Making astronomy incredibly easy, engaging and affordable for anyone with a desire to see outer space for themselves.

NASA Astrophysics Data System (ADS)

Paolucci, Michael

2015-08-01

We have built a social interface and funding model based on collaborative consumption to empower public access to powerful telescopes.Slooh’s robotic observatories put anyone with a desire to look up and wonder in the driver’s seat of powerful mountaintop telescopes. Our members have taken millions of images of over 50,000 objects in the night sky, from tracking asteroids for NASA to discovering supernovae. Slooh launched December 25th, 2003 from our flagship observatory at the Institute of Astrophysics of the Canary Islands and in the ensuing decade we’ve built a network of 20+ observatory partners around the world to capture every magical moment in outer space. We are the world’s largest community of people peering into space together.About SloohSlooh makes astronomy incredibly easy, engaging and affordable for anyone with a desire to see outer space for themselves. Since 2003 Slooh has connected telescopes to the Internet for access by the broader public. Slooh’s automated observatories develop celestial images in real-time for broadcast to the Internet. Slooh’s technology is protected by Patent No.: US 7,194,146 B2 which was awarded in 2006. Slooh members have taken over 3m photos/150,000 FITS of over 50,000 celestial objects, participated in numerous discoveries with leading astronomical institutions and made over 2,000 submissions to the Minor Planet Center. Slooh’s flagship observatories are situated on Mt. Teide, in partnership with the Institute of Astrophysics of the Canary Islands (IAC), and in Chile, in partnership with the Catholic University. Slooh has also broadcast live celestial events from partner observatories in Arizona, Japan, Hawaii, Cypress, Dubai, South Africa, Australia, New Zealand and Norway. Slooh’s free live broadcasts of potentially hazardous asteroids (PHAs), comets, transits, eclipses, solar activity etc. feature narration by astronomy experts Will Gater, Bob Berman, Paul Cox and Eric Edelman and are syndicated to media outlets worldwide. Slooh signed a Space Act Agreement with NASA in March 2014 to “Bring the Universe to Everyone and Help Protect Earth, Too.”

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

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 (as opposed to less than 1.5 million km per hour for our Sun). Because the bright central star does not exist in empty space but is surrounded by an envelope of gas, the stellar wind collides with this gas, pushing it out, like a snow plough. This forms a bubble, whose striking structure is clearly visible in the crisp Hubble image. The nebula N44F is one of a handful of known interstellar bubbles. Bubbles like these have been seen around evolved massive stars (called 'Wolf-Rayet stars'), and also around clusters of stars (where they are called 'super-bubbles'). But they have rarely been viewed around isolated stars, as is the case here. On closer inspection N44F harbours additional surprises. The interior wall of its gaseous cavity is lined with several four to eight light-year high finger-like columns of cool dust and gas. (The structure of these 'columns' is similar to the Eagle Nebula’s iconic 'Pillars of Creation' photographed by Hubble a decade ago, and is seen in a few other nebulae as well). The fingers are created by a blistering ultraviolet radiation from the central star. Like wind socks caught in a gale, they point in the direction of the energy flow. These pillars look small in this image only because they are much farther away from us then the Eagle Nebula’s pillars. N44F is located about 160 000 light-years in the neighbouring dwarf galaxy the Large Magellanic Cloud, in the direction of the southern constellation Dorado. N44F is part of the larger N44 complex, which contains a large super-bubble, blown out by the combined action of stellar winds and multiple supernova explosions. N44 itself is roughly 1000 light-years across. Several compact star-forming regions, including N44F, are found along the rim of the central super-bubble. This image was taken with Hubble's Wide Field Planetary Camera 2, using filters that isolate light emitted by sulphur (shown in blue, a 1200-second exposure) and hydrogen gas (shown in red, a 1000-second exposure).

Celestial Navigation for High School Students.

ERIC Educational Resources Information Center

Bell, Carroll Wilson

Reported is a study of a syllabus designed to teach students how to determine a position by celestial means. The syllabus was intended to augment existing curricula and be a topic for special interest groups and not designed as a semester-long course in itself. Each of the 14 lessons included was preceded by specific objectives written in…

The Second Realization of the International Celestial Reference Frame by Very Long Baseline Interferometry

NASA Astrophysics Data System (ADS)

Fey, A. L.; Gordon, D.; Jacobs, C. S.; Ma, C.; Gaume, R. A.; Arias, E. F.; Bianco, G.; Boboltz, D. A.; Böckmann, S.; Bolotin, S.; Charlot, P.; Collioud, A.; Engelhardt, G.; Gipson, J.; Gontier, A.-M.; Heinkelmann, R.; Kurdubov, S.; Lambert, S.; Lytvyn, S.; MacMillan, D. S.; Malkin, Z.; Nothnagel, A.; Ojha, R.; Skurikhina, E.; Sokolova, J.; Souchay, J.; Sovers, O. J.; Tesmer, V.; Titov, O.; Wang, G.; Zharov, V.

2015-08-01

We present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. ICRF2 contains precise positions of 3414 compact radio astronomical objects and has a positional noise floor of ∼40 μas and a directional stability of the frame axes of ∼10 μas. A set of 295 new “defining” sources was selected on the basis of positional stability and the lack of extensive intrinsic source structure. The positional stability of these 295 defining sources and their more uniform sky distribution eliminates the two greatest weaknesses of the first realization of the International Celestial Reference Frame (ICRF1). Alignment of ICRF2 with the International Celestial Reference System was made using 138 positionally stable sources common to both ICRF2 and ICRF1. The resulting ICRF2 was adopted by the International Astronomical Union as the new fundamental celestial reference frame, replacing ICRF1 as of 2010 January 1.

Advanced X-ray Astrophysics Facility (AXAF) science instruments

NASA Technical Reports Server (NTRS)

Winkler, Carl E.; Dailey, Carroll C.; Cumings, Nesbitt P.

1991-01-01

The overall AXAF program is summarized, with particular emphasis given to its science instruments. The science objectives established for AXAF are to determine the nature of celestial objects, from normal stars to quasars, to elucidate the nature of the physical processes which take place in and between astronomical objects, and to shed light on the history and evolution of the universe. Attention is given to the AXAF CCD imaging spectrometer, which is to provide spectrally and temporally resolved imaging, or, in conjunction with transmission grating, high-resolution dispersed spectral images of celestial sources. A high-resolution camera, an X-ray spectrometer, and the Bragg Crystal Spectrometer are also discussed.

NASA Team Begins Testing of a New-Fangled Optic

NASA Image and Video Library

2017-12-08

It’s an age-old astronomical truth: To resolve smaller and smaller physical details of distant celestial objects, scientists need larger and larger light-collecting mirrors. This challenge is not easily overcome given the high cost and impracticality of building and — in the case of space observatories — launching large-aperture telescopes. However, a team of scientists and engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has begun testing a potentially more affordable alternative called the photon sieve. This new-fangled telescope optic could give scientists the resolution they need to see finer details still invisible with current observing tools – a jump in resolution that could help answer a 50-year-old question about the physical processes heating the sun's million-degree corona. Read more: go.nasa.gov/2abhanr Credit: NASA/Goddard/W. Hrybyk

Celestial Object Imaging Model and Parameter Optimization for an Optical Navigation Sensor Based on the Well Capacity Adjusting Scheme.

PubMed

Wang, Hao; Jiang, Jie; Zhang, Guangjun

2017-04-21

The simultaneous extraction of optical navigation measurements from a target celestial body and star images is essential for autonomous optical navigation. Generally, a single optical navigation sensor cannot simultaneously image the target celestial body and stars well-exposed because their irradiance difference is generally large. Multi-sensor integration or complex image processing algorithms are commonly utilized to solve the said problem. This study analyzes and demonstrates the feasibility of simultaneously imaging the target celestial body and stars well-exposed within a single exposure through a single field of view (FOV) optical navigation sensor using the well capacity adjusting (WCA) scheme. First, the irradiance characteristics of the celestial body are analyzed. Then, the celestial body edge model and star spot imaging model are established when the WCA scheme is applied. Furthermore, the effect of exposure parameters on the accuracy of star centroiding and edge extraction is analyzed using the proposed model. Optimal exposure parameters are also derived by conducting Monte Carlo simulation to obtain the best performance of the navigation sensor. Finally, laboratorial and night sky experiments are performed to validate the correctness of the proposed model and optimal exposure parameters.

Celestial Object Imaging Model and Parameter Optimization for an Optical Navigation Sensor Based on the Well Capacity Adjusting Scheme

PubMed Central

Wang, Hao; Jiang, Jie; Zhang, Guangjun

2017-01-01

The simultaneous extraction of optical navigation measurements from a target celestial body and star images is essential for autonomous optical navigation. Generally, a single optical navigation sensor cannot simultaneously image the target celestial body and stars well-exposed because their irradiance difference is generally large. Multi-sensor integration or complex image processing algorithms are commonly utilized to solve the said problem. This study analyzes and demonstrates the feasibility of simultaneously imaging the target celestial body and stars well-exposed within a single exposure through a single field of view (FOV) optical navigation sensor using the well capacity adjusting (WCA) scheme. First, the irradiance characteristics of the celestial body are analyzed. Then, the celestial body edge model and star spot imaging model are established when the WCA scheme is applied. Furthermore, the effect of exposure parameters on the accuracy of star centroiding and edge extraction is analyzed using the proposed model. Optimal exposure parameters are also derived by conducting Monte Carlo simulation to obtain the best performance of the navigation sensor. Finally, laboratorial and night sky experiments are performed to validate the correctness of the proposed model and optimal exposure parameters. PMID:28430132

COMET - ASTRONOMY (KOHOUTEK)

NASA Image and Video Library

1973-12-14

S73-38390 (6 Dec. 1973) --- An Earth-based photograph of the Comet Kohoutek in the sky on Dec. 6, 1973, when the celestial phenomenon was more than 70 million miles from the sun and some 119 million miles from Earth. This picture was taken from a dark mountain top area of Haleakala (Island of Maui) Hawaii, using a 35mm Nikon camera with a 55mm lens, a 300-second exposure at f/1.2 and with Tri-X film. The photographer was Frank Giovane. The indicated visible tail of the comet appears to be about 10 million miles long. Other reports have inferred that the length of the tail is up to 13 million miles. The Skylab 4 crewmen have reported that Kohoutek's tail-length was from two to three degrees or from four to six million miles as viewed with the naked eye from the Skylab space station in Earth orbit. Photo credit: NASA/Frank Giovane

Synthetic guide star generation

DOEpatents

Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

2008-06-10

A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

Flow Visualization of Aircraft in Flight by Means of Background Oriented Schlieren Using Celestial Objects

NASA Technical Reports Server (NTRS)

Hill, Michael A.; Haering, Edward A., Jr.

2017-01-01

The Background Oriented Schlieren using Celestial Objects series of flights was undertaken in the spring of 2016 at National Aeronautics and Space Administration Armstrong Flight Research Center to further develop and improve a flow visualization technique which can be performed from the ground upon flying aircraft. Improved hardware and imaging techniques from previous schlieren tests were investigated. A United States Air Force T-38C and NASA B200 King Air aircraft were imaged eclipsing the sun at ranges varying from 2 to 6 nautical miles, at subsonic and supersonic speeds.

Synthetic guide star generation

DOEpatents

Payne, Stephen A.; Page, Ralph H.; Ebbers, Christopher A.; Beach, Raymond J.

2004-03-09

A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

The Future of Past Skies: Historical Celestial Cartography at the Adler Planetarium

NASA Astrophysics Data System (ADS)

Raposo, Pedro M. P.

2018-01-01

The Adler Planetarium is home to a world-class collection of scientific instruments, rare books and works on paper. Since 2014, Adler staff has been digitizing a wide selection of items relating to celestial cartography, including: more than 236 rare books and atlases; 97 works on paper; globes and other artifacts, amounting to 58 objects; and approximately 3,750 Carte du Ciel prints. This work has been carried out under the auspices of the Celestial Cartography Digitization Project (CCDP), which is sponsored by the National Endowment for the Humanities. This poster presentation will include: 1) an update on the project; 2) a description of related resources and tools available to the research community; 3) examples of how the Adler Planetarium is integrating the history of celestial cartography with its public programs; 4) an overview of a prospective citizen science project involving the identification of constellations in historical atlases and charts.

On population of hazardous celestial bodies in the near-Earth space

NASA Astrophysics Data System (ADS)

Shustov, B. M.; Naroenkov, S. A.; Efremova, E. V.

2017-01-01

In recent years, following the Chelyabinsk event of February 15, 2013, the lower size limit for presumably dangerous near-Earth objects has been decreased manyfold (essentially, from 140 m to 10 m). This has drawn an increased attention to the properties of the population of decameter-sized bodies, in particular, the bodies that approach the Earth from the sunward side (daytime sky). The current paper is concerned with various properties of this population. The properties of the ensemble are analyzed using both observational data from other authors and theoretical estimates obtained by cloning virtual bodies. This question is of great practical importance, as the means for detecting such bodies (for example, the SODA project) need to be developed with consideration for the requirements imposed by the population properties. We have shown that the average rate of entering near-Earth space (NES), i.e., at distances less than 1 million km from the Earth, for decameter-sized and larger bodies from the daytime sky (elongation values of entry points less than 90°) is approximately 620 objects per year for elongation angles of the detection point <90° and approximately 220 objects per year for elongation angles of the detection point <45°.

OPTICAL SPECTRA OF CANDIDATE INTERNATIONAL CELESTIAL REFERENCE FRAME (ICRF) FLAT-SPECTRUM RADIO SOURCES

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

Titov, O.; Stanford, Laura M.; Johnston, Helen M.

2013-07-01

Continuing our program of spectroscopic observations of International Celestial Reference Frame (ICRF) sources, we present redshifts for 120 quasars and radio galaxies. Data were obtained with five telescopes: the 3.58 m European Southern Observatory New Technology Telescope, the two 8.2 m Gemini telescopes, the 2.5 m Nordic Optical Telescope (NOT), and the 6.0 m Big Azimuthal Telescope of the Special Astrophysical Observatory in Russia. The targets were selected from the International VLBI Service for Geodesy and Astrometry candidate International Celestial Reference Catalog which forms part of an observational very long baseline interferometry (VLBI) program to strengthen the celestial reference frame.more » We obtained spectra of the potential optical counterparts of more than 150 compact flat-spectrum radio sources, and measured redshifts of 120 emission-line objects, together with 19 BL Lac objects. These identifications add significantly to the precise radio-optical frame tie to be undertaken by Gaia, due to be launched in 2013, and to the existing data available for analyzing source proper motions over the celestial sphere. We show that the distribution of redshifts for ICRF sources is consistent with the much larger sample drawn from Faint Images of the Radio Sky at Twenty cm (FIRST) and Sloan Digital Sky Survey, implying that the ultra-compact VLBI sources are not distinguished from the overall radio-loud quasar population. In addition, we obtained NOT spectra for five radio sources from the FIRST and NRAO VLA Sky Survey catalogs, selected on the basis of their red colors, which yielded three quasars with z > 4.« less

Water in the trail of the Chelyabinsk bolide

NASA Astrophysics Data System (ADS)

Gladysheva, O. G.

2017-09-01

At 03:20 UTC on February 15, 2013 a very bright bolide entered Earth's atmosphere. Fragments of the meteorite fell to the earth's surface. Examination of these fragments revealed that several of them were located directly on the surface of the celestial body [1], while the majority lay at a depth of less than 2.5 m from the surface [2, 3]. The stone meteorite's durability, >15 MPa, corresponded to <1% of the initial mass, while the rest of the object possessed a low durability of 1 MPa [4]. Moreover, Fe3+ hydroxyls were discovered in meteorite samples, the formation of which required water [5]. The glow at the head of the bolide trail, lasting 8 seconds after the flight of the object, and the development of the cloud trail indicate that the celestial body carried water. The Chinese weather satellite Feng-Yun 2D discovered ice debris (water) in the bolide trail [6]. Here, we will demonstrate that the Chelyabinsk chondrite was delivered to the Earth by an ice-bearing celestial body.

Motion of the Jovian commensurability resonances and the character of the celestial mechanics in the asteroid zone - Implication for kinematics and structure

NASA Technical Reports Server (NTRS)

Torbett, M.; Smoluchowski, R.

1982-01-01

The motion of the Jovian commensurability resonances during the early evolution of the solar system induced by the dissipation of the accretion disk results in fundamental differences in the celestial mechanics of objects over which a resonance passes from that observed for a stationary resonance. Objects experiencing resonance passage acquire irreversible increases of average eccentricity to large values accounting for the present-day random velocities of the asteroids. Semi-major axes are similarly irreversibly decreased by amounts capable of clearing the Kirkwood gaps. The gap widths are in agreement with observation.

Killer rocks and the celestial police - The search for near-earth asteroids

NASA Technical Reports Server (NTRS)

Yeomans, Donald K.

1991-01-01

The discovery of asteroids near the earth as the result of search programs is detailed with attention given to methods for locating, tracking, and identifying asteroids. The concept of 'prediscovery' is discussed in which new asteroids are tracked backward in time through previous celestial observational data. The need for more comprehensive programs is identified in order to locate objects that present a clear danger of colliding with the earth.

Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey

NASA Astrophysics Data System (ADS)

Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G.; Siverd, Robert J.; Lund, Michael B.; Kuhn, Rudolf B.; James, David; Gaudi, B. Scott

2018-01-01

The Kilodegree Extremely Little Telescope (KELT) has been surveying more than 70% of the celestial sphere for nearly a decade. While the primary science goal of the survey is the discovery of transiting, large-radii planets around bright host stars, the survey has collected more than 106 images, with a typical cadence between 10–30 minutes, for more than four million sources with apparent visual magnitudes in the approximate range 7< V< 13. Here, we provide a catalog of 52,741 objects showing significant large-amplitude fluctuations likely caused by stellar variability, as well as 62,229 objects identified with likely stellar rotation periods. The detected variability ranges in rms-amplitude from ∼3 mmag to ∼2.3 mag, and the detected periods range from ∼0.1 to ≳2000 days. We provide variability upper limits for all other ∼4,000,000 sources. These upper limits are principally a function of stellar brightness, but we achieve typical 1σ sensitivity on 30 min timescales down to ∼5 mmag at V∼ 8, and down to ∼43 mmag at V∼ 13. We have matched our catalog to the TESS Input catalog and the AAVSO Variable Star Index to precipitate the follow-up and classification of each source. The catalog is maintained as a living database on the Filtergraph visualization portal at the URL https://filtergraph.com/kelt_vars.

Profile fitting in crowded astronomical images

NASA Astrophysics Data System (ADS)

Manish, Raja

Around 18,000 known objects currently populate the near Earth space. These constitute active space assets as well as space debris objects. The tracking and cataloging of such objects relies on observations, most of which are ground based. Also, because of the great distance to the objects, only non-resolved object images can be obtained from the observations. Optical systems consist of telescope optics and a detector. Nowadays, usually CCD detectors are used. The information that is sought to be extracted from the frames are the individual object's astrometric position. In order to do so, the center of the object's image on the CCD frame has to be found. However, the observation frames that are read out of the detector are subject to noise. There are three different sources of noise: celestial background sources, the object signal itself and the sensor noise. The noise statistics are usually modeled as Gaussian or Poisson distributed or their combined distribution. In order to achieve a near real time processing, computationally fast and reliable methods for the so-called centroiding are desired; analytical methods are preferred over numerical ones of comparable accuracy. In this work, an analytic method for the centroiding is investigated and compared to numerical methods. Though the work focuses mainly on astronomical images, same principle could be applied on non-celestial images containing similar data. The method is based on minimizing weighted least squared (LS) error between observed data and the theoretical model of point sources in a novel yet simple way. Synthetic image frames have been simulated. The newly developed method is tested in both crowded and non-crowded fields where former needs additional image handling procedures to separate closely packed objects. Subsequent analysis on real celestial images corroborate the effectiveness of the approach.

How dim is dim? Precision of the celestial compass in moonlight and sunlight

PubMed Central

Dacke, M.; Byrne, M. J.; Baird, E.; Scholtz, C. H.; Warrant, E. J.

2011-01-01

Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim—and the polarization pattern too weak—to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision. PMID:21282173

Identification of 1.4 Million Active Galactic Nuclei In the Mid-Infrared Using WISE Data

DTIC Science & Technology

2015-11-01

galaxies – infrared: stars – galaxies : active – quasars: general Supporting material: machine-readable table 1. INTRODUCTION The International Celestial...AGN-dominated galaxies , optical emission is thought to originate from the compact accretion disk surrounding the supermassive black hole (SMBH), while... galaxies , an optical centroid can be shifted relative to the radio position because of contamination from the host galaxy . Depending on the distance to

A list of some bright objects which S-052 can observe

NASA Technical Reports Server (NTRS)

Mcquire, J. P.

1972-01-01

In order to find out the precise orientation of the photographs obtained by the High Altitude Observatory's ATM white light coronagraph, celestial objects must appear on each roll of film. A list of such bright objects and the times during which they can be observed is presented.

Announcing the Venus Transit 2004 (VT-2004) Programme

NASA Astrophysics Data System (ADS)

2004-02-01

Rare Celestial Event to be Observed by Millions Summary On June 8, 2004, Venus - the Earth's sister planet - will pass in front of the Sun. This event, a 'transit', is extremely rare - the last one occurred in 1882, 122 years ago. Easily observable in Europe, Asia, Africa and Australia, it is likely to attract the attention of millions of people on these continents and, indeed, all over the world. On this important occasion, the European Southern Observatory (ESO) has joined forces with the European Association for Astronomy Education (EAAE), the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) and the Observatoire de Paris in France, as well as the Astronomical Institute of the Academy of Sciences of the Czech Republic to establish the Venus Transit 2004 (VT-2004) public education programme. It is supported by the European Commission in the framework of the European Science and Technology Week and takes advantage of this extraordinary celestial event to expose the public - in a well-considered, interactive and exciting way - to a number of fundamental issues at the crucial interface between society and basic science. VT-2004 has several components, including an instructive and comprehensive website (www.vt-2004.org). It is directed towards the wide public in general and the media, school students and their teachers, as well as amateur astronomers in particular. It invites all interested persons to participate actively in the intercontinental VT-2004 Observing Campaign (that reenacts historical Venus Transit observations) and the VT-2004 Video Contest. During the VT-2004 Final Event in November, the winners of the Video Contest will be chosen by an international jury. This meeting will also serve to discuss the project and its impact. The outcome of this rare celestial event and the overall experience from this unique public education project will clearly be of very wide interest, not just in the field of astronomy.

Spacelab

NASA Image and Video Library

1990-12-09

This is a presentation of two comparison images of the Spiral Galaxy M81 in the constellation URA Major. The galaxy is about 12-million light years from Earth. The left image is the Spiral Galaxy M81 as photographed by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 Mission (STS-35) on December 9, 1990. This UIT photograph, made with ultraviolet light, reveals regions where new stars are forming at a rapid rate. The right image is a photograph of the same galaxy in red light made with a 36-inch (0.9-meter) telescope at the Kitt Peak National Observatory near Tucson, Arizona. The Astro Observatory was designed to explore the universe by observing and measuring ultraviolet radiation from celestial objects. Three instruments made up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had management responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

[Searching for Rare Celestial Objects Automatically from Stellar Spectra of the Sloan Digital Sky Survey Data Release Eight].

PubMed

Si, Jian-min; Luo, A-li; Wu, Fu-zhao; Wu, Yi-hong

2015-03-01

There are many valuable rare and unusual objects in spectra dataset of Sloan Digital Sky Survey (SDSS) Data Release eight (DR8), such as special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on, so it is extremely significant to search for rare and unusual celestial objects from massive spectra dataset. A novel algorithm based on Kernel dense estimation and K-nearest neighborhoods (KNN) has been presented, and applied to search for rare and unusual celestial objects from 546 383 stellar spectra of SDSS DR8. Their densities are estimated using Gaussian kernel density estimation, the top 5 000 spectra in descend order by their densities are selected as rare objects, and the top 300 000 spectra in ascend order by their densities are selected as normal objects. Then, KNN were used to classify the rest objects, and simultaneously K nearest neighbors of the 5 000 rare spectra are also selected as rare objects. As a result, there are totally 21 193 spectra selected as initial rare spectra, which include error spectra caused by deletion, redden, bad calibration, spectra consisting of different physically irrelevant components, planetary nebulas, QSOs, special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on. By cross identification with SIMBAD, NED, ADS and major literature, it is found that three DZ white dwarfs, one WDMS, two CVs with company of G-type star, three CVs candidates, six DC white dwarfs, one DC white dwarf candidate and one BL Lacertae (BL lac) candidate are our new findings. We also have found one special DA white dwarf with emission lines of Ca II triple and Mg I, and one unknown object whose spectrum looks like a late M star with emission lines and its image looks like a galaxy or nebula.

Measuring Distances to Remote Galaxies and Quasars.

ERIC Educational Resources Information Center

McCarthy, Patrick J.

1988-01-01

Describes the use of spectroscopy and the redshift to measure how far an object is by measuring how fast it is receding from earth. Lists the most distant quasars yet found. Tables include "Redshift vs. Distance" and "Distances to Celestial Objects for Various Cosmologies." (CW)

Carbon Observatory’s First Data on This Week @NASA - August 15, 2014

NASA Image and Video Library

2014-08-15

A month after its launch, the Orbiting Carbon Observatory-2, NASA’s first spacecraft dedicated to studying atmospheric carbon dioxide – has reached its final operating orbit and returned its first science data. “First light” test data were collected on August 6 as OCO-2 flew over central New Guinea, confirming the health of the spacecraft’s science instrument’s. Also, ATV-5 Delivers Cargo, Cygnus Departs Station, Super Celestial Show, Black Hole Blurs X-ray Light, Million Pound Move and more!

Nondispersive spectroscopy of celestial X-ray sources

NASA Technical Reports Server (NTRS)

Holt, S. S.

1979-01-01

The spectroscope aboard the Einstein Observatory which utilizes nondispersive techniques is presented. Examples of kinds of thermal and nonthermal features that can be seen as well as the possibility of seeing small traces of thermal features in either much higher temperature objects or nonthermal objects are considered.

Relative Navigation of Formation-Flying Satellites

NASA Technical Reports Server (NTRS)

Long, Anne; Kelbel, David; Lee, Taesul; Leung, Dominic; Carpenter, J. Russell; Grambling, Cheryl

2002-01-01

This paper compares autonomous relative navigation performance for formations in eccentric, medium and high-altitude Earth orbits using Global Positioning System (GPS) Standard Positioning Service (SPS), crosslink, and celestial object measurements. For close formations, the relative navigation accuracy is highly dependent on the magnitude of the uncorrelated measurement errors. A relative navigation position accuracy of better than 10 centimeters root-mean-square (RMS) can be achieved for medium-altitude formations that can continuously track at least one GPS signal. A relative navigation position accuracy of better than 15 meters RMS can be achieved for high-altitude formations that have sparse tracking of the GPS signals. The addition of crosslink measurements can significantly improve relative navigation accuracy for formations that use sparse GPS tracking or celestial object measurements for absolute navigation.

Dynamics of Natural and Artificial Celestial Bodies

NASA Astrophysics Data System (ADS)

Pretka-Ziomek, Halina; Wnuk, Edwin; Seidelmann, P. Kenneth; Richardson, David.

2002-01-01

This volume contains papers presented at the US/European Celestial Mechanics Workshop organized by the Astronomical Observatory of Adam Mickiewicz University in Poznan, Poland and held in Poznan, from 3 to 7 July 2000. The purpose of the workshop was to identify future research in celestial mechanics and astrometry and encourage collaboration among scientists from eastern and western countries. Also an emphasis was placed on attracting young members of the fields from around the world and encouraging them to undertake new research efforts needed for advancements in those fields. There was a full program of invited and contributed presentations on selected subjects and each day ended with a discussion period on a general subject in celestial mechanics. The discussion topics and the leaders were: Resonances and Chaos -- A. Morbidelli; Artificial Satellite Orbits -- K.T. Alfriend; Near Earth Objects -- K. Muinonen; Small Solar System Bodies -- I. Williams; and Summary -- P.K. Seidelmann. The goal of the discussions was to identify what we did not know and how we might further our knowledge. It was felt, in addition, that Poznan, Poland, with a core of scientists covering a range of ages, would provide an example of how a research and educational group could be developed elsewhere. Also, Poznan is a central location convenient to eastern and western countries. Thus, the gathering of people and the papers presented are to be the bases for building the future of astrometry and celestial mechanics. Link: http://www.wkap.nl/prod/b/1-4020-0115-0

Astronomical Knowledge from Holy Books

NASA Astrophysics Data System (ADS)

Farmanyan, Sona V.; Devrikyan, Vardan G.; Mickaelian, Areg M.

2016-10-01

We investigate religious myths related to astronomy from different cultures in an attempt to identify common subjects and characteristics. The paper focuses on astronomy in religion. The initial review covers records from Holy books about sky related superstitious beliefs and cosmological understanding. The purpose of this study is to introduce sky related religious and national traditions (particularly based on different calendars; Solar or Lunar). We carried out a comparative study of astronomical issues contained in a number of Holy books. We come to the conclusion that the perception of celestial objects varies from culture to culture, and from religion to religion and preastronomical views had a significant impact on humankind, particularly on religious diversities. We prove that Astronomy is the basis of cultures, and that national identity and mythology and religion were formed due to the special understanding of celestial objects.

Awesome Universe: an exhibition with images that showcase celestial objects as seen by ESO's observatories and associated activities

NASA Astrophysics Data System (ADS)

Marin-Farrona, A. M.

2015-05-01

In September 2013, an ESO exhibition was shown in Santander: ``Awesome Universe -- the Cosmos through the eyes of the European Southern Observatory". Around the exhibition, were proposed several activities: guide tours for children, younger and adults, workshops, film projections... In this way, the exhibition was visited by more than two thousand persons. We must keep in mind that Santander is a small city and its population does not usually take part in outreach activity. With this contribution, we want to teach the way in which it is possible to take advantage of science exhibitions. It made possible to show stunning images that showcase celestial objects as seen by ESO's observatories to the great majority of Santander population, and to awaken their interest in or enthusiasm for science.

GALEX 1st Light Near and Far Ultraviolet -100

NASA Image and Video Library

2003-05-28

NASA's Galaxy Evolution Explorer took this image on May 21 and 22, 2003. The image was made from data gathered by the two channels of the spacecraft camera during the mission's "first light" milestone. It shows about 100 celestial objects in the constellation Hercules. The reddish objects represent those detected by the camera's near ultraviolet channel over a 5-minute period, while bluish objects were detected over a 3-minute period by the camera's far ultraviolet channel. The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. http://photojournal.jpl.nasa.gov/catalog/PIA04281

The ADS All Sky Survey: footprints of astronomy literature, in the sky

NASA Astrophysics Data System (ADS)

Pepe, Alberto; Goodman, A. A.; Muench, A. A.; Seamless Astronomy Group at the CfA

2014-01-01

The ADS All-Sky Survey (ADSASS) aims to transform the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource for astronomers, into a data resource. The ADS is not a data repository per se, but it implicitly contains valuable holdings of astronomical data, in the form of images, tables and object references contained within articles. The objective of the ADSASS effort is to extract these data and make them discoverable and available through existing data viewers. In this talk, the ADSASS viewer - http://adsass.org/ - will be presented: a sky heatmap of astronomy articles based on the celestial objects they reference. The ADSASS viewer is as an innovative research and visual search tool for it allows users to explore astronomical literature based on celestial location, rather than keyword string. The ADSASS is a NASA-funded initiative carried out by the Seamless Astronomy Group at the Harvard-Smithsonian Center for Astrophysics.

Embodying Earth's Place in the Solar System

ERIC Educational Resources Information Center

Plummer, Julia

2015-01-01

Elementary students find it difficult to connect the apparent motion of objects in the sky with how celestial objects actually move in the solar system. As a university astronomy education researcher, the author has been investigating methods to help children learn astronomy through workshops and summer camps at science museums and planetariums.…

Sun Earth Day 2012, The Transit of Venus: From Mauna Kea to the World

NASA Astrophysics Data System (ADS)

Mayo, Louis

2012-10-01

For 2012, NASA’s Sun Earth Day program ( http://sunearthday.nasa.gov/ and http://venustransit.nasa.gov/ ), now in its 13th year, featured the transit of Venus as well as other close celestial encounters. A NASA sponsored team of scientists, social media experts, telescope technicians, students, and the NASA EDGE webcasting team journeyed to the 14,000 foot summit of Mauna Kea in Hawaii to view and share with the world this wondrous last in a lifetime show. Fifteen NASA missions participated providing educational resources and science content. And when it was all over, it was the biggest education event NASA ever held, bigger than the Super Bowl, the last shuttle flight, or Prince William’s wedding. Over 600 million web hits, 7.7 million web streams, and an estimated 500 million to 1 billion people reached. This presentation will highlight this phenomenal education program, discuss best practices, and show how we are replicating the Sun Earth Day approach and methods for other event based education programs.

The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III

NASA Astrophysics Data System (ADS)

Alam, Shadab; Albareti, Franco D.; Allende Prieto, Carlos; Anders, F.; Anderson, Scott F.; Anderton, Timothy; Andrews, Brett H.; Armengaud, Eric; Aubourg, Éric; Bailey, Stephen; Basu, Sarbani; Bautista, Julian E.; Beaton, Rachael L.; Beers, Timothy C.; Bender, Chad F.; Berlind, Andreas A.; Beutler, Florian; Bhardwaj, Vaishali; Bird, Jonathan C.; Bizyaev, Dmitry; Blake, Cullen H.; Blanton, Michael R.; Blomqvist, Michael; Bochanski, John J.; Bolton, Adam S.; Bovy, Jo; Shelden Bradley, A.; Brandt, W. N.; Brauer, D. E.; Brinkmann, J.; Brown, Peter J.; Brownstein, Joel R.; Burden, Angela; Burtin, Etienne; Busca, Nicolás G.; Cai, Zheng; Capozzi, Diego; Carnero Rosell, Aurelio; Carr, Michael A.; Carrera, Ricardo; Chambers, K. C.; Chaplin, William James; Chen, Yen-Chi; Chiappini, Cristina; Chojnowski, S. Drew; Chuang, Chia-Hsun; Clerc, Nicolas; Comparat, Johan; Covey, Kevin; Croft, Rupert A. C.; Cuesta, Antonio J.; Cunha, Katia; da Costa, Luiz N.; Da Rio, Nicola; Davenport, James R. A.; Dawson, Kyle S.; De Lee, Nathan; Delubac, Timothée; Deshpande, Rohit; Dhital, Saurav; Dutra-Ferreira, Letícia; Dwelly, Tom; Ealet, Anne; Ebelke, Garrett L.; Edmondson, Edward M.; Eisenstein, Daniel J.; Ellsworth, Tristan; Elsworth, Yvonne; Epstein, Courtney R.; Eracleous, Michael; Escoffier, Stephanie; Esposito, Massimiliano; Evans, Michael L.; Fan, Xiaohui; Fernández-Alvar, Emma; Feuillet, Diane; Filiz Ak, Nurten; Finley, Hayley; Finoguenov, Alexis; Flaherty, Kevin; Fleming, Scott W.; Font-Ribera, Andreu; Foster, Jonathan; Frinchaboy, Peter M.; Galbraith-Frew, J. G.; García, Rafael A.; García-Hernández, D. A.; García Pérez, Ana E.; Gaulme, Patrick; Ge, Jian; Génova-Santos, R.; Georgakakis, A.; Ghezzi, Luan; Gillespie, Bruce A.; Girardi, Léo; Goddard, Daniel; Gontcho, Satya Gontcho A.; González Hernández, Jonay I.; Grebel, Eva K.; Green, Paul J.; Grieb, Jan Niklas; Grieves, Nolan; Gunn, James E.; Guo, Hong; Harding, Paul; Hasselquist, Sten; Hawley, Suzanne L.; Hayden, Michael; Hearty, Fred R.; Hekker, Saskia; Ho, Shirley; Hogg, David W.; Holley-Bockelmann, Kelly; Holtzman, Jon A.; Honscheid, Klaus; Huber, Daniel; Huehnerhoff, Joseph; Ivans, Inese I.; Jiang, Linhua; Johnson, Jennifer A.; Kinemuchi, Karen; Kirkby, David; Kitaura, Francisco; Klaene, Mark A.; Knapp, Gillian R.; Kneib, Jean-Paul; Koenig, Xavier P.; Lam, Charles R.; Lan, Ting-Wen; Lang, Dustin; Laurent, Pierre; Le Goff, Jean-Marc; Leauthaud, Alexie; Lee, Khee-Gan; Lee, Young Sun; Licquia, Timothy C.; Liu, Jian; Long, Daniel C.; López-Corredoira, Martín; Lorenzo-Oliveira, Diego; Lucatello, Sara; Lundgren, Britt; Lupton, Robert H.; Mack, Claude E., III; Mahadevan, Suvrath; Maia, Marcio A. G.; Majewski, Steven R.; Malanushenko, Elena; Malanushenko, Viktor; Manchado, A.; Manera, Marc; Mao, Qingqing; Maraston, Claudia; Marchwinski, Robert C.; Margala, Daniel; Martell, Sarah L.; Martig, Marie; Masters, Karen L.; Mathur, Savita; McBride, Cameron K.; McGehee, Peregrine M.; McGreer, Ian D.; McMahon, Richard G.; Ménard, Brice; Menzel, Marie-Luise; Merloni, Andrea; Mészáros, Szabolcs; Miller, Adam A.; Miralda-Escudé, Jordi; Miyatake, Hironao; Montero-Dorta, Antonio D.; More, Surhud; Morganson, Eric; Morice-Atkinson, Xan; Morrison, Heather L.; Mosser, Benôit; Muna, Demitri; Myers, Adam D.; Nandra, Kirpal; Newman, Jeffrey A.; Neyrinck, Mark; Nguyen, Duy Cuong; Nichol, Robert C.; Nidever, David L.; Noterdaeme, Pasquier; Nuza, Sebastián E.; O'Connell, Julia E.; O'Connell, Robert W.; O'Connell, Ross; Ogando, Ricardo L. C.; Olmstead, Matthew D.; Oravetz, Audrey E.; Oravetz, Daniel J.; Osumi, Keisuke; Owen, Russell; Padgett, Deborah L.; Padmanabhan, Nikhil; Paegert, Martin; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K.; Pâris, Isabelle; Park, Changbom; Pattarakijwanich, Petchara; Pellejero-Ibanez, M.; Pepper, Joshua; Percival, Will J.; Pérez-Fournon, Ismael; P´rez-Ra`fols, Ignasi; Petitjean, Patrick; Pieri, Matthew M.; Pinsonneault, Marc H.; Porto de Mello, Gustavo F.; Prada, Francisco; Prakash, Abhishek; Price-Whelan, Adrian M.; Protopapas, Pavlos; Raddick, M. Jordan; Rahman, Mubdi; Reid, Beth A.; Rich, James; Rix, Hans-Walter; Robin, Annie C.; Rockosi, Constance M.; Rodrigues, Thaíse S.; Rodríguez-Torres, Sergio; Roe, Natalie A.; Ross, Ashley J.; Ross, Nicholas P.; Rossi, Graziano; Ruan, John J.; Rubiño-Martín, J. A.; Rykoff, Eli S.; Salazar-Albornoz, Salvador; Salvato, Mara; Samushia, Lado; Sánchez, Ariel G.; Santiago, Basílio; Sayres, Conor; Schiavon, Ricardo P.; Schlegel, David J.; Schmidt, Sarah J.; Schneider, Donald P.; Schultheis, Mathias; Schwope, Axel D.; Scóccola, C. G.; Scott, Caroline; Sellgren, Kris; Seo, Hee-Jong; Serenelli, Aldo; Shane, Neville; Shen, Yue; Shetrone, Matthew; Shu, Yiping; Silva Aguirre, V.; Sivarani, Thirupathi; Skrutskie, M. F.; Slosar, Anže; Smith, Verne V.; Sobreira, Flávia; Souto, Diogo; Stassun, Keivan G.; Steinmetz, Matthias; Stello, Dennis; Strauss, Michael A.; Streblyanska, Alina; Suzuki, Nao; Swanson, Molly E. C.; Tan, Jonathan C.; Tayar, Jamie; Terrien, Ryan C.; Thakar, Aniruddha R.; Thomas, Daniel; Thomas, Neil; Thompson, Benjamin A.; Tinker, Jeremy L.; Tojeiro, Rita; Troup, Nicholas W.; Vargas-Magaña, Mariana; Vazquez, Jose A.; Verde, Licia; Viel, Matteo; Vogt, Nicole P.; Wake, David A.; Wang, Ji; Weaver, Benjamin A.; Weinberg, David H.; Weiner, Benjamin J.; White, Martin; Wilson, John C.; Wisniewski, John P.; Wood-Vasey, W. M.; Ye`che, Christophe; York, Donald G.; Zakamska, Nadia L.; Zamora, O.; Zasowski, Gail; Zehavi, Idit; Zhao, Gong-Bo; Zheng, Zheng; Zhou, Xu; Zhou, Zhimin; Zou, Hu; Zhu, Guangtun

2015-07-01

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.

