitationH. Nayyeri et al 2017 ApJS 228 7. doi:10.3847/1538-4365/228/1/7

Hubble Finds Planet Orbiting Pair of Stars

NASA Image and Video Library

2017-12-08

Two's company, but three might not always be a crowd — at least in space. Astronomers using NASA's Hubble Space Telescope, and a trick of nature, have confirmed the existence of a planet orbiting two stars in the system OGLE-2007-BLG-349, located 8,000 light-years away towards the center of our galaxy. The planet orbits roughly 300 million miles from the stellar duo, about the distance from the asteroid belt to our sun. It completes an orbit around both stars roughly every seven years. The two red dwarf stars are a mere 7 million miles apart, or 14 times the diameter of the moon's orbit around Earth. The Hubble observations represent the first time such a three-body system has been confirmed using the gravitational microlensing technique. Gravitational microlensing occurs when the gravity of a foreground star bends and amplifies the light of a background star that momentarily aligns with it. The particular character of the light magnification can reveal clues to the nature of the foreground star and any associated planets. The three objects were discovered in 2007 by an international collaboration of five different groups: Microlensing Observations in Astrophysics (MOA), the Optical Gravitational Lensing Experiment (OGLE), the Microlensing Follow-up Network (MicroFUN), the Probing Lensing Anomalies Network (PLANET), and the Robonet Collaboration. These ground-based observations uncovered a star and a planet, but a detailed analysis also revealed a third body that astronomers could not definitively identify. Image caption: This artist's illustration shows a gas giant planet circling a pair of red dwarf stars in the system OGLE-2007-BLG-349, located 8,000 light-years away. The Saturn-mass planet orbits roughly 300 million miles from the stellar duo. The two red dwarf stars are 7 million miles apart. Credit: NASA, ESA, and G. Bacon (STScI) Read more: go.nasa.gov/2dcfMns NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four

Star Formation in Distant Red Galaxies: Spitzer Observations in the Hubble Deep Field-South

NASA Astrophysics Data System (ADS)

Webb, Tracy M. A.; van Dokkum, Pieter; Egami, Eiichi; Fazio, Giovanni; Franx, Marijn; Gawiser, Eric; Herrera, David; Huang, Jiasheng; Labbé, Ivo; Lira, Paulina; Marchesini, Danilo; Maza, José; Quadri, Ryan; Rudnick, Gregory; van der Werf, Paul

2006-01-01

We present Spitzer 24 μm imaging of 1.5Hubble Deep Field-South of the Multiwavelength Survey by Yale-Chile. We detect 65% of the DRGs with KAB<23.2 mag at S24μm>~40 μJy and conclude that the bulk of the DRG population is dusty active galaxies. A mid-infrared (MIR) color analysis with IRAC data suggests that the MIR fluxes are not dominated by buried AGNs, and we interpret the high detection rate as evidence for a high average star formation rate of =130+/-30 Msolar yr-1. From this, we infer that DRGs are important contributors to the cosmic star formation rate density at z~2, at a level of ~0.02 Msolar yr-1 Mpc-3 to our completeness limit of KAB=22.9 mag.

Hubble Camera Resumes Science Operation With Picture Of 'Butterfly' In Space.

NASA Technical Reports Server (NTRS)

2002-01-01

nitrogen atoms. Scientists are still testing and calibrating the newly installed instruments on Hubble , the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and the Space Telescope Imaging Spectrograph (STIS). These instruments will be ready to make observations in a few weeks. Credit: Massimo Stiavelli (STScI), and NASA other team member: Inge Heyer (STScI) Image files in GIF and JPEG format and captions may be accessed on the Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1983-01-01

This is a photograph of a 1/15 scale model of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13- meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

Hubble Space Telescope Deployment-Artist's Concept

NASA Technical Reports Server (NTRS)

1980-01-01

This artist's concept depicts the Hubble Space Telescope after being released into orbit, with the high gain anternas and solar arrays deployed and the aperture doors opened. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13-meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

Hubble Space Telescope Deployment-Artist's Concept

NASA Technical Reports Server (NTRS)

1980-01-01

This artist's concept depicts the Hubble Space Telescope (HST) being positioned for release from the Space Shuttle orbiter by the Remote Manipulator System (RMS). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13- meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

Hubble Space Telescope Deployment-Artist's Concept

NASA Technical Reports Server (NTRS)

1980-01-01

This artist's concept depicts the Hubble Space Telescope (HST) being raised to a vertical position in the cargo bay of the Space Shuttle orbiter. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13-meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1980-01-01

This artist's concept depicts the Hubble Space Telescope (HST) being raised to a vertical position in the cargo bay of the Space Shuttle orbiter. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13-meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1980-01-01

This artist's concept depicts the Hubble Space Telescope (HST) being positioned for release from the Space Shuttle orbiter by the Remote Manipulator System (RMS). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13- meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1985-04-01

This image illustrates the overall Hubble Space Telescope (HST) configuration. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1980-01-01

This artist's concept depicts the Hubble Space Telescope after being released into orbit, with the high gain anternas and solar arrays deployed and the aperture doors opened. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13-meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

Hubble Space Telescope 2004 Battery Update

NASA Technical Reports Server (NTRS)

Hollandsworth, Roger; Armantrout, Jon; Rao, Gopalakrishna M.

2004-01-01

Battery cell wear out mechanisms and signatures are examined and compared to orbital data from the six on-orbit Hubble Space Telescope (HST) batteries, and the Flight Spare Battery (FSB) Test Bed at Marshall Space Fiight Center (MSFC), which is instrumented with individual cell voltage monitoring.

Analysis of Hubble Space Telescope Observations of an Outburst of Comet 29P/Schwassmann-Wachmann 1

NASA Astrophysics Data System (ADS)

Schambeau, Charles Alfred; Fernandez, Yanga R.; Samarasinha, Nalin H.; Kundu, Arunav

2016-10-01

We present results of a continuing analysis on the spin state of the enigmatic Comet 29P/Schwassmann-Wachmann 1 (SW1). Previous works have reported possible constraints on the spin state including a non-principal axis state [1] or a rotation period of tens of days [2]. This diversity of published answers highlights the complexity of determining the spin state of an active comet nucleus. Previous work by our group using 3D Monte Carlo coma modeling of ground-based outburst observations from 2008 [3] has placed constraints on the spin period for a set of assumed spin-pole orientations. Due to the nature of the 2008 outburst morphology no constraints on the spin-pole orientation could be found.We present here an analysis of Hubble Space Telescope WFPC2 observations of SW1 shortly after a 1996 outburst [4] with which we have further constrained the spin state. The 0.046-arcsec/pixel scale (176 km/pixel at SW1) of the PC detector gives an order-of-magnitude improvement in spatial resolution over our ground-based observations. Two sets of observations from UT 1996 Mar. 11.3 and 12.1 show the ejected dust forming an asymmetric outflow contained on the sunward side of the coma. A projected outflow velocity of 0.15 ± 0.02 km/s was measured, similar to our measured value from the 2008 observations. Enhancements of the images were performed [5] to bring out subtle variations in coma brightness (i.e., jets) and to allow us to search for signatures of the nucleus' rotation during the outburst. Three curved features are seen in both sets of observations and were modeled using the 3D Monte Carlo coma model [6]. We find a spin period on the order of several days, in agreement with our earlier 2008 analysis.[1] Meech, K. J., et al.: 1993, Astron. J., 106, 1222. [2] Miles, R., et al.: 2016, Icarus, 272, 327. [3] Schambeau, C. A., et al.: 2016, Icarus, submitted. [4] Feldman, P. D., et al.: 1996, AAS/DPS Meeting Abstracts, 28, 1084. [5] Samarasinha, N. and Larson, S.: 2014, Icarus

Hubble Team Unveils Most Colorful View of Universe Captured by Space Telescope

NASA Image and Video Library

2014-06-04

Astronomers using NASA's Hubble Space Telescope have assembled a comprehensive picture of the evolving universe – among the most colorful deep space images ever captured by the 24-year-old telescope. Researchers say the image, in new study called the Ultraviolet Coverage of the Hubble Ultra Deep Field, provides the missing link in star formation. The Hubble Ultra Deep Field 2014 image is a composite of separate exposures taken in 2003 to 2012 with Hubble's Advanced Camera for Surveys and Wide Field Camera 3. Credit: NASA/ESA Read more: 1.usa.gov/1neD0se NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

A Hubble Cosmic Couple

NASA Image and Video Library

2017-12-08

Here we see the spectacular cosmic pairing of the star Hen 2-427 — more commonly known as WR 124 — and the nebula M1-67 which surrounds it. Both objects, captured here by the NASA/ESA Hubble Space Telescope are found in the constellation of Sagittarius and lie 15,000 light-years away. The star Hen 2-427 shines brightly at the very center of this explosive image and around the hot clumps of surrounding gas that are being ejected into space at over 93,210 miles (150,000 km) per hour. Hen 2-427 is a Wolf–Rayet star, named after the astronomers Charles Wolf and Georges Rayet. Wolf–Rayet are super-hot stars characterized by a fierce ejection of mass. The nebula M1-67 is estimated to be no more than 10,000 years old — just a baby in astronomical terms — but what a beautiful and magnificent sight it makes. Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Reveals Stellar Fireworks in ‘Skyrocket’ Galaxy

NASA Image and Video Library

2017-12-08

Fireworks shows are not just confined to Earth’s skies. NASA’s Hubble Space Telescope has captured a spectacular fireworks display in a small, nearby galaxy, which resembles a July 4th skyrocket. A firestorm of star birth is lighting up one end of the diminutive galaxy Kiso 5639. The dwarf galaxy is shaped like a flattened pancake, but because it is tilted edge-on, it resembles a skyrocket, with a brilliant blazing head and a long, star-studded tail. Kiso 5639 is a rare, nearby example of elongated galaxies that occur in abundance at larger distances, where we observe the universe during earlier epochs. Astronomers suggest that the frenzied star birth is sparked by intergalactic gas raining on one end of the galaxy as it drifts through space. “I think Kiso 5639 is a beautiful, up-close example of what must have been common long ago,” said lead researcher Debra Elmegreen of Vassar College, in Poughkeepsie, New York. “The current thinking is that galaxies in the early universe grow from accreting gas from the surrounding neighborhood. It’s a stage that galaxies, including our Milky Way, must go through as they are growing up.” Observations of the early universe, such as Hubble’s Ultra-Deep Field, reveal that about 10 percent of all galaxies have these elongated shapes, and are collectively called “tadpoles.” But studies of the nearby universe have turned up only a few of these unusual galaxies, including Kiso 5639. The development of the nearby star-making tadpole galaxies, however, has lagged behind that of their peers, which have spent billions of years building themselves up into many of the spiral galaxies seen today. Elmegreen used Hubble’s Wide Field Camera 3 to conduct a detailed imaging study of Kiso 5639. The images in different filters reveal information about an object by dissecting its light into its component colors. Hubble’s crisp resolution helped Elmegreen and her team analyze the giant star-forming clumps in Kiso 5639 and

Hubble Space Telescope: High speed photometer instrument handbook. Version 2.0

NASA Technical Reports Server (NTRS)

White, Richard L. (Editor)

1990-01-01

This manual is a guide for astronomers who intend to use the High Speed Photometer (HSP), one of the scientific instruments onboard the Hubble Space Telescope (HST). All the information needed for ordinary uses of the HSP is presented, including: (1) an overview of the instrument; (2) a detailed description of some details of the HSP-ST system that may be important for some observations; (3) tables and figures describing the sensitivity and limitations of the HSP; (4) how to go about planning an observation with the HSP; and (5) a description of the standard calibration to be applied to HSP data and the resulting data products.