GALEX 1st Light Near Ultraviolet

NASA Image and Video Library

2003-05-28

This image was taken on May 21 and 22, 2003, by NASA Galaxy Evolution Explorer. The image was made from data gathered during the missions first light milestone, and shows celestial objects in the constellation Hercules.

A Clementine collection: Moonglow

NASA Astrophysics Data System (ADS)

1994-06-01

The Clementine story began in 1990 when NASA administrator Richard Truly asked the Department of Defense to consider a joint NASA/DOD mission that would achieve goals mutually beneficial to both organizations. That request was given to the then Strategic Defense Initiative Organization (SDIO) to investigate. A mission was conceived to test the latest in space-based imaging components, using the moon and a near-earth asteroid as celestial targets. The Clementine mission is the result of those early investigations. This collection is an early sampling of the 1.8 million images acquired by the Clementine spacecraft.

Star Watch: The Amateur Astronomer's Guide to Finding, Observing, and Learning about Over 125 Celestial Objects

NASA Astrophysics Data System (ADS)

Harrington, Philip S.

2003-07-01

Your Passport to the Universe The night sky is alive with many wonders--distant planets, vast star clusters, glowing nebulae, and expansive galaxies, all waiting to be explored. Let respected astronomy writer Philip Harrington introduce you to the universe in Star Watch, a complete beginner's guide to locating, observing, and understanding these celestial objects. You'll start by identifying the surface features of the Moon, the banded cloud tops of Jupiter, the stunning rings of Saturn, and other members of our solar system. Then you'll venture out beyond our solar system, where you'll learn tips and tricks for finding outstanding deep-sky objects from stars to galaxies, including the entire Messier catalog--a primary goal of every serious beginner. Star Watch features a detailed physical description of each target, including size, distance, and structure, as well as concise directions for locating the objects, handy finder charts, hints on the best times to view each object, and descriptions of what you'll really see through a small telescope or binoculars and with the naked eye. Star Watch will transport you to the farthest depths of space--and return you as a well-traveled, experienced stargazer.

Method for deploying multiple spacecraft

NASA Technical Reports Server (NTRS)

Sharer, Peter J. (Inventor)

2007-01-01

A method for deploying multiple spacecraft is disclosed. The method can be used in a situation where a first celestial body is being orbited by a second celestial body. The spacecraft are loaded onto a single spaceship that contains the multiple spacecraft and the spacecraft is launched from the second celestial body towards a third celestial body. The spacecraft are separated from each other while in route to the third celestial body. Each of the spacecraft is then subjected to the gravitational field of the third celestial body and each of the spacecraft assumes a different, independent orbit about the first celestial body. In those situations where the spacecraft are launched from Earth, the Sun can act as the first celestial body, the Earth can act as the second celestial body and the Moon can act as the third celestial body.

Synergies in Astrometry: Predicting Navigational Error of Visual Binary Stars

NASA Astrophysics Data System (ADS)

Gessner Stewart, Susan

2015-08-01

Celestial navigation can employ a number of bright stars which are in binary systems. Often these are unresolved, appearing as a single, center-of-light object. A number of these systems are, however, in wide systems which could introduce a margin of error in the navigation solution if not handled properly. To illustrate the importance of good orbital solutions for binary systems - as well as good astrometry in general - the relationship between the center-of-light versus individual catalog position of celestial bodies and the error in terrestrial position derived via celestial navigation is demonstrated. From the list of navigational binary stars, fourteen such binary systems with at least 3.0 arcseconds apparent separation are explored. Maximum navigational error is estimated under the assumption that the bright star in the pair is observed at maximum separation, but the center-of-light is employed in the navigational solution. The relationships between navigational error and separation, orbital periods, and observers' latitude are discussed.

Megalithic Monument of Abuli, Georgia, and Possible Astronomical Signi cance

NASA Astrophysics Data System (ADS)

Jijelava, Badri; Simonia, Irakli

2016-08-01

Background/Objectives: In recent years, in purpose of investigation of the artefacts, the ancient culture and religion, based on the astronomy knowledge play significant role. The aim of this work is to identify the orientations of the religious megalithic complexes and their correlation to the celestial luminaries. Methods/Statistical Analysis: We harmonized the archeological data, ethnographical, historical information and restoration of ancient celestial sphere (using special astronomy application), which give us possibility to identify the correlations between the acronychal or helical rising/ set of luminaries and directions of megalithic objects. Very often such connections are stored in a current folklore too. Findings: This technique of investigations give us more clear understanding of ancient universe. Using this method, we can receive latent information about the ancient Gods - Luminaries, clarify current mythology, date of the megalithic complex. Application/Improvements: This method of investigation is an additional instrument for archeological investigations,

Searching for Super Massive Binary Black Holes in the VLBA Calibrator Survey

NASA Astrophysics Data System (ADS)

High, Brittney C.; Peck, Alison B.; Beasley, Anthony J.

2016-01-01

Due to its incredible resolving power, the Very Long Baseline Array (VLBA) allows astronomers to view radio emission from celestial objects in incredible detail. This makes the VLBA the best instrument for studying the dynamics of active galactic nuclei, or compact regions at the centers of galaxies where black holes are thought to reside. Since most galaxies harbor supermassive black holes at their centers, and some galaxies merge with others, supermassive binary black hole systems arise. Though a number of these systems have been found, only one system contains black holes within 10 pc apart. During the summer, we analyzed new observations from the VLBA Calibrator Survey (VCS) on approximately 2200 sources in the hopes of detecting more close supermassive binary black hole candidates. Here we present the results from reducing and categorizing these sources. We also discuss the importance of the VCS and its role in enabling observations of the most distant celestial objects.

Improving Neural Network Generalization Ability Using Outlier Analysis and Voronoi Tessellation

NASA Technical Reports Server (NTRS)

Ho, Michelle; McIntosh, Dawn M.; Srivastava, Ashok N.

2006-01-01

The data used in this study was obtained from the Sloan Digital Sky Survey (SDSS), which provides astronomers with what is currently the most extensive mapping of the universe, covering 25% of the sky and cataloging the spectral properties (e.g., luminosity, color, surface temperature) of over 100 million celestial objects. Images generated by the SDSS are collected through 5 filters named u, g, r, l, and z that have respective wavelengths of 3540, 4750, 6222, 7632, and 9049 A. By measuring the photometric redshifts of the aforementioned wavelengths of a galaxy, astronomers can ascertain the extent to which galaxy is receding from which the distance to the galaxy can be calculated. Data collected for a small select group of galaxies (approximately 30, 000) contains accurate measurements of the galaxies' redshifts, in addition to measurements of their spectral properties. The above dataset containing both redshift measurements as well as spectral properties of the selected galaxies served as the training set for the purposes of this study; the data set containing only the spectra properties of a separate group of galaxies served as the test set.

Astro-1 Image Taken by the Ultraviolet Imaging Telescope

NASA Technical Reports Server (NTRS)

1990-01-01

This is a presentation of two comparison images of the Spiral Galaxy M81 in the constellation URA Major. The galaxy is about 12-million light years from Earth. The left image is the Spiral Galaxy M81 as photographed by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 Mission (STS-35) on December 9, 1990. This UIT photograph, made with ultraviolet light, reveals regions where new stars are forming at a rapid rate. The right image is a photograph of the same galaxy in red light made with a 36-inch (0.9-meter) telescope at the Kitt Peak National Observatory near Tucson, Arizona. The Astro Observatory was designed to explore the universe by observing and measuring ultraviolet radiation from celestial objects. Three instruments made up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had management responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

Orbit Modification of Earth-Crossing Asteroids/Comets Using Rendezvous Spacecraft and Laser Ablation

NASA Technical Reports Server (NTRS)

Park, Sang-Young; Mazanek, Daniel D.

2005-01-01

This report describes the approach and results of an end-to-end simulation to deflect a long-period comet (LPC) by using a rapid rendezvous spacecraft and laser ablation system. The laser energy required for providing sufficient deflection DELTA V and an analysis of possible intercept/rendezvous spacecraft trajectories are studied in this analysis. These problems minimize a weighted sum of the flight time and required propellant by using an advanced propulsion system. The optimal thrust-vector history and propellant mass to use are found in order to transfer a spacecraft from the Earth to a targeted celestial object. One goal of this analysis is to formulate an optimization problem for intercept/rendezvous spacecraft trajectories. One approach to alter the trajectory of the object in a highly controlled manner is to use pulsed laser ablative propulsion. A sufficiently intense laser pulse ablates the surface of a near-Earth object (NEO) by causing plasma blowoff. The momentum change from a single laser pulse is very small. However, the cumulative effect is very effective because the laser can interact with the object over long periods of time. The laser ablation technique can overcome the mass penalties associated with other nondisruptive approaches because no propellant is required to generate the DELTA V (the material of the celestial object is the propellant source). Additionally, laser ablation is effective against a wide range of surface materials and does not require any landing or physical attachment to the object. For diverting distant asteroids and comets, the power and optical requirements of a laser ablation system on or near the Earth may be too extreme to contemplate in the next few decades. A hybrid solution would be for a spacecraft to carry a laser as a payload to a particular celestial body. The spacecraft would require an advanced propulsion system capable of rapid rendezvous with the object and an extremely powerful electrical generator, which is likely needed for the propulsion system as well. The spacecraft would station-keep with the object at a small standoff distance while the laser ablation is performed.

An historic discovery around the corner from school: Ceres, a solar system object with an uncertain identity.

NASA Astrophysics Data System (ADS)

Stira, Salvatore

2016-04-01

Ceres is the largest object in the asteroid belt between Mars and Jupiter, and it was discovered on January 1, 1801, by the Italian astronomer Giuseppe Piazzi. The study of Ceres is especially relevant to my students because this celestial body was discovered in Palermo, in the astronomic observatory located in the UNESCO world heritage site "Palazzo dei Normanni", around 500 meters away from the institute where I teach, and because Ceres was considered the patron goddess of Sicily. Moreover, it received scientists and media attention recently because it was explored by the NASA Dawn spacecraft in 2015. The categorization of Ceres has changed more than once and has been the subject of some disagreement. It was originally considered a planet, but was reclassified as an asteroid in the 1850s when many other objects in similar orbits were discovered. Its status changed again in 2006 when it was promoted to dwarf planet, a classification it shares with Pluto and other Kuiper belt objects. The study of this celestial body has a notable educational value, since the uncertain identity of Ceres constitutes an occasion to reflect on the criterions of classification of the natural objects. The history of its discovery allows the students to understand as the scientific method doesn't always consist in the verification of hypothesis through experiments but it sometimes asks for the forecast of facts through mathematical calculations, repeated and methodic observations, the collaboration between scientists of different sectors and nationality. Furthermore, it is a particularly suitable topic for interdisciplinary connections, as regards both scientific and humanistic matters. In order to promote the scientific competences of my first class students, I have developed a learning unit on Ceres, thanks to good cooperation with the Palermo Observatory scientists, particularly active in the astronomic dissemination towards the schools and the citizens. The most meaningful activities of the learning units have been: 1) Working in groups: classification of solar system objects through the use of cards with figures and description of the celestial bodies. 2) A guided tour to Palermo Astronomic Observatory Museum, where stored instruments used by Piazzi for observation of Ceres and the original scientific documentation regarding this important discovery. 3) Internet search of information on the mission Dawn and implementation of Learning objects on this matter. 4) A guided visit to the exhibition "Cerere, da Piazzi a Dawn"; This learning unit, that has aroused interest and active participation among the students, cannot be regarded as closed, because it can be used for the discussion of other matters (for instance the search of the life on other celestial bodies).

GALEX 1st Light Far Ultraviolet

NASA Image and Video Library

2003-05-28

This image was taken May 21 and 22, 2003 by NASA Galaxy Evolution Explorer. The image was made from data gathered by the far ultraviolet channel of the spacecraft camera during the mission first light milestone. It shows about 400 celestial objects

Record-Breaking Radio Astronomy Project to Measure Sky with Extreme Precision

NASA Astrophysics Data System (ADS)

2009-11-01

Astronomers will tie together the largest collection of the world's radio telescopes ever assembled to work as a single observing tool in a project aimed at improving the precision of the reference frame scientists use to measure positions in the sky. The National Science Foundation's Very Long Baseline Array (VLBA) will be a key part of the project, which is coordinated by the International VLBI Service for Geodesy and Astrometry. For 24 hours, starting Wednesday, November 18, and ending Thursday, November 19, 35 radio telescopes located on seven continents will observe 243 distant quasars. The quasars, galaxies with supermassive black holes at their cores, are profuse emitters of radio waves, and also are so distant that, despite their actual motions in space, they appear stationary as seen from Earth. This lack of apparent motion makes them ideal celestial landmarks for anchoring a grid system, similar to earthly latitude and longitude, used to mark the positions of celestial objects. Data from all the radio telescopes will be combined to make them work together as a system capable of measuring celestial positions with extremely high precision. The technique used, called very long baseline interferometry (VLBI), has been used for decades for both astronomical and geodetic research. However, no previous position-measuring observation has used as many radio telescopes or observed as many objects in a single session. The previous record was a 23-telescope observation. At a meeting in Brazil last August, the International Astronomical Union adopted a new reference frame for celestial positions that will be used starting on January 1. This new reference frame uses a set of 295 quasars to define positions, much like surveyor's benchmarks in a surburban subdivision. Because even with 35 radio telescopes around the world, there are some gaps in sky coverage, the upcoming observation will observe 243 of the 295. By observing so many quasars in a single observing session, problems of linking positions from one observing session to another can be avoided, the astronomers say. The result will be a much stronger, more precise, reference grid. Telescopes in Asia, Australia, Europe, North America, South America, Antarctica, and in the Pacific will participate. Improving the celestial positional grid will allow astronomers better to pinpoint the locations and measure the motions of objects in the sky. As astronomers increasingly study objects using multiple telescopes observing at different wavelengths, such as visible light, radio, infrared, etc., the improved positional grid will allow more accurate overlaying of the different images. The improved celestial reference frame also strengthens a terrestrial reference frame used for radio-telescope measurements that contribute to geophysical research. The precise geodetic measurements help geophysicists understand phenomena such as plate tectonics, earth tides, and processes that affect our planet's orientation in space. The VLBA is a continent-wide radio telescope system with 10, 240-ton dish antennas ranging from Hawaii to the Virgin Islands. Operated from the National Radio Astronomy Observatory's Pete V. Domenici Science Operations Center in Socorro, New Mexico, the VLBA offers the greatest resolving power, or ability to see fine detail, of any telescope in astronomy. The multi-telescope observation will be accompanied by public-outreach activities in celebration of the International Year of Astronomy. A public web page devoted to the observation will be hosted at Bordeaux Observatory, and some of the participating telescopes will have webcams available.

Optical Spectra of Candidate International Celestial Reference Frame (ICRF) Flat-spectrum Radio Sources. III.

NASA Astrophysics Data System (ADS)

Titov, O.; Pursimo, T.; Johnston, Helen M.; Stanford, Laura M.; Hunstead, Richard W.; Jauncey, David L.; Zenere, Katrina A.

2017-04-01

In extending our spectroscopic program, which targets sources drawn from the International Celestial Reference Frame (ICRF) Catalog, we have obtained spectra for ˜160 compact, flat-spectrum radio sources and determined redshifts for 112 quasars and radio galaxies. A further 14 sources with featureless spectra have been classified as BL Lac objects. Spectra were obtained at three telescopes: the 3.58 m European Southern Observatory New Technology Telescope, and the two 8.2 m Gemini telescopes in Hawaii and Chile. While most of the sources are powerful quasars, a significant fraction of radio galaxies is also included from the list of non-defining ICRF radio sources.

Optical Spectra of Candidate International Celestial Reference Frame (ICRF) Flat-spectrum Radio Sources. III

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

Titov, O.; Stanford, Laura M.; Pursimo, T.

In extending our spectroscopic program, which targets sources drawn from the International Celestial Reference Frame (ICRF) Catalog, we have obtained spectra for ∼160 compact, flat-spectrum radio sources and determined redshifts for 112 quasars and radio galaxies. A further 14 sources with featureless spectra have been classified as BL Lac objects. Spectra were obtained at three telescopes: the 3.58 m European Southern Observatory New Technology Telescope, and the two 8.2 m Gemini telescopes in Hawaii and Chile. While most of the sources are powerful quasars, a significant fraction of radio galaxies is also included from the list of non-defining ICRF radiomore » sources.« less

Celestial mechanics - Methods of the theory of motion of 'artificial' celestial bodies

NASA Astrophysics Data System (ADS)

Duboshin, G. N.

This book is concerned with the translational motion of 'artificial' celestial bodies. The difference between natural celestial bodies, which are ordinarily considered by celestial mechanics, and 'artificial' celestial bodies is discussed, taking into account hypothetical celestial bodies introduced in connection with mathematical developments and problems, invisible celestial bodies whose existence can be assumed on the basis of some plausible hypothesis, and man-made satellites of the earth. The book consists of two parts. The first part presents introductory material, and examines a number of general mathematical questions to provide a basis for the studies conducted in the second part. Subjects considered in the first part are related to basic problems, integration methods, and perturbation theory. In the second part, attention is given to the motion of artificial celestial bodies in the gravitational field of the basic planet, external perturbations regarding the motion of these bodies, the motion of the bodies in the earth-moon system, and periodic solutions.

Polarized Light in Astronomy.

ERIC Educational Resources Information Center

King, D. J.

1983-01-01

The application of very sensitive electronic detecting devices during the last decade has revolutionized and revitalized the study of polarization in celestial objects. The nature of polarization, how polaroids work, interstellar polarization, dichroic filters, polarization by scattering, and modern polarimetry are among the topics discussed. (JN)

Brown dwarfs: at last filling the gap between stars and planets.

PubMed

Zuckerman, B

2000-02-01

Until the mid-1990s a person could not point to any celestial object and say with assurance that "here is a brown dwarf." Now dozens are known, and the study of brown dwarfs has come of age, touching upon major issues in astrophysics, including the nature of dark matter, the properties of substellar objects, and the origin of binary stars and planetary systems.

In The Night Sky: Sky Lore.

ERIC Educational Resources Information Center

Judge, April

1997-01-01

Presents picture books, collections of star stories, poetry, magazines, radio programs, biographies, nonfiction, and activities to help young students (preschool-grade 8) understand what celestial objects meant to ancient civilizations and to provide insights into the customs and attitudes of other cultures; alternative literary experiences; and…

[Galaxy/quasar classification based on nearest neighbor method].

PubMed

Li, Xiang-Ru; Lu, Yu; Zhou, Jian-Ming; Wang, Yong-Jun

2011-09-01

With the wide application of high-quality CCD in celestial spectrum imagery and the implementation of many large sky survey programs (e. g., Sloan Digital Sky Survey (SDSS), Two-degree-Field Galaxy Redshift Survey (2dF), Spectroscopic Survey Telescope (SST), Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) program and Large Synoptic Survey Telescope (LSST) program, etc.), celestial observational data are coming into the world like torrential rain. Therefore, to utilize them effectively and fully, research on automated processing methods for celestial data is imperative. In the present work, we investigated how to recognizing galaxies and quasars from spectra based on nearest neighbor method. Galaxies and quasars are extragalactic objects, they are far away from earth, and their spectra are usually contaminated by various noise. Therefore, it is a typical problem to recognize these two types of spectra in automatic spectra classification. Furthermore, the utilized method, nearest neighbor, is one of the most typical, classic, mature algorithms in pattern recognition and data mining, and often is used as a benchmark in developing novel algorithm. For applicability in practice, it is shown that the recognition ratio of nearest neighbor method (NN) is comparable to the best results reported in the literature based on more complicated methods, and the superiority of NN is that this method does not need to be trained, which is useful in incremental learning and parallel computation in mass spectral data processing. In conclusion, the results in this work are helpful for studying galaxies and quasars spectra classification.

Brown dwarfs: At last filling the gap between stars and planets

PubMed Central

Zuckerman, Ben

2000-01-01

Until the mid-1990s a person could not point to any celestial object and say with assurance that “here is a brown dwarf.” Now dozens are known, and the study of brown dwarfs has come of age, touching upon major issues in astrophysics, including the nature of dark matter, the properties of substellar objects, and the origin of binary stars and planetary systems. PMID:10655468

Enhanced Algorithms for EO/IR Electronic Stabilization, Clutter Suppression, and Track-Before-Detect for Multiple Low Observable Targets

NASA Astrophysics Data System (ADS)

Tartakovsky, A.; Brown, A.; Brown, J.

The paper describes the development and evaluation of a suite of advanced algorithms which provide significantly-improved capabilities for finding, fixing, and tracking multiple ballistic and flying low observable objects in highly stressing cluttered environments. The algorithms have been developed for use in satellite-based staring and scanning optical surveillance suites for applications including theatre and intercontinental ballistic missile early warning, trajectory prediction, and multi-sensor track handoff for midcourse discrimination and intercept. The functions performed by the algorithms include electronic sensor motion compensation providing sub-pixel stabilization (to 1/100 of a pixel), as well as advanced temporal-spatial clutter estimation and suppression to below sensor noise levels, followed by statistical background modeling and Bayesian multiple-target track-before-detect filtering. The multiple-target tracking is performed in physical world coordinates to allow for multi-sensor fusion, trajectory prediction, and intercept. Output of detected object cues and data visualization are also provided. The algorithms are designed to handle a wide variety of real-world challenges. Imaged scenes may be highly complex and infinitely varied -- the scene background may contain significant celestial, earth limb, or terrestrial clutter. For example, when viewing combined earth limb and terrestrial scenes, a combination of stationary and non-stationary clutter may be present, including cloud formations, varying atmospheric transmittance and reflectance of sunlight and other celestial light sources, aurora, glint off sea surfaces, and varied natural and man-made terrain features. The targets of interest may also appear to be dim, relative to the scene background, rendering much of the existing deployed software useless for optical target detection and tracking. Additionally, it may be necessary to detect and track a large number of objects in the threat cloud, and these objects may not always be resolvable in individual data frames. In the present paper, the performance of the developed algorithms is demonstrated using real-world data containing resident space objects observed from the MSX platform, with backgrounds varying from celestial to combined celestial and earth limb, with instances of extremely bright aurora clutter. Simulation results are also presented for parameterized variations in signal-to-clutter levels (down to 1/1000) and signal-to-noise levels (down to 1/6) for simulated targets against real-world terrestrial clutter backgrounds. We also discuss algorithm processing requirements and C++ software processing capabilities from our on-going MDA- and AFRL-sponsored development of an image processing toolkit (iPTK). In the current effort, the iPTK is being developed to a Technology Readiness Level (TRL) of 6 by mid-2010, in preparation for possible integration with STSS-like, SBIRS high-like and SBSS-like surveillance suites.

From Hipparcos to Gaia

NASA Astrophysics Data System (ADS)

Eyer, L.; Dubath, P.; Saesen, S.; Evans, D. W.; Wyrzykowski, L.; Hodgkin, S.; Mowlavi, N.

2012-04-01

The measurement of the positions, distances, motions and luminosities of stars represents the foundations of modern astronomical knowledge. Launched at the end of the eighties, the ESA Hipparcos satellite was the first space mission dedicated to such measurements. Hipparcos improved position accuracies by a factor of 100 compared to typical ground-based results and provided astrometric and photometric multi-epoch observations of 118,000 stars over the entire sky. The impact of Hipparcos on astrophysics has been extremely valuable and diverse. Building on this important European success, the ESA Gaia cornerstone mission promises an even more impressive advance. Compared to Hipparcos, it will bring a gain of a factor 50 to 100 in position accuracy and of a factor of 10,000 in star number, collecting photometric, spectrophotometric and spectroscopic data for one billion celestial objects. During its 5-year flight, Gaia will measure objects repeatedly, up to a few hundred times, providing an unprecedented database to study the variability of all types of celestial objects. Gaia will bring outstanding contributions, directly or indirectly, to most fields of research in astrophysics, such as the study of our Galaxy and of its stellar constituents, and the search for planets outside the solar system.

High Resolution Asteroid Profile by Multi Chord Occultation Observations

NASA Astrophysics Data System (ADS)

Degenhardt, Scott

2009-05-01

For millennia man has observed celestial objects occulting other bodies and distant stars. We have used these celestial synchronicities to measure the properties of objects. On January 1, 1801 Italian astronomer Giusappe Piazzi discovered the first asteroid that would soon be named Ceres. To date 190,000 of these objects have been catalogued, but only a fraction of these have accurate measurements of their true size and shape. The International Occultation Timing Association (IOTA) currently facilitates the prediction and reduction of asteroidal occultations. By measuring the shadow cast on the earth by an asteroid during a stellar occultation one can directly measure the physical size, shape, and position in space of this body to accuracies orders of magnitudes better than the best ground based adaptive optics telescope and can provide verification to 3D inverted reflective lightcurve prediction models. Recent novel methods developed by IOTA involving an individual making multiple observations through unattended remote observing stations have made way for numerous chords of occultation measurement through a single body yielding high resolution profiles of asteroid bodies. Methodology of how observing stations are deployed will be demonstrated, results of some of these observations are presented as comparisons to their inverted lightcurve are shown.

The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0

NASA Astrophysics Data System (ADS)

Kochanek, C. S.; Shappee, B. J.; Stanek, K. Z.; Holoien, T. W.-S.; Thompson, Todd A.; Prieto, J. L.; Dong, Subo; Shields, J. V.; Will, D.; Britt, C.; Perzanowski, D.; Pojmański, G.

2017-10-01

The All-Sky Automated Survey for Supernovae (ASAS-SN) is working toward imaging the entire visible sky every night to a depth of V˜ 17 mag. The present data covers the sky and spans ˜2-5 years with ˜100-400 epochs of observation. The data should contain some ˜1 million variable sources, and the ultimate goal is to have a database of these observations publicly accessible. We describe here a first step, a simple but unprecedented web interface https://asas-sn.osu.edu/ that provides an up to date aperture photometry light curve for any user-selected sky coordinate. The V band photometry is obtained using a two-pixel (16.″0) radius aperture and is calibrated against the APASS catalog. Because the light curves are produced in real time, this web tool is relatively slow and can only be used for small samples of objects. However, it also imposes no selection bias on the part of the ASAS-SN team, allowing the user to obtain a light curve for any point on the celestial sphere. We present the tool, describe its capabilities, limitations, and known issues, and provide a few illustrative examples.

QUIKVIS- CELESTIAL TARGET AVAILABILITY INFORMATION

NASA Technical Reports Server (NTRS)

Petruzzo, C.

1994-01-01

QUIKVIS computes the times during an Earth orbit when geometric requirements are satisfied for observing celestial objects. The observed objects may be fixed (stars, etc.) or moving (sun, moon, planets). QUIKVIS is useful for preflight analysis by those needing information on the availability of celestial objects to be observed. Two types of analyses are performed by QUIKVIS. One is used when specific objects are known, the other when targets are unknown and potentially useful regions of the sky must be identified. The results are useful in selecting candidate targets, examining the effects of observation requirements, and doing gross assessments of the effects of the orbit's right ascension of the ascending node (RAAN). The results are not appropriate when high accuracy is needed (e.g. for scheduling actual mission operations). The observation duration is calculated as a function of date, orbit node, and geometric requirements. The orbit right ascension of the ascending node can be varied to account for the effects of an uncertain launch time of day. The orbit semimajor axis and inclination are constant throughout the run. A circular orbit is assumed, but a simple program modification will allow eccentric orbits. The geometric requirements that can be processed are: 1) minimum separation angle between the line of sight to the object and the earth's horizon; 2) minimum separation angle between the line of sight to the object and the spacecraft velocity vector; 3) maximum separation angle between the line of sight to the object and the zenith direction; and 4) presence of the spacecraft in the earth's shadow. The user must supply a date or date range, the spacecraft orbit and inclination, up to 700 observation targets, and any geometric requirements to be met. The primary output is the time per orbit that conditions are satisfied, with options for sky survey maps, time since a user-specified orbit event, and bar graphs illustrating overlapping requirements. The output is printed in visually convenient lineprinter form but is also available on data files for use by postprocessors such as external XY plotters. QUIKVIS is written in FORTRAN 77 for batch or interactive execution and has been implemented on a DEC VAX 11/780 operating under VMS with a central memory requirement of approximately 500K of 8 bit bytes. QUIKVIS was developed in 1986 and revised in 1987.

The eleventh and twelfth data releases of the Sload Digital Sky Survey: final data from SDSS-III

DOE PAGES

Alam, S.; Slosar, A.; Albareti, F. D.; ...

2015-07-01

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12more » adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg 2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg 2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg 2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.« less

The eleventh and twelfth data release of the Sloan Digital Sky Survey: Final data from SDSS-III

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

Alam, Shadab; Albareti, Franco D.; Prieto, Carlos Allende

2015-07-20

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12more » adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg 2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg 2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg 2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.« less

THE ELEVENTH AND TWELFTH DATA RELEASES OF THE SLOAN DIGITAL SKY SURVEY: FINAL DATA FROM SDSS-III

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

Alam, Shadab; Albareti, Franco D.; Prieto, Carlos Allende

2015-07-15

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12more » adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg{sup 2} of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg{sup 2} of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg{sup 2}; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.« less

Ground Testing of Prototype Hardware and Processing Algorithms for a Wide Area Space Surveillance System (WASSS)

NASA Astrophysics Data System (ADS)

Goldstein, N.; Dressler, R. A.; Richtsmeier, S. S.; McLean, J.; Dao, P. D.; Murray-Krezan, J.; Fulcoly, D. O.

2013-09-01

Recent ground testing of a wide area camera system and automated star removal algorithms has demonstrated the potential to detect, quantify, and track deep space objects using small aperture cameras and on-board processors. The camera system, which was originally developed for a space-based Wide Area Space Surveillance System (WASSS), operates in a fixed-stare mode, continuously monitoring a wide swath of space and differentiating celestial objects from satellites based on differential motion across the field of view. It would have greatest utility in a LEO orbit to provide automated and continuous monitoring of deep space with high refresh rates, and with particular emphasis on the GEO belt and GEO transfer space. Continuous monitoring allows a concept of change detection and custody maintenance not possible with existing sensors. The detection approach is equally applicable to Earth-based sensor systems. A distributed system of such sensors, either Earth-based, or space-based, could provide automated, persistent night-time monitoring of all of deep space. The continuous monitoring provides a daily record of the light curves of all GEO objects above a certain brightness within the field of view. The daily updates of satellite light curves offers a means to identify specific satellites, to note changes in orientation and operational mode, and to queue other SSA assets for higher resolution queries. The data processing approach may also be applied to larger-aperture, higher resolution camera systems to extend the sensitivity towards dimmer objects. In order to demonstrate the utility of the WASSS system and data processing, a ground based field test was conducted in October 2012. We report here the results of the observations made at Magdalena Ridge Observatory using the prototype WASSS camera, which has a 4×60° field-of-view , <0.05° resolution, a 2.8 cm2 aperture, and the ability to view within 4° of the sun. A single camera pointed at the GEO belt provided a continuous night-long record of the intensity and location of more than 50 GEO objects detected within the camera's 60-degree field-of-view, with a detection sensitivity similar to the camera's shot noise limit of Mv=13.7. Performance is anticipated to scale with aperture area, allowing the detection of dimmer objects with larger-aperture cameras. The sensitivity of the system depends on multi-frame averaging and an image processing algorithm that exploits the different angular velocities of celestial objects and SOs. Principal Components Analysis (PCA) is used to filter out all objects moving with the velocity of the celestial frame of reference. The resulting filtered images are projected back into an Earth-centered frame of reference, or into any other relevant frame of reference, and co-added to form a series of images of the GEO objects as a function of time. The PCA approach not only removes the celestial background, but it also removes systematic variations in system calibration, sensor pointing, and atmospheric conditions. The resulting images are shot-noise limited, and can be exploited to automatically identify deep space objects, produce approximate state vectors, and track their locations and intensities as a function of time.

Space Geodesy, VLBI, and the Fourth Pillar of Geodesy - Spacetime Curvature

NASA Astrophysics Data System (ADS)

Combrinck, Ludwig

2014-12-01

Typically geodesy is described as having ``three pillars'': the variations in Earth's shape, gravity field, and rotation. These pillars form the conceptual and observational basis for the celestial and terrestrial reference frames required for Earth and space observations. However, it is no longer adequate to base the conceptual and observational basis on only three pillars. Spacetime curvature as described by the General Theory of Relativity (GTR) is an integral component of all space geodesy techniques and influences all measurements, techniques, and data reduction. Spacetime curvature is therefore the fourth pillar. It is the measurement of the shape of spacetime and its variations. Due to accuracies of Very Long Baseline Interferometry (VLBI) and optical celestial reference frame measurements reaching the tens of micro-arcsecond level in the near future, it is essential to recognize the impact of spacetime seeing on the accuracy objectives of the Global Geodetic Observing System. Spacetime seeing (resulting from spacetime curvature) is analogous to astronomical seeing (resulting from atmospheric conditions), as all of spacetime is affected by microlensing/weak lensing to some extent as a result of mass (normal baryonic and darkmatter) distribution, placing a limit on the realization of the celestial reference frame.

The Improvement of Automated Spectral Identification Tool ASERA

NASA Astrophysics Data System (ADS)

Yuan, Hailong; zhang, Yanxia

2015-08-01

The regular survey of Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has acquired over four millions spectra of celestial objects by the summer of 2014, covering about a third of the whole sky area. More spectra will be obtained as the survey projects (eg. LAMOST, SDSS) keeps going on. To effectively make use of the massive spectral data, various advanced data analysis methods and technologies are in great requirement. ASERA, A Spectrum Eye Recognition Assistant, provides a simple convenient solution for the user to access spectra from LAMOST and SDSS, identify their types (QSO, galaxy, and various types of stars) and estimate their redshifts in an interactive graphic interface. The toolkit is at first especially designed for quasar identification. By shifting the quasar template overlaping the target spectrum interactively, one can easily find out the best broad emission line position and the redshift value. Now, besides the quasar template, various templates for different types of galaxies (early type, later type, starburst, bulge, elliptical and luminous red galaxies) and stars (O, B, A, F, G, K, M, WD, CV, Double Stars and Emission-Line-Objects) are added. We also have developed many new useful functionalities for inspecting and analyzing spectra, such as zooming, line fitting, smoothing and automatic result saving. The target information from input catalogues and data processing result from the pipeline as well as fitting parameters for various types of templates, can be presented at the same time. Several volume processing components are developed to support the cooperation with MySQL database, internet resources and SSAP services. ASERA will be a strong helper for astronomers to recognize spectra.

GALEX 1st Light Far Ultraviolet

NASA Technical Reports Server (NTRS)

2003-01-01

This image was taken May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered by the far ultraviolet channel of the spacecraft camera during the mission's 'first light' milestone. It shows about 400 celestial objects, appearing in blue, detected over a 3-minute, 20-second period in the constellation Hercules.

The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas.

The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years.

The historical tension between astronomical theory and observation

NASA Astrophysics Data System (ADS)

Gingerich, O.

A review of instances in the history of astronomy wherein conflicts between the results of theory and observation occurred, to be later ameliorated or exaggerated by further evidence, is presented. Among the examples are Aristotle's arguments that the form of a celestial body will always be spherical to evenly distribute the mass, and the currently held concept that all celestial objects greater than a few kilometers in radius will be spherical due to gravitational forces. Ptolemy's observations of planetary orbits, however, are noted to have accurately resulted in a numerical model which did not factually represent planetary orbits. It is noted that observation is usually performed with a theory in mind, and interpretation is therefore hindered from clear analysis of phenomena which do not conform to previously held mental models.

Observation of Celestial Phenomena in Ancient China

NASA Astrophysics Data System (ADS)

Sun, Xiaochun

Because of the need for calendar-making and portent astrology, the Chinese were diligent and meticulous observers of celestial phenomena. China has maintained the longest continuous historical records of celestial phenomena in the world. Extraordinary or abnormal celestial events were particularly noted because of their astrological significance. The historical records cover various types of celestial phenomena, which include solar and lunar eclipses, sunspots, "guest stars" (novae or supernovae as we understand today), comets and meteors, and all kinds of planetary phenomena. These records provide valuable historical data for astronomical studies today.

Proceedings of the Near-Earth-Object Interception Workshop

NASA Technical Reports Server (NTRS)

Canavan, G. J. (Editor); Solem, J. C. (Editor); Rather, John D. G. (Editor)

1993-01-01

The National Aeronautics and Space Administration Headquarters sponsored the Near-Earth-Object Interception Workshop hosted by the Los Alamos National Laboratory on 14-16 Jan. 1992 at the J. Robert Oppenheimer Study Center in Los Alamos, New Mexico. The Workshop evaluated the issues involved in intercepting celestial objects that could hit the Earth. It covered the technologies for acquiring, tracking, and homing, as well as those for sending interceptors to inspect, rendezvous with, land on, irradiate, deflect, or destroy them. This report records the presentations and technical options reviewed.

Stargazing

ERIC Educational Resources Information Center

Mayes, Valynda

2010-01-01

In 2009, we had the year of astronomy. Even President Obama hosted an astronomy night on the White House lawn. Your explorations of nature need not be limited to daylight hours--though it is important to point our when celestial objects like the Moon are visible during the day to counter misconceptions. This year, introduce your students to the…

Spatial Thinking as the Dimension of Progress in an Astronomy Learning Progression

ERIC Educational Resources Information Center

Plummer, Julia D.

2014-01-01

The big idea of "celestial motion", observational astronomy phenomena explained by the relative position and motion of objects in the solar system and beyond, is central to astronomy in primary and secondary education. In this paper, I argue that students' progress in developing productive, scientific explanations for this class of…

Evidence of an Upper Bound on the Masses of Planets and Its Implications for Giant Planet Formation

NASA Astrophysics Data System (ADS)

Schlaufman, Kevin C.

2018-01-01

Celestial bodies with a mass of M≈ 10 {M}{Jup} have been found orbiting nearby stars. It is unknown whether these objects formed like gas-giant planets through core accretion or like stars through gravitational instability. I show that objects with M≲ 4 {M}{Jup} orbit metal-rich solar-type dwarf stars, a property associated with core accretion. Objects with M≳ 10 {M}{Jup} do not share this property. This transition is coincident with a minimum in the occurrence rate of such objects, suggesting that the maximum mass of a celestial body formed through core accretion like a planet is less than 10 {M}{Jup}. Consequently, objects with M≳ 10 {M}{Jup} orbiting solar-type dwarf stars likely formed through gravitational instability and should not be thought of as planets. Theoretical models of giant planet formation in scaled minimum-mass solar nebula Shakura–Sunyaev disks with standard parameters tuned to produce giant planets predict a maximum mass nearly an order of magnitude larger. To prevent newly formed giant planets from growing larger than 10 {M}{Jup}, protoplanetary disks must therefore be significantly less viscous or of lower mass than typically assumed during the runaway gas accretion stage of giant planet formation. Either effect would act to slow the Type I/II migration of planetary embryos/giant planets and promote their survival. These inferences are insensitive to the host star mass, planet formation location, or characteristic disk dissipation time.

Stars on the Ceiling

NASA Astrophysics Data System (ADS)

Krupp, E. C.

2016-01-01

Astronomy and celestial imagery have been incorporated into architectural ceilings from antiquity to the present to reference the sky on behalf of a variety of agendas. Burial chambers in Egyptian pyramids and tombs, the Osiris chapel on the roof of Ptolemaic Egypt's Temple of Dendera, ancient Chinese tombs, painted rock shelters in California and the American Southwest, the cupola above a hot bath from medieval Jordan, elaborately illustrated ceilings in Italian cathedrals and palaces, the main concourse in New York's Grand Central Terminal, and a variety of other public buildings in America all brought the sky inside to convey relationships between the architecture, people, and the cosmos. In these interior environments, the symbolic function of the astronomical ceiling is driven by the thematic function of the building. At Griffith Observatory in Los Angeles three signature spaces are equipped with astronomically illustrated ceilings. In content and location, these prominent murals operate symbolically to convey meaning through public display and unexpectedly prompt people to think more expansively about the universe. This artwork is familiar in Los Angeles, but its use in a public observatory puts it outside the range of most commentaries on public art. Although experienced by more than seventy-six million persons over the last eighty years, Griffith Observatory's celestial murals are not well known. Their history, content, character, meaning, and purpose are detailed here.

Protection of celestial environments and the law of outer space

NASA Astrophysics Data System (ADS)

Tennen, Leslie; Race, Margaret

The law of outer space expressly addresses the matter of preservation and protection of natural celestial environments from harmful contamination and disruption by mankind in the explo-ration and use of outer space, including the moon and other celestial bodies. The Outer Space Treaty, however, does not prohibit all human impact to an extraterrestrial environment, but rather permits a wide range of activities that could have significant environmental ramifications. This legal regime may be in conflict with the interests of preserving celestial environments for scientific research, especially when considered in relation to activities conducted for commercial purposes. Nevertheless, the Moon Agreement provides a mechanism by which special protective measures can be implemented to protect particular areas of the moon and other celestial bodies for scientific investigation. This paper examines the current status of the law of outer space vis-a-vis the protection and preservation of natural celestial environments. Particular emphasis is placed on the policies on which the legal obligations are based, together with consideration of the non-appropriation principle, and the commercial use of lunar and other celestial resources and areas. In addition, the concepts of international scientific preserves, special regions, keep out zones, and planetary parks are compared and evaluated as potential means to limit the disturbance to celestial environments caused by the activities of mankind.

Observation in the MINOS far detector of the shadowing of cosmic rays by the sun and moon

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

Jaffe, D.E.; Bishai, M.; Diwan, M.V.

2010-10-10

The shadowing of cosmic ray primaries by the moon and sun was observed by the MINOS far detector at a depth of 2070 mwe using 83.54 million cosmic ray muons accumulated over 1857.91 live-days. The shadow of the moon was detected at the 5.6 {sigma} level and the shadow of the sun at the 3.8 {sigma} level using a log-likelihood search in celestial coordinates. The moon shadow was used to quantify the absolute astrophysical pointing of the detector to be 0.17 {+-} 0.12{sup o}. Hints of interplanetary magnetic field effects were observed in both the sun and moon shadow.

Observation in the MINOS far detector of the shadowing of cosmic rays by the sun and moon

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

Adamson, P.; /Fermilab; Andreopoulos, C.

2010-08-01

The shadowing of cosmic ray primaries by the the moon and sun was observed by the MINOS far detector at a depth of 2070 mwe using 83.54 million cosmic ray muons accumulated over 1857.91 live-days. The shadow of the moon was detected at the 5.6 {sigma} level and the shadow of the sun at the 3.8 {sigma} level using a log-likelihood search in celestial coordinates. The moon shadow was used to quantify the absolute astrophysical pointing of the detector to be 0.17 {+-} 0.12{sup o}. Hints of Interplanetary Magnetic Field effects were observed in both the sun and moon shadow.

Satellite Ephemeris Correction via Remote Site Observation for Star Tracker Navigation Performance Improvement

DTIC Science & Technology

2016-03-01

squared RMS root mean squared GCRF Geocentric Celestial Reference Frame xi List of Figures Figure Page 1 Geometry of single observation...RA and DEC in the celestial sphere. The Geocentric Celestial Reference Frame (GCRF) is the standard geocentric frame that measures the RA east in the...Figure 2. Right ascension (α) and declination (δ) in the celestial sphere[6] 7 made between geocentric and topocentric angles. Geocentric is referred to

Microarsecond models for the celestial motions of the CIP and CEO

NASA Astrophysics Data System (ADS)

Capitaine, N.

2004-09-01

The Celestial intermediate pole (CIP) and Celestial ephemeris (orintermediate) origin (CEO/CIO) have been adopted by the IAU (c.f. IAU2000 Resolution B1.8) as the celestial pole and origin, respectively,to be used for realizing the intermediate celestial system between theInternational Terrestrial System (ITRS) and Geocentric CelestialReference System (GCRS). Resolution B1.8 has also recommended that theInternational Earth Rotation and Reference Systems Service (IERS)continue to provide users with data and algorithms for the conventionaltransformation. The IAU 2000 Resolutions have been implemented in theIERS 2003 Conventions including Tables and routines that provide thecelestial motions of the CIP and the CEO with a theoretical accuracy ofone microarcsecond after one century using either the classical or thenew transformation. This paper reports on the method used for achievingthis accuracy in the positions of the CIP and CIO and on the differencebetween this rigorous procedure and the pre-2003 classical one.

Dating the Moon: Teaching Lunar Stratigraphy and the Nature of Science

ERIC Educational Resources Information Center

Murphy, Edward; Bell, Randy

2013-01-01

As our closest celestial neighbor, the Moon is a familiar and inspiring object to investigate using a small telescope, binoculars, or even photographs or one of the many high quality maps available online. The wondrously varied surface of the Moon--filled with craters, mountains, volcanic flows, scarps, and rilles--makes the Moon an excellent…

Anania Shirakatsi's Cosmographical and Natural Philosophical Views

NASA Astrophysics Data System (ADS)

Danielyan, Eduard

2014-10-01

The observation of the heaven and celestial bodies has taken place since ancient times in the Armenian Highland. The notions of the sphericity of the Earth and celestial bodies, and other theses (about elements, comparative sizes of celestial bodies, antipodes, earthquakes, criticism of astrology, etc.) were reflected and elaborated in "Cosmography" of Anania Shirakatsi (VII century AD), as well as "Ashkharhatsoyts" ("Geography") of Movses Khorenatsi (V century AD) and his continuer Anania Shirakatsi. The road of observation and study of the Milky Way - the fundamental kernel of the development of astronomy - has led the human mind to galaxies, the cognition of the infinite capabilities of the development of matter, that is to say, from the studies of the elements constituting the Earth and other spherical bodies in the Universe (studied by Aristotle) to the Heliocentric system by Copernicus (1473-1543), from the cosmogonic ideas of Democritus (460-370 BC) about the multitude of worlds and the character of the Milky Way and their reflection in natural philosophic views of Anania Shirakatsi to the discovery of non-stationary objects and processes in the Universe owing to the activity of the nuclei of galaxies, according to the cosmogonic conception of academician Victor Ambartsumyan. Anania Shirakatsi's scientific heritage greatly contributed to the development of Armenian and world natural scientific thought.

A Snapshot-Based Mechanism for Celestial Orientation.

PubMed

El Jundi, Basil; Foster, James J; Khaldy, Lana; Byrne, Marcus J; Dacke, Marie; Baird, Emily

2016-06-06

In order to protect their food from competitors, ball-rolling dung beetles detach a piece of dung from a pile, shape it into a ball, and roll it away along a straight path [1]. They appear to rely exclusively on celestial compass cues to maintain their bearing [2-8], but the mechanism that enables them to use these cues for orientation remains unknown. Here, we describe the orientation strategy that allows dung beetles to use celestial cues in a dynamic fashion. We tested the underlying orientation mechanism by presenting beetles with a combination of simulated celestial cues (sun, polarized light, and spectral cues). We show that these animals do not rely on an innate prediction of the natural geographical relationship between celestial cues, as other navigating insects seem to [9, 10]. Instead, they appear to form an internal representation of the prevailing celestial scene, a "celestial snapshot," even if that scene represents a physical impossibility for the real sky. We also find that the beetles are able to maintain their bearing with respect to the presented cues only if the cues are visible when the snapshot is taken. This happens during the "dance," a behavior in which the beetle climbs on top of its ball and rotates about its vertical axis [11]. This strategy for reading celestial signals is a simple but efficient mechanism for straight-line orientation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Characterization of Non-Gravitational Perturbations That Act on Near-Earth Asteroid Orbits

NASA Astrophysics Data System (ADS)

Margot, Jean-Luc; Greenberg, Adam H.; Verma, Ashok K.; Taylor, Patrick A.

2017-10-01

The Yarkovsky effect is a thermal process acting upon the orbits of small celestial bodies which can cause these orbits to slowly expand or contract with time. The effect is subtle -- typical drift rates lie near 1e-4 au/My for a ~1 km diameter object -- and is thus generally difficult to measure. However, objects with long observation intervals, as well as objects with radar detections, serve as excellent candidates for the observation of this effect.We analyzed both optical and radar astrometry for all numbered Near-Earth Asteroids (NEAs), as well as several un-numbered NEAs. In order to quantify the likelihood of Yarkovsky detections, we developed a metric based on the quality of Yarkovsky fits as compared to that of gravity-only fits. Based on the metric results, we report 167 objects with measured Yarkovsky drifts.Our Yarkovsky sample is the largest published set of such detections, and presents an opportunity to examine the physical properties of these NEAs and the Yarkovsky effect in a statistical manner. In particular, we confirm the Yarkovsky effect's theoretical size dependence of 1/D, where D is diameter. We also examine the efficiency with which this effect converts absorbed light into orbital drift. Using our set of 167 objects, we find typical efficiences of around 5%. This efficiency can be used to place bounds on spin and thermal properties. We report the ratio of positive to negative drift rates and interpret this ratio in terms of prograde/retrograde rotators and main belt escape mechanisms. The observed ratio has a probability of 1 in 9 million of occurring by chance, which confirms the presence of a non-gravitational influence. We examine how the presence of radar data affect the strength and precision of our detections. We find that, on average, the precision of radar+optical detections improves by a factor of approximately 1.6 for each additional apparition with ranging data compared to that of optical-only solutions.

Formation Control of the MAXIM L2 Libration Orbit Mission

NASA Technical Reports Server (NTRS)

Folta, David; Hartman, Kate; Howell, Kathleen; Marchand, Belinda

2004-01-01

The Micro-Arcsecond Imaging Mission (MAXIM), a proposed concept for the Structure and Evolution of the Universe (SEU) Black Hole Imaging mission, is designed to make a ten million-fold improvement in X-ray image clarity of celestial objects by providing better than 0.1 microarcsecond imaging. To achieve mission requirements, MAXIM will have to improve on pointing by orders of magnitude. This pointing requirement impacts the control and design of the formation. Currently the architecture is comprised of 25 spacecraft, which will form the sparse apertures of a grazing incidence X-ray interferometer covering the 0.3-10 keV bandpass. This configuration will deploy 24 spacecraft as optics modules and one as the detector. The formation must allow for long duration continuous science observations and also for reconfiguration that permits re-pointing of the formation. In this paper, we provide analysis and trades of several control efforts that are dependent upon the pointing requirements and the configuration and dimensions of the MAXIM formation. We emphasize the utilization of natural motions in the Lagrangian regions that minimize the control efforts and we address both continuous and discrete control via LQR and feedback linearization. Results provide control cost, configuration options, and capabilities as guidelines for the development of this complex mission.

A Big Year for Small Bodies

NASA Astrophysics Data System (ADS)

Mayo, Louis; Erickson, K.

2013-10-01

2013 is a watershed year for celestial events involving the solar system’s unsung heroes, small bodies. The Cosmic Valentine of Asteroid 2012 DA14 which passed within ~ 3.5 Earth radii of the Earth's surface (February 15, 2013), Comet C/2011 L4 PANSTARRS and the Thanksgiving 2013 pass of Comet ISON, which will pass less than 0.012 AU (1.8 million km) from the solar surface and could be visible during the day. All this in addition to Comet Lemmon and a host of meteor showers makes 2013 a landmark year to deliver the excitement of planetary science to the audiences worldwide. To deliver the excitement and wonder of our solar system’s small bodies to worldwide audiences, NASA’s JPL and GSFC education teams in partnership with NASA EDGE will reach out to the public through multiple venues including broadcast media, social media, science and math focused educational activities, observing challenges, interactive visualization tools like “Eyes on the Solar System” and more culminating in the Thanksgiving Day Comet ISON perihelion passage. This talk will highlight NASA’s focused education effort to engage the public in small bodies science and the role these objects play in our understanding of the formation and evolution of the solar system.

One from many

NASA Image and Video Library

2016-02-01

This image, taken by the NASA/ESA Hubble Space Telescope, shows a peculiar galaxy known as NGC 1487, lying about 30 million light-years away in the southern constellation of Eridanus. Rather than viewing a celestial object, it is actually better to think of this as an event. Here, we are witnessing two or more galaxies in the act of merging together to form a single new galaxy. Each progenitor has lost almost all traces of its original appearance, as stars and gas have been thrown hither and thither by gravity in an elaborate cosmic whirl. Unless one is very much bigger than the other, galaxies are always disrupted by the violence of the merging process. As a result, it is very difficult to determine precisely what the original galaxies looked like and, indeed, how many of them there were. In this case, it is possible that we are seeing the merger of several dwarf galaxies that were previously clumped together in a small group. Although older yellow and red stars can be seen in the outer regions of the new galaxy, its appearance is dominated by large areas of bright blue stars, illuminating the patches of gas that gave them life. This burst of star formation may well have been triggered by the merger.

Frontiers in Relativistic Celestial Mechanics, Vol. 2, Applications and Experiments

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei

2014-08-01

Relativistic celestial mechanics - investigating the motion celestial bodies under the influence of general relativity - is a major tool of modern experimental gravitational physics. With a wide range of prominent authors from the field, this two-volume series consists of reviews on a multitude of advanced topics in the area of relativistic celestial mechanics - starting from more classical topics such as the regime of asymptotically-flat spacetime, light propagation and celestial ephemerides, but also including its role in cosmology and alternative theories of gravity as well as modern experiments in this area. This second volume of a two-volume series covers applications of the theory as well as experimental verifications. From tools to determine light travel times in curved space-time to laser ranging between earth and moon and between satellites, and impacts on the definition of time scales and clock comparison techniques, a variety of effects is discussed. On the occasion of his 80-th birthday, these two volumes honor V. A. Brumberg - one of the pioneers in modern relativistic celestial mechanics. Contributions include: J. Simon, A. Fienga: Victor Brumberg and the French school of analytical celestial mechanics T. Fukushima: Elliptic functions and elliptic integrals for celestial mechanics and dynamical astronomy P. Teyssandier: New tools for determining the light travel time in static, spherically symmetric spacetimes beyond the order G2 J. Müller, L. Biskupek, F. Hofmann and E. Mai: Lunar laser ranging and relativity N. Wex: Testing relativistic celestial mechanics with radio pulsars I. Ciufolini et al.: Dragging of inertial frames, fundamental physics, and satellite laser ranging G. Petit, P. Wolf, P. Delva: Atomic time, clocks, and clock comparisons in relativistic spacetime: a review

An Overview of Geodetic and Astrometric VLBI at the Hartebeesthoek Radio Astronomy Observatory

NASA Astrophysics Data System (ADS)

de Witt, A.; Gaylard, M.; Quick, J.; Combrinck, L.

2013-08-01

For astronomical Very Long Baseline Interferometry (VLBI), the Hartebeesthoek Radio Astronomy Observatory (HartRAO), in South Africa operates as part of a number of networks including the European and Australian VLBI networks, global arrays and also space VLBI. HartRAO is the only African representative in the international geodetic VLBI network and participates in regular astrometric and geodetic VLBI programmes. HartRAO will play a major role in the realization of the next generation full-sky celestial reference frame, especially the improvement of the celestial reference frame in the South. The observatory also provides a base for developing the African VLBI Network (AVN), a project to convert redundant satellite Earth-station antennas across Africa to use for radio astronomy. The AVN would greatly facilitate VLBI observations of southern objects. We present an overview of the current capabilities as well as future opportunities for astrometric and geodetic VLBI at HartRAO.

Astronomy and catastrophes through myth and old texts.

NASA Astrophysics Data System (ADS)

Bon, E.; Ćirković, M.; Stojić, Igor; Gavrilović, Nataša

In the old myths and iconographies there are some motives that indicate at least one cataclysmic event that influenced many old religions and myths, that could be linked to the impact of the celestial object. We investigate the hypothesis of coherent catastrophism put forward in recent years by Clube, Bailey, Napier and others from both astrobiological and culturogical points of view. The conventional idea that the quasi-periodic break-up of celestial bodies influence terrestrial conditions can today be placed in both wider (astro-biological) and deeper (historico-culturological) context. In particular, we point out that the link between the Neolithic history of astronomy, and origin of Mithraism. We speculate that the main icon of Mithraic religion could pinpoint an event that happened around 4000 BC, when the spring equinox entered the constellation of Taurus. We also, link some motives in other old religions and myths to the same event, or to some similar events that inspired those myths.

Visual interface for space and terrestrial analysis

NASA Technical Reports Server (NTRS)

Dombrowski, Edmund G.; Williams, Jason R.; George, Arthur A.; Heckathorn, Harry M.; Snyder, William A.

1995-01-01

The management of large geophysical and celestial data bases is now, more than ever, the most critical path to timely data analysis. With today's large volume data sets from multiple satellite missions, analysts face the task of defining useful data bases from which data and metadata (information about data) can be extracted readily in a meaningful way. Visualization, following an object-oriented design, is a fundamental method of organizing and handling data. Humans, by nature, easily accept pictorial representations of data. Therefore graphically oriented user interfaces are appealing, as long as they remain simple to produce and use. The Visual Interface for Space and Terrestrial Analysis (VISTA) system, currently under development at the Naval Research Laboratory's Backgrounds Data Center (BDC), has been designed with these goals in mind. Its graphical user interface (GUI) allows the user to perform queries, visualization, and analysis of atmospheric and celestial backgrounds data.

Research on the error model of airborne celestial/inertial integrated navigation system

NASA Astrophysics Data System (ADS)

Zheng, Xiaoqiang; Deng, Xiaoguo; Yang, Xiaoxu; Dong, Qiang

2015-02-01

Celestial navigation subsystem of airborne celestial/inertial integrated navigation system periodically correct the positioning error and heading drift of the inertial navigation system, by which the inertial navigation system can greatly improve the accuracy of long-endurance navigation. Thus the navigation accuracy of airborne celestial navigation subsystem directly decides the accuracy of the integrated navigation system if it works for long time. By building the mathematical model of the airborne celestial navigation system based on the inertial navigation system, using the method of linear coordinate transformation, we establish the error transfer equation for the positioning algorithm of airborne celestial system. Based on these we built the positioning error model of the celestial navigation. And then, based on the positioning error model we analyze and simulate the positioning error which are caused by the error of the star tracking platform with the MATLAB software. Finally, the positioning error model is verified by the information of the star obtained from the optical measurement device in range and the device whose location are known. The analysis and simulation results show that the level accuracy and north accuracy of tracking platform are important factors that limit airborne celestial navigation systems to improve the positioning accuracy, and the positioning error have an approximate linear relationship with the level error and north error of tracking platform. The error of the verification results are in 1000m, which shows that the model is correct.

The electrification of spacecraft

NASA Technical Reports Server (NTRS)

Akishin, A. I.; Novikov, L. S.

1985-01-01

Physical and applied aspects of the electrification of space vehicles and natural celestial objects are discussed, the factors resulting in electrification of spacecraft are analyzed, and methods of investigating various phenomena associated with this electrification and ways of protecting spacecraft against the influence of static electricity are described. The booklet is intended for the general reader interested in present day questions of space technology.

Panoramic Stokes-polarimeter

NASA Astrophysics Data System (ADS)

Syniavskyi, I. I.; Ivanov, Yu. S.; Vidmachenko, A. P.; Karpov, N. V.

2013-12-01

This article proposes optical layout of the imaging polarimeter based on the polarization films to measure the linear polarization of point and extended celestial objects. The spectral range of device is 420-850 nm, field of view 0.25°x0.25°. The device is designed to equip the telescope with a diameter of primary mirror about 400 mm and aperture f/12.

Navigation Concepts for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Long, Anne; Leung, Dominic; Kelbel, David; Beckman, Mark; Grambling, Cheryl

2003-01-01

This paper evaluates the performance that can be achieved using candidate ground and onboard navigation approaches for operation of the James Webb Space Telescope, which will be in an orbit about the Sun-Earth L2 libration point. The ground navigation approach processes standard range and Doppler measurements from the Deep Space Network The onboard navigation approach processes celestial object measurements and/or ground-to- spacecraft Doppler measurements to autonomously estimate the spacecraft s position and velocity and Doppler reference frequency. Particular attention is given to assessing the absolute position and velocity accuracy that can be achieved in the presence of the frequent spacecraft reorientations and momentum unloads planned for this mission. The ground navigation approach provides stable navigation solutions using a tracking schedule of one 30-minute contact per day. The onboard navigation approach that uses only optical quality celestial object measurements provides stable autonomous navigation solutions. This study indicates that unmodeled changes in the solar radiation pressure cross-sectional area and modeled momentum unload velocity changes are the major error sources. These errors can be mitigated by modeling these changes, by estimating corrections to compensate for the changes, or by including acceleration measurements.

An Arabic report about supernova SN 1006 by Ibn Sīnā (Avicenna)

NASA Astrophysics Data System (ADS)

Neuhäuser, R.; Ehrig-Eggert, C.; Kunitzsch, P.

2017-01-01

We present here an Arabic report about supernova 1006 (SN 1006) written by the famous Persian scholar Ibn Sina (Lat. Avicenna, AD 980-1037), which was not discussed in astronomical literature before. The short observational report about a new star is part of Ibn Sina's book called al-Shifa', a work about philosophy including physics, astronomy, and meteorology. We present the Arabic text and our English translation. After a detailed discussion of the dating of the observation, we show that the text specifies that the transient celestial object was stationary and/or tail-less ("a star among the stars"), that it "remained for close to three months getting fainter and fainter until it disappeared", that it "threw out sparks", i.e. it was scintillating and very bright, and that the color changed with time. The information content is consistent with the other Arabic and non-Arabic reports about SN 1006. Hence, it is quite clear that Ibn Sina refers to SN 1006 in his report, given as an example for transient celestial objects in a discussion of Aristotle's "Meteorology". Given the wording and the description, e.g. for the color evolution, this report is independent from other reports known so far.

Astronomical Knowledge in Holy Books

NASA Astrophysics Data System (ADS)

Farmanyan, Sona V.; Mickaelian, Areg M.

2015-08-01

We investigate religious myths related to astronomy from different cultures in an attempt to identify common subjects and characteristics. The paper focuses on astronomy in religion. The initial review covers records from Holy books about sky related superstitious beliefs and cosmological understanding. The purpose of this study is to introduce sky related religious and national traditions (particularly based on different calendars; Solar or Lunar). We carried out a comparative study of astronomical issues contained in a number of Holy books: Ancient Egyptian Religion (Pyramid Texts), Zoroastrianism (Avesta), Hinduism (Vedas), Buddhism (Tipitaka), Confucianism (Five Classics), Sikhism (Guru Granth Sahib), Christianity (Bible), Islam (Quran), Druidism (Mabinogion) and Maya Religion (Popol Vuh). These books include various information on the creation of the Universe, Sun and Moon, the age of the Universe, Cosmic sizes, understanding about the planets, stars, Milky Way and description of the Heavens in different religions. We come to the conclusion that the perception of celestial objects varies from culture to culture, and from religion to religion and preastronomical views had a significant impact on humankind, particularly on religious diversities. We prove that Astronomy is the basis of cultures, and that national identity and mythology and religion were formed due to the special understanding of celestial objects.

Measurement of the Radial Velocity of Vega and SAO 104807 by high resolution spectrometry

NASA Astrophysics Data System (ADS)

Rosas, F.; Ordoñez, J.; Suarez, W.; Quijano, A.

2017-07-01

The radial velocity is the component of the velocity with which a celestial object approaches (blueshift) or go away (redshift) of the observer. The precise measurement of the redshift allowed to Humason and Hubble discover the expansion of the Universe. In 1998 two research teams simultaneously discovered that this expansion is accelerated, for that reason the hypothesis of the dark energy has been raised to explain the existing repulsion. The present work shows the measurement of the radial velocity of Vega and SAO104807 by high resolution spectrometry. Using the instruments of the Astronomical Observatory of the University of Nariño, located in the south of Colombia, was measured the displacement that the spectral lines of both celestial objects suffer due to the Doppler effect. The results obtained were quite close to those recorded in databases such as SIMBAD, according to the used equipment. The instruments used were: Celestron CGE Pro 1400 Telescope, Shelyak LHIRES III High Resolution Spectrometer and SBIG ST-8300 CCD Camera. The characteristics of the spectrometer are: Diffraction grating: 2400 lines/mm, Spectral dispersion (H alpha): 0:012 nm/pixel, Radial velocity resolution: 5 km/s.

Relation between the celestial reference system and the terrestrial reference system of a rigid earth

NASA Astrophysics Data System (ADS)

Aoki, Shinko

The equations of motion for a rigid earth under the influence of the sun and moon are solved analytically up to the second-order perturbation, and the results are used to elucidate the relationship between the celestial and terrestrial reference systems. The derivations are given in detail, and consideration is given to celestial-ephemeris and instantaneous-rotation poles, wobble, the departure point as the origin of the local inertial system, the precession-nutation matrix, and techniques for improving the celestial reference system.

Combining sky and earth: desert ants (Melophorus bagoti) show weighted integration of celestial and terrestrial cues.

PubMed

Legge, Eric L G; Wystrach, Antoine; Spetch, Marcia L; Cheng, Ken

2014-12-01

Insects typically use celestial sources of directional information for path integration, and terrestrial panoramic information for view-based navigation. Here we set celestial and terrestrial sources of directional information in conflict for homing desert ants (Melophorus bagoti). In the first experiment, ants learned to navigate out of a round experimental arena with a distinctive artificial panorama. On crucial tests, we rotated the arena to create a conflict between the artificial panorama and celestial information. In a second experiment, ants at a feeder in their natural visually-cluttered habitat were displaced prior to their homing journey so that the dictates of path integration (feeder to nest direction) based on a celestial compass conflicted with the dictates of view-based navigation (release point to nest direction) based on the natural terrestrial panorama. In both experiments, ants generally headed in a direction intermediate to the dictates of celestial and terrestrial information. In the second experiment, the ants put more weight on the terrestrial cues when they provided better directional information. We conclude that desert ants weight and integrate the dictates of celestial and terrestrial information in determining their initial heading, even when the two directional cues are highly discrepant. © 2014. Published by The Company of Biologists Ltd.

YORP: Its origin

NASA Astrophysics Data System (ADS)

Paddack, Stephen; Rubincam, David P.

2015-11-01

It’s all about photons and their behavior. Yarkovsky (1844-1902) did not have the knowledge we have today about photons and radiation pressure. Nevertheless, he published a pamphlet in 1901 that small rotating celestial bodies could absorb sunlight and reradiate it as heat after a delay, resulting in possible orbital changes, setting the stage for radiation effects in celestial mechanics. Yarkovsly’s work remained obscure until Öpik recalled having read Yarkovsky’s pamphlet. Öpik brought Yarkovsky’s idea to the attention of John A. O’Keefe in the late 1960s. O’Keefe, the mentor for two aspiring PhD students, Paddack and Rubincam, told them about Yarkovsky. In 1968 Paddack postulated that the reflection of sunlight off of small, irregularly shaped celestial bodies could have a significant effect on their spin rates. He referred to this as a windmill effect. Paddack and O’Keefe tested the idea of windmill shapes causing spin by dropping crushed stones with irregular shapes into a swimming pool and watching them twirl. Paddack then mimicked the space environment by placing windmill-shaped artificial objects and tektites in a vacuum chamber on an almost frictionless bearing and spinning them up with a strong source of light, conclusively showing the relation of shape to spin. Earlier in 1954 Radzievskii wrote about the effects radiation pressure on variations in the albedo of small celestial bodies as a means of changing their spin rates. The uniform color of Paddack’s test bodies ruled out Radzievskii’s effect as the cause for the observed spin-up. The Yarkovsky effect was minimized because the test object had a coating of vapor-deposited aluminum with a very high albedo and consequently did not heat up. In 2000 Rubincam applied Paddack’s idea to small asteroids and called it the YORP effect (YORP = Yarkovsky-O’Keefe-Radzievskii-Paddack), to give it a catchy name and sell the idea. In 2007 results were published in Science about the observed behavior of asteroid (54509) 2000 PH5 stating that its spin rate changes because of the YORP effect (Lowery et al and Taylor et al). Since 2000 there have been more than 400 papers and talks with “YORP” in the title or the abstract.

First Radar Images of Halloween Asteroid

NASA Image and Video Library

2015-10-30

These first radar images of 2015 TB145 from the National Science Foundation 1,000-foot 305-meter Arecibo Observatory in Puerto Rico, indicate the near-Earth object is spherical in shape and approximately 2,000 feet 600 meters in diameter. The radar images were taken on Oct. 30, 2015, and the image resolution is 25 feet (7.5 meters) per pixel. The celestial object is more than likely a dead comet that has shed its volatiles after numerous passes around the sun. http://photojournal.jpl.nasa.gov/catalog/PIA20040

Unidentified Aerial and Celestial Objects. Appendix B

DTIC Science & Technology

1949-04-30

o.. oil ) - ••©•oöi o: arc, *.-.iox. ia a«:::.., i >;: J«1O» *-<>«■ 1. .* o? rtiol-’-o; oJ .** •/•• it «mole... lUV ’ .L * ., 166, a — Shamble«, Georgia — 26 July 1948 -;.a object reported i :. ii.jiderit pl65 and 166a (which presumably refer...formal DoD distribution statements. Treat as DoD only. Document partially illegible. E.O. 10501 dtd 5 Nov 1953; DDCTC ltr dtd 3 Nov 1971 a—— i

IPS guidestar selection for stellar mode (ASTRO)

NASA Technical Reports Server (NTRS)

Mullins, Larry; Wooten, Lewis

1988-01-01

This report describes how guide stars are selected for the Optical Sensor Package (OSP) for the Instrument Pointing System (IPS) when it is operating in the stellar mode on the ASTRO missions. It also describes how the objective loads are written and how the various roll angles are related; i.e., the celestial roll or position angle, the objective load roll angles, and the IPS gimbal angles. There is a brief description of how the IPS operates and its various modes of operation; i.e., IDOP, IDIN, and OSPCAL.

Fourier Plane Image Combination by Feathering

NASA Astrophysics Data System (ADS)

Cotton, W. D.

2017-09-01

Astronomical objects frequently exhibit structure over a wide range of scales whereas many telescopes, especially interferometer arrays, only sample a limited range of spatial scales. To properly image these objects, images from a set of instruments covering the range of scales may be needed. These images then must be combined in a manner to recover all spatial scales. This paper describes the feathering technique for image combination in the Fourier transform plane. Implementations in several packages are discussed and example combinations of single dish and interferometric observations of both simulated and celestial radio emission are given.

The research of the coupled orbital-attitude controlled motion of celestial body in the neighborhood of the collinear libration point L1

NASA Astrophysics Data System (ADS)

Shmyrov, A.; Shmyrov, V.; Shymanchuk, D.