An updated Type II supernova Hubble diagram

NASA Astrophysics Data System (ADS)

Gall, E. E. E.; Kotak, R.; Leibundgut, B.; Taubenberger, S.; Hillebrandt, W.; Kromer, M.; Burgett, W. S.; Chambers, K.; Flewelling, H.; Huber, M. E.; Kaiser, N.; Kudritzki, R. P.; Magnier, E. A.; Metcalfe, N.; Smith, K.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.

2018-03-01

We present photometry and spectroscopy of nine Type II-P/L supernovae (SNe) with redshifts in the 0.045 ≲ z ≲ 0.335 range, with a view to re-examining their utility as distance indicators. Specifically, we apply the expanding photosphere method (EPM) and the standardized candle method (SCM) to each target, and find that both methods yield distances that are in reasonable agreement with each other. The current record-holder for the highest-redshift spectroscopically confirmed supernova (SN) II-P is PS1-13bni (z = 0.335-0.012+0.009), and illustrates the promise of Type II SNe as cosmological tools. We updated existing EPM and SCM Hubble diagrams by adding our sample to those previously published. Within the context of Type II SN distance measuring techniques, we investigated two related questions. First, we explored the possibility of utilising spectral lines other than the traditionally used Fe IIλ5169 to infer the photospheric velocity of SN ejecta. Using local well-observed objects, we derive an epoch-dependent relation between the strong Balmer line and Fe IIλ5169 velocities that is applicable 30 to 40 days post-explosion. Motivated in part by the continuum of key observables such as rise time and decline rates exhibited from II-P to II-L SNe, we assessed the possibility of using Hubble-flow Type II-L SNe as distance indicators. These yield similar distances as the Type II-P SNe. Although these initial results are encouraging, a significantly larger sample of SNe II-L would be required to draw definitive conclusions. Tables A.1, A.3, A.5, A.7, A.9, A.11, A.13, A.15 and A.17 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A25

Hubble Peers into the Storm

NASA Image and Video Library

2017-12-08

This shot from the NASA/ESA Hubble Space Telescope shows a maelstrom of glowing gas and dark dust within one of the Milky Way’s satellite galaxies, the Large Magellanic Cloud (LMC). This stormy scene shows a stellar nursery known as N159, an HII region over 150 light-years across. N159 contains many hot young stars. These stars are emitting intense ultraviolet light, which causes nearby hydrogen gas to glow, and torrential stellar winds, which are carving out ridges, arcs, and filaments from the surrounding material. At the heart of this cosmic cloud lies the Papillon Nebula, a butterfly-shaped region of nebulosity. This small, dense object is classified as a High-Excitation Blob, and is thought to be tightly linked to the early stages of massive star formation. N159 is located over 160,000 light-years away. It resides just south of the Tarantula Nebula (heic1402), another massive star-forming complex within the LMC. This image comes from Hubble’s Advanced Camera for Surveys. The region was previously imaged by Hubble’s Wide Field Planetary Camera 2, which also resolved the Papillon Nebula for the first time. Credit: ESA/Hubble & NASA

Hubble Captures Bubbles And Baby Stars

NASA Image and Video Library

2017-12-08

Image release June 22, 2010 A spectacular new NASA/ESA Hubble Space Telescope image — one of the largest ever released of a star-forming region — highlights N11, part of a complex network of gas clouds and star clusters within our neighbouring galaxy, the Large Magellanic Cloud. This region of energetic star formation is one of the most active in the nearby Universe. The Large Magellanic Cloud contains many bright bubbles of glowing gas. One of the largest and most spectacular has the name LHA 120-N 11, from its listing in a catalogue compiled by the American astronomer and astronaut Karl Henize in 1956, and is informally known as N11. Close up, the billowing pink clouds of glowing gas make N11 resemble a puffy swirl of fairground candy floss. From further away, its distinctive overall shape led some observers to nickname it the Bean Nebula. The dramatic and colourful features visible in the nebula are the telltale signs of star formation. N11 is a well-studied region that extends over 1000 light-years. It is the second largest star-forming region within the Large Magellanic Cloud and has produced some of the most massive stars known. It is the process of star formation that gives N11 its distinctive look. Three successive generations of stars, each of which formed further away from the centre of the nebula than the last, have created shells of gas and dust. These shells were blown away from the newborn stars in the turmoil of their energetic birth and early life, creating the ring shapes so prominent in this image. Beans are not the only terrestrial shapes to be found in this spectacular high resolution image from the NASA/ESA Hubble Space Telescope. In the upper left is the red bloom of nebula LHA 120-N 11A. Its rose-like petals of gas and dust are illuminated from within, thanks to the radiation from the massive hot stars at its centre. N11A is relatively compact and dense and is the site of the most recent burst of star development in the region. Other star

Imaging the nuclear environment of NGC 1365 with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Kristen, Helmuth; Jorsater, Steven; Lindblad, Per Olof; Boksenberg, Alec

1997-12-01

The region surrounding the active nucleus of the barred spiral galaxy NGC 1365 is observed in the [Oiii] lambda 5007 line and neighbouring continuum using the Faint Object Camera (FOC) aboard the Hubble Space Telescope (HST). In the continuum light numerous bright ``super star clusters'' (SSCs) are seen in the nuclear region. They tend to fall on an elongated ring around the nucleus and contribute about 20 % of the total continuum flux in this wavelength regime. Without applying any extinction correction the brightest SSCs have an absolute luminosity M_B=-14fm1 +/- 0fm3 and are very compact with radii R la 3 pc. Complementary ground-based spectroscopy gives an extinction estimate A_B = 2fm5 +/- 0fm5 towards these regions, indicating a true luminosity M_B = -16fm6 +/- 0fm6 . The bright compact radio source NGC 1365:A is found to coincide spatially with one of the SSCs. We conclude that it is a ``radio supernova''. The HST observations resolve the inner structure of the conical outflow previously seen in the [Oiii] lambda 5007 line in ground-based observations, and reveal a complicated structure of individual emission-line clouds, some of which gather in larger agglomerations. The total luminosity in the [Oiii] line amounts to L_[OIII] =~ 3.7x 10(40) erg s(-1) where about 40 % is emitted by the clouds. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555, and observations at the European Southern Observatory (ESO), La Silla, Chile.

The Hubble Space Telescope UV Legacy Survey of Galactic globular clusters - XIII. ACS/WFC parallel-field catalogues

NASA Astrophysics Data System (ADS)

Simioni, M.; Bedin, L. R.; Aparicio, A.; Piotto, G.; Milone, A. P.; Nardiello, D.; Anderson, J.; Bellini, A.; Brown, T. M.; Cassisi, S.; Cunial, A.; Granata, V.; Ortolani, S.; van der Marel, R. P.; Vesperini, E.

2018-05-01

As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters, 110 parallel fields were observed with the Wide Field Channel of the Advanced Camera for Surveys, in the outskirts of 48 globular clusters, plus the open cluster NGC 6791. Totalling about 0.3 deg2 of observed sky, this is the largest homogeneous Hubble Space Telescope photometric survey of Galalctic globular clusters outskirts to date. In particular, two distinct pointings have been obtained for each target on average, all centred at about 6.5 arcmin from the cluster centre, thus covering a mean area of about 23 arcmin2 for each globular cluster. For each field, at least one exposure in both F475W and F814W filters was collected. In this work, we publicly release the astrometric and photometric catalogues and the astrometrized atlases for each of these fields.

Hubble Paints a Spattering of Blue

NASA Image and Video Library

2014-09-12

Far beyond the stars in the constellation of Leo (The Lion) is irregular galaxy IC 559. IC 559 is not your everyday galaxy. With its irregular shape and bright blue spattering of stars, it is a fascinating galactic anomaly. It may look like sparse cloud, but it is in fact full of gas and dust which is spawning new stars. Discovered in 1893, IC 559 lacks the symmetrical spiral appearance of some of its galactic peers and not does not conform to a regular shape. It is actually classified as a “type Sm” galaxy — an irregular galaxy with some evidence for a spiral structure. Irregular galaxies make up about a quarter of all known galaxies and do not fall into any of the regular classes of the Hubble sequence. Most of these uniquely shaped galaxies were not always so — IC 559 may have once been a conventional spiral galaxy that was then distorted and twisted by the gravity of a nearby cosmic companion. This image, captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3, combines a wide range of wavelengths spanning the ultraviolet, optical, and infrared parts of the spectrum. Image credit: ESA/Hubble, NASA, D. Calzetti (UMass) and the LEGUS Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

A Scientific Revolution: The Hubble and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2011-01-01

Astronomy is going through a scientific revolution, responding to a Rood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, Dr. Gardner will discuss some of the most important astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope.

HUBBLE SPACE TELESCOPE/ADVANCED CAMERA FOR SURVEYS OBSERVATIONS OF EUROPA'S ATMOSPHERIC ULTRAVIOLET EMISSION AT EASTERN ELONGATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saur, Joachim; Roth, Lorenz; Schilling, Nico

2011-09-10

We report results of a Hubble Space Telescope (HST) campaign with the Advanced Camera for Surveys to observe Europa at eastern elongation, i.e., Europa's leading side, on 2008 June 29. With five consecutive HST orbits, we constrain Europa's atmospheric O I 1304 A and O I 1356 A emissions using the prism PR130L. The total emissions of both oxygen multiplets range between 132 {+-} 14 and 226 {+-} 14 Rayleigh. An additional systematic error with values on the same order as the statistical errors may be due to uncertainties in modeling the reflected light from Europa's surface. The total emissionmore » also shows a clear dependence of Europa's position with respect to Jupiter's magnetospheric plasma sheet. We derive a lower limit for the O{sub 2} column density of 6 x 10{sup 18} m{sup -2}. Previous observations of Europa's atmosphere with the Space Telescope Imaging Spectrograph in 1999 of Europa's trailing side show an enigmatic surplus of radiation on the anti-Jovian side within the disk of Europa. With emission from a radially symmetric atmosphere as a reference, we searched for an anti-Jovian versus sub-Jovian asymmetry with respect to the central meridian on the leading side and found none. Likewise, we searched for departures from a radially symmetric atmospheric emission and found an emission surplus centered around 90 deg. west longitude, for which plausible mechanisms exist. Previous work about the possibility of plumes on Europa due to tidally driven shear heating found longitudes with strongest local strain rates which might be consistent with the longitudes of maximum UV emissions. Alternatively, asymmetries in Europa's UV emission can also be caused by inhomogeneous surface properties, an optically thick atmospheric contribution of atomic oxygen, and/or by Europa's complex plasma interaction with Jupiter's magnetosphere.« less

IUE and ground-based observations of the Hubble-Sandage variables in M31 and M33

NASA Technical Reports Server (NTRS)

Blaha, C.; Dodorico, S.; Gull, T. R.; Benvenuti, P.; Humphreys, R. M.

1984-01-01

Ultraviolet spectra were obtained from the International Ultraviolet Explorer for the brightest Hubble-Sandage (H-S) variables in M31 and M33. The ultraviolet fluxes were then used in combination with ground-based visual and infrared photometry to determine the energy distributions, luminosities, and temperatures of these stars. When corrected for interstellar extinction, the integrated energy distributions yield the total luminosities and blackbody temperatures of the H-S variables. The resulting bolometric magnitudes and temperatures confirm that these peculiar stars are indeed very luminous, hot stars. They occupy the same regions of the bolometric magnitude vs temperature diagram as Eta Car and P Cyg in the Galaxy and S Dor in the LMC.