2017-10-01

This article considers the motion of a celestial body within the restricted three-body problem of the Sun-Earth system. The equations of controlled coupled attitude-orbit motion in the neighborhood of collinear libration point L1 are investigated. The translational orbital motion of a celestial body is described using Hill's equations of circular restricted three-body problem of the Sun-Earth system. Rotational orbital motion is described using Euler's dynamic equations and quaternion kinematic equation. We investigate the problem of stability of celestial body rotational orbital motion in relative equilibrium positions and stabilization of celestial body rotational orbital motion with proposed control laws in the neighborhood of collinear libration point L1. To study stabilization problem, Lyapunov function is constructed in the form of the sum of the kinetic energy and special "kinematic function" of the Rodriguez-Hamiltonian parameters. Numerical modeling of the controlled rotational motion of a celestial body at libration point L1 is carried out. The numerical characteristics of the control parameters and rotational motion are given.

Modelling of celestial backgrounds

NASA Astrophysics Data System (ADS)

Hickman, Duncan L.; Smith, Moira I.; Lim, Jae-Wan; Jeon, Yun-Ho

2018-05-01

For applications where a sensor's image includes the celestial background, stars and Solar System Bodies compromise the ability of the sensor system to correctly classify a target. Such false targets are particularly significant for the detection of weak target signatures which only have a small relative angular motion. The detection of celestial features is well established in the visible spectral band. However, given the increasing sensitivity and low noise afforded by emergent infrared focal plane array technology together with larger and more efficient optics, the signatures of celestial features can also impact performance at infrared wavelengths. A methodology has been developed which allows the rapid generation of celestial signatures in any required spectral band using star data from star catalogues and other open-source information. Within this paper, the radiometric calculations are presented to determine the irradiance values of stars and planets in any spectral band.

Cygnus X-1

NASA Astrophysics Data System (ADS)

Bolton, C.; Murdin, P.

2000-11-01

Cygnus X-1 is one of the strongest x-ray sources. It is the first celestial object for which we had reasonably convincing evidence that it is a BLACK HOLE. Its x-ray properties include an ultra-soft spectrum, compared to massive x-ray binaries containing a neutron star, rapid (˜1 s) flickering, and high/low flux states with different spectral characteristics. In 1971, a RADIO SOURCE appeared at...

Seeing the Solar System through Two Perspectives. Part 1 of a Series Focusing on Learning Progressions

ERIC Educational Resources Information Center

Thornburgh, Bill R.; Tretter, Tom R.; Duckwall, Mark

2015-01-01

Space has fascinated and intrigued humans of all ages since time immemorial, and continues to do so today. The natural curiosity is engaged when looking up into the sky, notice patterns among celestial objects such as the Sun, Moon, and stars, and wonder. Scientific understanding of those patterns has progressed immensely over the span of human…

Astronomy in Inca Empire: a Ceque Based Calendar

NASA Astrophysics Data System (ADS)

Correa, Nathalia Silva Gomes; de Nader, R. V.

2007-08-01

This work is a brief report about different kinds of arrangements and organization of the Inca astronomical calendar, approaching archaeological vestiges in Cuzco, such as observatories aligned to celestial objects which were observed for the computation of the time. We also analyze the ceques lines that can be associated to these techniques of Inca astronomical observation, according to the chroniclers and the researches in archaeoastronomy.

Astrophysics of Reference Frame Tie Objects

NASA Technical Reports Server (NTRS)

Johnston, Kenneth J.; Boboltz, David; Fey, Alan Lee; Gaume, Ralph A.; Zacharias, Norbert

2004-01-01

The Astrophysics of Reference Frame Tie Objects Key Science program will investigate the underlying physics of SIM grid objects. Extragalactic objects in the SIM grid will be used to tie the SIM reference frame to the quasi-inertial reference frame defined by extragalactic objects and to remove any residual frame rotation with respect to the extragalactic frame. The current realization of the extragalactic frame is the International Celestial Reference Frame (ICRF). The ICRF is defined by the radio positions of 212 extragalactic objects and is the IAU sanctioned fundamental astronomical reference frame. This key project will advance our knowledge of the physics of the objects which will make up the SIM grid, such as quasars and chromospherically active stars, and relates directly to the stability of the SIM reference frame. The following questions concerning the physics of reference frame tie objects will be investigated.

Spatial water maze learning using celestial cues by the meadow vole, Microtus pennsylvanicus.

PubMed

Kavaliers, M; Galea, L A

1994-03-31

The Morris water maze is widely used to evaluate to evaluate the spatial learning ability of rodents under laboratory settings. The present study demonstrates that reproductive male meadow voles, Microtus pennsylvanicus, are able to acquire and retain a spatial water maze task using celestial cues. Voles were able to acquire a modified outdoor Morris water maze task over 4 trials per day, whereby they had to learn and remember the location of a submerged hidden platform, using the position of the sun and associated celestial cues. Their proficiency on this task was related to the availability of the celestial cues, with voles displaying significantly poorer spatial navigation on overcast than clear days and when the testing time (and position of the sun and associated celestial cues) was shifted from morning to afternoon. These findings with meadow voles support the ecological relevance of the water maze task.

Design of all-weather celestial navigation system

NASA Astrophysics Data System (ADS)

Sun, Hongchi; Mu, Rongjun; Du, Huajun; Wu, Peng

2018-03-01

In order to realize autonomous navigation in the atmosphere, an all-weather celestial navigation system is designed. The research of celestial navigation system include discrimination method of comentropy and the adaptive navigation algorithm based on the P value. The discrimination method of comentropy is studied to realize the independent switching of two celestial navigation modes, starlight and radio. Finally, an adaptive filtering algorithm based on P value is proposed, which can greatly improve the disturbance rejection capability of the system. The experimental results show that the accuracy of the three axis attitude is better than 10″, and it can work all weather. In perturbation environment, the position accuracy of the integrated navigation system can be increased 20% comparing with the traditional method. It basically meets the requirements of the all-weather celestial navigation system, and it has the ability of stability, reliability, high accuracy and strong anti-interference.

Position determination systems. [using orbital antenna scan of celestial bodies

NASA Technical Reports Server (NTRS)

Shores, P. W. (Inventor)

1976-01-01

A system for an orbital antenna, operated at a synchronous altitude, to scan an area of a celestial body is disclosed. The antenna means comprises modules which are operated by a steering signal in a repetitive function for providing a scanning beam over the area. The scanning covers the entire area in a pattern and the azimuth of the scanning beam is transmitted to a control station on the celestial body simultaneous with signals from an activated ground beacon on the celestial body. The azimuth of the control station relative to the antenna is known and the location of the ground beacon is readily determined from the azimuth determinations.

Principles of Celestial Navigation: An Online Resource for Introducing Practical Astronomy to the Public

NASA Astrophysics Data System (ADS)

Urban, Sean E.

2015-08-01

Astronomy is often called a "gateway" science because it inspires appreciation and awe among children and non-scientists. Applied astronomy, with practical, real-world applications, can entice even the most utilitarian people to take notice and learn about the subject. Traditional celestial navigation is an astronomy topic that captures the attention of the public. The U.S. Naval Observatory has led the development of a publicly available online celestial navigation educational module titled, "Principles of Celestial Navigation". It can be used world-wide to introduce people to astronomy. This poster describes some of the aspects of this teaching module.

The Celestial Basis of Civilization

NASA Astrophysics Data System (ADS)

Masse, W. B.

Scholars have long puzzled over the reasons for the ubiquity of celestial images in the residue of the world's earliest civilizations: in art, myth, religious cosmology, iconography, cosmogony, eschatological beliefs, and as portents for the conduct of royal and chiefly power. The general consensus is that these images represented a need by early societies to use the fixed celestial heavens in order to regulate ritual and agricultural cycles, and to satisfy a psychological need by people to relate themselves to their surrounding Universe. Such explanations are facile and miss an important aspect of the celestial heavens. The fixed celestial heavens served as the back-drop for a large number of often spectacular temporary naked-eye visible celestial events which animated the night and sometimes the daytime sky, and which created an 'otherworld' for virtually all cultural groups. In this paper I present a model derived from the detailed analysis of Hawaiian oral traditions and culture history in relation to historic astronomical records of temporary celestial events, and then apply this model to cultural traditions from Mesoamerica and other geographic regions in order to demonstrate that novae, supernovae, variable stars, comets, great meteor showers, aurorae, solar and lunar eclipses, and impacting Solar System debris, together played a critical role in the artistic, intellectual, and political development of early civilizations. These data not only provide important insights into the development of civilization, but also provide important details and longitudinal records of astronomical events and phenomena which are otherwise not readily available for scientific scrutiny.

An alternative model of free fall

NASA Astrophysics Data System (ADS)

Lattery, Mark

2018-03-01

In Two World Systems (Galileo 1632/1661 Dialogues Concerning Two New Sciences (New York: Prometheus)), Galileo attempted to unify terrestrial and celestial motions using the Aristotelian principle of circularity. The result was a model of free fall that correctly predicts the linear increase of the velocity of an object released from rest near the surface of the Earth. This historical episode provides an opportunity to communicate the nature of science to students.

Space Shuttle Project

NASA Image and Video Library

1995-03-18

The Space Shuttle Endeavour (STS-67) lands at Edwards Air Force Base in southern California after successfully completing NASA's longest plarned shuttle mission. The seven-member crew conducted round-the-clock observations with the ASTRO-2 observatory, a trio of telescopes designed to study the universe of ultraviolet astronomy. Because of Earth's protective ozone layer ultraviolet light from celestial objects does not reach gound-based telescopes, and such studies can only be conducted from space.

Relative Navigation of Formation Flying Satellites

NASA Technical Reports Server (NTRS)

Long, Anne; Kelbel, David; Lee, Taesul; Leung, Dominic; Carpenter, Russell; Gramling, Cheryl; Bauer, Frank (Technical Monitor)

2002-01-01

The Guidance, Navigation, and Control Center (GNCC) at Goddard Space Flight Center (GSFC) has successfully developed high-accuracy autonomous satellite navigation systems using the National Aeronautics and Space Administration's (NASA's) space and ground communications systems and the Global Positioning System (GPS). In addition, an autonomous navigation system that uses celestial object sensor measurements is currently under development and has been successfully tested using real Sun and Earth horizon measurements.The GNCC has developed advanced spacecraft systems that provide autonomous navigation and control of formation flyers in near-Earth, high-Earth, and libration point orbits. To support this effort, the GNCC is assessing the relative navigation accuracy achievable for proposed formations using GPS, intersatellite crosslink, ground-to-satellite Doppler, and celestial object sensor measurements. This paper evaluates the performance of these relative navigation approaches for three proposed missions with two or more vehicles maintaining relatively tight formations. High-fidelity simulations were performed to quantify the absolute and relative navigation accuracy as a function of navigation algorithm and measurement type. Realistically-simulated measurements were processed using the extended Kalman filter implemented in the GPS Enhanced Inboard Navigation System (GEONS) flight software developed by GSFC GNCC. Solutions obtained by simultaneously estimating all satellites in the formation were compared with the results obtained using a simpler approach based on differencing independently estimated state vectors.

Protection of the Lifeless Environment in the Solar System

NASA Astrophysics Data System (ADS)

Almar, I.

The main concern of planetary protection policy is how to protect the (hypothetical) extraterrestrial life against contamination and back-contamination. There is almost no interest in the preservation of the existing lifeless surfaces of extraterrestrial bodies, although some planetary transformation plans (in order to exploit hypothetical resources) were made public a long time ago. It should be remembered that planetary environments are practically unchanged since ages and damage caused by any human intervention would be irreversible. Our intention is not to prevent any commercial utilization of Solar System resources, but to make space exploration and exploitation of resources a controlled and well planned endeavor. The three main issues connected with the protection of the lifeless space environment are the following: 1/ The scientific aspect: a limited, well defined initiative to select by scientific investigation areas and objects of highest scientific priority on different celestial bodies. 2/ The legal aspect: to start the drafting of a declaration of principles supporting the protection of selected areas and objects on celestial bodies with a solid surface. It might evolve into an international legal instrument or treaty in order to limit the "free-for-all" intervention and use of Solar System resources. 3/ The societal aspect: to initiate a large scale discussion on the possible "ethical values" of the lifeless environment.

Simultaneous calibrations of Voyager celestial and inertial attitude control systems in flight

NASA Technical Reports Server (NTRS)

Jahanshahi, M. H.

1982-01-01

A mathematical description of the data reduction technique used to simultaneously calibrate the Voyager celestial and inertial attitude control subsystems is given. It is shown that knowledge of the spacecraft limit cycle motion, as measured by the celestial and the inertial sensors, is adequate to result in the estimates of a selected number of errors which adversely affect the spacecraft attitude knowledge.

"Bridging the Gap" through Australian Cultural Astronomy

NASA Astrophysics Data System (ADS)

Hamacher, Duane W.; Norris, Ray P.

2011-01-01

For more than 50,000 years, Indigenous Australians have incorporated celestial events into their oral traditions and used the motions of celestial bodies for navigation, time-keeping, food economics, and social structure. In this paper, we explore the ways in which Aboriginal people made careful observations of the sky, measurements of celestial bodies, and incorporated astronomical events into complex oral traditions by searching for written records of time-keeping using celestial bodies, the use of rising and setting stars as indicators of special events, recorded observations of variable stars, the solar cycle, and lunar phases (including ocean tides and eclipses) in oral tradition, as well as astronomical measurements of the equinox, solstice, and cardinal points.

Far ultraviolet wide field imaging and photometry - Spartan-202 Mark II Far Ultraviolet Camera

NASA Technical Reports Server (NTRS)

Carruthers, George R.; Heckathorn, Harry M.; Opal, Chet B.; Witt, Adolf N.; Henize, Karl G.

1988-01-01

The U.S. Naval Research Laboratory' Mark II Far Ultraviolet Camera, which is expected to be a primary scientific instrument aboard the Spartan-202 Space Shuttle mission, is described. This camera is intended to obtain FUV wide-field imagery of stars and extended celestial objects, including diffuse nebulae and nearby galaxies. The observations will support the HST by providing FUV photometry of calibration objects. The Mark II camera is an electrographic Schmidt camera with an aperture of 15 cm, a focal length of 30.5 cm, and sensitivity in the 1230-1600 A wavelength range.

Merged infrared catalogue

NASA Technical Reports Server (NTRS)

Schmitz, M.; Brown, L. W.; Mead, J. M.; Nagy, T. A.

1978-01-01

A compilation of equatorial coordinates, spectral types, magnitudes, and fluxes from five catalogues of infrared observations is presented. This first edition of the Merged Infrared Catalogue contains 11,201 oservations from the Two-Micron Sky Survey, Observations of Infrared Radiation from Cool Stars, the Air Force Geophysics Laboratory four Color Infrared Sky Survey and its Supplemental Catalog, and from Catalog of 10 micron Celestial Objects (HALL). This compilation is a by-product of a computerized infrared data base under development at Goddard Space Flight Center; the objective is to maintain a complete and current record of all infrared observations from 1 micron m to 1000 micron m of nonsolar system objects. These observations are being placed into a standardized system.

Formation Control of the MAXIM L2 Libration Orbit Mission

NASA Technical Reports Server (NTRS)

Folta, David; Hartman, Kate; Howell, Kathleen; Marchand, Belinda

2004-01-01

The Micro-Arcsecond X-ray Imaging Mission (MAXIM), a proposed concept for the Structure and Evolution of the Universe (SEU) Black Hole Imager mission, is designed to make a ten million-fold improvement in X-ray image clarity of celestial objects by providing better than 0.1 micro-arcsecond imaging. Currently the mission architecture comprises 25 spacecraft, 24 as optics modules and one as the detector, which will form sparse sub-apertures of a grazing incidence X-ray interferometer covering the 0.3-10 keV bandpass. This formation must allow for long duration continuous science observations and also for reconfiguration that permits re-pointing of the formation. To achieve these mission goals, the formation is required to cooperatively point at desired targets. Once pointed, the individual elements of the MAXIM formation must remain stable, maintaining their relative positions and attitudes below a critical threshold. These pointing and formation stability requirements impact the control and design of the formation. In this paper, we provide analysis of control efforts that are dependent upon the stability and the configuration and dimensions of the MAXIM formation. We emphasize the utilization of natural motions in the Lagrangian regions to minimize the control efforts and we address continuous control via input feedback linearization (IFL). Results provide control cost, configuration options, and capabilities as guidelines for the development of this complex mission.

Space-Based Astronomy: An Educator Guide with Activities for Science, Mathematics, and Technology Education

NASA Technical Reports Server (NTRS)

Vogt, Gregory L.

2001-01-01

If you go to the country, far from city lights, you can see about 3,000 stars on a clear night. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30 times, the number of stars you can see increases to the tens of thousands. With a medium-sized telescope with a light-collecting mirror 30 centimeters in diameter, you can see hundreds of thousands of stars. With a large observatory telescope, millions of stars become visible. This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy--astronomical observations made from outer space. It is not intended to serve as a curriculum. Instead, teachers should select activities from this guide that support and extend existing study. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. It tells, rather, the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. Teachers are encouraged to adapt these activities for the particular needs of their students. When selected activities from this guide are used in conjunction with traditional astronomy curricula, students benefit from a more complete experience.

Magnetic information affects the stellar orientation of young bird migrants

NASA Astrophysics Data System (ADS)

Weindler, Peter; Wiltschko, Roswitha; Wiltschko, Wolfgang

1996-09-01

WHEN young birds leave on their first migration, they are guided by innate information about their direction of migration. It is generally assumed that this direction is represented twice, namely with respect to celestial rotation and with respect to the Earth's magnetic field1,2. The interactions between the two cue systems have been analysed by exposing hand-raised young birds during the premigratory period to cue-conflict situations, in which celestial rotation and the magnetic field provided different information. Celestial rotation altered the course with respect to the magnetic field3-7, whereas conflicting magnetic information did not seem to affect the course with respect to the stars8,9. Celestial information thus seemed to dominate over magnetic information. Here we report that the interaction between the two cue systems is far more complex than this. Celestial rotation alone seems to provide only a tendency to move away from its centre (towards geographical south), which is then modified by information from the magnetic field to establish the distinctive, population-specific migratory direction.

Generation of dynamo waves by spatially separated sources in the Earth and other celestial bodies

NASA Astrophysics Data System (ADS)

Popova, E.

2017-12-01

The amplitude and the spatial configuration of the planetary and stellar magnetic field can changing over the years. Celestial bodies can have cyclic, chaotic or unchanging in time magnetic activity which is connected with a dynamo mechanism. This mechanism is based on the consideration of the joint influence of the alpha-effect and differential rotation. Dynamo sources can be located at different depths (active layers) of the celestial body and can have different intensities. Application of this concept allows us to get different forms of solutions and some of which can include wave propagating inside the celestial body. We analytically showed that in the case of spatially separated sources of magnetic field each source generates a wave whose frequency depends on the physical parameters of its source. We estimated parameters of sources required for the generation nondecaying waves. We discus structure of such sources and matter motion (including meridional circulation) in the liquid outer core of the Earth and active layers of other celestial bodies.

Martian and Asteroid Dusts as Toxicological Risks for Human Exploration Missions

NASA Technical Reports Server (NTRS)

James, John T.

2012-01-01

As the lunar dust toxicity project winds down, our attention is drawn to the potential toxicity of dust present at the surface of more distant celestial objects. Lunar dust has proven to be surprisingly toxic to the respiratory systems of test animals, so one might expect dust from other celestial bodies to hold toxicological surprises for us. At this point all one can do is consider what should be known about these dusts to characterize their toxicity, and then ask to what extent that information is known. In an ideal world it might be possible to suggest an exposure standard based on the known properties of a celestial dust without direct testing of the dust in laboratory animals. Factors known to affect the toxicity of mineral dusts under some conditions include the following: particle size distribution, particle shape/porosity, mineralogical properties (crystalline vs. amorphous), chemical properties and composition, and surface reactivity. Data from a recent Japanese mission to the S-type asteroid Itokawa revealed some surprises about the dust found there, given that there is only a very week gravitational field to hold the dust on the surface. On Mars the reddish-brown dust is widely distributed by global dust storms and by local clusters of dust devils. Past surface probes have revealed some of the properties of dust found there. Contemporary data from Curiosity and other surface probes will be weighed against the data needed to set a defensible safe exposure limit. Gaps will emerge.

Accurate spin axes and solar system dynamics: Climatic variations for the Earth and Mars

NASA Astrophysics Data System (ADS)

Edvardsson, S.; Karlsson, K. G.; Engholm, M.

2002-03-01

Celestial mechanical simulations from a purely classical point of view of the solar system, including our Moon and the Mars moons - Phobos and Deimos - are carried out for 2 millions of years before present. Within the classical approximation, the results are derived at a very high level of accuracy. Effects from general relativity for a number of variables are investigated and found to be small. For climatic studies of about 1 Myr, general relativity can safely be ignored. Three different and independent integration schemes are used in order to exclude numerical anomalies. The converged results from all methods are found to be in complete agreement. For verification, a number of properties such as spin axis precession, nutation, and orbit inclination for Earth and Mars have been calculated. Times and positions of equinoxes and solstices are continously monitored. As also observed earlier, the obliquity of the Earth is stabilized by the Moon. On the other hand, the obliquity of Mars shows dramatic variations. Climatic influences due to celestial variables for the Earth and Mars are studied. Instead of using mean insolation as in the usual applications of Milankovitch theory, the present approach focuses on the instantaneous solar radiation power (insolation) at each summer solstice. Solar radiation power is compared to the derivative of the icevolume and these quantities are found to be in excellent agreement. Orbital precessions for the inner planets are studied as well. In the case of Mercury, it is investigated in detail.

Mega starbirth cluster is biggest, brightest and hottest ever seen

NASA Astrophysics Data System (ADS)

2003-10-01

Artist’s impression of the Lynx Arc hi-res Size hi-res: 4519 kb Credits: European Space Agency, NASA and Robert A.E. Fosbury (European Space Agency/Space Telescope-European Coordinating Facility, Germany) Artist’s impression of the Lynx Arc This illustration shows an artist’s impression of the so-called Lynx arc, a newly identified distant super-cluster that contains a million blue-white stars twice as hot as similar stars in our Milky Way galaxy. The Lynx arc is one million times brighter than the well-known Orion Nebula, a nearby prototypical ‘starbirth’ region visible with small telescopes. The stars in the Lynx arc are more than twice as hot as the Orion Nebula’s central stars, with surface temperatures up to 80 000°C. Though there are much bigger and brighter star-forming regions than the Orion Nebula in our local Universe, none are as bright as the Lynx arc, nor do they contain such large numbers of hot stars. The stars are so hot that a very large fraction of their light is emitted in the ultraviolet that makes the gas glow with the green and red colours illustrated here. The so-called Lynx Arc is one million times brighter than the well-known Orion Nebula, a nearby prototypical 'starbirth' region visible with small telescopes. The newly identified super-cluster contains a million blue-white stars that are twice as hot as similar stars in our Milky Way galaxy. It is a rarely glimpsed example of the early days of the Universe where furious firestorms of starbirth blazed across the skies. The spectacular cluster's opulence is dimmed when seen from Earth only by the fact that it is 12 000 million light years away. The discovery of this unique and tantalising object was the result of a systematic study of distant clusters of galaxies carried out with major X-ray, optical and infrared telescopes, including the NASA/ESA Hubble Space Telescope, ROSAT and the Keck Telescopes. Bob Fosbury, of the European Space Agency's Space Telescope-European Coordinating Facility in Germany, and a team of international co-authors report the discovery in the 20 October 2003 issue of the Astrophysical Journal. The mega-cluster of stars appears as a puzzling red arc behind a distant galaxy cluster 5400 million light-years away in the northern constellation of Lynx. The arc is the stretched and magnified image of a mysterious celestial object about 12 000 million light-years away (at a redshift of 3.36), far beyond the cluster of galaxies. This means that the remote source existed when the Universe was less than 2000 million years old. Fosbury and colleagues first tried to identify the arc by analysing the light from the object, but the team was not able to recognise the pattern of colours in the spectral signature of the remote object. While looking for matches with the colour spectrum, Fosbury realised that the light was related to that of the nearby Orion Nebula, a star-forming region in our own Milky Way. However where the Orion Nebula is powered by only four hot and bright blue stars, the Lynx Arc must contain around a million such stars! Furthermore, the spectrum shows that the stars in the Lynx Arc are more than twice as hot as the Orion Nebula's central stars, with surface temperatures up to 80 000°C. Though there are much bigger and brighter star-forming regions than the Orion Nebula in our local Universe, none are as bright as the Lynx Arc, nor do they contain such large numbers of hot stars. Even the most massive, normal nearby stars are no hotter than around 40 000°C. However, stars forming from the original, pristine gas in the early Universe can be more massive and consequently much hotter - perhaps up to 120 000°C. The earliest stars may have been as much as several hundred solar masses, but the chemical make-up of the Universe today prevents stars from forming beyond about 100 solar masses. Such 'primordial' super-hot stars are thought to be the first luminous objects to condense after the Big Bang cooled. Astronomers believe that these first 'monster' stars formed considerably earlier than the Lynx Arc - up to 1800 million years earlier. "This remarkable object is the closest we have come so far to seeing what such primordial objects might look like when our telescopes become powerful enough to see them," says Fosbury. The desire to find and study the first luminous objects in the Universe is the main scientific drive behind the construction of the NASA/ESA/CSA James Webb Space Telescope, scheduled for launch in 2011. Notes for editors The team is composed of R. A. E. Fosbury (European Space Agency/Space Telescope-European Coordinating Facility, Germany), M. Villar-Martín and A. Humphrey (University of Hertfordshire, UK), M. Lombardi and P. Rosati (European Southern Observatory, Germany), D. Stern (Institute of Geophysics and Planetary Physics, USA), R. N. Hook (ST-ECF/STScI, USA), B. P. Holden and S. A. Stanford (University of California, USA), G. K. Squires (SIRTF Science Center, USA), M. Rauch (The Observatories of the Carnegie Institution of Washington, USA) and W. L. W. Sargent (California Institute of Technology, USA). For broadcasters, animations of the discovery, interviews and general Hubble Space Telescope background footage are available from the ESA Television Service, see http://television.esa.int, and from http://www.spacetelescope.org/video/heic0312_vnr.html

Establishing a celestial VLBI reference frame. 1: Searching for VLBI sources

NASA Technical Reports Server (NTRS)

Preston, R. A.; Morabito, D. D.; Williams, J. G.; Slade, M. A.; Harris, A. W.; Finley, S. G.; Skjerve, L. J.; Tanida, L.; Spitzmesser, D. J.; Johnson, B.

1978-01-01

The Deep Space Network is currently engaged in establishing a new high-accuracy VLBI celestial reference frame. The present status of the task of finding suitable celestial radio sources for constructing this reference frame is discussed. To date, 564 VLBI sources were detected, with 166 of these lying within 10 deg of the ecliptic plane. The variation of the sky distribution of these sources with source strength is examined.

A Native Intelligence Metric for Artificial Systems

DTIC Science & Technology

2002-08-01

an example to help clarify the GCEA. Say we are S and we stumble upon Stonehenge . We don’t wonder whether humans carried the stones (some...stones S encounters that may be exhibiting alignment with celestial bodies at certain seasonal times. S determines that the designer of Stonehenge had...matching of the stones with particular celestial events. The various celestial events and our prehistoric Stonehenge designer’s awareness of these events

The International Ultraviolet Explorer: Case study in spacecraft design

NASA Technical Reports Server (NTRS)

Freeman, H. R.; Longanecker, G. W.

1979-01-01

The International Ultraviolet Explorer (IUE) is a geosynchronous scientific satellite that was conceived as an international space observatory capable of measuring UV spectra of faint celestial bodies. Simple operational procedures allow the astronomers to joystick the spaceborne telescope about the sky, using familiar ground-based observatory techniques. The present paper deals with the IUE project objectives, the technical problems, constraints, trade-offs, and the problem solving techniques used in the IUE program.

Astrometry for Astrophysics

NASA Astrophysics Data System (ADS)

van Altena, William F.

Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From Detected Photons to the Celestial Sphere: 13. Geometrical optics and astrometry D. Schroeder; 14. CCD imaging detectors S. Howell; 15. Using CCDs in the time-delayed integration mode D. Rabinowitz; 16. Statistical astronomy A. Brown; 17. Analyzing poorly-sampled images: HST imaging astrometry J. Anderson; 18. Image deconvolution J. Nuñez; 19. From measures to celestial coordinates Z. H. Tang and W. van Altena; 20. Astrometric catalogs: concepts, history and necessity C. López; 21. Trigonometric parallaxes F. Benedict and B. McArthur; Part V. Applications of Astrometry to Topics in Astrophysics: 22. Galactic structure astrometry R. Méndez; 23. Binary and multiple stars E. Horch; 24. Binaries: HST, Hipparcos and Gaia D. Pourbaix; 25. Star clusters I. Platais; 26. Solar System astrometry F. Mignard; 27. Extrasolar planets A. Sozzetti; 28. Astrometric measurement and cosmology R. Easther; Appendices; Index.

Astrometry for Astrophysics

NASA Astrophysics Data System (ADS)

van Altena, William F.

2012-11-01

Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From Detected Photons to the Celestial Sphere: 13. Geometrical optics and astrometry D. Schroeder; 14. CCD imaging detectors S. Howell; 15. Using CCDs in the time-delayed integration mode D. Rabinowitz; 16. StaStatistical astronomy A. Brown; 17. Analyzing poorly-sampled images: HST imaging astrometry J. Anderson; 18. Image deconvolution J. Nuñez; 19. From measures to celestial coordinates Z. H. Tang and W. van Altena; 20. Astrometric catalogs: concepts , history and necessity C. Löpez; 21. Trigonometric parallaxes F. Benedict and B. McArthur; Part V. Applications of Astrometry to Topics in Astrophysics: 22. Galactic structure astrometry R. Méndez; 23. Binary and multiple stars E. Horch; 24. Binaries: HST, Hipparcos and Gaia D. Pourbaix; 25. Star clusters I. Platais; 26. Solar System astrometry F. Mignard; 27. Extrasolar planets A. Sozzetti; 28. Astrometric measurement and cosmology R. Easther; Appendices; Index.

14 CFR 63.55 - Experience requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... satisfactory flight navigation including celestial and radio navigation and dead reckoning. A pilot who has... exclusively for practicing long-range navigation methods, with emphasis on celestial navigation and dead...

14 CFR 63.55 - Experience requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... satisfactory flight navigation including celestial and radio navigation and dead reckoning. A pilot who has... exclusively for practicing long-range navigation methods, with emphasis on celestial navigation and dead...

14 CFR 63.55 - Experience requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... satisfactory flight navigation including celestial and radio navigation and dead reckoning. A pilot who has... exclusively for practicing long-range navigation methods, with emphasis on celestial navigation and dead...

14 CFR 63.55 - Experience requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... satisfactory flight navigation including celestial and radio navigation and dead reckoning. A pilot who has... exclusively for practicing long-range navigation methods, with emphasis on celestial navigation and dead...

14 CFR 63.55 - Experience requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... satisfactory flight navigation including celestial and radio navigation and dead reckoning. A pilot who has... exclusively for practicing long-range navigation methods, with emphasis on celestial navigation and dead...

Solar oscillation time delay measurement assisted celestial navigation method

NASA Astrophysics Data System (ADS)

Ning, Xiaolin; Gui, Mingzhen; Zhang, Jie; Fang, Jiancheng; Liu, Gang

2017-05-01

Solar oscillation, which causes the sunlight intensity and spectrum frequency change, has been studied in great detail, both observationally and theoretically. In this paper, owing to the existence of solar oscillation, the time delay between the sunlight coming from the Sun directly and the sunlight reflected by the other celestial body such as the satellite of planet or asteroid can be obtained with two optical power meters. Because the solar oscillation time delay is determined by the relative positions of the spacecraft, reflective celestial body and the Sun, it can be adopted as the navigation measurement to estimate the spacecraft's position. The navigation accuracy of single solar oscillation time delay navigation system depends on the time delay measurement accuracy, and is influenced by the distance between spacecraft and reflective celestial body. In this paper, we combine it with the star angle measurement and propose a solar oscillation time delay measurement assisted celestial navigation method for deep space exploration. Since the measurement model of time delay is an implicit function, the Implicit Unscented Kalman Filter (IUKF) is applied. Simulations demonstrate the effectiveness and superiority of this method.

The significance of the Sun, Moon and celestial bodies to societies in the Carpathian basin during the Bronze Age

NASA Astrophysics Data System (ADS)

Pásztor, Emília

2011-06-01

Celestial events often exerted a great or even decisive influence on the life of ancient communities. They may provide some of the foundations on which an understanding of the deeper meaning of mythologies, religious systems and even folk tales can be based. These influences are reflected and may be detected in the archaeological material as well. There is good evidence that celestial (especially solar and perhaps lunar) phenomena played a particularly important rôle in the worldview of prehistoric Europe. To reveal the social and ideational significance of concepts relating to the celestial bodies in the prehistory of the Carpathian Basin, complex investigations on orientations of houses and graves, prestige archaeological finds and iconography have been accomplished. The results indicate ideological and/or social changes, which developed into a likely organized ideological system in large part of Central Europe including the Carpathian Basin by the Late Bronze Age. It might also be the first period in prehistory when people became really interested in celestial phenomena.

Vector navigation in desert ants, Cataglyphis fortis: celestial compass cues are essential for the proper use of distance information.

PubMed

Sommer, Stefan; Wehner, Rüdiger

2005-10-01

Foraging desert ants navigate primarily by path integration. They continually update homing direction and distance by employing a celestial compass and an odometer. Here we address the question of whether information about travel distance is correctly used in the absence of directional information. By using linear channels that were partly covered to exclude celestial compass cues, we were able to test the distance component of the path-integration process while suppressing the directional information. Our results suggest that the path integrator cannot process the distance information accumulated by the odometer while ants are deprived of celestial compass information. Hence, during path integration directional cues are a prerequisite for the proper use of travel-distance information by ants.

ESA's new view of the Milky Way - in gamma rays!

NASA Astrophysics Data System (ADS)

2003-11-01

Integral's gamma-ray map of the galaxy hi-res Size hi-res: 430 kb Credits: ESA/SPI team A portion of Integral's gamma-ray map of the galaxy A portion of Integral's gamma-ray map of the galaxy. This false colour picture was taken by the spectrometer on board Integral (SPI) between December 2002 and March 2003. The yellow dots correspond to bright known gamma-rays sources, whilst blue areas indicate regions of low emission. Data similar to these, but in a higher energy range, have been used to study where aluminium and iron are produced in the Galaxy. Since its formation from a cloud of hydrogen and helium gas, around 12 000 million years ago, the Milky Way has gradually been enriched with heavier chemical elements. This has allowed planets and, indeed, life on Earth to form. Today, one of those heavier elements - radioactive aluminium - is spread throughout the Galaxy and, as it decays into magnesium, gives out gamma rays with a wavelength known as the '1809 keV line'. Integral has been mapping this emission with the aim of understanding exactly what is producing all this aluminium. In particular, Integral is looking at the aluminium 'hot spots' that dot the Galaxy to determine whether these are caused by individual celestial objects or the chance alignment of many objects. Astronomers believe that the most likely sources of the aluminium are supernovae (exploding high-mass stars) and, since the decay time of the aluminium is around one million years, Integral's map shows how many stars have died in recent celestial history. Other possible sources of the aluminium include 'red giant' stars or hot blue stars that give out the element naturally. To decide between these options, Integral is also mapping radioactive iron, which is only produced in supernovae. Theories suggest that, during a supernova blast, aluminium and iron should be produced together in the same region of the exploding star. Thus, if the iron's distribution coincides with that of the aluminium, it will prove that the overwhelming majority of aluminium comes indeed from supernovae. These measurements are difficult and have not been possible so far, since the gamma-ray signature of radioactive iron is about six times fainter than that of the aluminium. However, as ESA's powerful Integral observatory accumulates more data in the course of the next year, it will finally be possible to reveal the signature of radioactive iron. This test will tell astronomers whether their theories of how elements form are correct. In addition to these maps, Integral is also looking deeply into the centre of the Galaxy, to make the most detailed map ever of 'antimatter' there. Antimatter is like a mirror image to normal matter and is produced during extremely energetic atomic processes: for example, the radioactive decay of aluminium. Its signature is known as the '511 keV line.' Even though Integral's observations are not yet complete, they show that there is too much antimatter in the centre of the Galaxy to be coming from aluminium decay alone. They also show clearly that there must be many sources of antimatter because it is not concentrated around a single point. There are many possible sources for this antimatter. As well as supernovae, old red stars and hot blue stars, there are jets from neutron stars and black holes, stellar flares, gamma-ray bursts and interaction between cosmic rays and the dusty gas clouds of interstellar space. Chris Winkler, Integral's Project Scientist, says: "We have collected excellent data in the first few months of activity but we can and will do much more in the next year. Integral's accuracy and sensitivity have already exceeded our expectations and, in the months to come, we could get the answers to some of astronomy's most intriguing questions." Note to editors: These and other preliminary results, plus a thorough description of the Integral spacecraft and mission are published this month in a dedicated issue of the journal Astronomy and Astrophysics. At its 105th meeting on 6 October 2003, ESA's Science Programme Committee unanimously decided to extend the Integral mission until December 2008. The International Gamma Ray Astrophysics Laboratory (Integral) is the first space observatory that can simultaneously observe celestial objects in gamma rays, X-rays and visible light. Integral was launched on a Russian Proton rocket on 17 October 2002 into a highly elliptical orbit around Earth. Its principal targets include regions of the galaxy where chemical elements are being produced and compact objects, such as black holes. SPI measures the energy of incoming gamma rays with extraordinary accuracy. It is more sensitive to faint radiation than any previous gamma ray instrument and allows the precise nature of gamma ray sources to be determined. SPI's Principal Investigators are: J.-P. Roques, (CESR Toulouse, France), V. Schönfelder (MPE Garching, Germany).