A Modified Rodrigues Parameter-based Nonlinear Observer Design for Spacecraft Gyroscope Parameters Estimation

NASA Astrophysics Data System (ADS)

Yong, Kilyuk; Jo, Sujang; Bang, Hyochoong

This paper presents a modified Rodrigues parameter (MRP)-based nonlinear observer design to estimate bias, scale factor and misalignment of gyroscope measurements. A Lyapunov stability analysis is carried out for the nonlinear observer. Simulation is performed and results are presented illustrating the performance of the proposed nonlinear observer under the condition of persistent excitation maneuver. In addition, a comparison between the nonlinear observer and alignment Kalman filter (AKF) is made to highlight favorable features of the nonlinear observer.

Hubble's View of the Polar Ring of Arp 230

NASA Image and Video Library

2015-01-30

This Picture of the Week shows Arp 230, also known as IC 51, observed by the NASA/ESA Hubble Space Telescope. Arp 230 is a galaxy of an uncommon or peculiar shape, and is therefore part of the Atlas of Peculiar Galaxies produced by Halton Arp. Its irregular shape is thought to be the result of a violent collision with another galaxy sometime in the past. The collision could also be held responsible for the formation of the galaxy’s polar ring. The outer ring surrounding the galaxy consists of gas and stars and rotates over the poles of the galaxy. It is thought that the orbit of the smaller of the two galaxies that created Arp 230 was perpendicular to the disk of the second, larger galaxy when they collided. In the process of merging the smaller galaxy would have been ripped apart and may have formed the polar ring structure astronomers can observe today. Arp 230 is quite small for a lenticular galaxy, so the two original galaxies forming it must both have been smaller than the Milky Way. A lenticular galaxy is a galaxy with a prominent central bulge and a disk, but no clear spiral arms. They are classified as intermediate between an elliptical galaxy and a spiral galaxy. Credit: ESA/Hubble & NASA, Acknowledgement: Flickr user Det58 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

European astronomers' successes with the Hubble Space Telescope*

NASA Astrophysics Data System (ADS)

1997-02-01

[Figure: Laguna Nebula] Their work spans all aspects of astronomy, from the planets to the most distant galaxies and quasars, and the following examples are just a few European highlights from Hubble's second phase, 1994-96. A scarcity of midget stars Stars less massive and fainter than the Sun are much numerous in the Milky Way Galaxy than the big bright stars that catch the eye. Guido De Marchi and Francesco Paresce of the European Southern Observatory as Garching, Germany, have counted them. With the wide-field WFPC2 camera, they have taken sample censuses within six globular clusters, which are large gatherings of stars orbiting independently in the Galaxy. In every case they find that the commonest stars have an output of light that is only one-hundredth of the Sun's. They are ten times more numerous than stars like the Sun. More significant for theories of the Universe is a scarcity of very faint stars. Some astronomers have suggested that vast numbers of such stars could account for the mysterious dark matter, which makes stars and galaxies move about more rapidly than expected from the mass of visible matter. But that would require an ever-growing count of objects at low brightnesses, and De Marchi and Paresce find the opposite to be the case -- the numbers diminish. There may be a minimum size below which Nature finds starmaking difficult. The few examples of very small stars seen so far by astronomers may be, not the heralds of a multitude of dark-matter stars, but rareties. Unchanging habits in starmaking Confirmation that very small stars are scarce comes from Gerry Gilmore of the Institute of Astronomy in Cambridge (UK). He leads a European team that analyses long-exposure images in the WFPC2 camera, obtained as a by-product when another instrument is examining a selected object. The result is an almost random sample of well-observed stars and galaxies. The most remarkable general conclusion is that the make-up of stellar populations never seems to

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

NASA Associate Administrator of the Science Mission Directorate Dr. Edward J. Weiler speaks at the podium as Sen. Barbara A. Mikulski, D-Md., left, listens during a press conference where NASA unveiled new images from NASA's Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility inspect the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on its handling fixture. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-18

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility inspect the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on its handling fixture. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-18

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS is HST's first cryogenic instrument -- its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 derees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-16

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS is HST's first cryogenic instrument -- its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 derees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

Hubble Spotlights a Celestial Sidekick

NASA Image and Video Library

2017-12-08

This image was captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), a highly efficient wide-field camera covering the optical and near-infrared parts of the spectrum. While this lovely image contains hundreds of distant stars and galaxies, one vital thing is missing — the object Hubble was actually studying at the time! This is not because the target has disappeared. The ACS actually uses two detectors: the first captures the object being studied — in this case an open star cluster known as NGC 299 — while the other detector images the patch of space just ‘beneath’ it. This is what can be seen here. Technically, this picture is merely a sidekick of the actual object of interest — but space is bursting with activity, and this field of bright celestial bodies offers plenty of interest on its own. It may initially seem to show just stars, but a closer look reveals many of these tiny objects to be galaxies. The spiral galaxies have arms curving out from a bright center. The fuzzier, less clearly shaped galaxies might be ellipticals. Some of these galaxies contain millions or even billions of stars, but are so distant that all of their starry residents are contained within just a small pinprick of light that appears to be the same size as a single star! The bright blue dots are very hot stars, sometimes distorted into crosses by the struts supporting Hubble’s secondary mirror. The redder dots are cooler stars, possibly in the red giant phase when a dying star cools and expands. Credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's Hubble Sees Asteroid Spout Six Comet-like Tails

NASA Image and Video Library

2013-11-13

This NASA Hubble Space Telescope set of images reveals a never-before-seen set of six comet-like tails radiating from a body in the asteroid belt, designated P/2013 P5. The asteroid was discovered as an unusually fuzzy-looking object with the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) survey telescope in Hawaii. The multiple tails were discovered in Hubble images taken on Sept. 10, 2013. When Hubble returned to the asteroid on Sept. 23, the asteroid's appearance had totally changed. It looked as if the entire structure had swung around. One interpretation is that the asteroid's rotation rate has been increased to the point where dust is falling off the surface and escaping into space where the pressure of sunlight sweeps out fingerlike tails. According to this theory, the asteroid's spin has been accelerated by the gentle push of sunlight. The object, estimated to be no more than 1,400 feet across, has ejected dust for at least five months, based on analysis of the tail structure. These visible-light, false-color images were taken with Hubble's Wide Field Camera 3. Object Name: P/2013 P5 Image Type: Astronomical/Annotated Credit: NASA, ESA, and D. Jewitt (UCLA) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Frontier Fields view of MACSJ0717.5+3745

NASA Image and Video Library

2015-10-22

This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACSJ0717.5+3745. This is one of six being studied by the Hubble Frontier Fields programme, which together have produced the deepest images of gravitational lensing ever made. Due to the huge mass of the cluster it is bending the light of background objects, acting as a magnifying lens. It is one of the most massive galaxy clusters known, and it is also the largest known gravitational lens. Of all of the galaxy clusters known and measured, MACS J0717 lenses the largest area of the sky.

Hubble Space Telescope approaches Shuttle Endeavour

NASA Image and Video Library

1993-12-04

STS061-93-031 (4 Dec 1993) --- Part of the vast Indian Ocean forms the backdrop for this scene of the Hubble Space Telescope (HST) as it approaches the Space Shuttle Endeavour. Denham Sound and Shark Bay, on Australia's west coast, are just below the waiting mechanical arm at lower right corner.

NASA’s Hubble Telescope Finds Potential Kuiper Belt Targets for New Horizons Pluto Mission

NASA Image and Video Library

2017-12-08

This is an artist’s impression of a Kuiper Belt object (KBO), located on the outer rim of our solar system at a staggering distance of 4 billion miles from the Sun. A HST survey uncovered three KBOs that are potentially reachable by NASA’s New Horizons spacecraft after it passes by Pluto in mid-2015. Credit: NASA, ESA, and G. Bacon (STScI) --- Peering out to the dim, outer reaches of our solar system, NASA’s Hubble Space Telescope has uncovered three Kuiper Belt objects (KBOs) the agency’s New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015. The KBOs were detected through a dedicated Hubble observing program by a New Horizons search team that was awarded telescope time for this purpose. “This has been a very challenging search and it’s great that in the end Hubble could accomplish a detection – one NASA mission helping another,” said Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado, principal investigator of the New Horizons mission. The Kuiper Belt is a vast rim of primordial debris encircling our solar system. KBOs belong to a unique class of solar system objects that has never been visited by spacecraft and which contain clues to the origin of our solar system. The KBOs Hubble found are each about 10 times larger than typical comets, but only about 1-2 percent of the size of Pluto. Unlike asteroids, KBOs have not been heated by the sun and are thought to represent a pristine, well preserved deep-freeze sample of what the outer solar system was like following its birth 4.6 billion years ago. The KBOs found in the Hubble data are thought to be the building blocks of dwarf planets such as Pluto. Read more: 1.usa.gov/1vzUcyK NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling

NASA’s Hubble Sees Martian Moon Orbiting the Red Planet

NASA Image and Video Library

2017-12-08

While photographing Mars, NASA’s Hubble Space Telescope captured a cameo appearance of the tiny moon Phobos on its trek around the Red Planet. Discovered in 1877, the diminutive, potato-shaped moon is so small that it appears star-like in the Hubble pictures. Phobos orbits Mars in just 7 hours and 39 minutes, which is faster than Mars rotates. The moon’s orbit is very slowly shrinking, meaning it will eventually shatter under Mars’ gravitational pull, or crash onto the planet. Hubble took 13 separate exposures over 22 minutes to create a time-lapse video showing the moon’s orbital path. Credit: NASA, ESA, and Z. Levay (STScI) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Space Telescope STIS Observations of the Wolf-Rayet Star HD 5980 in the Small Magellanic Cloud. II. The Interstellar Medium Components

NASA Astrophysics Data System (ADS)

Koenigsberger, Gloria; Georgiev, Leonid; Peimbert, Manuel; Walborn, Nolan R.; Barbá, Rodolfo; Niemela, Virpi S.; Morrell, Nidia; Tsvetanov, Zlatan; Schulte-Ladbeck, Regina

2001-01-01

Observations of the interstellar and circumstellar absorption components obtained with the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) along the line of sight toward the Wolf-Rayet-luminous blue variable (LBV) system HD 5980 in the Small Magellanic Cloud are analyzed. Velocity components from C I, C I*, C II, C II*, C IV, N I, N V, O I, Mg II, Al II, Si II, Si II*, Si III, Si IV, S II, S III, Fe II, Ni II, Be I, Cl I, and CO are identified, and column densities estimated. The principal velocity systems in our data are (1) interstellar medium (ISM) components in the Galactic disk and halo (Vhel=1.1+/-3, 9+/-2 km s-1) (2) ISM components in the SMC (Vhel=+87+/-6, +110+/-6, +132+/-6, +158+/-8, +203+/-15 km s-1) (3) SMC supernova remnant SNR 0057-7226 components (Vhel=+312+/-3, +343+/-3, +33, +64 km s-1) (4) circumstellar (CS) velocity systems (Vhel=-1020, -840, -630, -530, -300 km s-1) and (5) a possible system at -53+/-5 km s-1 (seen only in some of the Si II lines and marginally in Fe II) of uncertain origin. The supernova remnant SNR 0057-7226 has a systemic velocity of +188 km s-1, suggesting that its progenitor was a member of the NGC 346 cluster. Our data allow estimates to be made of Te~40,000 K, ne~100 cm-3, N(H)~(4-12)×1018 cm-2 and a total mass between 400 and 1000 Msolar for the supernova remnant (SNR) shell. We detect C I absorption lines primarily in the +132 and +158 km s-1 SMC velocity systems. As a result of the LBV-type eruptions in HD 5980, a fast-wind/slow-wind circumstellar interaction region has appeared, constituting the earliest formation stages of a windblown H II bubble surrounding this system. Variations over a timescale of 1 year in this circumstellar structure are detected. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

http://www.nasa.gov/image-feature/goddard/hubble-spots-the-layers-of-ngc-3923

NASA Image and Video Library

2015-05-15

The glowing object in this Hubble Space Telescope image is an elliptical galaxy called NGC 3923. It is located over 90 million light-years away in the constellation of Hydra. NGC 3923 is an example of a shell galaxy where the stars in its halo are arranged in layers. Finding concentric shells of stars enclosing a galaxy is quite common and is observed in many elliptical galaxies. In fact, every tenth elliptical galaxy exhibits this onion-like structure, which has never been observed in spiral galaxies. The shell-like structures are thought to develop as a consequence of galactic cannibalism, when a larger galaxy ingests a smaller companion. As the two centers approach, they initially oscillate about a common center, and this oscillation ripples outwards forming the shells of stars just as ripples on a pond spread when the surface is disturbed. NGC 3923 has over twenty shells, with only a few of the outer ones visible in this image, and its shells are much more subtle than those of other shell galaxies. The shells of this galaxy are also interestingly symmetrical, while other shell galaxies are more skewed. Credit: ESA/Hubble & NASA

Hubble Finds New Dark Spot on Neptune

NASA Image and Video Library

1998-08-02

In 1995, NASA Hubble Space Telescope discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet northern hemisphere was tilted away from Earth, the new feature appeared near the limb of the planet.

The very local Hubble flow: Computer simulations of dynamical history

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Karachentsev, I. D.; Valtonen, M. J.; Dolgachev, V. P.; Domozhilova, L. M.; Makarov, D. I.

2004-02-01

The phenomenon of the very local (≤3 Mpc) Hubble flow is studied on the basis of the data of recent precision observations. A set of computer simulations is performed to trace the trajectories of the flow galaxies back in time to the epoch of the formation of the Local Group. It is found that the ``initial conditions'' of the flow are drastically different from the linear velocity-distance relation. The simulations enable one also to recognize the major trends of the flow evolution and identify the dynamical role of universal antigravity produced by the cosmic vacuum.

Are Ultra-faint Galaxies at z = 6-8 Responsible for Cosmic Reionization? Combined Constraints from the Hubble Frontier Fields Clusters and Parallels

NASA Astrophysics Data System (ADS)

Atek, Hakim; Richard, Johan; Jauzac, Mathilde; Kneib, Jean-Paul; Natarajan, Priyamvada; Limousin, Marceau; Schaerer, Daniel; Jullo, Eric; Ebeling, Harald; Egami, Eiichi; Clement, Benjamin

2015-11-01

We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure the galaxy rest-frame ultraviolet luminosity function (UV LF) in the redshift range z ˜ 6-8. We combine observations in three lensing clusters, A2744, MACS 0416, and MACS 0717, and their associated parallel fields to select high-redshift dropout candidates. We use the latest lensing models to estimate the flux magnification and the effective survey volume in combination with completeness simulations performed in the source plane. We report the detection of 227 galaxy candidates at z = 6-7 and 25 candidates at z ˜ 8. While the total survey area is about 4 arcmin2 in each parallel field, it drops to about 0.6-1 arcmin2 in the cluster core fields because of the strong lensing. We compute the UV LF at z ˜ 7 using the combined galaxy sample and perform Monte Carlo simulations to determine the best-fit Schechter parameters. We are able to reliably constrain the LF down to an absolute magnitude of MUV = -15.25, which corresponds to 0.005 L⋆. More importantly, we find that the faint-end slope remains steep down to this magnitude limit with α =-{2.04}-0.17+0.13. We find a characteristic magnitude of {M}\\star =-{20.89}-0.72+0.60 and log(ϕ⋆) = -{3.54}-0.45+0.48. Our results confirm the most recent results in deep blank fields but extend the LF measurements more than two magnitudes deeper. The UV LF at z ˜ 8 is not very well constrained below MUV = -18 owing to the small number statistics and incompleteness uncertainties. To assess the contribution of galaxies to cosmic reionization, we derive the UV luminosity density at z ˜ 7 by integrating the UV LF down to an observational limit of MUV = -15. We show that our determination of log(ρUV) = 26.2 ± 0.13 (erg s-1 Hz-1 Mpc-3) can be sufficient to maintain reionization with an escape fraction of ionizing radiation of fesc = 10%-15%. Future Hubble Frontier Fields observations will certainly improve the constraints on the UV LF at

Hubble's makes a double galaxy gaze

NASA Image and Video Library

2017-12-08

Some astronomical objects have endearing or quirky nicknames, inspired by mythology or their own appearance. Take, for example, the constellation of Orion (The Hunter), the Sombrero Galaxy, the Horsehead Nebula, or even the Milky Way. However, the vast majority of cosmic objects appear in astronomical catalogs and are given rather less poetic names based on the order of their discovery. Two galaxies are clearly visible in this Hubble image, the larger of which is NGC 4424. This galaxy is cataloged in the New General Catalog of Nebulae and Clusters of Stars (NGC), which was compiled in 1888. The NGC is one of the largest astronomical catalogs, which is why so many Hubble Pictures of the Week feature NGC objects. In total there are 7,840 entries in the catalog and they are also generally the larger, brighter, and more eye-catching objects in the night sky, and hence the ones more easily spotted by early stargazers. The smaller, flatter, bright galaxy sitting just below NGC 4424 is named LEDA 213994. The Lyon-Meudon Extragalactic Database (LEDA) is far more modern than the NGC and contains millions of objects. Many NGC objects still go by their initial names simply because they were christened within the NGC first. However, since astronomers can't resist a good acronym and “Leda” is more appealing than “the LMED,” the smaller galaxy is called "Leda." Leda was a princess in Ancient Greek mythology. Image credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Nabs Space Invaders?

NASA Image and Video Library

2017-12-08

The gravitational field surrounding this massive cluster of galaxies, Abell 68, acts as a natural lens in space to brighten and magnify the light coming from very distant background galaxies. Like a fun house mirror, lensing creates a fantasy landscape of arc-like images and mirror images of background galaxies. The foreground cluster is 2 billion light-years away, and the lensed images come from galaxies far behind it. In this photo, the image of a spiral galaxy at upper left has been stretched and mirrored into a shape similar to that of a simulated alien from the classic 1970s computer game "Space Invaders!" A second, less distorted image of the same galaxy appears to the left of the large, bright elliptical galaxy. In the upper right of the photo is another striking feature of the image that is unrelated to gravitational lensing. What appears to be purple liquid dripping from a galaxy is a phenomenon called ram-pressure stripping. The gas clouds within the galaxy are being stripped out and heated up as the galaxy passes through a region of denser intergalactic gas. This image was taken in infrared light by Hubble’s Wide Field Camera 3, and combined with near-infrared observations from Hubble’s Advanced Camera for Surveys. The image is based in part on data spotted by Nick Rose in the Hubble’s Hidden Treasures image processing competition. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington. Credit: NASA and ESA Acknowledgement: N. Rose For image files and more information about Abell 68, visit: hubblesite.org/news/2013/09 www.spacetelescope.org/news/heic04 heritage.stsci.edu/2013/09 www

Hubble Nabs Space Invaders?

NASA Image and Video Library

2017-12-08

The gravitational field surrounding this massive cluster of galaxies, Abell 68, acts as a natural lens in space to brighten and magnify the light coming from very distant background galaxies. Like a fun house mirror, lensing creates a fantasy landscape of arc-like images and mirror images of background galaxies. The foreground cluster is 2 billion light-years away, and the lensed images come from galaxies far behind it. In this photo, the image of a spiral galaxy at upper left has been stretched and mirrored into a shape similar to that of a simulated alien from the classic 1970s computer game "Space Invaders!" A second, less distorted image of the same galaxy appears to the left of the large, bright elliptical galaxy. In the upper right of the photo is another striking feature of the image that is unrelated to gravitational lensing. What appears to be purple liquid dripping from a galaxy is a phenomenon called ram-pressure stripping. The gas clouds within the galaxy are being stripped out and heated up as the galaxy passes through a region of denser intergalactic gas. This image was taken in infrared light by Hubble’s Wide Field Camera 3, and combined with near-infrared observations from Hubble’s Advanced Camera for Surveys. The image is based in part on data spotted by Nick Rose in the Hubble’s Hidden Treasures image processing competition. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington. To read more go to: 1.usa.gov/Z6uDUp Credit: NASA and ESA Acknowledgement: N. Rose For image files and more information about Abell 68, visit: hubblesite.org/news/2013/09 www.spacetelescope.org/news/heic04 heritage.stsci.edu/2013/09 www

Important observations and parameters for a salt water intrusion model

USGS Publications Warehouse

Shoemaker, W.B.

2004-01-01

Sensitivity analysis with a density-dependent ground water flow simulator can provide insight and understanding of salt water intrusion calibration problems far beyond what is possible through intuitive analysis alone. Five simple experimental simulations presented here demonstrate this point. Results show that dispersivity is a very important parameter for reproducing a steady-state distribution of hydraulic head, salinity, and flow in the transition zone between fresh water and salt water in a coastal aquifer system. When estimating dispersivity, the following conclusions can be drawn about the data types and locations considered. (1) The "toe" of the transition zone is the most effective location for hydraulic head and salinity observations. (2) Areas near the coastline where submarine ground water discharge occurs are the most effective locations for flow observations. (3) Salinity observations are more effective than hydraulic head observations. (4) The importance of flow observations aligned perpendicular to the shoreline varies dramatically depending on distance seaward from the shoreline. Extreme parameter correlation can prohibit unique estimation of permeability parameters such as hydraulic conductivity and flow parameters such as recharge in a density-dependent ground water flow model when using hydraulic head and salinity observations. Adding flow observations perpendicular to the shoreline in areas where ground water is exchanged with the ocean body can reduce the correlation, potentially resulting in unique estimates of these parameter values. Results are expected to be directly applicable to many complex situations, and have implications for model development whether or not formal optimization methods are used in model calibration.

Important observations and parameters for a salt water intrusion model.

PubMed

Shoemaker, W Barclay

2004-01-01

Sensitivity analysis with a density-dependent ground water flow simulator can provide insight and understanding of salt water intrusion calibration problems far beyond what is possible through intuitive analysis alone. Five simple experimental simulations presented here demonstrate this point. Results show that dispersivity is a very important parameter for reproducing a steady-state distribution of hydraulic head, salinity, and flow in the transition zone between fresh water and salt water in a coastal aquifer system. When estimating dispersivity, the following conclusions can be drawn about the data types and locations considered. (1) The "toe" of the transition zone is the most effective location for hydraulic head and salinity observations. (2) Areas near the coastline where submarine ground water discharge occurs are the most effective locations for flow observations. (3) Salinity observations are more effective than hydraulic head observations. (4) The importance of flow observations aligned perpendicular to the shoreline varies dramatically depending on distance seaward from the shoreline. Extreme parameter correlation can prohibit unique estimation of permeability parameters such as hydraulic conductivity and flow parameters such as recharge in a density-dependent ground water flow model when using hydraulic head and salinity observations. Adding flow observations perpendicular to the shoreline in areas where ground water is exchanged with the ocean body can reduce the correlation, potentially resulting in unique estimates of these parameter values. Results are expected to be directly applicable to many complex situations, and have implications for model development whether or not formal optimization methods are used in model calibration.