Osculating Keplerian Elements for Highly Non-Keplerian Orbits

DTIC Science & Technology

2017-03-27

1.52133 2 McInnes, C. R., “The Existence and Stability of Families of Displacement Two-Body Orbits”, Celestial Mechanics and Dynamical Astronomy , Vol...j.actaastro.2011.08.012 5 Xu, M. and Xu, S., “Nonlinear dynamical analysis for displaced orbits above a planet”, Celestial Mechanics and Dynamical Astronomy ...Celestial Mechanics and Dynamical Astronomy , Vol. 110, No. 3, 2011, pp. 199-215. doi: 10.1007/s10569-011-9351-5 7 Macdonald, M., McKay, R. J., Vasile, M

The Hands of the Pleiades: The Celestial Clock in the Classical Arabic Poetry of Dhū al-Rumma

NASA Astrophysics Data System (ADS)

Adams, W. B.

2011-06-01

In the desert poetry of Dhū al-Rumma (d. 117 AH/735 CE), astronomical phenomena sometimes function as familiar celestial timepieces that indicate the poetic timeframe literally and accurately. The literary, lexical, floral and astronomical analyses of a selection from this poetry illustrate the role of the Pleiades star cluster as a celestial clock and illuminate the utility of naked-eye astronomy in interpreting Arabic poetry of the early Islamic period.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1998-01-01

This is a computer rendering of the fully developed Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF). In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-ray such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1995-01-14

This is an artist's concept of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), fully developed in orbit in a star field with Earth. In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-ray such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-01-01

This is a computer rendering of the fully developed Chandra X-ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), in orbit in a star field. In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

Automatic grid azimuth by hour angle of the sun, a star or a planet using an electronic theodolite Kern E2

NASA Astrophysics Data System (ADS)

Solaric, Nikola

1991-03-01

The paper describes a procedure for automatic determinations of the grid azimuth of an object on the earth surface by the hour angle of a celestial object (the sun, a star, or a planet), using the electronic theodolite Kern E2. The observation procedure is simple because the electronic calculator is directing the procedure, and the degree of accuracy is immediately determined. With this method, the external rms error of a single set is approximately two times smaller than in the case of the altitude method. The paper includes a flowchart of the program.

Students' development of astronomy concepts across time

NASA Astrophysics Data System (ADS)

Plummer, Julia Diane

2006-02-01

The National Science Education Standards (NRC, 1996) recommend that students understand the apparent patterns of motion of the sun, moon and stars visible by the end of early elementary school. However, little information exists on students' knowledge of apparent celestial motion or instruction in this area. The goals of this dissertation were to describe children's knowledge of apparent celestial motion across elementary and middle school, explore early elementary students' ability to learn these topics through planetarium instruction, and begin the development of a learning progression for these concepts, First, third, and eighth grade students (N=60) were interviewed using a planetarium-like setting that allowed the students to demonstrate their ideas both verbally and with their own motions on an artificial sky. Analysis of these interviews suggests that students are not making the types of observations of the sky necessary to learn apparent celestial motion and any instruction they may have received has not helped them reach an accurate understanding of most topics. Most students at each grade level could not accurately describe the patterns of motion. Though the older students were more accurate in most of their descriptions than the younger students, in several areas the eighth grade students showed no improvement over the third grade students. The use of kinesthetic learning techniques in a planetarium program was also explored as a method to improve understanding of celestial motion. Pre- and post-interviews were conducted with participants from seven classes of first and second grade students (N=63). Students showed significant improvement in all areas of apparent celestial motion covered by the planetarium program and surpassed the middle school students' understanding of these concepts in most areas. This suggests that students in early elementary school are capable of learning the accurate description of apparent celestial motion. The results demonstrate the value of both kinesthetic learning techniques and the rich visual environment of the planetarium for improved understanding of celestial motion. Based on the results of these studies, I developed a learning progression describing how children may progress through successively more complex ways of understanding apparent celestial motion across elementary grades.

Selfie in Cupola module

NASA Image and Video Library

2015-05-24

ISS043E241729 (05/24/2015) --- Expedition 43 commander and NASA astronaut Terry Virts is seen here inside of the station’s Cupola module. The Cupola is designed for the observation of operations outside the ISS such as robotic activities, the approach of vehicles, and spacewalks. It also provides spectacular views of Earth and celestial objects for use in astronaut observation experiments. It houses the robotic workstation that controls the space station’s robotic arm and can accommodate two crewmembers simultaneously.

A Deep Space Orbit Determination Software: Overview and Event Prediction Capability

NASA Astrophysics Data System (ADS)

Kim, Youngkwang; Park, Sang-Young; Lee, Eunji; Kim, Minsik

2017-06-01

This paper presents an overview of deep space orbit determination software (DSODS), as well as validation and verification results on its event prediction capabilities. DSODS was developed in the MATLAB object-oriented programming environment to support the Korea Pathfinder Lunar Orbiter (KPLO) mission. DSODS has three major capabilities: celestial event prediction for spacecraft, orbit determination with deep space network (DSN) tracking data, and DSN tracking data simulation. To achieve its functionality requirements, DSODS consists of four modules: orbit propagation (OP), event prediction (EP), data simulation (DS), and orbit determination (OD) modules. This paper explains the highest-level data flows between modules in event prediction, orbit determination, and tracking data simulation processes. Furthermore, to address the event prediction capability of DSODS, this paper introduces OP and EP modules. The role of the OP module is to handle time and coordinate system conversions, to propagate spacecraft trajectories, and to handle the ephemerides of spacecraft and celestial bodies. Currently, the OP module utilizes the General Mission Analysis Tool (GMAT) as a third-party software component for highfidelity deep space propagation, as well as time and coordinate system conversions. The role of the EP module is to predict celestial events, including eclipses, and ground station visibilities, and this paper presents the functionality requirements of the EP module. The validation and verification results show that, for most cases, event prediction errors were less than 10 millisec when compared with flight proven mission analysis tools such as GMAT and Systems Tool Kit (STK). Thus, we conclude that DSODS is capable of predicting events for the KPLO in real mission applications.

132. STANDARD NAVAL AIR STATIONS CELESTIAL NAVIGATION, ELEVATIONS AND SECTIONS, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

132. STANDARD NAVAL AIR STATIONS CELESTIAL NAVIGATION, ELEVATIONS AND SECTIONS, BUDOCKS, OCTOBER 14, 1943. QP ACC 9689. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

Celestial Seasonings: Astronomy and Rock Art in the American Southwest

NASA Astrophysics Data System (ADS)

Krupp, E. C.

1994-12-01

Astronomical interpretations of prehistoric rock art have played a significant part in the development of modern archaeoastronomy since 1975, when interest was renewed in the possibility that the Crab supernova explosion of 1054 A.D. was represented in rock art of the American Southwest. (This hypothesis was actually first formulated in 1955.) In the last two decades, a variety of astronomical functions for rock art have been proposed and investigated. These include representation of specific historical celestial events, symbolic representation of elements of celestial myths, star maps, markers for astronomical observing stations markers for celestially tempered shrines, images intended to invoke and exploit cosmo-magical power, seasonally significant light-and-shadow displays. Examples of astronomical connotations in prehistoric rock art from the Southwest and California illustrate the necessity of understanding the culture in any attempt to understand its astronomy.

Spectral Irradiance Calibration in the Infrared. 11; Comparison of (alpha) Bootis and 1 Ceres with a Laboratory Standard

NASA Technical Reports Server (NTRS)

Witteborn, Fred C.; Cohen, Martin; Bregman, Jesse D.; Wooden, Diane H.; Heere, Karen; Shirley, Eric L.

1999-01-01

Infrared spectra of two celestial objects frequently used as flux standards are calibrated against an absolute laboratory flux standard at a spectral resolving power of 100 to 200. The spectrum of the KI.5 III star alpha Boo is measured from 3 to 30 microns, and that of the C-type asteroid 1 Ceres from 5 to 30 microns. While these "standard" spectra do not have the apparent precision of those based on calculated models, they do not require the assumptions involved in theoretical models of stars and asteroids. Specifically, they provide a model-independent means of calibrating celestial flux in the spectral range from 12 to 30 microns, where accurate absolute photometry is not available. The agreement found between the spectral shapes of alpha Boo and Ceres based on laboratory standards and those based on observed ratios to alpha CMa (Sirius) and alpha Lyr (Vega), flux-calibrated by theoretical modeling of these hot stars, strengthens our confidence in the applicability of the stellar models as primary irradiance standards.

Aerothermal Instrumentation Loads To Implement Aeroassist Technology in Future Robotic and Human Missions to MARS and Other Locations Within the Solar System

NASA Technical Reports Server (NTRS)

Parmar, Devendra S.; Shams, Qamar A.

2002-01-01

The strategy of NASA to explore space objects in the vicinity of Earth and other planets of the solar system includes robotic and human missions. This strategy requires a road map for technology development that will support the robotic exploration and provide safety for the humans traveling to other celestial bodies. Aeroassist is one of the key elements of technology planning for the success of future robot and human exploration missions to other celestial bodies. Measurement of aerothermodynamic parameters such as temperature, pressure, and acceleration is of prime importance for aeroassist technology implementation and for the safety and affordability of the mission. Instrumentation and methods to measure such parameters have been reviewed in this report in view of past practices, current commercial availability of instrumentation technology, and the prospects of improvement and upgrade according to the requirements. Analysis of the usability of each identified instruments in terms of cost for efficient weight-volume ratio, power requirement, accuracy, sample rates, and other appropriate metrics such as harsh environment survivability has been reported.

Spectral Irradiance Calibration in the Infrared 11: Comparison of (alpha) Boo and 1 Ceres with a Laboratory Standard

NASA Technical Reports Server (NTRS)

Witteborn, Fred C.; Cohen, Martin; Bregman, Jess D.; Wooden, Diane; Heere, Karen; Shirley, Eric L.

1998-01-01

Infrared spectra of two celestial objects frequently used as flux standards are calibrated against an absolute laboratory flux standard at a spectral resolving power of 100 to 200. The spectrum of the K1.5III star, alpha Boo, is measured from 3 microns to 30 microns and that of the C-type asteroid, 1 Ceres, from 5 microns to 30 microns. While these 'standard' spectra do not have the apparent precision of those based on calculated models, they do not require the assumptions involved in theoretical models of stars and asteroids. Specifically they provide a model-independent means of calibrating celestial flux in the spectral range from 12 microns to 30 microns where accurate absolute photometry is not available. The agreement found between the spectral shapes of alpha Boo and Ceres based on laboratory standards, and those based on observed ratios to alpha CMa (Sirius) and alpha Lyr (Vega), flux calibrated by theoretical modeling of these hot stars strengthens our confidence in the applicability of the stellar models as primary irradiance standards.

Hartung's Astronomical Objects for Southern Telescopes

NASA Astrophysics Data System (ADS)

Malin, David; Frew, David J.

1995-10-01

Many of the most spectacular astronomical objects are found in the southern skies. With this up-to-date, superbly illustrated handbook, both the amateur with binoculars and the expert with a telescope can make discoveries about new and interesting objects. Professor E. J. Hartung first produced his comprehensive and highly respected guide in 1968. Now the book has been greatly expanded and thoroughly revised, enhancing its character as an indispensable information source. With over 150 illustrations, new material is included on constellations and celestial coordinate systems as well as more modern descriptions of stars, nebulae and galaxies. The authors have included a new "southern Messier" list of objects. The authors' passion for their subject make this a unique and inspirational book. Many of the beautiful photographs were taken by David Malin, the world's leading astronomical photographer. The result will fascinate active and armchair astronomers alike.

Gufa, a Unique Cultural Ritual-a Tale of a Forbidden Sun and a Girl

NASA Astrophysics Data System (ADS)

Shrestha, Pritisha

2016-10-01

Gufa, one of the traditional rituals, has been performed in Nepal since time immemorial by indigenous Newar people. In Gufa, a young girl who just had her first period is hidden in a sunless room for twelve consecutive days. This paper expounds the importance of ritual and its nexus with astronomy especially while interpreting how the daily motions of celestial objects have influenced the establishment and devolvement of a deep-rooted custom of Gufa.

A consistent time frame for Chaucer's Canterbury Pilgrimage

NASA Astrophysics Data System (ADS)

Kummerer, K. R.

2001-08-01

A consistent time frame for the pilgrimage that Geoffrey Chaucer describes in The Canterbury Tales can be established if the seven celestial assertions related to the journey mentioned in the text can be reconciled with each other and the date of April 18 that is also mentioned. Past attempts to establish such a consistency for all seven celestial assertions have not been successful. The analysis herein, however, indicates that in The Canterbury Tales Chaucer accurately describes the celestial conditions he observed in the April sky above the London(Canterbury region of England in the latter half of the fourteenth century. All seven celestial assertions are in agreement with each other and consistent with the April 18 date. The actual words of Chaucer indicate that the Canterbury journey began during the 'seson' he defines in the General Prologue and ends under the light of the full Moon on the night of April 18, 1391.

Dynamical configurations of celestial systems comprised of multiple irregular bodies

NASA Astrophysics Data System (ADS)

Jiang, Yu; Zhang, Yun; Baoyin, Hexi; Li, Junfeng

2016-09-01

This manuscript considers the main features of the nonlinear dynamics of multiple irregular celestial body systems. The gravitational potential, static electric potential, and magnetic potential are considered. Based on the three established potentials, we show that three conservative values exist for this system, including a Jacobi integral. The equilibrium conditions for the system are derived and their stability analyzed. The equilibrium conditions of a celestial system comprised of n irregular bodies are reduced to 12n - 9 equations. The dynamical results are applied to simulate the motion of multiple-asteroid systems. The simulation is useful for the study of the stability of multiple irregular celestial body systems and for the design of spacecraft orbits to triple-asteroid systems discovered in the solar system. The dynamical configurations of the five triple-asteroid systems 45 Eugenia, 87 Sylvia, 93 Minerva, 216 Kleopatra, and 136617 1994CC, and the six-body system 134340 Pluto are calculated and analyzed.

On the Late Development and Possible Astronomical Origin of the Gyroscope

NASA Astrophysics Data System (ADS)

Brecher, Kenneth

2013-01-01

The invention of the gyroscope is usually attributed to the French physicist Jean-Bernard-Leon Foucault in the year 1852. He certainly created the word and also used his gyroscope to demonstrate the rotation of the Earth. However, the gyroscope was actually invented around 1812 by the German scientist Johann Bohnenberger who called his device simply the “machine”. Bohnenberger was a professor of astronomy and mathematics and published a book about astronomy in 1811. Several other scientists, including American physicist Walter R. Johnson (who called his apparatus the “rotascope”), independently invented the gyroscope. Each of these devices employed a central object (sphere or disc) that could spin on a shaft. This object was placed between three independent gimbals, two of which could move freely. Bohnenberger’s “machine” has much the same appearance as an armillary sphere. Those astronomical devices had been produced for at least the preceding three centuries and were widely dispersed and well known throughout Europe. They were used to display the apparent motion of celestial bodies. However, armillary spheres were used only as simulations of celestial appearances, not as actual demonstrations of physical phenomena. It is not known if the inertial properties of armillary spheres (and also of terrestrial and celestial globes) had been studied before about 1800. Nonetheless, as a matter of practice, gimbal systems similar to those found in gyroscopes were used on ships to level oil lamps at least as early as the sixteenth century AD. And the ideas behind armillary spheres date back at least a millennium before that. So why did the invention of the gyroscope in its modern form take such a long time when the individual underlying components had been around and utilized for some two millennia? Perhaps because the understanding of angular momentum, including its conservation, was not developed until the start of the 19th century and also because the technologies necessary to make practical gyroscopes were only developed later in the 19th century. This study was supported in part by NSF Grant # DUE-0715975 for Project LITE.

Nature, life and mind. An essay on the essence.

PubMed

Marinkovic, S; Pajić, S; Tomić, O

Our long-standing scientific work and love to the fine art and nature for many years succeeded in making a unifying description of the three domains, at a time when a high specialisation in science, and even in art, has neglected the necessary entirety. Some neurons of a rat cerebral cortex were labelled with true blue and photographed under a fluorescent microscope. A monkey brain was sectioned in the axial plane. Several slices of the human motor cortex were stained with cresyl violet. A cerebral hemisphere image was modified, and another image was created in Adobe Photoshop. Some 10 billion years after the Big Bang life appeared on the Earth, reaching its peak with development of the brain. The humans started exploration of the local nature to survive, and the universe for psychological support. The antique philosophers Leucippes, Democritus and Heraclitus were the first to create a unifying atomic theory and to suggest the eternal movement of the matter. Newton and Kepler explained the movement of the celestial objects, whereas Einstein, Planck, Bohr, Hubbel, Howking and many others connected the quantum physics and elementary forces with the essence of the universe. Leonardo da Vinci, and later many others as well, united science and art. Philosophers and mathematicians created the phenomena which do not exist in nature. Nature designed the human brain, more complex than the universe itself, which in turn created millions of the artworks and scientific discoveries. The might of the mind in some domains overcomes the power of nature.

Animation Sequence of Comet Wild2 Once More Demonstrates Shape Peculiarities of Small Celestial Bodies

NASA Astrophysics Data System (ADS)

Kochemasov, G. G.

The outstanding success of the Stardust mission having acquired in January 2004 images of Comet Wild2 allows us to compare them with images of some other small objects: satellites, asteroids, comets and confirm the earlier conclusion about prevailing shaping forces [1, 2]. The excellent images of the Comet Wild2 core (the best up to date among comets, Internet) show that it is not ``a ball of dirty ice and rock'' but rather a convexo-concave object resembling other small bodies. They all, independently of their nature, sizes, compositions, demonstrate oblong ``banana''-type style. This is a result of pressing in one side and bulging out another antipodean one (the fundamental wave action). Comet Wild2 (5.4 km long core) in this sense can be perfectly compared with asteroid Mathilde (60 km) and satellite Thebe (˜ 116 km). All three have deeply concave hemisphere opposed by clearly convex one. Bulging out friable material often induces deep fracturing of convex hemispheres. This is well visible in comet Borrelli (8 km long core) and especially pronounced in asteroids Eros (33 km) and Annefrank (`˜ 6 km). Deep ``saddle'' at the convex side of both makes their images rather similar. Another characteristic of small oblong bodies is a principal shape difference of two elongated ends: one is blunt, another sharp. Principally, it is the same process which makes the ``banana''-shape (wave1) but of a smaller scale (wave2). The blunt end is made by pressing in, the sharp end by bulging out. Obviously, an impact sculpturing cannot give similar complex forms in so different bodies. The main principal shaping is done by standing inertia-gravity waves arising in celestial bodies in response to their movement in elliptical orbits with periodically changing accelerations. The fundamental wave1 makes convexo-concave shape, the first overtone wave2 sharp-blunt ends. Larger celestial bodies: satellites, planets, stars react to these waves by universal tectonic dichotomy and sectoring [3]. The arctic-antarctic symptom (after Earth) is typical manifestation of sectoring with two antepodean sectors: one pressed in, another bulged out. References: [1] Kochemasov G.G. (1999) On convexo-concave shape of small celestial bodies // ``Asteroids, Comets, Meteors'' conference, Cornell Univ., U.S.A., July 1999, Abstract # 24. 22; [2] Kochemasov G.G. (2002) ``Dirty snowball'' -- now is too primitive for a scientific description of comets // 34th COSPAR Scientific Assembly at the World Space Congress 2002, 10-19 Oct. 2002, Houston, Texas, USA, (CD-ROM); [3] Kochemasov G.G. (1999) Theorems of wave planetary tectonics // Geophys. Res. Abstr., Vol. 1, # 3, 700.

Celestial dynamics and astrometry in expanding universe

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei

2012-08-01

Post - Newtonian theory of motion of celestial bodies and propagation of light was instrumental in conducting the critical experimental tests of general relativity and in building the astronomical ephemerides of celestial bodies in the solar system with an unparalleled precision. The cornerstone of the theory is the postulate that the solar system is gravitationally isolated from the rest of the universe and the background spacetime is asymptotically flat. The present talk abolishes this postulate and lays down the principles of celestial dynamics of particles and light moving in gravitational field of a localized astronomical system embedded to the expanding universe. We formulate the precise mathematical concept of the Newtonian limit of Einstein ’s field equations in the conformally - flat spacetime and analyse the geodesic equations of motion o f particles and light in this limit. We demonstrate that the equations of motion of particles and light can be reduced to their Newtonian counterparts by doing conformal transformations of time and space coordinates. However, the Newtonian equations for particles and light differ by terms of the first order in the Hubble constant. This leads to the important conclusion that the equations of motion used currently by Space Navigation Centres and Astronomical Observatories for calculating orbits of celestial bodies, are incomplete and missing some terms of cosmological origin. We explicitly identify the missing terms and demonstrate that they bring about a noticeable discrepancy between the observed and calculated astronomical ephemerides. We argue that a number of observed celestial anomalies in the solar system can be explained as caused by the Hubble expansion of the universe.

Report of the panel on earth rotation and reference frames, section 7

NASA Technical Reports Server (NTRS)

Dickey, Jean O.; Dickman, Steven R.; Eubanks, Marshall T.; Feissel, Martine; Herring, Thomas A.; Mueller, Ivan I.; Rosen, Richard D.; Schutz, Robert E.; Wahr, John M.; Wilson, Charles R.

1991-01-01

Objectives and requirements for Earth rotation and reference frame studies in the 1990s are discussed. The objectives are to observe and understand interactions of air and water with the rotational dynamics of the Earth, the effects of the Earth's crust and mantle on the dynamics and excitation of Earth rotation variations over time scales of hours to centuries, and the effects of the Earth's core on the rotational dynamics and the excitation of Earth rotation variations over time scales of a year or longer. Another objective is to establish, refine and maintain terrestrial and celestrial reference frames. Requirements include improvements in observations and analysis, improvements in celestial and terrestrial reference frames and reference frame connections, and improved observations of crustal motion and mass redistribution on the Earth.

Contemplation and Calculation: The Universe Discovered.

ERIC Educational Resources Information Center

Solovyov, Yury

1992-01-01

Discusses how early notions about celestial mechanics were restructured, one by one, involving the following concepts: the celestial sphere and its rotation; the spherical earth; planetary motion; and models for the solar system initiated by Eudoxus, Hipparchus, Ptolemy, and Copernicus. (JJK)

Celestial Navigation

ERIC Educational Resources Information Center

Rosenkrantz, Kurt

2005-01-01

In the unit described in this article, students discover the main principles of navigation, build tools to observe celestial bodies, and apply their new skills to finding their position on Earth. Along the way students see how science, mathematics, technology, and history are intertwined.

Teaching Astronomy in non-formal education: stars workshop

NASA Astrophysics Data System (ADS)

Hernán-Obispo, M.; Crespo-Chacón, I.; Gálvez, M. C.; López-Santiago, J.

One of the fields in which teaching Astronomy is more demanded is non-formal education. The Stars Workshop we present in this contribution consisted on an introduction to Astronomy and observation methods. The main objectives were: to know the main components of the Universe, their characteristics and the scales of size and time existing between them; to understand the movement of the different celestial objects; to know the different observational techniques; to value the different historical explanations about the Earth and the position of Humanity in the Universe. This Stars Workshop was a collaboration with the Escuela de Tiempo Libre Jumavi, which is a school dedicated to the training and non-formal education in the leisure field.

Commission 8: Astrometry

NASA Astrophysics Data System (ADS)

Evans, Dafydd Wyn; Zacharias, Norbert; Kumkova, Irina; Andrei, Alexandre; Brown, Anthony; Gouda, Naoteru; Popescu, Petre; Souchay, Jean; Unwin, Stephen; Zhu, Zi

2012-04-01

Gaia is continuing well with its development and construction and is expected to achieve parallax accuracies of about 10 to 300 μas for 6 to 20 mag. It is scheduled to launch in 2013. The ICRF2 was adopted by the IAU in 2009 as the new fundamental celestial reference frame. The UCAC project concluded with the publication of its 4th data release (all-sky, over 100 million stars). The JASMINE project will launch the Nano-JASMINE satellite in 2012 and continues with the development of its other satellites which will complement the Gaia project. The PPMXL (Heidelberg) and XPM (Ukraine) catalogues provide improved astrometric accuracies from new reductions of USNO-B (USNO-A) and 2MASS data. It is disappointing that the SIM project was cancelled during this triennium. It would have further complemented the above two satellite projects and would have gone even beyond Gaia in astrometric accuracy.

Eclipse 2017: Through the eyes of NASA

NASA Astrophysics Data System (ADS)

Mayo, Louis; NASA/GSFC Heliophysics Education Consortium

2016-10-01

The August 21, 2017 eclipse will be the first time a total solar eclipse has traversed the Continental US since June 8th, 1918. Anticipation y for energy for this eclipse is off the charts. Over 500 million in North America alone will catch the eclipse in either partial or total phase. Parts of South America, Africa, and Europe will see a partial eclipse as well. NASA is planning to take full advantage of this unique celestial event as an education and public engagement opportunity by leveraging its extensive networks of partners, numerous social media platforms, broadcast media, and its significant unique space assets and people to bring the eclipse to America and the world as only NASA can. This talk will outline NASA's education plans in some detail replicating our many Big Events successes including the 2012 Transit of Venus and the MSL/Curiosity landing and show how scientists and the public can get involved.

The 2017 Total Solar Eclipse: Through the Eyes of NASA

NASA Astrophysics Data System (ADS)

Young, C. Alex; Mayo, Louis; Ng, Carolyn; Cline, Troy; Lewis, Elaine; Reed, Shannon; Debebe, Asidesach; Stephenson, Bryan; Odenwald, Sten; Hill, Steele; Wright, Ernest

2017-01-01

The August 21, 2017 eclipse will be the first time a total solar eclipse has traversed the Continental US since June 8th, 1918. Anticipation and energy for this eclipse is off the charts! Over 500 million in North America alone will catch the eclipse in either partial or total phase. Parts of South America, Africa, and Europe will see a partial eclipse as well. NASA is planning to take full advantage of this unique celestial event as an education and public engagement opportunity by leveraging its extensive networks of partners, numerous social media platforms, broadcast media, and its significant unique space assets and people to bring the eclipse to America and the world as only NASA can.This talk will outline NASA’s education plans in some detail replicating our many Big Events successes including the 2012 Transit of Venus and the MSL/Curiosity landing and show how scientists and the public can get involved.

Chapter 18: Web-based Tools - NED VO Services

NASA Astrophysics Data System (ADS)

Mazzarella, J. M.; NED Team

The NASA/IPAC Extragalactic Database (NED) is a thematic, web-based research facility in widespread use by scientists, educators, space missions, and observatory operations for observation planning, data analysis, discovery, and publication of research about objects beyond our Milky Way galaxy. NED is a portal into a systematic fusion of data from hundreds of sky surveys and tens of thousands of research publications. The contents and services span the entire electromagnetic spectrum from gamma rays through radio frequencies, and are continuously updated to reflect the current literature and releases of large-scale sky survey catalogs. NED has been on the Internet since 1990, growing in content, automation and services with the evolution of information technology. NED is the world's largest database of crossidentified extragalactic objects. As of December 2006, the system contains approximately 10 million objects and 15 million multi-wavelength cross-IDs. Over 4 thousand catalogs and published lists covering the entire electromagnetic spectrum have had their objects cross-identified or associated, with fundamental data parameters federated for convenient queries and retrieval. This chapter describes the interoperability of NED services with other components of the Virtual Observatory (VO). Section 1 is a brief overview of the primary NED web services. Section 2 provides a tutorial for using NED services currently available through the NVO Registry. The "name resolver" provides VO portals and related internet services with celestial coordinates for objects specified by catalog identifier (name); any alias can be queried because this service is based on the source cross-IDs established by NED. All major services have been updated to provide output in VOTable (XML) format that can be accessed directly from the NED web interface or using the NVO registry. These include access to images via SIAP, Cone- Search queries, and services providing fundamental, multi-wavelength extragalactic data such as positions, redshifts, photometry and spectral energy distributions (SEDs), and sizes (all with references and uncertainties when available). Section 3 summarizes the advantages of accessing the NED "name resolver" and other NED services via the web to replace the legacy "server mode" custom data structure previously available through a function library provided only in the C programming language. Section 4 illustrates visualization via VOPlot of an SED and the spatial distribution of sources from a NED All-Sky (By Parameters) query. Section 5 describes the new NED Spectral Archive, illustrating how VOTables are being used to standardize the data and metadata as well as the physical units of spectra made available by authors of journal articles and producers of major survey archives; quick-look spectral analysis through convenient interoperability with the SpecView (STScI) Java applet is also shown. Section 6 closes with a summary of the capabilities described herein, which greatly simplify interoperability of NED with other components of the VO, enabling new opportunities for discovery, visualization, and analysis of multiwavelength data.

Celestial Pole Offsets: Conversion From (dX, dY) to (d(psi), d(epsilon). Version 3

DTIC Science & Technology

2005-05-01

observed angular offset of the celestial pole from its modelled position, expressed in terms of changes in ecliptic longitude and obliquity . These...the mean obliquity of the ecliptic of date (≈ J2000.0). As the celestial pole precesses farther from the ICRS Z-axis, two effects must be accounted for...to only a few significant digits. With dX ′ and dY ′ in hand we compute dψ = dX ′/ sin ² d² = dY ′ (8) where ² is the mean obliquity of the ecliptic

On the Origin of Rotation of a Celestial Body

NASA Astrophysics Data System (ADS)

Vujičić, V. A.

1988-03-01

The differential equations of the self-rotation of a celestial body have been evaluated. From an integral of these equations a formula for angular velocity of the celestial body was obtained. This formula after being applied to the rotation of the Sun and of the Earth gives, respectively, the following angular velocity ranges: 0.588×10-6<ω<18, 187×10-6 and 0.7533×10-5<ω<12,4266×10-5. These are up to three times narrower than those previously obtained by Savić and Kašanin [1].

Re-calibration of the magnetic compass in hand-raised European robins (Erithacus rubecula)

PubMed Central

Alert, Bianca; Michalik, Andreas; Thiele, Nadine; Bottesch, Michael; Mouritsen, Henrik

2015-01-01

Migratory birds can use a variety of environmental cues for orientation. A primary calibration between the celestial and magnetic compasses seems to be fundamental prior to a bird’s first autumn migration. Releasing hand-raised or rescued young birds back into the wild might therefore be a problem because they might not have established a functional orientation system during their first calendar year. Here, we test whether hand-raised European robins that did not develop any functional compass before or during their first autumn migration could relearn to orient if they were exposed to natural celestial cues during the subsequent winter and spring. When tested in the geomagnetic field without access to celestial cues, these birds could orient in their species-specific spring migratory direction. In contrast, control birds that were deprived of any natural celestial cues throughout remained unable to orient. Our experiments suggest that European robins are still capable of establishing a functional orientation system after their first autumn. Although the external reference remains speculative, most likely, natural celestial cues enabled our birds to calibrate their magnetic compass. Our data suggest that avian compass systems are more flexible than previously believed and have implications for the release of hand-reared migratory birds. PMID:26388258

The astronomy of Andean myth: The history of a cosmology

NASA Astrophysics Data System (ADS)

Sullivan, William F.

It is shown that Andean myth, on one level, represents a technical language recording astronomical observations of precession and, at the same time, an historical record of simultaneous social and celestial transformations. Topographic and architectural terms of Andean myth are interpreted as a metaphor for the organization of and locations on the celestial sphere. Via ethoastronomical date, mythical animals are identified as stars and placed on the celestial sphere according to their topographical location. Tested in the planetarium, these arrays generate cluster of dates - 200 B.C. and 650 A.D. Analysis of the names of Wiraqocha and Manco Capac indicates they represent Saturn and Jupiter and that their mythical meeting represents their conjunction in 650 A.D. The astronomy of Andean myth is then used as an historical tool to examine how the Andean priest-astronomers recorded the simultaneous creation of the avllu and of this distinctive astronomical system about 200 B.C. The idea that the agricultural avllu, with its double descent system stressing the importance of paternity, represents a transformation of society from an earlier matrilineal/horticultural era is examined in light of the sexual imagery employed in myth. Wiraqocha's androgyny and the division of the celestial sphere into male (ecliptic) and female (celestial equator = earth) are interpreted as cosmological validations of the new social structure.

Urania in the Marketplace: The Blue Comet (A Railroad’s Astronomical Heritage)

NASA Astrophysics Data System (ADS)

Rumstay, Kenneth S.

2017-01-01

Between 1929 February 21 and 1941 September 27 the Central New Jersey Railroad operated a luxury passenger train between Jersey City and Atlantic City. Named The Blue Comet, the locomotive, tender, and coaches sported a unique royal blue paint scheme designed to evoke images of celestial bodies speeding through space. Inside each car were etched window panes and lampshades featuring stars and comets. Each coach sported the name of a famous comet on its side; these comets were of course named for their discoverers. Some of the astronomers honored in this unique fashion remain famous to this day, or at least their comets do. The names D’Arrest, Barnard, Encke, Faye, Giacobini, Halley, Olbers, Temple, Tuttle, and Westphal are familiar ones. But Biela, Brorsen, deVico, Spitaler, and Winnecke have now largely faded into obscurity; their stories are recounted here.Although more than seventy years have elapsed since its last run, The Blue Comet, perhaps the most famous passenger train in American history, lives on in the memories of millions of passengers and railfans. This famous train returned to the attention of millions of television viewers on the evening of 2007 June 3, in an episode of the HBO series The Sopranos.This work was supported by a faculty development grant from Valdosta State University.

The Blue Comet: A Railroad's Astronomical Heritage

NASA Astrophysics Data System (ADS)

Rumstay, Kenneth S.

2009-01-01

Between 1929 February 21 and 1941 September 27, the Central New Jersey Railroad operated a luxury passenger train between Jersey City and Atlantic City. Named The Blue Comet, the locomotive, tender, and coaches sported a unique royal blue paint scheme designed to evoke images of celestial bodies speeding through space. Inside each car were etched window panes and lampshades featuring stars and comets. And each coach sported the name of a famous comet on its side; these comets were of course named for their discoverers. Some of the astronomers honored in this unique fashion remain famous to this day, or at least their comets do. The names D'Arrest, Barnard, Encke, Faye, Giacobini, Halley, Olbers, Temple, Tuttle, and Westphal are familiar ones. But Biela, Brorsen, deVico, Spitaler, and Winnecke have now largely faded into obscurity; their stories are recounted here. Although more than sixty years have elapsed since its last run, The Blue Comet, perhaps the most famous passenger train in American history, lives on in the memories of millions of passengers and railfans. This famous train returned to the attention of millions of television viewers on the evening of 2007 June 3, in an episode of the HBO series The Sopranos. This work was supported by a faculty development grant from Valdosta State University.

High-Tech 'Heart' of New-Generation Radio Telescope Passes First Test

NASA Astrophysics Data System (ADS)

2008-08-01

The Expanded Very Large Array (EVLA), part of the National Radio Astronomy Observatory (NRAO), took a giant step toward completion on August 7 with successful testing of advanced digital hardware designed to combine signals from its upgraded radio-telescope antennas to produce high resolution images of celestial objects. Successful Moment NRAO Crew Views Successful Computer Display Of WIDAR "First Fringes" Seated, front to back: Barry Clark, Ken Sowinski, Michael Rupen, Kevin Ryan. Standing, front to rear: Mark McKinnon, Rick Perley, Hichem Ben Frej. CREDIT: Dave Finley, NRAO/AUI/NSF Click on image for larger file. By upgrading the 1970s-era electronics of its original Very Large Array (VLA), NRAO is creating a major new radio telescope that is ten times more sensitive than before. Using the EVLA, astronomers will observe fainter and more-distant objects than previously possible and use vastly improved analysis tools to decipher their physics. The heart of the new electronics that makes this transformation possible is a high-performance, special-purpose supercomputer, called the WIDAR Correlator. It has been designed and is being built by the National Research Council of Canada at the Dominion Radio Astrophysical Observatory (DRAO) of the Herzberg Institute for Astrophysics, and serves as Canada's contribution to the EVLA project. The design of the correlator incorporates an NRC-patented new digital electronic architecture. The successful test, at the VLA site 50 miles west of Socorro, New Mexico, used prototype correlator electronics to combine the signals from two upgraded VLA antennas to turn them into a single, high-resolution telescope system, called an interferometer. The technical term for this achievement is called "first fringes." Each upgraded EVLA antenna produces 100 times more data than an original VLA antenna. When all 27 antennas are upgraded, they will pump data into the WIDAR correlator at a rate equal to 48 million digital telephone calls. To process this torrent of data, the correlator will make 10 million billion calculations per second. Powerful, multi-antenna imaging radio-telescope systems use pairs of antennas as their basic building blocks. Each of the VLA's 27 giant dish antennas is combined electronically with every other antenna to form a multitude of pairs. Each pair contributes unique information that is used to build a highly-detailed image of some astronomical object. The successful two-antenna test thus verifies the design of the new correlator. "This achievement marks the first time that the complete chain of electronics for the EVLA has worked together, and represents a huge milestone in the project. Our congratulations go to our Canadian colleagues and to the NRAO staff members participating in this project. This is a job well done," said Fred Lo, Director of the National Radio Astronomy Observatory. The VLA Expansion, a ten-year project approved in 2001, is funded by 55 million from the United States National Science Foundation (NSF) and 1.75 million from the Mexican government. The Canadian correlator represents a contribution of about $17 million to the project. Throughout the project, the VLA has continued to operate, using a mix of the old and new-style antennas to provide an ongoing research tool. Over its lifetime, the VLA has been the most scientifically-productive ground-based telescope in the history of astronomy. When completed in 2012, the EVLA will be the most powerful centimeter-wavelength radio telescope in the world. The technology developed for the EVLA will enable progress on the next generation radio telescope called the Square Kilometer Array (SKA). The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Plots of amplitude (top) and phase (bottom) from WIDAR correlator "first fringes" on August 7, 2008.