The Hubble Constant from SN Refsdal

NASA Astrophysics Data System (ADS)

Vega-Ferrero, J.; Diego, J. M.; Miranda, V.; Bernstein, G. M.

2018-02-01

Hubble Space Telescope observations from 2015 December 11 detected the expected fifth counter-image of supernova (SN) Refsdal at z = 1.49. In this Letter, we compare the time-delay predictions from numerous models with the measured value derived by Kelly et al. from very early data in the light curve of the SN Refsdal and find a best value for {H}0={64}-11+9 {km} {{{s}}}-1 {{Mpc}}-1 (68% CL), in excellent agreement with predictions from cosmic microwave background and recent weak lensing data + baryon acoustic oscillations + Big Bang nucleosynthesis (from the DES Collaboration). This is the first constraint on H 0 derived from time delays between multiple-lensed SN images, and the first with a galaxy cluster lens, subject to systematic effects different from other time-delay H 0 estimates. Additional time-delay measurements from new multiply imaged SNe will allow derivation of competitive constraints on H 0.

NASA's Hubble Sees Asteroid Spout Six Comet-like Tails

NASA Image and Video Library

2013-11-13

P/2013 P5 on September 23, 2013. --- This NASA Hubble Space Telescope set of images reveals a never-before-seen set of six comet-like tails radiating from a body in the asteroid belt, designated P/2013 P5. The asteroid was discovered as an unusually fuzzy-looking object with the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) survey telescope in Hawaii. The multiple tails were discovered in Hubble images taken on Sept. 10, 2013. When Hubble returned to the asteroid on Sept. 23, the asteroid's appearance had totally changed. It looked as if the entire structure had swung around. One interpretation is that the asteroid's rotation rate has been increased to the point where dust is falling off the surface and escaping into space where the pressure of sunlight sweeps out fingerlike tails. According to this theory, the asteroid's spin has been accelerated by the gentle push of sunlight. The object, estimated to be no more than 1,400 feet across, has ejected dust for at least five months, based on analysis of the tail structure. These visible-light, false-color images were taken with Hubble's Wide Field Camera 3. Object Name: P/2013 P5 Image Type: Astronomical/Annotated Credit: NASA, ESA, and D. Jewitt (UCLA) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's Hubble Sees Asteroid Spout Six Comet-like Tails

NASA Image and Video Library

2013-11-13

P/2013 P5 on September 10, 2013. --- This NASA Hubble Space Telescope set of images reveals a never-before-seen set of six comet-like tails radiating from a body in the asteroid belt, designated P/2013 P5. The asteroid was discovered as an unusually fuzzy-looking object with the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) survey telescope in Hawaii. The multiple tails were discovered in Hubble images taken on Sept. 10, 2013. When Hubble returned to the asteroid on Sept. 23, the asteroid's appearance had totally changed. It looked as if the entire structure had swung around. One interpretation is that the asteroid's rotation rate has been increased to the point where dust is falling off the surface and escaping into space where the pressure of sunlight sweeps out fingerlike tails. According to this theory, the asteroid's spin has been accelerated by the gentle push of sunlight. The object, estimated to be no more than 1,400 feet across, has ejected dust for at least five months, based on analysis of the tail structure. These visible-light, false-color images were taken with Hubble's Wide Field Camera 3. Object Name: P/2013 P5 Image Type: Astronomical/Annotated Credit: NASA, ESA, and D. Jewitt (UCLA) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Space Telescope Fine Guidance Sensors Instrument Handbook, version 4.0

NASA Technical Reports Server (NTRS)

Holfeltz, S. T. (Editor)

1994-01-01

This is a revised version of the Hubble Space Telescope Fine Guidance Sensor Instrument Handbook. The main goal of this edition is to help the potential General Observer (GO) learn how to most efficiently use the Fine Guidance Sensors (FGS's). First, the actual performance of the FGS's as scientific instruments is reviewed. Next, each of the available operating modes of the FGS's are reviewed in turn. The status and findings of pertinent calibrations, including Orbital Verification, Science Verification, and Instrument Scientist Calibrations are included as well as the relevant data reduction software.

Hubble Friday - Heavy Metal Stars

NASA Image and Video Library

2017-12-08

Hubble rocks out with heavy metal stars! This 10.5-billion-year-old globular cluster, NGC 6496, is home to heavy-metal stars of a celestial kind! The stars comprising this spectacular spherical cluster are enriched with much higher proportions of metals — elements heavier than hydrogen and helium are curiously known as metals in astronomy — than stars found in similar clusters. A handful of these high-metallicity stars are also variable stars, meaning that their brightness fluctuates over time. NGC 6496 hosts a selection of long-period variables — giant pulsating stars whose brightness can take up to, and even over, a thousand days to change — and short-period eclipsing binaries, which dim when eclipsed by a stellar companion. The nature of the variability of these stars can reveal important information about their mass, radius, luminosity, temperature, composition, and evolution, providing astronomers with measurements that would be difficult or even impossible to obtain through other methods. NGC 6496 was discovered in 1826 by Scottish astronomer James Dunlop. The cluster resides at about 35,000 light-years away in the southern constellation of Scorpius (The Scorpion). Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt Text credit: European Space Agency Read more: go.nasa.gov/1U2wqGW

Hubble Space Telescope: A cosmic time machine

NASA Technical Reports Server (NTRS)

Westphal, J. A.; Harms, R. J.; Brandt, J. C.; Bless, R. C.; Macchetto, F. D.; Jefferys, W. H.

1991-01-01

The mission of the Hubble Space Telescope (HST) is to explore the expanding and evolving universe. During the 3,000 operating hours every year for the next 15 years or more, the HST will be used to study: galaxies; pulsars; globular clusters; neighboring stars where planets may be forming; binary star systems; condensing gas clouds and their chemical composition; and the rings of Saturn and the swirling ultraviolet clouds of Venus. The major technical achievements - its nearly perfect mirrors, its precise guidance system of rate gyroscopes, reaction wheels, star trackers, and fine guidance sensors are briefly discussed. The scientific instruments on board HST are briefly described. The integration of the equipment and instruments is outlined. The Space Telescope Science Institute (STScI) has approved time for 162 observations from among 556 proposals. The mission operation and data flow are explained.

Hubble Space Telescope Observations of the Nucleus Fragment 73P/Schwassmann-Wachmann 3-B

NASA Astrophysics Data System (ADS)

Toth, I.; Lamy, P. L.; Weaver, H. A.

2003-05-01

The nucleus of 73P/Schwassmann-Wachmann 3 (73P/SW3), a Jupiter-Family comet, has non-tidally broken into at least three components A, B and C, in autumn 1995. Fragment B was detected with the Planetary Camera 2 of the Hubble Space Telescope on 26 November 2001. i.e., after the comet's perihelion passage on 27.9 January 2001, when it was at 3.25 AU from the Sun, 2.33 AU from the Earth, and at a solar phase angle of 7.4o. The high spatial resolution of the PC2 allowed to separate the signal of the faint nucleus fragment from that of its active coma, and we measured its R magnitude from our images taken with the F675W filter. Assuming a spherical body whose geometric albedo is 0.04 and a linear phase coefficient of 0.04 mag/deg for the R band, we derived an effective radius of 0.68+/-0.04 km. The short time span of our HST observations did not allow to determine its shape but the lower limit of its axial ratio a/b (assuming a prolate spheroid) is ˜1.16. From the pre-breakup radius of the original nucleus of 1.3 km determined by Boehnhardt et al. (2002: EMPl 90, 131), we found that the fractional volume of fragment B is about 14%. Its size of a few hundred meters, typical of fragments of other split comets, is probably too large for a primordial building block and indicate that it still is a conglomerate; further disintegration of this fragment remains possible. Its level of activity is remarkably high in spite of a heliocentric distance of ˜3.2 AU, just beyond the limit for sublimation of water ice (2.8 AU). We measured an Afρ of 19.6-23.2 cm but the determination of a dust production rate is precluded by the absence of gas production rates at the time of our observation. Ground-based observations performed in 2001 by Boehnhardt et al. (2002: EMPl 90, 131) indicate that another fragment (E) has already disappeared, and we conclude that this may well be short-term fate of fragment B as it may not survive its next perihelion passage in 2006. The tau-Herculids meteor

Hubble Space Telescope nears Shuttle Endeavour

NASA Image and Video Library

1993-12-04

STS061-73-040 (4 Dec 1993) --- Backdropped against the blackness of space, the Hubble Space Telescope (HST) nears the Space Shuttle Endeavour. With the aid of the Remote Manipulator System (RMS), the STS-61 crew members later grappled the spacecraft and berthed it in the cargo bay for five-days of servicing chores by four space walkers.

Probing the z > 6 Universe with the First Hubble Frontier Fields Cluster A2744

NASA Astrophysics Data System (ADS)

Atek, Hakim; Richard, Johan; Kneib, Jean-Paul; Clement, Benjamin; Egami, Eiichi; Ebeling, Harald; Jauzac, Mathilde; Jullo, Eric; Laporte, Nicolas; Limousin, Marceau; Natarajan, Priyamvada

2014-05-01

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared data with ancillary optical images to search for gravitationally lensed high-redshift (z >~ 6) galaxies. We report the detection of 15 I 814 dropout candidates at z ~ 6-7 and one Y 105 dropout at z ~ 8 in a total survey area of 1.43 arcmin2 in the source plane. The predictions of our lens model also allow us to identify five multiply imaged systems lying at redshifts between z ~ 6 and z ~ 8. Thanks to constraints from the mass distribution in the cluster, we were able to estimate the effective survey volume corrected for completeness and magnification effects. This was in turn used to estimate the rest-frame ultraviolet luminosity function (LF) at z ~ 6-8. Our LF results are generally in agreement with the most recent blank field estimates, confirming the feasibility of surveys through lensing clusters. Although based on a shallower observations than what will be achieved in the final data set including the full Advanced Camera for Survey observations, the LF presented here goes down to M UV ~-18.5, corresponding to 0.2L sstarf at z ~ 7 with one identified object at M UV ~-15 thanks to the highly magnified survey areas. This early study forecasts the power of using massive galaxy clusters as cosmic telescopes and its complementarity to blank fields. Based on observations made with the NASA/ESA Hubble Space Telescope (HST), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 13495 and 11689. Based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory

The Hubble Constant to 1%: Physics beyond LambdaCDM

NASA Astrophysics Data System (ADS)

Riess, Adam

2017-08-01

By steadily advancing the precision and accuracy of the Hubble constant, we now see 3.4-sigma evidence for a deviation from the standard LambdaCDM model and thus the exciting chance of discovering new fundamental physics such as exotic dark energy, a new relativistic particle, dark matter interactions, or a small curvature, to name a few possibilities. We propose a coordinated program to accomplish three goals with one set of observations: (1) improve the precision of the best route to H_0 with HST observations of Cepheids in the hosts of 11 SNe Ia, lowering the uncertainty to 1.3% to reach the discovery threshold of 5-sigma and begin resolving the underlying source of the deviation; (2) continue testing the quality of Cepheid distances, so far the most accurate and reliable indicators in the near Universe, using the tip of the red giant branch (TRGB); and (3) use oxygen-rich Miras to confirm the present tension with the CMB and establish a future route available to JWST. We can achieve all three goals with one dataset and take the penultimate step to reach 1% precision in H_0 after Gaia. With its long-pass filter and NIR capability, we can collect these data with WFC3 many times faster than previously possible while overcoming the extinction and metallicity effects that challenged the first generation of H_0 measurements. Our results will complement the leverage available at high redshift from other cosmological tools such as BAO, the CMB, and SNe Ia, and will provide a 40% improvement on the WFIRST measurements of dark energy. Reaching this precision will be a fitting legacy for the telescope charged to resolve decades of uncertainty regarding the Hubble constant.