The International Celestial Reference Frame (ICRF) and the Relationship Between Frames

NASA Technical Reports Server (NTRS)

Ma, Chopo

2000-01-01

The International Celestial Reference Frame (ICRF), a catalog of VLBI source positions, is now the basis for astrometry and geodesy. Its construction and extension/maintenance will be discussed as well as the relationship of the ICRF, ITRF, and EOP/nutation.

Celestial mechanics with geometric algebra

NASA Technical Reports Server (NTRS)

Hestenes, D.

1983-01-01

Geometric algebra is introduced as a general tool for Celestial Mechanics. A general method for handling finite rotations and rotational kinematics is presented. The constants of Kepler motion are derived and manipulated in a new way. A new spinor formulation of perturbation theory is developed.

It All Depends on Your Attitude.

ERIC Educational Resources Information Center

Kastner, Bernice

1992-01-01

Presents six learning exercises that introduce students to the mathematics used to control and track spacecraft attitude. Describes the geocentric system used for Earthbound location and navigation, the celestial sphere, the spacecraft-based celestial system, time-dependent angles, observer-fixed coordinate axes, and spacecraft rotational axes.…

Students' Development of Astronomy Concepts across Time

NASA Astrophysics Data System (ADS)

Plummer, Julia

Students in Grades 1, 3, and 8 (N = 60) were interviewed while using a planetarium-like setting that allowed the students to demonstrate their ideas about apparent celestial motion both verbally and with their own motions. Though the older students were generally more accurate in many conceptual areas compared with the younger students, in several areas, the eighth-grade students showed no improvement over the third-grade students. The use of kinesthetic learning techniques in a planetarium program was also explored as a method to improve understanding of celestial motion. Pre- and postinterviews were conducted with participants from seven classes of first- and second-grade students (N = 63). Students showed significant improvement in all areas of apparent celestial motion covered by the planetarium program and surpassed the middle school students' understanding of these concepts in most areas. Based on the results of these studies, a learning progression was developed describing how children may progress through successively more complex ways of understanding apparent celestial motion across elementary grades.

Perceptual Strategies of Pigeons to Detect a Rotational Centre—A Hint for Star Compass Learning?

PubMed Central

Helduser, Sascha; Mouritsen, Henrik; Güntürkün, Onur

2015-01-01

Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy. PMID:25807499

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. I. ASTROMETRY

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

Lanyi, G. E.; Jacobs, C. S.; Naudet, C. J.

2010-05-15

We present astrometric results for compact extragalactic objects observed with the Very Long Baseline Array at radio frequencies of 24 and 43 GHz. Data were obtained from ten 24 hr observing sessions made over a five-year period. These observations were motivated by the need to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies to enable improved deep space navigation after 2016 and to improve state-of-the-art astrometry. Source coordinates for 268 sources were estimated at 24 GHz and for 131 sources at 43 GHz. The median formal uncertainties of right ascension and declination at 24 GHz are 0.08more » and 0.15 mas, respectively. Median formal uncertainties at 43 GHz are 0.20 and 0.35 mas, respectively. Weighted root-mean-square differences between the 24 and 43 GHz positions and astrometric positions based on simultaneous 2.3 and 8.4 GHz Very Long Baseline Interferometry observations, such as the ICRF, are less than about 0.3 mas in both coordinates. With observations over five years we have achieved a precision at 24 GHz approaching that of the ICRF but unaccounted systematic errors limit the overall accuracy of the catalogs.« less

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

Nonuniformity of the Earth's rotation and the motion of the poles

NASA Technical Reports Server (NTRS)

Sidorenkov, N. S.

1983-01-01

The study of the nonuniformity of the Earth's rotation and the motion of the poles has great practical and theoretical significance. This study makes it possible to determine the coordinates of celestial and terrestrial objects, and to gain information in many domains of earth science. This paper reviews studies of rotation nonuniformity and polar motion, giving attention to astronomical data; the nature of periodic oscillations of the Earth's rotation; the nature of long-period variations of the Earth's rotation rate; and the use of Earth-rotation data in hydrometeorology.

Polarization characteristics of an altazimuth sky scanner

NASA Technical Reports Server (NTRS)

Garrison, L. M.; Blaszczak, Z.; Green, A. E. S.

1980-01-01

A theoretical description of the polarization characteristics of an altazimuth sky scanner optical system based on Mueller-Stokes calculus is presented. This computer-driven optical system was designed to perform laboratory studies of skylight and of celestial objects during day or night, and has no space limitations; however, the two parallel 45 deg tilt mirrors introduce some intrinsic polarization. Therefore, proper data interpretation requires a theoretical understanding of the polarization features of the instrument and accurate experimental determination of the Mueller-Stokes matrix elements describing the polarizing and depolarizing action of the system.

Drevnyaya astronomiya Yuzhnoj Ameriki %t Ancient astronomy of the South America

NASA Astrophysics Data System (ADS)

Yurevich, V. A.

The article portrays our knowledge of the astronomy of the South America before its discovery by European. The archeoastronomical monuments display that the astronomy was the basis for the calendar, and its probable reconstruction is proposed. The author demonstrated that all solar and moon directions of the horizon astronomy were used in it. First chronicles and ethnographic data give information about the cosmological ideas of native-Americans, their worships of the celestial objects (the Sun, Moon), implication of astronomical phenomena in their religious rituals and feasts.

Observation of GEO Satellite Above Thailand’s Sky

NASA Astrophysics Data System (ADS)

Kasonsuwan, K.; Wannawichian, S.; Kirdkao, T.

2017-09-01

The direct observations of Geostationary Orbit (GEO) satellites above Thailand’s sky by 0.7-meters telescope were proceeded at Inthanon Mt., Chiang Mai, Thailand. The observation took place at night with Sidereal Stare Mode (SSM). With this observing mode, the moving object will appear as a streak. The star identification for image calibration is based on (1) a star catalogue, (2) the streak detection of the satellite using the software and (3) the extraction of the celestial coordinate of the satellite as a predicted position. Finally, the orbital elements for GEO satellites were calculated.

Flight software operation of the Hubble Space Telescope fine guidance sensor

NASA Technical Reports Server (NTRS)

Rodden, J. J.; Dougherty, H. J.; Cormier, D. J.

1988-01-01

The Hubble Space Telescope (HST) is to carry five major scientific instruments to collect imagery, spectrographic, and photometric astronomical data. The Pointing Control System is designed to achieve pointing accuracies and line of sight jitter levels an order of magnitude less than can be achieved with ground mounted telescopes. This paper describes the operation of the pointing control system flight software in targeting a celestial object in a science instrument aperture and in performing the coordinate transformations necessary for commanding the fine guidance sensor and determining the attitude-error corrections.

Schwarzschild Solution: A Historical Perspective

NASA Astrophysics Data System (ADS)

Bartusiak, Marcia

2016-03-01

While eighteenth-century Newtonians had imagined a precursor to the black hole, the modern version has its roots in the first full solution to Einstein's equations of general relativity, derived by the German astronomer Karl Schwarzschild on a World War I battlefront just weeks after Einstein introduced his completed theory in November 1915. This talk will demonstrate how Schwarzschild's solution is linked to the black hole and how it took more than half a century for the physics community to accept that such a bizarre celestial object could exist in the universe.

Inquiry and Astronomy: Preservice Teachers' Investigations of Celestial Motion

ERIC Educational Resources Information Center

Plummer, Julia D.; Zahm, Valerie M.; Rice, Rebecca

2010-01-01

This study investigated the impact of an open inquiry experience on elementary science methods students' understanding of celestial motion as well as the methods developed by students to answer their own research questions. Pre/post interviews and assessments were used to measure change in participants' understanding (N = 18). A qualitative…

Solar system lithograph set for earth and space science

NASA Technical Reports Server (NTRS)

1995-01-01

A color lithographs of many of the celestial bodies within our solar system are contained in this educational set of materials. Printed on the back of each lithograph is information regarding the particular celestial body. A sheet with information listing NASA resources and electronic resources for education is included.

Relativistic Astronomy

NASA Astrophysics Data System (ADS)

Zhang, Bing; Li, Kunyang

2018-02-01

The “Breakthrough Starshot” aims at sending near-speed-of-light cameras to nearby stellar systems in the future. Due to the relativistic effects, a transrelativistic camera naturally serves as a spectrograph, a lens, and a wide-field camera. We demonstrate this through a simulation of the optical-band image of the nearby galaxy M51 in the rest frame of the transrelativistic camera. We suggest that observing celestial objects using a transrelativistic camera may allow one to study the astronomical objects in a special way, and to perform unique tests on the principles of special relativity. We outline several examples that suggest transrelativistic cameras may make important contributions to astrophysics and suggest that the Breakthrough Starshot cameras may be launched in any direction to serve as a unique astronomical observatory.

Terrestrial-passage theory: failing a test.

PubMed

Reed, Charles F; Krupinski, Elizabeth A

2009-01-01

Terrestrial-passage theory proposes that the 'moon' and 'sky' illusions occur because observers learn to expect an elevation-dependent transformation of visual angle. The transformation accompanies daily movement through ordinary environments of fixed-altitude objects. Celestial objects display the same visual angle at all elevations, and hence are necessarily non-conforming with the ordinary transformation. On hypothesis, observers should target angular sizes to appear greater at elevation than at horizon. However, in a sample of forty-eight observers there was no significant difference between the perceived angular size of a constellation of stars at horizon and that predicted for a specific elevation. Occurrence of the illusion was not restricted to those observers who expected angular expansion. These findings fail to support the terrestrial-passage theory of the illusion.

Did a Comet Deliver the Chelyabinsk Meteorite?

NASA Astrophysics Data System (ADS)

Gladysheva, O. G.

2017-09-01

An explosion of a celestial body occurred on the fifteenth of February, 2013, near Chelyabinsk (Russia). The explosive energy was determined as 500 kt of TNT, on the basis of which the mass of the bolide was estimated at 107 kg, and its diameter at 19 m [1]. Fragments of the meteorite, such as LL5/S4-WO type ordinary chondrite [2] with a total mass only of 2•103 kg, fell to the earth's surface [3]. Here, we will demonstrate that the deficit of the celestial body's mass can be explained by the arrival of the Chelyabinsk chondrite on Earth by a significantly more massive but fragile ice-bearing celestial body.

UBVRI PHOTOMETRIC STANDARD STARS AROUND THE CELESTIAL EQUATOR: UPDATES AND ADDITIONS

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

Landolt, Arlo U.

2009-05-15

New broadband UBVRI photoelectric observations on the Johnson-Kron-Cousins photometric system have been made of 202 stars around the sky, and centered at the celestial equator. These stars constitute both an update of and additions to a previously published list of equatorial photometric standard stars. The list is capable of providing, for both celestial hemispheres, an internally consistent homogeneous broadband standard photometric system around the sky. When these new measurements are included with those previously published by Landolt (1992), the entire list of standard stars in this paper encompasses the magnitude range 8.90 < V < 16.30, and the color indexmore » range -0.35 < (B - V) < +2.30.« less

AstroNavigation: Freely-available Online Instruction for Performing a Sight Reduction

NASA Astrophysics Data System (ADS)

Gessner Stewart, Susan; Grundstrom, Erika; Caudel, Dave

2015-08-01

A reliable method of obtaining your geographic location from observations of celestial bodies is globally available. This online learning module, developed through a collaboration between Vanderbilt University and the U.S. Naval Observatory, serves to address the need for freely-available comprehensive instruction in celestial navigation online. Specifically targeted are the steps of preforming a sight reduction to obtain a terrestrial position using this technique. Difficult concepts such as plotting on a navigational chart and the complexities of using navigation publications are facilitated through this online content delivery, rooted in effective course design principles. There is good potential in using celestial navigation as a tool for stimulating interest in astronomy given its resourcefulness and accessibility.

Determination of meteor flux distribution over the celestial sphere

NASA Technical Reports Server (NTRS)

Andreev, V. V.; Belkovich, O. I.; Filimonova, T. K.; Sidorov, V. V.

1992-01-01

A new method of determination of meteor flux density distribution over the celestial sphere is discussed. The flux density was derived from observations by radar together with measurements of angles of arrival of radio waves reflected from meteor trails. The role of small meteor showers over the sporadic background is shown.

A Study of Planetarium Effectiveness on Student Achievement, Perceptions and Retention.

ERIC Educational Resources Information Center

Ridky, Robert William

Reported is a study to determine the effect of planetarium instruction in terms of immediate attainment, attitude, and retention in the teaching of selected celestial motion and non-celestial motion concepts, when contrasted to or combined with the inquiry activities utilized by the nationally developed science curricula. Observations were made on…

The consistency of the current conventional celestial and terrestrial reference frames and the conventional EOP series

NASA Astrophysics Data System (ADS)

Heinkelmann, R.; Belda-Palazon, S.; Ferrándiz, J.; Schuh, H.

2015-08-01

For applications in Earth sciences, navigation, and astronomy the celestial (ICRF) and terrestrial (ITRF) reference frames as well as the orientation among them, the Earth orientation parameters (EOP), have to be consistent at the level of 1 mm and 0.1 mm/yr (GGOS recommendations). We assess the effect of unmodelled geophysical signals in the regularized coordinates and the sensitivity with respect to different a priori EOP and celestial reference frames. The EOP are determined using the same VLBI data but with station coordinates fixed on different TRFs. The conclusion is that within the time span of data incorporated into ITRF2008 (Altamimi, et al., 2011) the ITRF2008 and the IERS 08 C04 are consistent. This consistency involves that non-linear station motion such as unmodelled geophysical signals partly affect the IERS 08 C04 EOP. There are small but not negligible inconsistencies between the conventional celestial reference frame, ICRF2 (Fey, et al., 2009), the ITRF2008 and the conventional EOP that are quantified by comparing VTRF2008 (Böckmann, et al., 2010) and ITRF2008.

Gravitational mechanism of active life of the Earth, planets and satellites

NASA Astrophysics Data System (ADS)

Barkin, Yury

2010-05-01

From positions of geodynamic model of the forced gravitational swing, wobble and displacements of shells of a planet are studied and fundamental problems of geodynamics, geology, geophysics, planetary sciences are solved etc.: 1) The mechanism of cyclic variations of activity of natural processes in various time scales. 2) The power of endogenous activity of planetary natural processes on planets and satellites. 3) The phenomenon of polar inversion of natural processes on planets and satellites. 4) Spasmodic and catastrophic changes of activity of natural processes. 5) The phenomenon of twisting of hemispheres (latitude zones or belts) of celestial bodies. 6) Formation of the pear-shaped form of celestial bodies and the mechanism of its change. 7) The ordered planetary structures of geological formations. 8) The phenomena of bipolarity of celestial bodies and antipodality of geology formations. Mechanism. The fundamental feature of a structure of celestial bodies is their shell structure. The most investigated is the internal structure of the Earth. For the Moon and wide set of other bodies of solar system models of an internal structure have been constructed on the basis of the data of observations obtained at studying of their gravitational fields as a result of realization of the appropriate space missions. The basic components for the majority of celestial bodies are the core, the mantle and the crust. To other shells we concern atmospheres (for example, at Venus, Mars, the Titan etc.) and oceanic shells (the Titan, the Earth, Enceladus etc.). Shells are the complex (composite) formations. Planets and satellites are not spherical celestial bodies. The centers of mass of shells of the given planet (or the satellite) and their appropriate principal axes of inertia do not coincide. Accordingly, all their shells are characterized by the certain dynamic oblatenesses. Differences of dynamical oblatenesses results in various forced influences of external celestial bodies on shells of the given body. Dynamical oblatenesses of shells, thus, characterize the endogenous activity of a planet by external celestial bodies. Other important factor of endogenous activity of a planet is a eccentric position of the centers of mass of the shells (for example, of the core and the mantle). The eccentricity of the shells is inherited during geological evolution of a planet as system of shells (Barkin, 2002). Consequences of exitation of the Earth system. The new tides (Barkin, 2005) are caused by relative displacements of the core and mantle. These displacements are reflected in variations of many natural processes due to gravitational action of the core. The displacing core causes deformations of all layers of viscous-elastic mantle. In the given work from more general positions the mechanisms of excitation of a system of shells of the Earth under action of a gravitational attraction of the Sun, the Moon and planets, the phenomena of their relative swings, translational displacements and turns relatively from each other, and the wide list geodynamical consequences of the specified excitation of the Earth are studied. At once we shall emphasize, that the developed geodynamic model has allowed to carry out the important dynamic researches of displacements of shells of the Earth, their deformations and changes, and variations of its natural processes and for the first time to explain the nature of such fundamental phenomena and processes in geodynamics, geology and geophysics as: cyclicity of natural processes and its mechanism; power of processes in various time scales; unity of cyclic processes and universality of their frequency bases; synchronism of geodynamic, geophysical, biophysical and social events; inversion, contrast and opposite directed changes of activity of natural processes in opposite hemispheres of the Earth; step-by-step variations of natural processes, sawtooth course of activity of natural processes in various time scales; orderliness in an distribution of geological formations on the Earth, planets and satellites; existence of antipodal formations on planets and satellites; the phenomenon of twisting of hemispheres of bodies of solar system, twisting of layers and latitudinal zones of shells of celestial bodies including inner layers and shells, etc. All the specified phenomena from the resulted list to some extent are discussed in the given work and illustrated on the basis of modern researches in Earth's sciences and the researches executed by means of space missions. In a complex, the executed researches have shown universality of discussed mechanisms and their important role in dynamics and geoevolution of planets and satellites in other planetary systems, and also stars and pulsars with the systems of planets (Barkin, 2009). Cyclicity. The excitation on the part of external celestial bodies of the system core-mantle depends from relative positions of external celestial bodies, from particularities of their perturbed orbital motions and from rotary motion of the planet. The specified motions have a cyclic nature which is shown in various time scales. Hence, and excitation of shells and their layers will have also cyclic character and to be shown in various time scales. Hence, cyclic variations of all planetary natural processes in all the variety widely should be observed, as takes place in reality. The periods of variations are characterized by extremely wide range - from hours up to tens and hundreds millions years. If the core makes slow secular drift relatively to the mantle all layers and shells of the Earth test secular deformation, thermodynamic and other changes. The cavity of the core and its flows are changed slowly that results in secular variations of a magnetic field (Barkin, 2002, 2009). Inversion and asymmetry of cyclic and secular variations of natural processes. The essence of it rather wide distributed phenomena is, that activity of natural processes varies in an antiphase in opposite hemispheres of the Earth (first of all in northern and southern hemispheres). Told concerns to all geodynamic and geophysical processes, to variations of physical fields, to tectonic and geodetic reorganizations of layers of the Earth, to redistributions of atmospheric, oceanic and other fluid masses of the Earth. The certain asymmetry of displays of processes in northern and southern hemispheres on the other hand is marked. So secular trends of some processes are contrast in northern and southern hemispheres, i.e. velocities of secular changes are essentially different. All described phenomena are caused first of all by cyclic oscillations and secular drift of the core to the north (in present epoch). In longer time scales the similar phenomena of inversion, dissymmetry also have place and determine a nature and style of displacements of continents and lithospheric plates, planetary magmatic activity and plume tectonics as a whole, formation of mountains, elevations and depressions, systems of lineaments and cracks, regressions and transgressions of sea level (Barkin, 2002). Synchronous steps of activity of natural processes. 'For an explanation of observably step-by-step variations of geodynamic and geophysical processes the mechanism of sharp sporadic relative displacements of the core and the mantle and deformations of the mantle in the certain periods of time (the phenomenon of "galloping of the core') is offered.

The depth of the honeybee's backup sun-compass systems.

PubMed

Dovey, Katelyn M; Kemfort, Jordan R; Towne, William F

2013-06-01

Honeybees have at least three compass mechanisms: a magnetic compass; a celestial or sun compass, based on the daily rotation of the sun and sun-linked skylight patterns; and a backup celestial compass based on a memory of the sun's movements over time in relation to the landscape. The interactions of these compass systems have yet to be fully elucidated, but the celestial compass is primary in most contexts, the magnetic compass is a backup in certain contexts, and the bees' memory of the sun's course in relation to the landscape is a backup system for cloudy days. Here we ask whether bees have any further compass systems, for example a memory of the sun's movements over time in relation to the magnetic field. To test this, we challenged bees to locate the sun when their known celestial compass systems were unavailable, that is, under overcast skies in unfamiliar landscapes. We measured the bees' knowledge of the sun's location by observing their waggle dances, by which foragers indicate the directions toward food sources in relation to the sun's compass bearing. We found that bees have no celestial compass systems beyond those already known: under overcast skies in unfamiliar landscapes, bees attempt to use their landscape-based backup system to locate the sun, matching the landscapes or skylines at the test sites with those at their natal sites as best they can, even if the matches are poor and yield weak or inconsistent orientation.

On the definition and use of the ecliptic in modern astronomy

NASA Astrophysics Data System (ADS)

Capitaine, N.; Soffel, M.

2015-08-01

The ecliptic was a fundamental reference plane for astronomy from antiquity to the realization and use of the FK5 reference system. The situation has changed considerably with the adoption of the International Celestial Reference system (ICRS) by the IAU in 1998 and the IAU resolutions on reference systems that were adopted from 2000 to 2009. First, the ICRS has the property of being independent of epoch, ecliptic or equator. Second, the IAU 2000 resolutions, which specified the systems of space-time coordinates within the framework of General Relativity, for the solar system (the Barycentric Celestial Reference System, BCRS) and the Earth (the Geocentric Celestial Reference System, GCRS), did not refer to any ecliptic and did not provide a definition of a GCRS ecliptic. These resolutions also provided the definition of the pole of the nominal rotation axis (the Celestial intermediate pole, CIP) and of new origins on the equator (the Celestial and Terrestrial intermediate origins, CIO and TIO), which do not require the use of an ecliptic. Moreover, the models and standards adopted by the IAU 2006 and IAU 2009 resolutions are largely referred to the ICRS, BCRS, GCRS as well as to the new pole and origins. Therefore, the ecliptic has lost much of its importance. We review the consequences of these changes and improvements in the definition and use of the ecliptic and we discuss whether the concept of an ecliptic is still needed for some specific use in modern astronomy.

Modular Mount Control System for Telescopes

NASA Astrophysics Data System (ADS)

Mooney, J.; Cleis, R.; Kyono, T.; Edwards, M.

The Space Observatory Control Kit (SpOCK) is the hardware, computers and software used to run small and large telescopes in the RDS division of the Air Force Research Laboratories (AFRL). The system is used to track earth satellites, celestial objects, terrestrial objects and aerial objects. The system will track general targets when provided with state vectors in one of five coordinate systems. Client-toserver and server-to-gimbals communication occurs via human-readable s-expressions that may be evaluated by the computer language called Racket. Software verification is achieved by scripts that exercise these expressions by sending them to the server, and receiving the expressions that the server evaluates. This paper describes the adaptation of a modular mount control system developed primarily for LEO satellite imaging on large and small portable AFRL telescopes with a goal of orbit determination and the generation of satellite metrics.

The PMA Catalogue: 420 million positions and absolute proper motions

NASA Astrophysics Data System (ADS)

Akhmetov, V. S.; Fedorov, P. N.; Velichko, A. B.; Shulga, V. M.

2017-07-01

We present a catalogue that contains about 420 million absolute proper motions of stars. It was derived from the combination of positions from Gaia DR1 and 2MASS, with a mean difference of epochs of about 15 yr. Most of the systematic zonal errors inherent in the 2MASS Catalogue were eliminated before deriving the absolute proper motions. The absolute calibration procedure (zero-pointing of the proper motions) was carried out using about 1.6 million positions of extragalactic sources. The mean formal error of the absolute calibration is less than 0.35 mas yr-1. The derived proper motions cover the whole celestial sphere without gaps for a range of stellar magnitudes from 8 to 21 mag. In the sky areas where the extragalactic sources are invisible (the avoidance zone), a dedicated procedure was used that transforms the relative proper motions into absolute ones. The rms error of proper motions depends on stellar magnitude and ranges from 2-5 mas yr-1 for stars with 10 mag < G < 17 mag to 5-10 mas yr-1 for faint ones. The present catalogue contains the Gaia DR1 positions of stars for the J2015 epoch. The system of the PMA proper motions does not depend on the systematic errors of the 2MASS positions, and in the range from 14 to 21 mag represents an independent realization of a quasi-inertial reference frame in the optical and near-infrared wavelength range. The Catalogue also contains stellar magnitudes taken from the Gaia DR1 and 2MASS catalogues. A comparison of the PMA proper motions of stars with similar data from certain recent catalogues has been undertaken.

Mariner 9 celestial mechanics experiment - A status report.

NASA Technical Reports Server (NTRS)

Lorell, J.; Shapiro, I. I.

1973-01-01

There are two basic efforts in the Mariner 9 celestial mechanics experiment: the determination of the gravity field of Mars and the performance of a very precise test of the theory of general relativity. In addition, there are a number of astrodynamic constants that are being determined. All the analyses are based on the Mariner 9 radio tracking data.

Relationships between log N-log S and celestial distribution of gamma-ray bursts

NASA Technical Reports Server (NTRS)

Nishimura, J.; Yamagami, T.

1985-01-01

The apparent conflict between log N-log S curve and isotropic celestial distribution of the gamma ray bursts is discussed. A possible selection effect due to the time profile of each burst is examined. It is shown that the contradiction is due to this selection effect of the gamma ray bursts.

Determination of the observation conditions of celestial bodies with the aid of the DISPO system

NASA Technical Reports Server (NTRS)

Kazakov, R. K.; Krivov, A. V.

1984-01-01

The interactive system for determining the observation conditions of celestial bodies is described. A system of programs was created containing a part of the DISPO Display Interative System of Orbit Planning. The system was used for calculating the observatiion characteristics of Halley's comet during its approach to Earth in 1985-86.

Preventing Commercial Colonialism and Retaining Sovereignty Over National Policy and Military Strategy in Space

DTIC Science & Technology

2018-04-09

29 National Interests in Space – Commercial or State-Driven Celestial Expansion? ....... 31 Celestial Market Opportunities – When Will Commercial...Space Markets Open? ...... 38 Implications of Commercial Space Operations ............................................................ 45 Chapter 5...Successful development of competitiveness involves seeking to dominate or control an existing or emergent market . The development of market domination into

Sensory bases of navigation.

PubMed

Gould, J L

1998-10-08

Navigating animals need to know both the bearing of their goal (the 'map' step), and how to determine that direction (the 'compass' step). Compasses are typically arranged in hierarchies, with magnetic backup as a last resort when celestial information is unavailable. Magnetic information is often essential to calibrating celestial cues, though, and repeated recalibration between celestial and magnetic compasses is important in many species. Most magnetic compasses are based on magnetite crystals, but others make use of induction or paramagnetic interactions between short-wavelength light and visual pigments. Though odors may be used in some cases, most if not all long-range maps probably depend on magnetite. Magnetitebased map senses are used to measure only latitude in some species, but provide the distance and direction of the goal in others.

Integral's first look at the gamma-ray Universe

NASA Astrophysics Data System (ADS)

2002-12-01

The high-energy Universe is a violent place of exploding stars and their collapsed remnants such as the ultra-compressed neutron stars and, at the most extreme, all-consuming black holes. These celestial objects create X-rays and gamma rays that are many times more powerful than the optical radiation we can see with our eyes and optical telescopes. Integral’s Principal Investigators - the scientists responsible for the instruments on board - explain the crucial role that high-energy missions like Integral play in astronomy. “X-ray and gamma-ray astronomy is a pathfinder to unusual objects. At optical wavelengths, the number of stars is staggering. At X-ray and gamma-ray wavelengths, there are fewer objects, but the ones that remain are the really peculiar ones.” As a first test, Integral observed the Cygnus region of the sky, looking particularly at that enigmatic object, Cygnus X-1. Since the 1960s, we have known this object to be a constant generator of high-energy radiation. Most scientists believe that Cygnus X-1 is the site of a black hole, containing around five times the mass of our Sun and devouring a nearby star. Observing Cygnus X-1, which is relatively close by in our own Galaxy - ‘only’ 10 000 light years from us - is a very important step towards understanding black holes. This will also help understand the monstrous black hole - three million times the mass of our Sun - at the centre of our Galaxy. During the initial investigations, scientists had a pleasant surprise when Integral captured its first gamma-ray burst. These extraordinary celestial explosions are unpredictable, occurring from random directions about twice a day. Their precise origin is contentious: they could be the result of massive stars collapsing in the distant Universe or alternatively the result of a collision between two neutron stars. Integral promises to provide vital clues to solving this particular celestial mystery. To study these peculiarities, Integral carries two powerful gamma-ray instruments. It has a camera, or imager, called IBIS and a spectrometer, SPI. Spectrometers are used to measure the energy of the gamma rays received. Gamma-ray sources are often extremely variable and can fluctuate within minutes or seconds. It is therefore crucial to record data simultaneously in different wavelengths. To achieve this, Integral also carries an X-ray and an optical monitor (JEM-X and OMC). All four instruments will observe the same objects, at the same time. In this way they can capture fleeting events completely. Integral sends the data from all the instruments to the Integral Science Data Centre (ISDC) near Geneva, Switzerland, where they are processed for eventual release to the scientific community. “We have been optimising the instruments’ performance to produce the best overall science. We expect to be ready for astronomers around the world to use Integral by the end of the year,” says Arvind Parmar, acting Integral Project Scientist at ESA. “These images and spectra prove that Integral can certainly do the job it was designed to do, and more", which is to unlock some of the secrets of the high-energy Universe. Integral’s primary mission will last for two years, but it is carrying enough fuel to continue for five years, all being well. Notes to Editors Integral was launched on board a Russian Proton rocket from the Baikonur Cosmodrome, Kazakhstan, on 17 October 2002. The satellite was placed in a tilted orbit that looped from 600 to 153 000 kilometres above the Earth and back again. Integral’s own thrusters then steered the spacecraft, in a series of five manoeuvres, into its operational orbit, between 9 000 and 153 000 kilometres above the Earth. Although Integral orbits above the Earth's atmosphere and weather, it still has ‘space weather’ to contend with. Space weather consists of a constant rain of tiny particles that can temporarily blind detectors designed to register gamma radiation. “The flashes last about 0.1 seconds and have to be filtered out with software,” says Pietro Ubertini, IBIS Principal Investigator. JEM-X proved to be particularly susceptible to space weather and scientists had to ‘re-tune’ it. * * * Cygnus X-1 is one of the brightest high-energy emitters in the sky. Relative to its parent constellation, Cygnus - the Swan, Cygnus X-1 it is located about halfway along the row of stars that mark the Swan’s neck, at about 10 000 light years from Earth. Cygnus X-1 was discovered in the 1960s and is thought to be a black hole, ripping its companion star to pieces. The companion star, HDE 226868, is a blue supergiant with a surface temperature of around 31 000K. It orbits the black hole once every 5.6 days.

Ocelli contribute to the encoding of celestial compass information in the Australian desert ant Melophorus bagoti.

PubMed

Schwarz, Sebastian; Albert, Laurence; Wystrach, Antoine; Cheng, Ken

2011-03-15

Many animal species, including some social hymenoptera, use the visual system for navigation. Although the insect compound eyes have been well studied, less is known about the second visual system in some insects, the ocelli. Here we demonstrate navigational functions of the ocelli in the visually guided Australian desert ant Melophorus bagoti. These ants are known to rely on both visual landmark learning and path integration. We conducted experiments to reveal the role of ocelli in the perception and use of celestial compass information and landmark guidance. Ants with directional information from their path integration system were tested with covered compound eyes and open ocelli on an unfamiliar test field where only celestial compass cues were available for homing. These full-vector ants, using only their ocelli for visual information, oriented significantly towards the fictive nest on the test field, indicating the use of celestial compass information that is presumably based on polarised skylight, the sun's position or the colour gradient of the sky. Ants without any directional information from their path-integration system (zero-vector) were tested, also with covered compound eyes and open ocelli, on a familiar training field where they have to use the surrounding panorama to home. These ants failed to orient significantly in the homeward direction. Together, our results demonstrated that M. bagoti could perceive and process celestial compass information for directional orientation with their ocelli. In contrast, the ocelli do not seem to contribute to terrestrial landmark-based navigation in M. bagoti.

Celestial Treasury

NASA Astrophysics Data System (ADS)

Lachièze-Rey, Marc; Luminet, Jean-Pierre

2001-07-01

Throughout history, the mysterious dark skies have inspired our imaginations in countless ways, influencing our endeavors in science and philosophy, religion, literature, and art. Filled with 380 full-color illustrations, Celestial Treasury shows the influence of astronomical theories and the richness of illustrations in Western civilization through the ages. The authors explore the evolution of our understanding of astronomy and weave together ancient and modern theories in a fascinating narrative. They incorporate a wealth of detail from Greek verse, medieval manuscripts and Victorian poetry with contemporary spacecraft photographs and computer-generated star charts. Celestial Treasury is more than a beautiful book: it answers a variety of questions that have intrigued scientists and laymen for centuries. -- How did philosophers and scientists try to explain the order that governs celestial motion? -- How did geometers and artists measure and map the skies? -- How many different answers have been proposed for the most fundamental of all questions: When and how did Earth come about? -- Who inhabits the heavens--gods, angels or extraterrestrials? No other book recounts humankind's fascination with the heavens as compellingly as Celestial Treasury. Marc Lachièze-Rey is a director of research at the Centre National pour la Récherche Scientifique and astrophysicist at the Centre d'Etudes de Saclay. He is the author of The Cosmic Background Radiation (Cambridge, 1999), and and The Quest for Unity, (Oxford, 1999 ), as well as many books in French. Jean-Pierre Luminet is a research director of the Centre National pour la Rechérche Scientifique, based at the Paris-Meudon observatory. He is the author of Black Holes, (Cambridge 1992), as well as science documentaries for television.

Radio Meteors Observations Techniques at RI NAO

NASA Astrophysics Data System (ADS)

Vovk, Vasyl; Kaliuzhnyi, Mykola

2016-07-01

The Solar system is inhabited with large number of celestial bodies. Some of them are well studied, such as planets and vast majority of big asteroids and comets. There is one group of objects which has received little attention. That is meteoroids with related to them meteors. Nowadays enough low-technology high-efficiency radio-technical solutions are appeared which allow to observe meteors daily. At RI NAO three methodologies for meteor observation are developed: single-station method using FM-receiver, correlation method using FM-receiver and Internet resources, and single-station method using low-cost SDR-receiver.

Saturn Apollo Program

NASA Image and Video Library

1972-04-16

The sixth marned lunar landing mission, the Apollo 16 (SA-511), carrying three astronauts: Mission commander John W. Young, Command Module pilot Thomas K. Mattingly II, and Lunar Module pilot Charles M. Duke, lifted off on April 16, 1972. The Apollo 16 continued the broad-scale geological, geochemical, and geophysical mapping of the Moon's crust, begun by the Apollo 15, from lunar orbit. This mission marked the first use of the Moon as an astronomical observatory by using the ultraviolet camera/spectrograph. It photographed ultraviolet light emitted by Earth and other celestial objects. The Lunar Roving Vehicle was also used. The mission ended on April 27, 1972.

History of the astronomical almanacs, yarbooks and calendars, the particapation of the Kyiv University Observatory in their creation

NASA Astrophysics Data System (ADS)

Kazantseva, L. V.

2017-05-01

Astronomical Ephemeris, information about the circumstances of apparition various celestial objects long been used for professionals as well as amateur astronomy. The story of annual reference books with similar information was studied not well. In publications sometimes appear inconsistent and incomplete data. In particular, little known facts about participation of Kyiv astronomers in the creation of such publications, it was since the nineteenth century. The analysis of archival sources and funds Astronomical Museum allow drawing conclusions about the significant contribution the University Observatory to ephemeris service

Lear jet telescope system

NASA Technical Reports Server (NTRS)

Erickson, E. F.; Goorvitch, D.; Dix, M. G.; Hitchman, M. J.

1974-01-01

The telescope system was designed as a multi-user facility for observations of celestial objects at infrared wavelengths, where ground-based observations are difficult or impossible due to the effects of telluric atmospheric absorption. The telescope is mounted in a Lear jet model 24B which typically permits 70 min. of observing per flight at altitudes in excess of 45,000 ft (13 km). Telescope system installation is discussed, along with appropriate setup and adjustment procedures. Operation of the guidance system is also explained, and checklists are provided which pertain to the recommended safe operating and in-flight trouble-shooting procedures for the equipment.