The Hubble Legacy Archive: Data Processing in the Era of AstroDrizzle

NASA Astrophysics Data System (ADS)

Strolger, Louis-Gregory; Hubble Legacy Archive Team, The Hubble Source Catalog Team

2015-01-01

The Hubble Legacy Archive (HLA) expands the utility of Hubble Space Telescope wide-field imaging data by providing high-level composite images and source lists, perusable and immediately available online. The latest HLA data release (DR8.0) marks a fundamental change in how these image combinations are produced, using DrizzlePac tools and Astrodrizzle to reduce geometric distortion and provide improved source catalogs for all publicly available data. We detail the HLA data processing and source list schemas, what products are newly updated and available for WFC3 and ACS, and how these data products are further utilized in the production of the Hubble Source Catalog. We also discuss plans for future development, including updates to WFPC2 products and field mosaics.

The Hubble Space Telescope: Problems and Solutions.

ERIC Educational Resources Information Center

Villard, Ray

1990-01-01

Presented is the best understanding of the flaw discovered in the optics of the Hubble Space Telescope and the possible solutions to the problems. The spherical aberration in the telescope's mirror and its effect on the quality of the telescope's imaging ability is discussed. (CW)

The shape and surface variation of 2 Pallas from the Hubble Space Telescope.

PubMed

Schmidt, B E; Thomas, P C; Bauer, J M; Li, J-Y; McFadden, L A; Mutchler, M J; Radcliffe, S C; Rivkin, A S; Russell, C T; Parker, J Wm; Stern, S A

2009-10-09

We obtained Hubble Space Telescope images of 2 Pallas in September 2007 that reveal distinct color and albedo variations across the surface of this large asteroid. Pallas's shape is an ellipsoid with radii of 291 (+/-9), 278 (+/-9), and 250 (+/-9) kilometers, implying a density of 2400 (+/-250) kilograms per cubic meter-a value consistent with a body that formed from water-rich material. Our observations are consistent with the presence of an impact feature, 240 (+/-25) kilometers in diameter, within Pallas's ultraviolet-dark terrain. Our observations imply that Pallas is an intact protoplanet that has undergone impact excavation and probable internal alteration.

Hubble Images Reveal Jupiter's Auroras

NASA Technical Reports Server (NTRS)

1996-01-01

These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.

The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.

The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.

The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.

The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.

This image and

Astronomy from Space: The Hubble, Herschel and James Webb Space Telescopes

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2009-01-01

Space-based astronomy is going through a renaissance, with three Great Observatories currently flying: Hubble in the visible and ultraviolet, Spitzer in the infrared and Chandra in X-rays. The future looks equally bright. The final servicing mission to Hubble will take place in February 2009 and promises to make the observatory more capable than ever with two new cameras, and refurbishment that will allow it to last at least five years. The upcoming launch of the Herschel Space Telescope will open the far-infrared to explore the cool and dusty Universe. Finally, we look forward to the launch of the James Webb Space Telescope in 2013, which wil provide a successor to both Hubble and Spitzer. In this talk, the author discusses some of the highlights of scientific discovery in the last 10 years and reveals the promise to the next 10 years.

Hubble Space Telescope Observations of the Disk and Jet of HH 30

NASA Astrophysics Data System (ADS)

Burrows, Christopher J.; Stapelfeldt, Karl R.; Watson, Alan M.; Krist, John E.; Ballester, Gilda E.; Clarke, John T.; Crisp, David; Gallagher, John S., III; Griffiths, Richard E.; Hester, J. Jeff; Hoessel, John G.; Holtzman, Jon A.; Mould, Jeremy R.; Scowen, Paul A.; Trauger, John T.; Westphal, James A.

1996-12-01

HH 30 in Taurus has been imaged with the Hubble Space Telescope WFPC2. The images show in reflected light a flared disk with a radius of about 250 AU that obscures the protostar. The disk resembles detailed accretion disk models that constrain its density distribution and show that its inclination is less than 100. There are bipolar emission-line jets perpendicular to the disk, a very clear demonstration of the standard paradigm for accretion disk and jet systems. However, asymmetries in the light distribution show that the disk has not completely settled into a quasi-equilibrium accretion state, or that some of the observed scattering is from an asymmetric envelope. The emission-line jet itself is resolved into a number of knots with typical lengths and separations of 0".4, much smaller and more numerous than indicated by lower resolution ground-based studies. There are indications of still finer structures in the jet all the way to the resolution limit of 0".1. The knots have proper motions ranging from 100 to 300 km s-1 and are therefore generated at the surprisingly high rate of about 0.4 knots per jet per year. The jet appears to be collimated within a cone of opening angle 3° and can be seen to within 30 AU of the star. Both single- and multiple-scattering disk models have a range of possible solutions, but by requiring pressure support and temperature equilibrium, a self-consistent model emerges. There is evidence for pressure support because the disk appears to have a Gaussian height profile. The temperature at each point in the disk is determined by the disk geometry, which in turn fixes the temperature in a self- consistent manner. The extinction to the protostar is unknown but constrained to be greater than 24 mag. The optical properties of the scattering grains in the disk are determined and found to imply a large scattering asymmetry, but they seem to follow the interstellar reddening law. The absolute magnitude and colors of the unseen protostar

Testing cold dark matter models using Hubble flow variations

NASA Astrophysics Data System (ADS)

Shi, Xiangdong

1999-05-01

COBE-normalized flat (matter plus cosmological constant) and open cold dark matter (CDM) models are tested by comparing their expected Hubble flow variations and the observed variations in a Type Ia supernova sample and a Tully-Fisher cluster sample. The test provides a probe of the CDM power spectrum on scales of 0.02h Mpc^-1<~ k<~ 0.2h Mpc^-1, free of the bias factor b. The results favour a low matter content universe, or a flat matter-dominated universe with a very low Hubble constant and/or a very small spectral index n^ps, with the best fits having Ο_0~ 0.3 to 0.4. The test is found to be more discriminative to the open CDM models than to the flat CDM models. For example, the test results are found to be compatible with those from the X-ray cluster abundance measurements at smaller length-scales, and consistent with the galaxy and cluster correlation analysis of Peacock & Dodds at similar length-scales, if our universe is flat; but the results are marginally incompatible with the X-ray cluster abundance measurements if our universe is open. The open CDM results are consistent with that of Peacock & Dodds only if the matter density of the universe is less than about 60 per cent of the critical density. The shortcoming of the test is discussed, so are ways to minimize it.

Hubble Gazes Into a Black Hole of Puzzling Light

NASA Image and Video Library

2017-12-08

The beautiful spiral galaxy visible in the center of the image is known as RX J1140.1+0307, a galaxy in the Virgo constellation imaged by the NASA/ESA Hubble Space Telescope, and it presents an interesting puzzle. At first glance, this galaxy appears to be a normal spiral galaxy, much like the Milky Way, but first appearances can be deceptive! The Milky Way galaxy, like most large galaxies, has a supermassive black hole at its center, but some galaxies are centered on lighter, intermediate-mass black holes. RX J1140.1+0307 is such a galaxy — in fact, it is centered on one of the lowest black hole masses known in any luminous galactic core. What puzzles scientists about this particular galaxy is that the calculations don’t add up. With such a relatively low mass for the central black hole, models for the emission from the object cannot explain the observed spectrum. There must be other mechanisms at play in the interactions between the inner and outer parts of the accretion disk surrounding the black hole. Credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Observational constraints on holographic dark energy with varying gravitational constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Jianbo; Xu, Lixin; Saridakis, Emmanuel N.

2010-03-01

We use observational data from Type Ia Supernovae (SN), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and observational Hubble data (OHD), and the Markov Chain Monte Carlo (MCMC) method, to constrain the cosmological scenario of holographic dark energy with varying gravitational constant. We consider both flat and non-flat background geometry, and we present the corresponding constraints and contour-plots of the model parameters. We conclude that the scenario is compatible with observations. In 1σ we find Ω{sub Λ0} = 0.72{sup +0.03}{sub −0.03}, Ω{sub k0} = −0.0013{sup +0.0130}{sub −0.0040}, c = 0.80{sup +0.19}{sub −0.14} and Δ{sub G}≡G'/G = −0.0025{sup +0.0080}{sub −0.0050},more » while for the present value of the dark energy equation-of-state parameter we obtain w{sub 0} = −1.04{sup +0.15}{sub −0.20}.« less

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1989-01-01

This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1986-01-01

This is an artist's concept of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

Hubble Views a Cosmic Skyrocket

NASA Image and Video Library

2017-12-08

NASA image release July 3, 2012 Caption: Resembling a Fourth of July skyrocket, Herbig-Haro 110 is a geyser of hot gas from a newborn star that splashes up against and ricochets off the dense core of a cloud of molecular hydrogen. Although the plumes of gas look like whiffs of smoke, they are actually billions of times less dense than the smoke from a July 4 firework. This Hubble Space Telescope photo shows the integrated light from plumes, which are light-years across. -- Herbig-Haro (HH) objects come in a wide array of shapes, but the basic configuration stays the same. Twin jets of heated gas, ejected in opposite directions away from a forming star, stream through interstellar space. Astronomers suspect that these outflows are fueled by gas accreting onto a young star surrounded by a disk of dust and gas. The disk is the "fuel tank," the star is the gravitational engine, and the jets are the exhaust. When these energetic jets slam into colder gas, the collision plays out like a traffic jam on the interstate. Gas within the shock front slows to a crawl, but more gas continues to pile up as the jet keeps slamming into the shock from behind. Temperatures climb sharply, and this curving, flared region starts to glow. These "bow shocks" are so named because they resemble the waves that form at the front of a boat. In the case of the single HH 110 jet, astronomers observe a spectacular and unusual permutation on this basic model. Careful study has repeatedly failed to find the source star driving HH 110, and there may be good reason for this: perhaps the HH 110 outflow is itself generated by another jet. Astronomers now believe that the nearby HH 270 jet grazes an immovable obstacle - a much denser, colder cloud core - and gets diverted off at about a 60-degree angle. The jet goes dark and then reemerges, having reinvented itself as HH 110. The jet shows that these energetic flows are like the erratic outbursts from a Roman candle. As fast-moving blobs of gas catch up

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

U.S. Senator Barbara A. Mikulski, D-Md., left foreground, NASA Administrator Charles F. Bolden, center, and NASA Deputy Administrator Lori Garver, right, along with members of the STS-125 and STS-31 space shuttle crews listen during a press conference where NASA unveiled new images from the Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The unveiled images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

Constraints on cosmological parameters in power-law cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rani, Sarita; Singh, J.K.; Altaibayeva, A.

In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters H{sub 0} (Hubble constant) and q (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with the results of ΛCDM . We also forecast constraints using a simulated data set for the future JDEM, supernovae survey. Our studies give better insight into power law cosmology than the earlier done analysis by Kumar [arXiv:1109.6924] indicating it tuning well with Union2.1 compilation data but not withmore » H(z) data. However, the constraints obtained on and i.e. H{sub 0} average and q average using the simulated data set for the future JDEM, supernovae survey are found to be inconsistent with the values obtained from the H(z) and Union2.1 compilation data. We also perform the statefinder analysis and find that the power-law cosmological models approach the standard ΛCDM model as q → −1. Finally, we observe that although the power law cosmology explains several prominent features of evolution of the Universe, it fails in details.« less

A Type II Supernova Hubble Diagram from the CSP-I, SDSS-II, and SNLS Surveys

NASA Astrophysics Data System (ADS)

de Jaeger, T.; González-Gaitán, S.; Hamuy, M.; Galbany, L.; Anderson, J. P.; Phillips, M. M.; Stritzinger, M. D.; Carlberg, R. G.; Sullivan, M.; Gutiérrez, C. P.; Hook, I. M.; Howell, D. Andrew; Hsiao, E. Y.; Kuncarayakti, H.; Ruhlmann-Kleider, V.; Folatelli, G.; Pritchet, C.; Basa, S.

2017-02-01

The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae (SNe II) combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey II SN, and the Supernova Legacy Survey. Applying the Photometric Color Method (PCM) to 73 SNe II with a redshift range of 0.01-0.5 and with no spectral information, we derive an intrinsic dispersion of 0.35 mag. A comparison with the Standard Candle Method (SCM) using 61 SNe II is also performed and an intrinsic dispersion in the Hubble diagram of 0.27 mag, I.e., 13% in distance uncertainties, is derived. Due to the lack of good statistics at higher redshifts for both methods, only weak constraints on the cosmological parameters are obtained. However, assuming a flat universe and using the PCM, we derive the universe’s matter density: {{{Ω }}}m={0.32}-0.21+0.30 providing a new independent evidence for dark energy at the level of two sigma. This paper includes data gathered with the 6.5 m Magellan Telescopes, with the du Pont and Swope telescopes located at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program N-2005A-Q-11, GN-2005B-Q-7, GN-2006A-Q-7, GS-2005A-Q-11, GS-2005B-Q-6, and GS-2008B-Q-56). Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156,078.D-0048, 080.A-0516, and 082.A-0526).

Hubble Chases a Small Stellar Galaxy in the Hunting Dog

NASA Image and Video Library

2017-12-08

On a clear evening in April of 1789, the renowned astronomer William Herschel continued his unrelenting survey of the night sky, hunting for new cosmic objects — and found cause to celebrate! He spotted this bright spiral galaxy, named NGC 4707, lurking in the constellation of Canes Venatici or The Hunting Dog. NGC 4707 lies roughly 22 million light-years from Earth. Over two centuries later, the NASA/ESA Hubble Space Telescope is able to "chase down" and view the same galaxy in far greater detail than Herschel could, allowing us to appreciate the intricacies and characteristics of NGC 4707 as never before. This striking image comprises observations from Hubble’s Advanced Camera for Surveys (ACS), one of a handful of high-resolution instruments currently aboard the space telescope. Herschel himself reportedly described NGC 4707 as a “small, stellar” galaxy; while it is classified as a spiral (type Sm), its overall shape, center, and spiral arms are very loose and undefined, and its central bulge is either very small or non-existent. It instead appears as a rough sprinkling of stars and bright flashes of blue on a dark canvas. The blue smudges seen across the frame highlight regions of recent or ongoing star formation, with newborn stars glowing in bright, intense shades of cyan and turquoise. Image credit: ESA/Hubble & NASA

A nuclear data approach for the Hubble constant measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pritychenko, B.

2015-06-09

An extraordinary number of Hubble constant measurements challenges physicists with selection of the best numerical value. The standard U.S. Nuclear Data Program (USNDP) codes and procedures have been applied to resolve this issue. The nuclear data approach has produced the most probable or recommended Hubble constant value of 67.00(770) (km/sec)/Mpc. This recommended value is based on the last 25 years of experimental research and includes contributions from different types of measurements. The present result implies (14.6±1.7) x 10 9 years as a rough estimate for the age of the Universe. The complete list of recommended results is given and possiblemore » implications are discussed.« less

The Carnegie–Chicago Hubble Program. III. The Distance to NGC 1365 via the Tip of the Red Giant Branch

NASA Astrophysics Data System (ADS)

Jang, In Sung; Hatt, Dylan; Beaton, Rachael L.; Lee, Myung Gyoon; Freedman, Wendy L.; Madore, Barry F.; Hoyt, Taylor J.; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

2018-01-01

The Carnegie–Chicago Hubble Program (CCHP) seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB) method. Based on deep Hubble Space Telescope ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax cluster that was host to the Type Ia supernova SN 2012fr. We have measured the extinction-corrected TRGB magnitude of NGC 1365 to be F814W = 27.34 ± 0.03stat ± 0.04sys mag. In advance of future direct calibration by Gaia, we adopt a provisional I-band TRGB luminosity set at the Large Magellanic Cloud and find a true distance modulus μ 0 = 31.29 ± 0.04stat ± 0.06sys mag or D = 18.1 ± 0.3stat ± 0.5sys Mpc. This measurement is in excellent agreement with recent Cepheid-based distances to NGC 1365 and reveals no significant difference in the distances derived from stars of Populations I and II for this galaxy. We revisit the error budget for the CCHP path to the Hubble constant based on the analysis presented here, i.e., that for one of the most distant Type Ia supernova hosts within our Program, and find that a 2.5% measurement is feasible with the current sample of galaxies and TRGB absolute calibration. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13691.

New Parallaxes of Galactic Cepheids from Spatially Scanning the Hubble Space Telescope: Implications for the Hubble Constant

NASA Astrophysics Data System (ADS)

Riess, Adam G.; Casertano, Stefano; Yuan, Wenlong; Macri, Lucas; Anderson, Jay; MacKenty, John W.; Bowers, J. Bradley; Clubb, Kelsey I.; Filippenko, Alexei V.; Jones, David O.; Tucker, Brad E.

2018-03-01

We present new measurements of the parallax of seven long-period (≥10 days) Milky Way (MW) Cepheid variables (SS CMa, XY Car, VY Car, VX Per, WZ Sgr, X Pup, and S Vul) using one-dimensional astrometric measurements from spatial scanning of Wide-Field Camera 3 on the Hubble Space Telescope (HST). The observations were obtained at ∼6 month intervals over 4 years. The distances are 1.7–3.6 kpc, with a mean precision of 45 μas (signal-to-noise ratio (S/N) ≈ 10) and a best precision of 29 μas (S/N = 14). The accuracy of the parallaxes is demonstrated through independent analyses of >100 reference stars. This raises to 10 the number of long-period Cepheids with significant parallax measurements, 8 obtained from this program. We also present high-precision mean F555W, F814W, and F160W magnitudes of these Cepheids, allowing a direct, zeropoint-independent comparison to >1800 extragalactic Cepheids in the hosts of 19 SNe Ia. This sample addresses two outstanding systematic uncertainties affecting prior comparisons of MW and extragalactic Cepheids used to calibrate the Hubble constant (H 0): their dissimilarity of periods and photometric systems. Comparing the new parallaxes to their predicted values derived from reversing the distance ladder gives a ratio (or independent scale for H 0) of 1.037 ± 0.036, consistent with no change and inconsistent at the 3.5σ level with a ratio of 0.91 needed to match the value predicted by Planck cosmic microwave background data in concert with ΛCDM. Using these data instead to augment the Riess et al. measurement of H 0 improves the precision to 2.3%, yielding 73.48 ± 1.66 km s‑1 Mpc‑1, and the tension with Planck + ΛCDM increases to 3.7σ. The future combination of Gaia parallaxes and HST spatial scanning photometry of 50 MW Cepheids can support a <1% calibration of H 0.

NASA's Hubble Space Telescope Finds Dead Stars 'Polluted with Planet Debris'

NASA Image and Video Library

2017-12-08

This is an artist’s impression of a white dwarf (burned-out) star accreting rocky debris left behind by the star’s surviving planetary system. It was observed by Hubble in the Hyades star cluster. At lower right, an asteroid can be seen falling toward a Saturn-like disk of dust that is encircling the dead star. Infalling asteroids pollute the white dwarf’s atmosphere with silicon. Credit: NASA, ESA, and G. Bacon (STScI) --- NASA's Hubble Space Telescope has found the building blocks for Earth-sized planets in an unlikely place-- the atmospheres of a pair of burned-out stars called white dwarfs. These dead stars are located 150 light-years from Earth in a relatively young star cluster, Hyades, in the constellation Taurus. The star cluster is only 625 million years old. The white dwarfs are being polluted by asteroid-like debris falling onto them. NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble View of a Nitrogen-Rich Nebula

NASA Image and Video Library

2015-06-26

This NASA/ESA Hubble Space Telescope image shows a planetary nebula named NGC 6153, located about 4,000 light-years away in the southern constellation of Scorpius (The Scorpion). The faint blue haze across the frame shows what remains of a star like the sun after it has depleted most of its fuel. When this happens, the outer layers of the star are ejected, and get excited and ionized by the energetic ultraviolet light emitted by the bright hot core of the star, forming the nebula. NGC 6153 is a planetary nebula that is elliptical in shape, with an extremely rich network of loops and filaments, shown clearly in this Hubble image. However, this is not what makes this planetary nebula so interesting for astronomers. Measurements show that NGC 6153 contains large amounts of neon, argon, oxygen, carbon and chlorine — up to three times more than can be found in the solar system. The nebula contains a whopping five times more nitrogen than our sun! Although it may be that the star developed higher levels of these elements as it grew and evolved, it is more likely that the star originally formed from a cloud of material that already contained a lot more of these elements. Text credit: European Space Agency Image credit: ESA/Hubble & NASA, Acknowledgement: Matej Novak NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

The NGC 1023 galaxy group: An anti-hubble flow?

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Dolgachev, V. P.; Domozhilova, L. M.

2010-10-01

We discuss recently published data indicating that the nearby galaxy group NGC 1023 includes an inner, virialized, quasi-stationary component together with an outer component comprising a flow of dwarf galaxies falling toward the center of the system. The inner component is similar to the Local Group of galaxies, but the Local Group is surrounded by a receding set of dwarf galaxies forming the local Hubble flow, rather than a system of approaching dwarfs. This clear difference in the structures of these two systems, which are very similar in other respects, may be associated with the dark energy in which they are immersed. Self-gravity dominates in the inner component of the Local Group, while the anti-gravity created by the cosmic dark-energy background dominates in the surrounding Hubble flow. In contrast, self-gravity likewise dominates throughout the NGC 1023 Group, both in its central component and in the surrounding “anti-Hubble” flow. NGC 1023 as a whole is apparently in an ongoing state of formation and virialization. We expect that there exists a receding flow similar to the local Hubble flow at distances of 1.4-3 Mpc from the center of the group, where anti-gravity should become stronger than the gravity of the system.

The Hubble Constant.

PubMed

Jackson, Neal

2007-01-01

I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. In the last 20 years, much progress has been made and estimates now range between 60 and 75 km s -1 Mpc -1 , with most now between 70 and 75 km s -1 Mpc -1 , a huge improvement over the factor-of-2 uncertainty which used to prevail. Further improvements which gave a generally agreed margin of error of a few percent rather than the current 10% would be vital input to much other interesting cosmology. There are several programmes which are likely to lead us to this point in the next 10 years.

The white dwarf mass-radius relation with Gaia, Hubble and FUSE

NASA Astrophysics Data System (ADS)

Joyce, Simon R. G.; Barstow, Martin A.; Casewell, Sarah L.; Holberg, Jay B.; Bond, Howard E.

2018-04-01

White dwarfs are becoming useful tools for many areas of astronomy. They can be used as accurate chronometers over Gyr timescales. They are also clues to the history of star formation in our galaxy. Many of these studies require accurate estimates of the mass of the white dwarf. The theoretical mass-radius relation is often invoked to provide these mass estimates. While the theoretical mass-radius relation is well developed, observational tests of this relation show a much larger scatter in the results than expected. High precision observational tests to confirm this relation are required. Gaia is providing distance measurements which will remove one of the main source of uncertainty affecting most previous observations. We combine Gaia distances with spectra from the Hubble and FUSE satelites to make precise tests of the white dwarf mass-radius relation.