A Celestial Reference Frame at X/ka-Band (8.4/32 Ghz) for Deep Space Navigation

NASA Technical Reports Server (NTRS)

Jacobs, C. S.; Clark, J. E.; Garcia-Miro, C.; Horiuchi, S.; Romero-Wolf, A.; Snedeker, L.; Sotuela, I.

2012-01-01

Deep space tracking and navigation are done in a quasi-inertial reference frame based upon the angular positions of distant active galactic nuclei (AGN). These objects, which are found at extreme distances characterized by median redshifts of z = 1, are ideal for reference frame definition because they exhibit no measurable parallax or proper motion. They are thought to be powered by super massive black holes whose gravitational energy drives galactic sized relativistic jets. These jets produce synchrotron emissions which are detectable by modern radio techniques such as Very Long baseline Interferometry (VLBI).

KSC-98pc1087

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility prepare Deep Space 1 for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

Lhires III High Resolution Spectrograph

NASA Astrophysics Data System (ADS)

Thizy, O.

2007-05-01

By spreading the light from celestial objects by wavelength, spectroscopists are like detectives looking for clues and identifying guilty phenomena that shape their spectra. We will review some basic principles in spectroscopy that will help, at our amateur level, to understand how spectra are shaped. We will review the Lhires III highresolution spectrograph Mark Three that was designed to reveal line profile details and subtle changes. Then, we will do an overview of educational and scientific projects that are conducted with the Lhires III and detail the COROT Be star program and the BeSS database for which the spectrograph is a key instrument.

OSO-6 Orbiting Solar Observatory

NASA Technical Reports Server (NTRS)

1972-01-01

The description, development history, test history, and orbital performance analysis of the OSO-6 Orbiting Solar Observatory are presented. The OSO-6 Orbiting Solar Observatory was the sixth flight model of a series of scientific spacecraft designed to provide a stable platform for experiments engaged in the collection of solar and celestial radiation data. The design objective was 180 days of orbital operation. The OSO-6 has telemetered an enormous amount of very useful experiment and housekeeping data to GSFC ground stations. Observatory operation during the two-year reporting period was very successful except for some experiment instrument problems.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility prepare Deep Space 1 for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near- Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Griffith Observatory: Hollywood's Celestial Theater

NASA Astrophysics Data System (ADS)

Margolis, Emily A.; Dr. Stuart W. Leslie

2018-01-01

The Griffith Observatory, perched atop the Hollywood Hills, is perhaps the most recognizable observatory in the world. Since opening in 1935, this Los Angeles icon has brought millions of visitors closer to the heavens. Through an analysis of planning documentation, internal newsletters, media coverage, programming and exhibition design, I demonstrate how the Observatory’s Southern California location shaped its form and function. The astronomical community at nearby Mt. Wilson Observatory and Caltech informed the selection of instrumentation and programming, especially for presentations with the Observatory’s Zeiss Planetarium, the second installed in the United States. Meanwhile the Observatory staff called upon some of Hollywood’s best artists, model makers, and scriptwriters to translate the latest astronomical discoveries into spectacular audiovisual experiences, which were enhanced with Space Age technological displays on loan from Southern California’s aerospace companies. The influences of these three communities- professional astronomy, entertainment, and aerospace- persist today and continue to make Griffith Observatory one of the premiere sites of public astronomy in the country.

Engage All Americans with Eclipse 2017 Through the Eyes of NASA

NASA Astrophysics Data System (ADS)

Ng, C.; Young, C. A.; Mayo, L.; Cline, T. D.; Stephenson, B. E.; Debebe, A.; Lewis, E. M.; Odenwald, S. F.; Hill, S. W.

2016-12-01

Join NASA and millions in the U.S. and around the world in observing the August 21, 2017 solar eclipse. This presentation will discuss NASA's education and communication plans for the 2017 eclipse, highlighting some programs, resources, and citizen science activities that will engage and educate many across the country and beyond. NASA will offer unique observations of this celestial event from the ground to space. Additionally, there are do-it-yourself (DIY) science, lunar and math challenges, art contests, Makerspace ideas, and various activities for learners of all ages. Education resources and tool kits may be of particular interest to formal and informal educators. Find out what events are happening in your neighborhood, and plan your own eclipse parties with resources and activities. Last but not the least, experience the eclipse on August 21 and learn more through NASA broadcast programming that will include telescopic views from multiple locations, simple measurements, and live and taped interviews.

A retrograde co-orbital asteroid of Jupiter.

PubMed

Wiegert, Paul; Connors, Martin; Veillet, Christian

2017-03-29

Recent theoretical work in celestial mechanics has revealed that an asteroid may orbit stably in the same region as a planet, despite revolving around the Sun in the sense opposite to that of the planet itself. Asteroid 2015 BZ 509 was discovered in 2015, but with too much uncertainty in its measured orbit to establish whether it was such a retrograde co-orbital body. Here we report observations and analysis that demonstrates that asteroid 2015 BZ 509 is indeed a retrograde co-orbital asteroid of the planet Jupiter. We find that 2015 BZ 509 has long-term stability, having been in its current, resonant state for around a million years. This is long enough to preclude precise calculation of the time or mechanism of its injection to its present state, but it may be a Halley-family comet that entered the resonance through an interaction with Saturn. Retrograde co-orbital asteroids of Jupiter and other planets may be more common than previously expected.

Dark Energy Survey finds more celestial neighbors | News

Science.gov Websites

Energy Survey finds more celestial neighbors August 17, 2015 icon icon icon New dwarf galaxy candidates could mean our sky is more crowded than we thought The Dark Energy Survey has now mapped one-eighth of Survey Collaboration The Dark Energy Survey has now mapped one-eighth of the full sky (red shaded region

Children Learning to Explain Daily Celestial Motion: Understanding Astronomy across Moving Frames of Reference

ERIC Educational Resources Information Center

Plummer, Julia D.; Wasko, Kyle D.; Slagle, Cynthia

2011-01-01

This study investigated elementary students' explanations for the daily patterns of apparent motion of the Sun, Moon, and stars. Third-grade students were chosen for this study because this age level is at the lower end of when many US standards documents suggest students should learn to use the Earth's rotation to explain daily celestial motion.…

Galileo Spacecraft Scan Platform Celestial Pointing Cone Control Gain Redesign

NASA Technical Reports Server (NTRS)

In, C-H. C.; Hilbert, K. B.

1994-01-01

During September and October 1991, pictures of the Gaspra asteroid and neighboring stars were taken by the Galileo Optical Navigation (OPNAV) Team for the purpose of navigation the spacecraft for a successful Gaspra encounter. The star tracks in these pictures showed that the scan platform celestial pointing cone controller performed poorly in compensating for wobble-induced cone offsets.

The dynamical behaviour of our planetary system. Proceedings. 4th Alexander von Humboldt Colloquium on Celestial Mechanics, Ramsau (Austria), 17 - 23 Mar 1996.

NASA Astrophysics Data System (ADS)

Dvorak, R.; Henrard, J.

1996-03-01

The following topics were dealt with: celestial mechanics, dynamical astronomy, planetary systems, resonance scattering, Hamiltonian mechanics non-integrability, irregular periodic orbits, escape, dynamical system mapping, fast Fourier method, precession-nutation, Nekhoroshev theorem, asteroid dynamics, the Trojan problem, planet-crossing orbits, Kirkwood gaps, future research, human comprehension limitations.

241. BUILDINGS 455, 456, 509, 510 AND 457 (CELESTIAL NAVIGATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

241. BUILDINGS 455, 456, 509, 510 AND 457 (CELESTIAL NAVIGATION COMPLEX), 1942-43. BUREAU OF YARDS AND DOCKS STANDARD PLANS. VIEW NORTH ACROSS WASP ST. SHOWING THE 4 TRAINING SILOS FROM LEFT TO RIGHT: BUILDINGS 455, 456, 509, AND 510; AND, BESIDE THEM, BUILDING 457. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

Celestial mechanics during the last two decades

NASA Technical Reports Server (NTRS)

Szebehely, V.

1978-01-01

The unprecedented progress in celestial mechanics (orbital mechanics, astrodynamics, space dynamics) is reviewed from 1957 to date. The engineering, astronomical and mathematical aspects are synthesized. The measuring and computational techniques developed parallel with the theoretical advances are outlined. Major unsolved problem areas are listed with proposed approaches for their solutions. Extrapolations and predictions of the progress for the future conclude the paper.

Johannes Kepler and the Supernova of 1604

NASA Astrophysics Data System (ADS)

Boner, P. J.

2006-08-01

The brilliant luminary that first appeared in October 1604 was considered by many contemporaries to be a new star of unrivalled magnitude. Shining forth near the historic conjunction of Mars, Jupiter and Saturn, the new star held important implications for several areas of interest, notably astrology, astronomy, chronology and theology. Addressing all of these areas in his comprehensive book, De stella nova (1606), Johannes Kepler (1571-1630) studied the new star extensively under the aegis of Holy Roman Emperor Rudolf II (1552-1612) in Prague. The focus of the following presentation is Kepler's theory of the new star's origins in the celestial ether. Describing the heavens poetically as a fertile expanse of "liquid fields", Kepler suggested that the new star sprung from the celestial ether much like the numerous living beings in the sublunary realm which were spontaneously generated from the Earth. As evidence for his claim, Kepler pointed to the conspicuous mathematical patterns similarly observed in earthly and celestial entities. Kepler's efficient cause for this explanation, known as the animate faculty, accounted for both the generation and form of new phenomena in the celestial and terrestrial realms. The new star of 1604 proved to be no exception.

A celestial assisted INS initialization method for lunar explorers.

PubMed

Ning, Xiaolin; Wang, Longhua; Wu, Weiren; Fang, Jiancheng

2011-01-01

The second and third phases of the Chinese Lunar Exploration Program (CLEP) are planning to achieve Moon landing, surface exploration and automated sample return. In these missions, the inertial navigation system (INS) and celestial navigation system (CNS) are two indispensable autonomous navigation systems which can compensate for limitations in the ground based navigation system. The accurate initialization of the INS and the precise calibration of the CNS are needed in order to achieve high navigation accuracy. Neither the INS nor the CNS can solve the above problems using the ground controllers or by themselves on the lunar surface. However, since they are complementary to each other, these problems can be solved by combining them together. A new celestial assisted INS initialization method is presented, in which the initial position and attitude of the explorer as well as the inertial sensors' biases are estimated by aiding the INS with celestial measurements. Furthermore, the systematic error of the CNS is also corrected by the help of INS measurements. Simulations show that the maximum error in position is 300 m and in attitude 40″, which demonstrates this method is a promising and attractive scheme for explorers on the lunar surface.

A Celestial Assisted INS Initialization Method for Lunar Explorers

PubMed Central

Ning, Xiaolin; Wang, Longhua; Wu, Weiren; Fang, Jiancheng

2011-01-01

The second and third phases of the Chinese Lunar Exploration Program (CLEP) are planning to achieve Moon landing, surface exploration and automated sample return. In these missions, the inertial navigation system (INS) and celestial navigation system (CNS) are two indispensable autonomous navigation systems which can compensate for limitations in the ground based navigation system. The accurate initialization of the INS and the precise calibration of the CNS are needed in order to achieve high navigation accuracy. Neither the INS nor the CNS can solve the above problems using the ground controllers or by themselves on the lunar surface. However, since they are complementary to each other, these problems can be solved by combining them together. A new celestial assisted INS initialization method is presented, in which the initial position and attitude of the explorer as well as the inertial sensors’ biases are estimated by aiding the INS with celestial measurements. Furthermore, the systematic error of the CNS is also corrected by the help of INS measurements. Simulations show that the maximum error in position is 300 m and in attitude 40″, which demonstrates this method is a promising and attractive scheme for explorers on the lunar surface. PMID:22163998

The role of the sun in the celestial compass of dung beetles

PubMed Central

Dacke, M.; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

2014-01-01

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day. PMID:24395963

The role of the sun in the celestial compass of dung beetles.

PubMed

Dacke, M; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

2014-01-01

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day.

Mariner Mars 1971 attitude control subsystem

NASA Technical Reports Server (NTRS)

Edmunds, R. S.

1974-01-01

The Mariner Mars 1971 attitude control subsystem (ACS) is discussed. It is comprised of a sun sensor set, a Canopus tracker, an inertial reference unit, two cold gas reaction control assemblies, two rocket engine gimbal actuators, and an attitude control electronics unit. The subsystem has the following eight operating modes: (1) launch, (2) sun acquisition, (3) roll search, (4) celestial cruise, (5) all-axes inertial, (6) roll inertial, (7) commanded turn, and (8) thrust vector control. In the celestial cruise mode, the position control is held to plus or minus 0.25 deg. Commanded turn rates are plus or minus 0.18 deg/s. The attitude control logic in conjunction with command inputs from other spacecraft subsystems establishes the ACS operating mode. The logic utilizes Sun and Canopus acquisition signals generated within the ACS to perform automatic mode switching so that dependence of ground control is minimized when operating in the sun acquisition, roll search, and celestial cruise modes. The total ACS weight is 65.7 lb, and includes 5.4 lb of nitrogen gas. Total power requirements vary from 9 W for the celestial cruise mode to 54 W for the commanded turn mode.

Visual navigation in desert ants Cataglyphis fortis: are snapshots coupled to a celestial system of reference?

PubMed

Akesson, Susanne; Wehner, Rüdiger

2002-07-01

Central-place foraging insects such as desert ants of the genus Cataglyphis use both path integration and landmarks to navigate during foraging excursions. The use of landmark information and a celestial system of reference for nest location was investigated by training desert ants returning from an artificial feeder to find the nest at one of four alternative positions located asymmetrically inside a four-cylinder landmark array. The cylindrical landmarks were all of the same size and arranged in a square, with the nest located in the southeast corner. When released from the compass direction experienced during training (southeast), the ants searched most intensely at the fictive nest position. When instead released from any of the three alternative directions of approach (southwest, northwest or northeast), the same individuals instead searched at two of the four alternative positions by initiating their search at the position closest to the direction of approach when entering the landmark square and then returning to the position at which snapshot, current landmark image and celestial reference information were in register. The results show that, in the ants' visual snapshot memory, a memorized landmark scene can temporarily be decoupled from a memorized celestial system of reference.

Gravity Acceleration and Gravity Paradox

NASA Astrophysics Data System (ADS)

Hanyongquan, Han; Yuteng, Tang

2017-10-01

The magnitude of the gravitational acceleration of the earth is derived from low of universal gravitation. If the size and mass of the gravitational force are proportional to any situation, then the celestial surface gravity is greater than the celestial center near the gravity, and objective facts do not match. Specific derivation method, F = GMm / R2 = mg, g = GM/R2 . c / Ú, G is the gravitational constant, M is the mass of the earth, and finally the g = 9.8 m/s 2 is obtained. We assume that the earth is a standard positive sphere, the earth's volume V = 4 ΠR3/3, assuming that the earth's density is ρ, then M = ρ 4 ΠR3/3 .. c / Ú, the c / Ú into c / Ú get: g = G ρ4 ΠR / 3 .. c / Û, the density of the earth is constant. Careful analysis of the formula c / Û The result of this calculation, we can reach conclusion the gravity acceleration g and the radius of the earth is proportional. In addition to the radius of the Earth c / U the right is constant, That is, the Earth's Gravity acceleration of the outer layer of the earth is greater than the Earth's Gravity acceleration of Inner layer. We are in High School, Huairou District, Beijing, China Author: hanyongquan tangyuteng TEL: 15611860790, 15810953809.

Empirical Corrections to Nutation Amplitudes and Precession Computed from a Global VLBI Solution

NASA Astrophysics Data System (ADS)

Schuh, H.; Ferrandiz, J. M.; Belda-Palazón, S.; Heinkelmann, R.; Karbon, M.; Nilsson, T.

2017-12-01

The IAU2000A nutation and IAU2006 precession models were adopted to provide accurate estimations and predictions of the Celestial Intermediate Pole (CIP). However, they are not fully accurate and VLBI (Very Long Baseline Interferometry) observations show that the CIP deviates from the position resulting from the application of the IAU2006/2000A model. Currently, those deviations or offsets of the CIP (Celestial Pole Offsets - CPO), can only be obtained by the VLBI technique. The accuracy of the order of 0.1 milliseconds of arc (mas) allows to compare the observed nutation with theoretical prediction model for a rigid Earth and constrain geophysical parameters describing the Earth's interior. In this study, we empirically evaluate the consistency, systematics and deviations of the IAU 2006/2000A precession-nutation model using several CPO time series derived from the global analysis of VLBI sessions. The final objective is the reassessment of the precession offset and rate, and the amplitudes of the principal terms of nutation, trying to empirically improve the conventional values derived from the precession/nutation theories. The statistical analysis of the residuals after re-fitting the main nutation terms demonstrates that our empirical corrections attain an error reduction by almost 15 micro arc seconds.

The periodic dynamics of the irregular heterogeneous celestial bodies

NASA Astrophysics Data System (ADS)

Lan, Lei; Yang, Mo; Baoyin, Hexi; Li, Junfeng

2017-02-01

In this paper, we develop a methodology to study the periodic dynamics of irregular heterogeneous celestial bodies. Heterogeneous bodies are not scarce in space. It has been found that bodies, such as 4 Vesta, 624 Hektor, 87 Sylvia, 16 Psyche and 25143 Itokawa, may all have varied internal structures. They can be divided into large-scale and small-scale cases. The varied internal structures of large-scale bodies always result from gradient pressure inside, which leads to compactness differences of the inner material. However, the heterogeneity of a small-scale body is always reflected by the different densities of different areas, which may originate from collision formation from multiple objects. We propose a modeling procedure for the heterogeneous bodies derived from the conventional polyhedral method and then compare its dynamical characteristics with those of the homogeneous case. It is found that zero-velocity curves, positions of equilibrium points, types of bifurcations in the continuation of the orbital family and the stabilities of periodic orbits near the heterogeneous body are different from those in the homogeneous case. The suborbicular orbits near the equatorial plane are potential parking orbits for a future mission, so we discuss the switching of the orbital stability of the family because it has fundamental significance to orbit maintenance and operations around actual asteroids.

[The celestial phenomena in A. Dürer's engraving Melancholia I].

PubMed

Weitzel, Hans

2009-01-01

The celestial body of Dürer's engraving Melencolia I is connected with his painting of a meteor, the Raveningham-painting; it is shown that the origin of this painting owns to the impact of the meteor of Ensisheim in 1492. Until now the celestial body, the balance, and the magic square are nearly consistently interpreted as the planet Saturn, the zodiac sign Libra, and the planet Jupiter, and the melancholy woman is subject to these heavenly bodies. Consequently, neoplatonic astrology has been the main focus of the engraving; including the rainbow, the engraving has also been interpreted biblically. The present paper, however, places emphasis on problems of the geometry as the reason of melancholy. Any astronomical meaning of the configuration of the numbers of the magic square is discarded.

Heavenly Networks. Celestial Maps and Globes in Circulation between Artisans, Mathematicians, and Noblemen in Renaissance Europe.

PubMed

Gessner, Samuel

2015-01-01

The aim of this paper is to examine the iconography on a set of star charts by Albrecht Dürer (1515), and celestial globes by Caspar Vopel (1536) and Christoph Schissler (1575). The iconography on these instruments is conditioned by strong traditions which include not only the imagery on globes and planispheres (star charts), but also ancient literature about the constellations. Where this iconography departs from those traditions, the change had to do with humanism in the sixteenth century. This "humanistic" dimension is interwoven with other concerns that involve both "social" and "technical" motivations. The interplay of these three dimensions illustrates how the iconography on celestial charts and globes expresses some features of the shared knowledge and shared culture between artisans, mathematicians, and nobles in Renaissance Europe.

Calibration of magnetic and celestial compass cues in migratory birds--a review of cue-conflict experiments.

PubMed

Muheim, Rachel; Moore, Frank R; Phillips, John B

2006-01-01

Migratory birds use multiple sources of compass information for orientation, including the geomagnetic field, the sun, skylight polarization patterns and star patterns. In this paper we review the results of cue-conflict experiments designed to determine the relative importance of the different compass mechanisms, and how directional information from these compass mechanisms is integrated. We focus on cue-conflict experiments in which the magnetic field was shifted in alignment relative to natural celestial cues. Consistent with the conclusions of earlier authors, our analyses suggest that during the premigratory season, celestial information is given the greatest salience and used to recalibrate the magnetic compass by both juvenile and adult birds. Sunset polarized light patterns from the region of the sky near the horizon appear to provide the calibration reference for the magnetic compass. In contrast, during migration, a majority of experiments suggest that birds rely on the magnetic field as the primary source of compass information and use it to calibrate celestial compass cues, i.e. the relative saliency of magnetic and celestial cues is reversed. An alternative possibility, however, is suggested by several experiments in which birds exposed to a cue conflict during migration appear to have recalibrated the magnetic compass, i.e. their response is similar to that of birds exposed to cue conflicts during the premigratory season. The general pattern to emerge from these analyses is that birds exposed to the cue conflict with a view of the entire sunset sky tended to recalibrate the magnetic compass, regardless of whether the cue conflict occurred during the premigratory or migratory period. In contrast, birds exposed to the cue conflict in orientation funnels and registration cages that restricted their view of the region of sky near the horizon (as was generally the case in experiments carried out during the migratory season) did not recalibrate the magnetic compass but, instead, used the magnetic compass to calibrate the other celestial compass systems. If access to critical celestial cues, rather than the timing of exposure to the cue conflict (i.e. premigratory vs migratory), determines whether recalibration of the magnetic compass occurs, this suggests that under natural conditions there may be a single calibration reference for all of the compass systems of migratory birds that is derived from sunset (and possibly also sunrise) polarized light cues from the region of sky near the horizon. In cue-conflict experiments carried out during the migratory season, there was also an interesting asymmetry in the birds' response to magnetic fields shifted clockwise and counterclockwise relative to celestial cues. We discuss two possible explanations for these differences: (1) lateral asymmetry in the role of the right and left eye in mediating light-dependent magnetic compass orientation and (2) interference from the spectral and intensity distribution of skylight at sunset with the response of the light-dependent magnetic compass.

Are Historical Observations ``Ancient'' or ``Modern''?

NASA Astrophysics Data System (ADS)

Griffin, R. Elizabeth

2016-10-01

The demarcation between ``old'', ``historic'' and ``heritage'' is fuzzy. To a large degree it depends upon purpose and usefulness, and it will always be subjective. At what point does the intrinsic value of an historic item outpace the mystique associated just with its age? When, for instance, does an ``old'' car become a ``vintage'' car? When do archived astronomical records contribute something of quantitative value to science? When can they be extricated from the realms of the museum and placed in the context of modern research? Celestial objects vary. Some do so explosively, often irreversibly; many vary periodically over time-scales from a hour or less to a century or more. Furthermore, all celestial objects change as they evolve, mostly so slowly as to be practically imperceptible, but while the general time-scale of that evolution is millions of years there are a few stages (such as the collapse from AGB towards planetary nebula and white dwarf) which happen rather suddenly, and invaluable examples of ``before-after'' can be found in some plate stores. Astrophysics has a comprehensive need to investigate the nature and time-scales of all types of change, especially ones which only access to its ``heritage'' data can describe. Surely in this day and age we have enough tools, capacity and technologies to fulfil such a basic requirement? The frustrating answer is that we do have some of the necessary tools, and most of the technologies, but as a community we lack ``capacity'' if that means manpower and funds. The problem is a technical one of accessing the older data in useable formats; it was generated by the universal change in detector technology from photography to electronic device, an exciting development in efficiency and scope that heralded a new era of research capability and data management, archiving and sharing, but it left pre-digital photographic data right out of the picture. Developments of that nature should have made research more inclusive, instead of the seriously exclusive picture that is currently seen. The longer the situation prevails, the greater the inertia and scepticism to be overcome. Fortunately, some of the challenges are being tackled successfully, the most productive to date being the dasch project (dasch.rc.fas.harvard.edu) at Harvard College Observatory to digitize and share all the images and objective-prism spectra from its collection (the world's biggest) of over 0.5M large plates. The DAO has commenced a programme to digitize its collection of > 16,000 high-dispersion spectra (~70% are good enough to scan and convert), and to scan plates from its larger but older Cassegrain collection of > 90,000 spectra upon request. The instrument for this Herculean task is its own PDS, now suitably upgraded to meet the demands of speed and accuracy; the DAO has also acquired and upgraded a second PDS, with which it plans to share the load. Some smaller observatories in Europe are trying with less sophisticated equipment, but the rest have not the resources to give such data transformation any priority. Despite the unquestionable advantages, it is still necessary to convince colleagues that the medium is not the message, and that the scientific need comes before technological expedience.

Solar sailing for radio astronomy and seti: An extrasolar mission to 550 AU

NASA Astrophysics Data System (ADS)

Matloff, Gregory L.

1994-11-01

Current or near-term technology is capable of propelling small payloads to 550 Astronomical Units (AU) on flights of decades duration. Beyond 550 AU, natural or artificial electromagnetic (EM) radiation emitted by galactic objects occulted by the Sun is greatly amplified by solar gravitational focusing. Propulsion systems capable of launching such an extrasolar probe include Jupiter gravity-assist, flat or inflatable solar sails unfurled from parabolic solar orbits sunward of the Earth, and the proton-reflecting 'Magsail'. Best performance for a near-future probe is obtained using the solar sail; a superconducting Magsail has great potential for course-correction purposes. A properly configured solar sail can also serve as a radio telescope and as a solar-energy collector to power the probe's instrumentation. The best direction for the probe's trajectory is towards the galactic anti-center. This is because of the astrophysical interest in amplified EM radiation from the galactic center and the large number of Sunlike stars in the galactic arm. Many of these stars could be surveyed for artificial radio emissions using the proposed probe by astronomers engaged in SETI (Search for ExtraTerrestrial Intelligence). By chance, the anti-galactic-center is not too far from the positions on the celestial sphere of the nearby Sunlike stars Tau Ceti and Epsilon Eridani. This random celestial arrangement increases the potential interest of the proposed mission. While focused on or near the galactic center, the probe could also examine a number of objects of astrophysical interest. These include supernova remnants, HI and HIII regions, and neutron stars or black holes near the galctic center. A number of alternative directions for probes of this type exists. Missions could be flown to sample amplified radio emissions from globular clusters such as M13 and M22 and extra-galactic objects such as the Magellanic Clouds and the Great Spiral Galaxy (M31) in Andromeda. For a number of reasons, the galactic center is superior to these objects, at least for the first flights of the SETI-sail.

Building a Learning Progression for Celestial Motion: An Exploration of Students' Reasoning about the Seasons

ERIC Educational Resources Information Center

Plummer, Julia D.; Maynard, L.

2014-01-01

We present the development of a construct map addressing the reason for the seasons, as a subset of a larger learning progression on celestial motion. Five classes of 8th grade students (N?=?38) participated in a 10-day curriculum on the seasons. We revised a hypothetical seasons construct map using a Rasch model analysis of students'…

High-Resolution Structural Monitoring of Ionospheric Absorption Events

DTIC Science & Technology

2013-07-01

ionospheric plasma conductivity 5 . This results in enhanced absorption of the cosmic high frequency (HF; typically 10 – 60 MHz) radio background ...7 riometry. Incorporation of an outrigger site, to enable treatment of the unknown structure of the celestial background and the effects of...riometry. Incorporation of an outrigger site, to enable treatment of the unknown structure of the celestial background and the effects of confusion

The CUREA 1996 Summer Program in Astrophysics at Mount Wilson Observatory

NASA Astrophysics Data System (ADS)

Snider, Joe; Faison, Michael

1996-05-01

The Consortium for Undergraduate Research and Education in Astronomy (CUREA) will present its hands-on course in astrophysics and observational astronomy at Mount Wilson Observatory for the seventh time, from August 7-20, 1996. Students and staff live and work at the Observatory, situated in the San Gabriel Mountains above Los Angeles. This is a beautiful site at which the atmospheric seeing conditions are equal to the best in the world. This poster paper presents in text and photographs some of the highlights of past programs. During the program informal discussions led by staff members provide the necessary background for using the following facilities: the Snow Horizontal Solar Telescope, which was the first major solar telescope in the world and the first telescope to be installed on Mount Wilson when G.E.Hale founded the Observatory; a high-resolution Littrow pit spectrograph; a 6-inch diffraction-limited refractor and 24- inch reflector; a photometer and a CCD detector; a unique atomic-beam apparatus for recording solar 5-minute oscillations; and this summer for the first time, the historic 100-inch Hooker Telescope. Attention is devoted to many observable solar phenomena, such as sunspots, granulation, limb darkening, important spectral lines, Zeeman splitting of solar lines, and the measurement of solar rotation using the Doppler shift of a spectral line. Nighttime observing includes celestial objects such as the Moon, planets, variable stars, clusters, galaxies and other deep-sky objects. Students learn how to process celestial photographs and spectral plates in the darkroom. Each student works on a special project she or he has chosen, and reports on it at the end of the program. Tours of research projects on the mountain, talks by visiting astronomers and field trips to JPL, Cal Tech and Palomar are included.

Can invertebrates see the e-vector of polarization as a separate modality of light?

PubMed

Labhart, Thomas

2016-12-15

The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, 'color-blind' humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert 'water below!' to water-seeking bugs. © 2016. Published by The Company of Biologists Ltd.

Can invertebrates see the e-vector of polarization as a separate modality of light?

PubMed Central

2016-01-01

ABSTRACT The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, ‘color-blind’ humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert ‘water below!’ to water-seeking bugs. PMID:27974532

The General History of Astronomy

NASA Astrophysics Data System (ADS)

Taton, René; Wilson, Curtis; Hoskin, editor Michael, , General

2009-09-01

Part V. Early Phases in the Reception of Newton's Theory: 14. The vortex theory in competition with Newtonian celestial dynamics Eric J. Aiton; 15. The shape of the Earth Seymour L. Chapin; 16. Clairaut and the motion of the lunar apse: The inverse-square law undergoes a test Craig B. Waff; 17. The precession of the equinoxes from Newton to d'Alembert and Euler Curtis Wilson; 18. The solar tables of Lacaille and the lunar tables of Mayer Eric G. Forbes and Curtis Wilson; 19. Predicting the mid-eighteenth-century return of Halley's Comet Craig B. Waff; Part VI. Celestial Mechanics During the Eighteenth Century: 20. The problem of perturbation analytically treated: Euler, Clairaut, d'Alembert Curtis Wilson; 21. The work of Lagrange in celestial mechanics Curtis Wilson; 22. Laplace Bruno Morando; Part VII. Observational Astronomy and the Application of Theory in the Late Eighteenth and Early Nineteenth Century: 23. Measuring solar parallax: The Venus transits of 1761 and 1769 and their nineteenth-century sequels Albert Van Helden; 24. The discovery of Uranus, the Titius-Bode and the asteroids Michael Hoskin; 25. Eighteenth-and nineteenth century developments in the theory and practice of orbit determination Brian G. Marsden; 26. The introduction of statistical reasoning into astronomy: from Newton to Poincaré Oscar Sheynin; 27. Astronomy and the theory of errors: from the method of averages to the method of least squares F. Schmeidler; Part VIII. The Development of Theory During the Nineteenth Century: 28. The golden age of celestial mechanics Bruno Morando; Part IX. The Application of Celestial Mechanics to the Solar System to the End of the Nineteenth Century: 29. Three centuries of lunar and planetary ephemerides and tables Bruno Morando; 30. Satellite ephemerides to 1900 Yoshihide Kozai; Illustrations; Combined index for Parts 2A and 2B.

How well does the Rayleigh model describe the E-vector distribution of skylight in clear and cloudy conditions? A full-sky polarimetric study.

PubMed

Suhai, Bence; Horváth, Gábor

2004-09-01

We present the first high-resolution maps of Rayleigh behavior in clear and cloudy sky conditions measured by full-sky imaging polarimetry at the wavelengths of 650 nm (red), 550 nm (green), and 450 nm (blue) versus the solar elevation angle thetas. Our maps display those celestial areas at which the deviation deltaalpha = /alphameas - alphaRyleigh/ is below the threshold alphathres = 5 degrees, where alphameas is the angle of polarization of skylight measured by full-sky imaging polarimetry, and alphaRayleigh is the celestial angle of polarization calculated on the basis of the single-scattering Rayleigh model. From these maps we derived the proportion r of the full sky for which the single-scattering Rayleigh model describes well (with an accuracy of deltaalpha = 5 degrees) the E-vector alignment of skylight. Depending on thetas, r is high for clear skies, especially for low solar elevations (40% < r < 70% for thetas < or = 13 degrees). Depending on the cloud cover and the solar illumination, r decreases more or less under cloudy conditions, but sometimes its value remains remarkably high, especially at low solar elevations (rmax = 69% for thetas = 0 degrees). The proportion r of the sky that follows the Rayleigh model is usually higher for shorter wavelengths under clear as well as cloudy sky conditions. This partly explains why the shorter wavelengths are generally preferred by animals navigating by means of the celestial polarization. We found that the celestial E-vector pattern generally follows the Rayleigh pattern well, which is a fundamental hypothesis in the studies of animal orientation and human navigation (e.g., in aircraft flying near the geomagnetic poles and using a polarization sky compass) with the use of the celestial alpha pattern.

Concise CIO based precession-nutation formulations

NASA Astrophysics Data System (ADS)

Capitaine, N.; Wallace, P. T.

2008-01-01

Context: The IAU 2000/2006 precession-nutation models have precision goals measured in microarcseconds. To reach this level of performance has required series containing terms at over 1300 frequencies and involving several thousand amplitude coefficients. There are many astronomical applications for which such precision is not required and the associated heavy computations are wasteful. This justifies developing smaller models that achieve adequate precision with greatly reduced computing costs. Aims: We discuss strategies for developing simplified IAU 2000/2006 precession-nutation procedures that offer a range of compromises between accuracy and computing costs. Methods: The chain of transformations linking celestial and terrestrial coordinates comprises frame bias, precession-nutation, Earth rotation and polar motion. We address the bias and precession-nutation (NPB) portion of the chain, linking the Geocentric Celestial Reference System (GCRS) with the Celestial Intermediate Reference System (CIRS), the latter based on the Celestial Intermediate Pole (CIP) and Celestial Intermediate Origin (CIO). Starting from direct series that deliver the CIP coordinates X,Y and (via the quantity s + XY/2) the CIO locator s, we look at the opportunities for simplification. Results: The biggest reductions come from truncating the series, but some additional gains can be made in the areas of the matrix formulation, the expressions for the nutation arguments and by subsuming long period effects into the bias quantities. Three example models are demonstrated that approximate the IAU 2000/2006 CIP to accuracies of 1 mas, 16 mas and 0.4 arcsec throughout 1995-2050 but with computation costs reduced by 1, 2 and 3 orders of magnitude compared with the full model. Appendices A to G are only available in electronic form at http://www.aanda.org

Celestial polarization patterns during twilight.

PubMed

Cronin, Thomas W; Warrant, Eric J; Greiner, Birgit

2006-08-01

Scattering of sunlight produces patterns of partially linearly polarized light in the sky throughout the day, and similar patterns appear at night when the Moon is bright. We studied celestial polarization patterns during the period of twilight, when the Sun is below the horizon, determining the degree and orientation of the polarized-light field and its changes before sunrise and after sunset. During twilight, celestial polarized light occurs in a wide band stretching perpendicular to the location of the hidden Sun and reaching typical degrees of polarization near 80% at wavelengths >600 nm. In the tropics, this pattern appears approximately 1 h before local sunrise or disappears approximately 1 h after local sunset (within 10 min. after the onset of astronomical twilight at dawn, or before its end at dusk) and extends with little change through the entire twilight period.

The Importance of Primary Martian Surface and Airfall Dust Sample Return for Toxicological Hazard Evaluations for Human Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.

2018-01-01

Manned missions to the Moon highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" . It was further reported that the allergic response to the dust worsened with each exposure. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment.

JPL VLBI Analysis Center IVS Annual Report for 2004

NASA Technical Reports Server (NTRS)

Jacobs, Chris

2005-01-01

This report describes the activities of the JPL VLBI analysis center for the year 2004. We continue to be celestial reference frame, terrestrial reference frame, earth orientation, and spacecraft navigation work using the VLBI technique. There are several areas of our work that are undergoing active development. In 2004 we demonstrated 1 mm level troposphere calibration on an intercontinental baseline. We detected our first X/Ka (8.4/32 GHz) VLBI fringes. We began to deploy Mark 5 recorders and to interface the Mark 5 units to our software correlator. We also have actively participated in the international VLBI community through our involvement in six papers at the February IVS meeting and by collaborating on a number of projects such as densifying the S/X celestial frame creating celestial frames at K (24 GHz) and Q-bands ($# GHz)>

Tree-level gluon amplitudes on the celestial sphere

NASA Astrophysics Data System (ADS)

Schreiber, Anders Ø.; Volovich, Anastasia; Zlotnikov, Michael

2018-06-01

Pasterski, Shao and Strominger have recently proposed that massless scattering amplitudes can be mapped to correlators on the celestial sphere at infinity via a Mellin transform. We apply this prescription to arbitrary n-point tree-level gluon amplitudes. The Mellin transforms of MHV amplitudes are given by generalized hypergeometric functions on the Grassmannian Gr (4 , n), while generic non-MHV amplitudes are given by more complicated Gelfand A-hypergeometric functions.