Hubble Peers Through the Elliptical Haze

NASA Image and Video Library

2017-12-08

Like a lighthouse in the fog, the luminous core of NGC 2768 slowly fades outwards to a dull white haze in this image taken by the NASA/ESA Hubble Space Telescope. NGC 2768 is an elliptical galaxy in the constellation of Ursa Major (The Great Bear). It is a huge bundle of stars, dominated by a bright central region, where a supermassive black hole feasts on a constant stream of gas and dust being fed to it by its galactic host. The galaxy is also marked by a prominent plume of dust reaching out from the center and lying perpendicular to the galaxy’s plane. This dust conceals a symmetrical, S-shaped pair of jets that are being produced by the supermassive black hole as it feeds. Credit: ESA/Hubble, NASA and S. Smartt (Queen's University Belfast) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Scaling Relations and Overabundance of Massive Clusters at z >~ 1 from Weak-lensing Studies with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Jee, M. J.; Dawson, K. S.; Hoekstra, H.; Perlmutter, S.; Rosati, P.; Brodwin, M.; Suzuki, N.; Koester, B.; Postman, M.; Lubin, L.; Meyers, J.; Stanford, S. A.; Barbary, K.; Barrientos, F.; Eisenhardt, P.; Ford, H. C.; Gilbank, D. G.; Gladders, M. D.; Gonzalez, A.; Harris, D. W.; Huang, X.; Lidman, C.; Rykoff, E. S.; Rubin, D.; Spadafora, A. L.

2011-08-01

We present weak gravitational lensing analysis of 22 high-redshift (z >~ 1) clusters based on Hubble Space Telescope images. Most clusters in our sample provide significant lensing signals and are well detected in their reconstructed two-dimensional mass maps. Combining the current results and our previous weak-lensing studies of five other high-z clusters, we compare gravitational lensing masses of these clusters with other observables. We revisit the question whether the presence of the most massive clusters in our sample is in tension with the current ΛCDM structure formation paradigm. We find that the lensing masses are tightly correlated with the gas temperatures and establish, for the first time, the lensing mass-temperature relation at z >~ 1. For the power-law slope of the M-TX relation (MvpropT α), we obtain α = 1.54 ± 0.23. This is consistent with the theoretical self-similar prediction α = 3/2 and with the results previously reported in the literature for much lower redshift samples. However, our normalization is lower than the previous results by 20%-30%, indicating that the normalization in the M-TX relation might evolve. After correcting for Eddington bias and updating the discovery area with a more conservative choice, we find that the existence of the most massive clusters in our sample still provides a tension with the current ΛCDM model. The combined probability of finding the four most massive clusters in this sample after the marginalization over cosmological parameters is less than 1%. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, under program 9290, 9919, and 10496.

Hubble Space Telescope observations of the optical counterpart to a ultra-compact high-velocity cloud

NASA Astrophysics Data System (ADS)

Sand, David J.

2017-01-01

As part of a comprehensive archival search for optical counterparts to ultra-compact high-velocity clouds (UCHVCs), our team has uncovered five Local Volume dwarf galaxies, two of which were not previously known. Among these was AGC 226067, also known as ALFALFA-Dw1, which appeared to be made up of several HI and blue optical clumps based on ground-based data, with at least one HII region. Here we present Hubble Space Telescope Advanced Camera for Surveys data of AGC 226067. The data show that AGC 226067 is made up of a ~7-30 Myr old stellar population with a [Fe/H]~-0.6. Further, there is no evidence for an old stellar population associated with the system, down to a limit of MV>-8. Based on this and the position of AGC 226067 in the outskirts of the M86 subgroup of the Virgo cluster we present various arguments for the origin of this strange stellar system.

Total Dose Survivability of Hubble Electronic Components

NASA Technical Reports Server (NTRS)

Xapsos, M. A.; Stauffer, C.; Jordan, T.; Poivey, C.; Haskins, D. N.; Lum, G.; Pergosky, A. M.; Smith, D. C.; LaBel, K. A.

2017-01-01

A total dose analysis for exposure of electronic parts at the box level is presented for the Hubble Space Telescope. This was done using solid angle sectoring/3-dimensional ray trace and Monte Carlo radiation transport simulations. Results are discussed in terms of parts that are potential total dose concerns.

HUBBLE provides multiple views of how to feed a black hole

NASA Astrophysics Data System (ADS)

1998-05-01

fuel from a devoured galaxy, it may be oblivious to the rest of the galaxy and the collision," said Ethan Schreier of the Space Telescope Science Institute, Baltimore, MD. Schreier and an international team of co-investigators used Hubble's Near Infrared Camera and Multi-Object Spectrometer to probe deeper into the galaxy's mysterious heart than anyone has before. The hot gas disk viewed by Hubble investigators is perpendicular to the galaxy's outer dust belt, while the black hole's own internal accretion disk of superhot gas falling into it is tilted approximately diagonally to these axes. "We have found a complicated situation of a disk within a disk within a disk, all pointing in different directions," Schreier said. It is not clear if the black hole was always present in the host galaxy or belonged to the spiral galaxy that fell into the core, or if it is the product of the merger of a pair of smaller black holes that lived in the two once-separate galaxies. Having an active galaxy just 10 million light-years away from Earth rather than hundreds of millions or billions of light-years distant offers astronomers a unique laboratory for understanding the elusive details of the behavior of supermassive black holes as fueled by galaxy collisions. "Though Hubble has seen hot gas disks around black holes in other galaxies, the infrared camera has for the first time allowed us to peer at this relatively nearby, very active, but obscured black hole region," Schreier added. The team of astronomers is awaiting further Hubble data to continue its study of the disk, as well as ground-based spectroscopic observations to measure the velocity of entrapped material around the black hole. This will allow the astronomers to better calculate the black hole's mass. The current results are scheduled to appear in the June 1, 1998 issue of Astrophysical Journal Letters. Images and further information related to these results are available on the Internet at the following URLs: http

Hubble Discovery Image of New Moon Orbiting Saturn

NASA Technical Reports Server (NTRS)

1995-01-01

This four-picture sequence (spanning 30 minutes) shows one of four new moons discovered by the Hubble Space Telescope, in images taken of Saturn on May 22, 1995, when Saturn's rings were tilted edge-on to Earth.

Identified as S/1995 S3, the moon appears as an elongated white spot near the center of each image. The new moon lies just outside Saturn's outermost 'F' ring and is no bigger than about 15 miles across. The brighter object to the left is the moon Epimetheus, which was discovered during the ring-plane crossing of 1966. Both moons change position from frame to frame because they are orbiting the planet.

Saturn appears as a bright white disk at far right, and the edge-on rings extend diagonally to the upper left. To the left of the vertical line, each image has been processed to remove residual light from the rings and accentuate any faint satellites orbiting near the rings. The long observing times necessary to detect the faint satellites have resulted in Saturn's bright, overexposed appearance.

Saturn ring plane crossings happen only once every 15 years, and historically have given astronomers an opportunity to discover new satellites that are normally lost in the glare of the planet's bright ring system.

The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

Large Hubble Survey Confirms Link between Mergers and Supermassive Black Holes with Relativistic Jets

NASA Image and Video Library

2015-05-28

Tidal disruption event Every galaxy has a black hole at its center. Usually they are quiet, without gas accretions, like the one in our Milky Way. But if a star creeps too close to the black hole, the gravitational tides can rip away the star’s gaseous matter. Like water spinning around a drain, the gas swirls into a disk around the black hole at such speeds that it heats to millions of degrees. As an inner ring of gas spins into the black hole, gas particles shoot outward from the black hole’s polar regions. Like bullets shot from a rifle, they zoom through the jets at velocities close to the speed of light. Astronomers using NASA’s Hubble Space Telescope observed correlations between supermassive black holes and an event similar to tidal disruption, pictured above in the Centaurus A galaxy. Certain galaxies have shining centers, illuminated by heated gas circling around a supermassive black hole. Matter escapes where it can, forming two jets of plasma moving near the speed of light. To learn more about the relationship between galaxies and the black holes at their cores, go to NASA’s Hubble Space Telescope: www.nasa.gov/mission_pages/hubble/main/ -------------------------------- Original caption: A team of astronomers using the Hubble Space Telescope found an unambiguous link between the presence of supermassive black holes that power high-speed, radio-signal-emitting jets and the merger history of their host galaxies. Almost all galaxies with the jets were found to be merging with another galaxy, or to have done so recently. Credit: NASA/ESA/STScI NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HUBBLE UNCOVERS MYSTERY OBJECTS IN THE DENSE CORE OF A NEARBY STAR CLUSTER

NASA Technical Reports Server (NTRS)

2002-01-01

Piercing the heart of a glittering swarm of stars, NASA's sharp-eyed Hubble Space Telescope unveils the central region of the globular cluster M22, a 12- to 14-billion-year-old grouping of stars in the constellation Sagittarius. The telescope's view of the cluster's core measures 3.3 light-years across. The stars near the cluster's core are 100,000 times more numerous than those in the Sun's neighborhood. Buried in the glow of starlight are about six 'mystery objects,' which astronomers estimate are no larger than one quarter the mass of the giant planet Jupiter, the solar system's heftiest planet. The mystery objects are too far and dim for Hubble to see directly. Instead, the orbiting observatory detected these unseen celestial bodies by looking for their gravitational effects on the light from far distant stars. In this case, the stars are far beyond the cluster in the galactic bulge, about 30,000 light-years from Earth at the center of the Milky Way Galaxy. M22 is 8,500 light-years away. The invisible objects betrayed their presence by bending the starlight gravitationally and amplifying it, a phenomenon known as microlensing. From February 22 to June 15, 1999, Hubble's Wide Field and Planetary Camera 2 looked through this central region and monitored 83,000 stars. During that time the orbiting observatory recorded six unexpectedly brief microlensing events. In each case a background star jumped in brightness for less than 20 hours before dropping back to normal. These transitory spikes in brightness mean that the object passing in front of the star must have been much smaller than a normal star. Hubble also detected one clear microlensing event. In that observation a star appeared about 10 times brighter over an 18-day span before returning to normal. Astronomers traced the leap in brightness to a dwarf star in the cluster floating in front of the background star. The inset photo shows the entire globular cluster of about 10 million stars. M22 is about 60

Planetary nebulae: 20 years of Hubble inquiry

NASA Astrophysics Data System (ADS)

Balick, Bruce

2012-08-01

The Hubble Space Telescope has served the critical roles of microscope and movie camera in the past 20 years of research on planetary nebulae (``PNe''). We have glimpsed the details of the evolving structures of neutral and ionized post-AGB objects, built ingenious heuristic models that mimic these structures, and constrained most of the relevant physical processes with careful observations and interpretation. We have searched for close physical binary stars with spatial resolution ~50 AU at 1 AU, located jets emerging from the nucleus at speeds up to 2000 km s-1 and matched newly discovered molecular and X-ray emission regions to physical substructures in order to better understand how stellar winds and ionizing radiation interact to form the lovely symmetries that are observed. Ultraviolet spectra of CNO in PNe help to uncover how stars process deep inside AGB stars with unstable nuclear burning zones. HST broadband imaging has been at the forefront of uncovering surprisingly complex wind morphologies produced at the tip of the AGB, and has led to an increasing realization of the potentially vital roles of close binary stars and emerging magnetic fields in shaping stellar winds.

Exploring for Galaxies in the First Billion Years with Hubble and Spitzer - Pathfinding for JWST

NASA Astrophysics Data System (ADS)