Astronomy, Divination, and Politics in the Neo-Assyrian Empire

NASA Astrophysics Data System (ADS)

Verderame, Lorenzo

Celestial divination had an important role in the complex political and military machine of the Neo-Assyrian empire. Thousand of cuneiform documents dealing with celestial divination have come to light from the excavated archives of this period, as the Assurbanipal's library. Among them letters and reports enlight the relation of the king with his experts (ummânu), who performed divination and apotropaic rituals for his protection.

The Moon Illusion

NASA Astrophysics Data System (ADS)

Rees, W. G.

1986-06-01

The Moon illusion, or celestial illusion, is the illusion that the Moon near the horizon is larger than the Moon near the zenith, usually by a factor of about 2 in the diameter. The illusion has been known for over 2,000 years, and many explanations have been advanced for it. Four modern theories are discussed in this paper, and new data are presented which tend to confirm the common 'flattened celestial vault' hypothesis.

Obliquity of the Ecliptic

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

The angle between the planes of the ecliptic and the equator. On the celestial sphere, the angle at which the ecliptic intersects the celestial equator. The current (year 2000) value of the obliquity of ecliptic, which is denoted by the symbol ɛ, is 23° 26' 21''. Its value varies by ±9'' over a period of 18.6 years as a consequence of a phenomenon called nutation. Over a much longer period (abou...

Correlation analysis of 1 to 30 MeV celestial gamma rays

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

Long, J.L.

1984-01-01

This paper outlines the development of a method of producing celestial sky maps from the data generated by the University of California, Riverside's double Compton scatter gamma ray telescope. The method makes use of a correlation between the telescope's data and theoretical calculated response functions. The results of applying this technique to northern hemisphere data obtained from a 1978 balloon flight from Palestine, Texas are included.

Tangible Things of American Astronomy

NASA Astrophysics Data System (ADS)

Schechner, Sara Jane

2018-01-01

As a science that studies celestial objects situated at vast distances from us, astronomy deals with few things that can be touched directly. And yet, astronomy has many tangible things—scientific instruments, observatories, and log books, for example—which link the past to the present. There is little question about maintaining things still valuable for scientific research purposes, but why should we care about documenting and preserving the old and obsolete? One answer is that material things, when closely examined, enhance our knowledge of astronomy’s history in ways that written texts alone cannot do. A second answer is that learning about the past helps us live critically in the present. In brief case studies, this talk will find meaning in objects that are extraordinary or commonplace. These will include a sundial, an almanac, telescopes, clocks, a rotating desk, photographic plates, and fly spankers.

The natural moon illusion: a multifactor angular account.

PubMed

Plug, C; Ross, H E

1994-01-01

It is argued that the failure to explain the celestial illusion results from conceptual confusion about perceived size and from disregard of the observational evidence relating to the natural moon illusion. The evidence shows that the illusion consists of a perceived angular size enlargement of horizon objects, by a factor of about 1.5-2.0 in diameter in comparison with elevated objects. Most measurements of the illusion have been made in terms of angular size, although in some proposed explanations an illusion of linear size is assumed. The magnitude of the illusion varies, particularly with the detail of the horizon scene. The illusion can be explained as the sum of several factors that affect perceived angular size: size contrast, vergence commands and eye or head position, aerial perspective, and colour. The relative contributions of these factors are assessed.

Places to Go: Connexions

ERIC Educational Resources Information Center

Downes, Stephen

2005-01-01

When compared with, say, blogging, the deployment of learning objects has been slow indeed. While blog aggregation services are recording millions of blogs and hundreds of millions of blog posts, academic learning object repositories number their resources only in the thousands, and even major corporate repositories have only one or two million…

ESA's Integral solves thirty-year old gamma-ray mystery

NASA Astrophysics Data System (ADS)

Integral solves mystery hi-res Size hi-res: 60 kb Credits: Credit: ESA, F. Lebrun (CEA-Saclay). ESA's Integral solves thirty-year old gamma-ray mystery The central regions of our galaxy, the Milky Way, as seen by Integral in gamma rays. With its superior ability to see faint details, Integral correctly reveals the individual sources that comprised the foggy, gamma-ray background seen by previous observatories. The brightest 91 objects seen in this image were classified by Integral as individual sources, while the others appear too faint to be properly characterized at this stage. During the spring and autumn of 2003, Integral observed the central regions of our Galaxy, collecting some of the perpetual glow of diffuse low-energy gamma rays that bathe the entire Galaxy. These gamma rays were first discovered in the mid-1970s by high-flying balloon-borne experiments. Astronomers refer to them as the 'soft' Galactic gamma-ray background, with energies similar to those used in medical X-ray equipment. Initially, astronomers believed that the glow was caused by interactions involving the atoms of the gas that pervades the Galaxy. Whilst this theory could explain the diffuse nature of the emission, since the gas is ubiquitous, it failed to match the observed power of the gamma rays. The gamma rays produced by the proposed mechanisms would be much weaker than those observed. The mystery has remained unanswered for decades. Now Integral's superb gamma-ray telescope IBIS, built for ESA by an international consortium led by Principal Investigator Pietro Ubertini (IAS/CNR, Rome, Italy), has seen clearly that, instead of a fog produced by the interstellar medium, most of the gamma-rays are coming from individual celestial objects. In the view of previous, less sensitive instruments, these objects appeared to merge together. In a paper published today in "Nature", Francois Lebrun (CEA Saclay, Gif sur Yvette, France) and his collaborators report the discovery of 91 gamma-ray sources towards the direction of the Galactic centre. Lebrun's team includes Ubertini and seventeen other European scientists with long-standing experience in high-energy astrophysics. Much to the team's surprise, almost half of these sources do not fall in any class of known gamma-ray objects. They probably represent a new population of gamma-ray emitters. The first clues about a new class of gamma-ray objects came last October, when Integral discovered an intriguing gamma-ray source, known as IGRJ16318-4848. The data from Integral and ESA's other high-energy observatory XMM-Newton suggested that this object is a binary system, probably including a black hole or neutron star, embedded in a thick cocoon of cold gas and dust. When gas from the companion star is accelerated and swallowed by the black hole, energy is released at all wavelengths, mostly in the gamma rays. However, Lebrun is cautious to draw premature conclusions about the sources detected in the Galactic centre. Other interpretations are also possible that do not involve black holes. For instance, these objects could be the remains of exploded stars that are being energised by rapidly rotating celestial 'powerhouses', known as pulsars. Observations with another Integral instrument (SPI, the Spectrometer on Integral) could provide Lebrun and his team with more information on the nature of these sources. SPI measures the energy of incoming gamma rays with extraordinary accuracy and allows scientist to gain a better understanding of the physical mechanisms that generate them. However, regardless of the precise nature of these gamma-ray sources, Integral's observations have convincingly shown that the energy output from these new objects accounts for almost ninety per cent of the soft gamma-ray background coming from the centre of the Galaxy. This result raises the tantalising possibility that objects of this type hide everywhere in the Galaxy, not just in its centre. Again, Lebrun is cautious, saying, "It is tempting to think that we can simply extrapolate our results to the entire Galaxy. However, we have only looked towards its centre and that is a peculiar place compared to the rest." Next on Integral's list of things to do is to extend this work to the rest of the Galaxy. Christoph Winkler, ESA's Integral Project Scientist, says, "We now have to work on the whole disc region of the Galaxy. This will be a tough and long job for Integral. But at the end, the reward will be an exhaustive inventory of the most energetic celestial objects in the Galaxy." Note to editors The paper explaining these results will appear on the 18 March 2004 issue of "Nature". The author list includes F. Lebrun, R. Terrier, A. Bazzano, G. Belanger, A. Bird, L. Bouchet, A. Dean, M. Del Santo, A. Goldwurm, N. Lund, H. Morand, A. Parmar, J. Paul, J.-P. Roques, V. Schoenfelder, A. Strong, P. Ubertini, R. Walter and C. Winkler. For information about the related INTEGRAL and XMM-Newton discovery of IGRJ16318-4848, see: http://www.esa.int/esaSC/Pr_21_2003_s_en.html Integral The International Gamma Ray Astrophysics Laboratory (Integral) is the first space observatory that can simultaneously observe celestial objects in gamma rays, X-rays and visible light. Integral was launched on a Russian Proton rocket on 17 October 2002 into a highly elliptical orbit around Earth. Its principal targets include regions of the galaxy where chemical elements are being produced and compact objects, such as black holes. IBIS, Imager on Board the Integral Satellite - IBIS provides sharper gamma-ray images than any previous gamma-ray instrument. It can locate sources to a precision of 30 arcseconds, the equivalent of measuring the height of a person standing in a crowd, 1.3 kilometres away. The Principal Investigators that built the instrument are P. Ubertini (IAS/CNR, Rome, Italy), F. Lebrun (CEA Saclay, Gif sur Yvette, France), G. Di Cocco (ITESRE, Bologna, Italy). IBIS is equipped with the first un-cooled semiconductor gamma-ray camera, called ISGRI, which is responsible for its outstanding sensitivity. ISGRI was developed and built for ESA by CEA Saclay, France. SPI, Spectrometer on Integral - SPI measures the energy of incoming gamma rays with extraordinary accuracy. It is more sensitive to faint radiation than any previous gamma ray instrument and allows the precise nature of gamma ray sources to be determined. The Principal Investigators that developed SPI are J.-P. Roques, (CESR, Toulouse, France) and V. Schoenfelder (MPE, Garching, Germany). XMM-Newton XMM-Newton can detect more X-ray sources than any previous observatory and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket from French Guiana. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects.

Nonstationary EO/IR Clutter Suppression and Dim Object Tracking

NASA Astrophysics Data System (ADS)

Tartakovsky, A.; Brown, A.; Brown, J.

2010-09-01

We develop and evaluate the performance of advanced algorithms which provide significantly improved capabilities for automated detection and tracking of ballistic and flying dim objects in the presence of highly structured intense clutter. Applications include ballistic missile early warning, midcourse tracking, trajectory prediction, and resident space object detection and tracking. The set of algorithms include, in particular, adaptive spatiotemporal clutter estimation-suppression and nonlinear filtering-based multiple-object track-before-detect. These algorithms are suitable for integration into geostationary, highly elliptical, or low earth orbit scanning or staring sensor suites, and are based on data-driven processing that adapts to real-world clutter backgrounds, including celestial, earth limb, or terrestrial clutter. In many scenarios of interest, e.g., for highly elliptic and, especially, low earth orbits, the resulting clutter is highly nonstationary, providing a significant challenge for clutter suppression to or below sensor noise levels, which is essential for dim object detection and tracking. We demonstrate the success of the developed algorithms using semi-synthetic and real data. In particular, our algorithms are shown to be capable of detecting and tracking point objects with signal-to-clutter levels down to 1/1000 and signal-to-noise levels down to 1/4.

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

The Bruce Medalists

NASA Astrophysics Data System (ADS)

Tenn, J. S.

2001-12-01

The Astronomical Society of the Pacific (ASP) has presented the Catherine Wolfe Bruce gold medal for lifetime contributions to astronomy most years since 1898. The 94 medalists include most of the scientists whose work has greatly changed astronomy since the late nineteenth century: Huggins, Pickering, Campbell, Hale, Eddington, Russell, Adams, Slipher, Hertzsprung, Hubble, Shapley, Oort, Baade, ... Major exceptions include those who died young, those who worked in teams, and, in the early years, women. Mathematicians appear to have been as likely to be honored as astronomers from the beginning, but the fortunes of physicist nominees have varied. The nomination process is an unusual one, with the directors of six observatories, three in the U.S. and three abroad, asked to nominate up to three candidates each year. For the first six decades the observatories rarely varied, and directors had long tenures. They nominated the same individuals repeatedly. Now both observatories and their directors vary regularly. Much can be learned about the changes in astronomy from the late nineteenth century, when observers worked alone with long refractors and a theorist could spend a lifetime computing the orbit of one comet, to the present, when most papers have multiple authors and a single project may include millions of objects. For example, celestial mechanics was the specialty of many of the early medalists but none since 1966. I have posted photographs, brief biographies, extensive bibliographies, and links to publications by and about all of the medalists, from Simon Newcomb in 1898 to Hans Bethe in 2001, at http://phys-astro.sonoma.edu/BruceMedalists/. I will discuss a bit of the history of the medal and some of the medalists.

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 light-years wide. The image was taken in June 1995 by the Burrell Schmidt telescope at the Case Western Reserve University's Warner and Swasey Observatory on Kitt Peak in Arizona. This release is issued jointly by NASA and ESA. Credits for Hubble image: NASA, Kailash Sahu, Stefano Casertano, Mario Livio, Ron Gilliland (Space Telescope Science Institute), Nino Panagia (European Space Agency/Space Telescope Science Institute), Michael Albrow and Mike Potter (Space Telescope Science Institute) Credits for ground-based image: Nigel A.Sharp, REU program/AURA/NOAO/NSF

Spectroscopy of Dwarf Stars Around the North Celestial Pole

NASA Astrophysics Data System (ADS)

Mikolaitis, Šarūnas; Tautvaišienė, Gražina; Drazdauskas, Arnas; Minkevičiūtė, Renata; Klebonas, Lukas; Bagdonas, Vilius; Pakšienė, Erika; Janulis, Rimvydas

2018-07-01

New space missions (e.g., NASA-TESS and ESA-PLATO) will perform an in-depth analysis of bright stars in large fields of the celestial sphere searching for extraterrestrial planets and investigating their host-stars. Asteroseismic observations will search for exoplanet-hosting stars with solar-like oscillations. In order to achieve all the goals, a full characterization of the stellar objects is important. However, accurate atmospheric parameters are available for less than 30% of bright dwarf stars of the solar neighborhood. In this study we observed high-resolution (R = 60,000) spectra for all bright (V < 8 mag) and cooler than F5 spectral class dwarf stars in the northern-most field of the celestial sphere with radius of 20° from the α(2000) = 161.°03 and δ(2000) = 86.°60 that is a center of one of the preliminary ESO-PLATO fields. Spectroscopic atmospheric parameters were determined for 140 slowly rotating stars, for 73% of them for the first time. The majority (83%) of the investigated stars are in the TESS object lists and all of them are in the preliminary PLATO field. Our results have no systematic differences when compared with other recent studies. We have 119 stars in common with the Geneva–Copenhagen Survey, where stellar parameters were determined photometrically, and find a 14 ± 125 K difference in effective temperatures, 0.01 ± 0.16 in log g, and ‑0.02 ± 0.09 dex in metallicities. Comparing our results for 39 stars with previous high-resolution spectral determinations, we find only a 7 ± 73 K difference in effective temperatures, 0.02 ± 0.09 in log g, and ‑0.02 ± 0.09 dex in metallicities. We also determined basic kinematic and orbital parameters for this sample of stars. From the kinematical point of view, almost all our stars belong to the thin disk substructure of the Milky Way. The derived galactocentric metallicity gradient is ‑0.066 ± 0.024 dex kpc‑1 (2.5σ significance) and the vertical metallicity gradient is ‑0.102 ± 0.099 dex kpc‑1 (1σ significance) that comply with the latest inside-out thin disk formation models, including those with stellar migration taken into account. Based on observations collected with the 1.65 m telescope and VUES spectrograph at the Molėtai Astronomical Observatory of Institute of Theoretical Physics and Astronomy, Vilnius University, for the SPFOT survey.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility test equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Saturn Apollo Program

NASA Image and Video Library

1972-04-16

The sixth manned lunar landing mission, the Apollo 16 (SA-511), carrying three astronauts: Mission Commander John W. Young, Command Module pilot Thomas K. Mattingly II, and Lunar Module pilot Charles M. Duke, lifted off on April 16, 1972. The Apollo 16 mission continued the broad-scale geological, geochemical, and geophysical mapping of the Moon’s crust, begun by the Apollo 15, from lunar orbit. This mission marked the first use of the Moon as an astronomical observatory by using the ultraviolet camera/spectrograph which photographed ultraviolet light emitted by Earth and other celestial objects. The Lunar Roving Vehicle, developed by the Marshall Space Flight Center, was also used. The mission ended on April 27, 1972.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This photograph was taken during encapsulation of the High Energy Astronomy Observatory (HEAO)-3. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This photograph shows the High Energy Astronomy Observatory (HEAO)-3 being prepared for encapsulation. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This photograph shows the High Energy Astronomy Observatory (HEAO)-3 being assembled at TRW, Inc. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.

MONET: a MOnitoring NEtwork of Telescopes

NASA Astrophysics Data System (ADS)

Hessman, F. V.; Beuermann, K.

2002-01-01

MONET is a planned network of two 1m-class robotic telescopes which will be used for various photometric monitoring projects -- variable stars, planet searches, AGN's, GRB's -- as well as by school children in Germany and over the world. The two host partners, the Univ. of Texas' McDonald Observatory and the South African Astronomical Observatory, will operate the telescopes in exchange for observing time on the network. MONET will be one of the first robotic telescope networks offering 1-m class telescopes, complete coverage of the sky, good longitude coverage for long observing sequences on objects near the celestial equator, and a heavy educational emphasis.

Cosmic neutrino pevatrons: A brand new pathway to astronomy, astrophysics, and particle physics

NASA Astrophysics Data System (ADS)

Anchordoqui, Luis A.; Barger, Vernon; Cholis, Ilias; Goldberg, Haim; Hooper, Dan; Kusenko, Alexander; Learned, John G.; Marfatia, Danny; Pakvasa, Sandip; Paul, Thomas C.; Weiler, Thomas J.

2014-05-01

The announcement by the IceCube Collaboration of the observation of 28 cosmic neutrino candidates has been greeted with a great deal of justified excitement. The data reported so far depart by 4.3σ from the expected atmospheric neutrino background, which raises the obvious question: “Where in the Cosmos are these neutrinos coming from?” We review the many possibilities which have been explored in the literature to address this question, including origins at either Galactic or extragalactic celestial objects. For completeness, we also briefly discuss new physical processes which may either explain or be constrained by IceCube data.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility check equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility remove a solar panel from Deep Space 1 as part of the preparations for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near- Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility check out Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Our Attempts in Astronomy

NASA Astrophysics Data System (ADS)

Vanichai, Yupa

During the last decade of twentieth century astronomical articles in Thai scientific magazines were out of date. Interacting galaxies blackholes and other celestial objects beyond solar system were hardly found. While a pocket book for deep space was purposefully written by a lecturer a website of astronomy for Thais was planned by the cooperation of two computer programmers. An obseravatory with 600-mm reflector was the first attempt by a Thai engineer. The product of the first 150-mm reflector Dosonian made in Thailand is sold in low price. Future optical programs are now being planned to be made by Thais. These people have recently worked together to develope astronomy in Thailand.

Comet and meteorite traditions of Aboriginal Australians

NASA Astrophysics Data System (ADS)

Hamacher, Duane W.

2014-06-01

This research contributes to the disciplines of cultural astronomy (the academic study of how past and present cultures understand and utilise celestial objects and phenomena) and geomythology (the study of geological events and the formation of geological features described in oral traditions). Of the hundreds of distinct Aboriginal cultures of Australia, many have oral traditions rich in descriptions and explanations of comets, meteors, meteorites, airbursts, impact events, and impact craters. These views generally attribute these phenomena to spirits, death, and bad omens. There are also many traditions that describe the formation of meteorite craters as well as impact events that are not known to Western science.

KSC-98pc1088

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility remove a solar panel from Deep Space 1 as part of the preparations for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

KSC-98pc1090

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility check equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

KSC-98pc1089

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility check out Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

KSC-98pc1091

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility test equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

Systems Engineering and Application of System Performance Modeling in SIM Lite Mission

NASA Technical Reports Server (NTRS)

Moshir, Mehrdad; Murphy, David W.; Milman, Mark H.; Meier, David L.

2010-01-01

The SIM Lite Astrometric Observatory will be the first space-based Michelson interferometer operating in the visible wavelength, with the ability to perform ultra-high precision astrometric measurements on distant celestial objects. SIM Lite data will address in a fundamental way questions such as characterization of Earth-mass planets around nearby stars. To accomplish these goals it is necessary to rely on a model-based systems engineering approach - much more so than most other space missions. This paper will describe in further detail the components of this end-to-end performance model, called "SIM-sim", and show how it has helped the systems engineering process.

Large aperture diffractive space telescope

DOEpatents

Hyde, Roderick A.

2001-01-01

A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

The Loneliest Young Star (Artist Concept)

NASA Image and Video Library

2016-07-27

This artist's concept shows an unusual celestial object called CX330 was first detected as a source of X-ray light in 2009 by NASA's Chandra X-Ray Observatory while it was surveying the bulge in the central region of the Milky Way. A 2016 study in the Monthly Notices of the Royal Astronomical Society found that CX330 is the most isolated young star that has been discovered. Researchers compared NASA's Wide-field Infrared Survey Explorer (WISE) data from 2010 with NASA's Spitzer Space Telescope data from 2007 to come to this conclusion. CX330 is not near any star-forming region. As of the most recent observation, which was August 2015, this object was outbursting, meaning it was launching "jets" of material that slam into the gas and dust around it. Astronomers plan to continue studying the object, including with future telescopes that could view CX330 in other wavelengths of light. http://photojournal.jpl.nasa.gov/catalog/PIA20700

General-relativistic celestial mechanics. 4: Theory of satellite motion

NASA Astrophysics Data System (ADS)

Damour, T.; Soffel, M.; Xu, C.

1993-09-01

The basic equations needed for developing a complete relativistic theory of artificial Earth satellites are explicitly written down. These equations are given both in a local, geocentric frame and in the global, barycentric one. They are derived within our recently introduced general-relativistic celestial mechanics framework. Our approach is more satisfactory than previous ones, especially with regard to its consistency, completeness, and flexibility. In particular, the problem of representing the relativistic gravitational effects associated with the quadrupole and higher multipole moments of the moving Earth, which caused difficulties in several other approaches, is easily dealth with in our approach, thanks to the use of previously developed tools: definition of relativistic multipole moments and transformation theory between reference frames. With this last paper in a series, we hope to indicate the way of using our formalism in specific problems in applied celestial mechanics and astrometry.

Polynomial equations for science orbits around Europa

NASA Astrophysics Data System (ADS)

Cinelli, Marco; Circi, Christian; Ortore, Emiliano

2015-07-01

In this paper, the design of science orbits for the observation of a celestial body has been carried out using polynomial equations. The effects related to the main zonal harmonics of the celestial body and the perturbation deriving from the presence of a third celestial body have been taken into account. The third body describes a circular and equatorial orbit with respect to the primary body and, for its disturbing potential, an expansion in Legendre polynomials up to the second order has been considered. These polynomial equations allow the determination of science orbits around Jupiter's satellite Europa, where the third body gravitational attraction represents one of the main forces influencing the motion of an orbiting probe. Thus, the retrieved relationships have been applied to this moon and periodic sun-synchronous and multi-sun-synchronous orbits have been determined. Finally, numerical simulations have been carried out to validate the analytical results.

Almanac services for celestial navigation

NASA Astrophysics Data System (ADS)

Nelmes, S.; Whittaker, J.

2015-08-01

Celestial navigation remains a vitally important back up to Global Navigation Satellite Systems (GNSS) and relies on the use of almanac services. HM Nautical Almanac Office (HMNAO) provides a number of these services. The printed book, The Nautical Almanac, produced yearly and now available as an electronic publication, is continuously being improved, making use of the latest ideas and ephemerides to provide the user with their required data. HMNAO also produces NavPac, a software package that assists the user in calculating their position as well as providing additional navigational and astronomical tools. A new version of NavPac will be released in 2015 that will improve the user experience. The development of applications for mobile devices is also being considered. HMNAO continues to combine the latest improvements and theories of astrometry with the creation of books and software that best meet the needs of celestial navigation users.

Infrared radiation scene generation of stars and planets in celestial background

NASA Astrophysics Data System (ADS)

Guo, Feng; Hong, Yaohui; Xu, Xiaojian

2014-10-01

An infrared (IR) radiation generation model of stars and planets in celestial background is proposed in this paper. Cohen's spectral template1 is modified for high spectral resolution and accuracy. Based on the improved spectral template for stars and the blackbody assumption for planets, an IR radiation model is developed which is able to generate the celestial IR background for stars and planets appearing in sensor's field of view (FOV) for specified observing date and time, location, viewpoint and spectral band over 1.2μm ~ 35μm. In the current model, the initial locations of stars are calculated based on midcourse space experiment (MSX) IR astronomical catalogue (MSX-IRAC) 2 , while the initial locations of planets are calculated using secular variations of the planetary orbits (VSOP) theory. Simulation results show that the new IR radiation model has higher resolution and accuracy than common model.

Archaic artifacts resembling celestial spheres

NASA Astrophysics Data System (ADS)

Dimitrakoudis, S.; Papaspyrou, P.; Petoussis, V.; Moussas, X.

We present several bronze artifacts from the Archaic Age in Greece (750-480 BC) that resemble celestial spheres or forms of other astronomical significance. They are studied in the context of the Dark Age transition from Mycenaean Age astronomical themes to the philosophical and practical revival of astronomy in the Classical Age with its plethora of astronomical devices. These artifacts, mostly votive in nature are spherical in shape and appear in a variety of forms their most striking characteristic being the depiction of meridians and/or an equator. Most of those artifacts come from Thessaly, and more specifically from the temple of Itonia Athena at Philia, a religious center of pan-Hellenic significance. Celestial spheres, similar in form to the small artifacts presented in this study, could be used to measure latitudes, or estimate the time at a known place, and were thus very useful in navigation.

Using Model Point Spread Functions to Identifying Binary Brown Dwarf Systems

NASA Astrophysics Data System (ADS)

Matt, Kyle; Stephens, Denise C.; Lunsford, Leanne T.

2017-01-01

A Brown Dwarf (BD) is a celestial object that is not massive enough to undergo hydrogen fusion in its core. BDs can form in pairs called binaries. Due to the great distances between Earth and these BDs, they act as point sources of light and the angular separation between binary BDs can be small enough to appear as a single, unresolved object in images, according to Rayleigh Criterion. It is not currently possible to resolve some of these objects into separate light sources. Stephens and Noll (2006) developed a method that used model point spread functions (PSFs) to identify binary Trans-Neptunian Objects, we will use this method to identify binary BD systems in the Hubble Space Telescope archive. This method works by comparing model PSFs of single and binary sources to the observed PSFs. We also use a method to compare model spectral data for single and binary fits to determine the best parameter values for each component of the system. We describe these methods, its challenges and other possible uses in this poster.

The Maximum Mass of a Planet

NASA Astrophysics Data System (ADS)

Schlaufman, Kevin C.

2018-06-01

Giant planet occurrence is a steeply increasing function of FGK dwarf host star metallicity, and this is interpreted as support for the core-accretion model of giant planet formation. On the other hand, the occurrence of low-mass stellar companions to FGK dwarf stars does not appear to depend on stellar metallicity. The mass at which objects no longer prefer metal-rich FGK dwarf host stars can therefore be used to infer the maximum mass of objects that form like planets through core accretion. I'll show that objects more massive than about 10 M_Jup do not orbit metal-rich host stars and that this transition is coincident with a minimum in the occurrence rate of such objects. These facts suggest that the maximum mass of a celestial body formed through core accretion like a planet is less than 10 M_Jup. This observation can be used to infer the properties of protoplanetary disks and reveals that the Type I and Type II disk migration problems---two major issues for the modern model of planet formation---are not problems at all.

Thai student existing understanding about the solar system model and the motion of the stars

NASA Astrophysics Data System (ADS)

Anantasook, Sakanan; Yuenyong, Chokchai

2018-01-01

The paper examined Thai student existing understanding about the solar system model and the motion of the stars. The participants included 141 Grade 9 students in four different schools of the Surin province, Thailand. Methodology regarded interpretive paradigm. The tool of interpretation included the Student Celestial Motion Conception Questionnaire (SCMCQ) and informal interview. Given understandings in the SCMCQ were read through and categorized according to students' understandings. Then, students were further probed as informal interview. Students' understandings in each category were counted and percentages computed. Finally, students' understandings across four different schools were compared and contrasted using the percentage of student responses in each category. The findings revealed that most students understand about Sun-Moon-Earth (SME) system and solar system model as well, they can use scientific explanations to explain the celestial objects in solar system and how they orbiting. Unfortunately, most of students (more than 70%) never know about the Polaris, the North Star, and 90.1% of them never know about the ecliptic, and probably also the 12 zodiac constellations. These existing understanding suggested some ideas of teaching and learning about solar system model and the motion of the stars. The paper, then, discussed some learning activities to enhance students to further construct meaning about solar system model and the motion of the stars.

Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

NASA Technical Reports Server (NTRS)

Memarsadeghi, Nargess; Mcfadden, Lucy A.; Skillman, David R.; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E.

2012-01-01

A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various image processing and computational algorithms for performing satellite searches to the electronic imaging and computer science community. Furthermore, we hope that this communication would enable Dawn mission scientists to improve their satellite search algorithms and tools and be better prepared for performing the same investigation in 2015, when the spacecraft is scheduled to approach and orbit the dwarf planet Ceres.

Tides in a body librating about a spin-orbit resonance: generalisation of the Darwin-Kaula theory

NASA Astrophysics Data System (ADS)

Frouard, Julien; Efroimsky, Michael

2017-09-01

The Darwin-Kaula theory of bodily tides is intended for celestial bodies rotating without libration. We demonstrate that this theory, in its customary form, is inapplicable to a librating body. Specifically, in the presence of libration in longitude, the actual spectrum of Fourier tidal modes differs from the conventional spectrum rendered by the Darwin-Kaula theory for a nonlibrating celestial object. This necessitates derivation of formulae for the tidal torque and the tidal heating rate, that are applicable under libration. We derive the tidal spectrum for longitudinal forced libration with one and two main frequencies, generalisation to more main frequencies being straightforward. (By main frequencies we understand those emerging due to the triaxiality of the librating body.) Separately, we consider a case of free libration at one frequency (once again, generalisation to more frequencies being straightforward). We also calculate the tidal torque. This torque provides correction to the triaxiality-caused physical libration. Our theory is not self-consistent: we assume that the tidal torque is much smaller than the permanent-triaxiality-caused torque, so the additional libration due to tides is much weaker than the main libration due to the permanent triaxiality. Finally, we calculate the tidal dissipation rate in a body experiencing forced libration at the main mode, or free libration at one frequency, or superimposed forced and free librations.

Use of the transect method in satellite survey missions with application to the infrared astronomical satellite /IRAS/

NASA Technical Reports Server (NTRS)

Mclaughlin, W. I.; Lundy, S. A.; Ling, H. Y.; Stroberg, M. W.

1980-01-01

The coverage of the celestial sphere or the surface of the earth with a narrow-field instrument onboard a satellite can be described by a set of swaths on the sphere. A transect is a curve on this sphere constructed to sample the coverage. At each point on the transect the number of times that the field-of-view of the instrument has passed over the point is recorded. This information is conveniently displayed as an integer-valued histogram over the length of the transect. The effectiveness of the transect method for a particular observing plan and the best placement of the transects depends upon the structure of the set of observations. Survey missions are usually characterized by a somewhat parallel alignment of the instrument swaths. Using autocorrelation and cross-correlation functions among the histograms the structure of a survey has been analyzed into two components, and each is illustrated by a simple mathematical model. The complex, all-sky survey to be performed by the Infrared Astronomical Satellite (IRAS) is synthesized in some detail utilizing the objectives and constraints of that mission. It is seen that this survey possesses the components predicted by the simple models and this information is useful in characterizing the properties of the IRAS survey and the placement of the transects as a function of celestial latitude and certain structural properties of the coverage.

Elliptical instability in stably stratified fluid interiors

NASA Astrophysics Data System (ADS)

Vidal, J.; Hollerbach, R.; Schaeffer, N.; Cebron, D.

2016-12-01

Self-sustained magnetic fields in celestial bodies (planets, moons, stars) are due to flows in internal electrically conducting fluids. These fluid motions are often attributed to convection, as it is the case for the Earth's liquid core and the Sun. However some past or present liquid cores may be stably stratified. Alternative mechanisms may thus be needed to understand the dynamo process in these celestial objects. Turbulent flows driven by mechanical forcings, such as tides or precession, seem very promising since they are dynamo capable. However the effect of density stratification is not clear, because it can stabilize or destabilize mechanically-driven flows.To mimic an elliptical distortion due to tidal forcing in spherical geometry (full sphere and shell), we consider a theoretical base flow with elliptical streamlines and an associated density profile. It allows to keep the numerical efficiency of spectral methods in this geometry. The flow satisfies the stress-free boundary condition. We perform the stability analysis of the base state using three-dimensional simulations to study both the linear and nonlinear regimes. Stable and unstable density profiles are considered. A complementary local stability analysis (WKB) is also performed. We show that elliptical instability can still grow upon a stable stratification. We also study the mixing of the stratification by the elliptical instability. Finally we look at the dynamo capability of these flows.

Nonlinear Uncertainty Propagation of Satellite State Error for Tracking and Conjunction Risk Assessment

DTIC Science & Technology

2017-12-18

Determination on Orbital Element Representations,” Celestial Mechanics and Dynamical Astronomy , Vol. 118, pp.165-195, 2014. [8] R. Weisman, M. Jah...Nonlinear Filtering,” Celestial Mechanics and Dynamical Astronomy , Vol. 118, pp.129-164, 2014. [10] R. Weisman, M. Majji, K. Alfriend, “Analytic...Conference on Mathematics and Astronomy : A Joint Long Journey, American Institute of Physics, 10.1063/1.3506064, Madrid, Spain, 2009. [33] X.L. Xu, Y.Q

Surface Photometry of Celestial Sources from a Space Vehicle: Introduction and Observational Procedures*

PubMed Central

Roach, Franklin E.; Carroll, Benjamin; Aller, Lawrence H.; Smith, Leroi

1972-01-01

Diffuse celestial sources of relatively low surface brightness such as the Milky Way, zodiacal light, and gegenschein (or contre lumière) can be studied most reliably from above the earth's atmosphere with equipment flown in artificial satellites. We review the techniques used and some of the difficulties encountered in day-time observations from satellites by the use of a special photometer and polarimeter flown in the orbiting skylab observatory, OSO-6. PMID:16591970

Pulmonary Inflammatory Responses to Acute Meteorite Dust Exposures - Implications for Human Space Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.; Vander Kaaden, K. E.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

2018-01-01

New initiatives to send humans to Mars within the next few decades are illustrative of the resurgence of interest in space travel. However, as with all exploration, there are risks. The Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts.

Polarization transition between sunlit and moonlit skies with possible implications for animal orientation and Viking navigation: anomalous celestial twilight polarization at partial moon.

PubMed

Barta, András; Farkas, Alexandra; Száz, Dénes; Egri, Ádám; Barta, Pál; Kovács, József; Csák, Balázs; Jankovics, István; Szabó, Gyula; Horváth, Gábor

2014-08-10

Using full-sky imaging polarimetry, we measured the celestial distribution of polarization during sunset and sunrise at partial (78% and 72%) and full (100%) moon in the red (650 nm), green (550 nm), and blue (450 nm) parts of the spectrum. We investigated the temporal change of the patterns of degree p and angle α of linear polarization of sunlit and moonlit skies at dusk and dawn. We describe here the position change of the neutral points of sky polarization, and present video clips about the celestial polarization transition at moonlit twilight. We found that at partial moon and at a medium latitude (47° 15.481' N) during this transition there is a relatively short (10-20 min) period when (i) the maximum of p of skylight decreases, and (ii) from the celestial α pattern neither the solar-antisolar nor the lunar-antilunar meridian can be unambiguously determined. These meridians can serve as reference directions of animal orientation and Viking navigation based on sky polarization. The possible influence of these atmospheric optical phenomena during the polarization transition between sunlit and moonlit skies on the orientation of polarization-sensitive crepuscular/nocturnal animals and the hypothesized navigation of sunstone-aided Viking seafarers is discussed.

Performance Plan: Progress Report, 1st Quarter, Fiscal Year 2000.

ERIC Educational Resources Information Center

Department of Education, Washington, DC. Student Financial Assistance.

This report by the Department of Education examines the progress made by the Student Financial Assistance (SFA) program in reaching its objectives. The report notes that for objective 1, customer satisfaction, more than 4 million direct loan records have been processed and over 1 million updates applied since winter 1999; that 84 percent of school…

Results of PRISMA/FFIORD extended mission and applicability to future formation flying and active debris removal missions

NASA Astrophysics Data System (ADS)

Delpech, Michel; Berges, Jean-Claude; Karlsson, Thomas; Malbet, Fabien

2013-07-01

CNES performed several experiments during the extended PRISMA mission which started in August 2011. A first session in October 2011 addressed two objectives: 1) demonstrate angles-only navigation to rendezvous with a non-cooperative object; 2) exercise transitions between RF-based and vision-based control during final formation acquisition. A complementary experiment in September 2012 mimicked some future astrometry mission and implemented the manoeuvres required to point the two satellite axis to a celestial target and maintain it fixed during some observation period. In the first sections, the paper presents the experiment motivations, describes its main design features including the guidance and control algorithms evolutions and provides a synthesis of the most significant results along with a discussion of the lessons learned. In the last part, the paper evokes the applicability of these experiment results to some active debris removal mission concept that is currently being studied.

Development of the instruments for the Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Madden, J. J.; Kniffen, D. A.

1986-01-01

The Gamma Ray Observatory (GRO) is to be launched in 1988 by the STS. The GRO will feature four very large instruments: the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), the Energetic Gamma Ray Experiment Telescope (EGRET) and the Burst and Transient Source Experiment (BATSE). The instruments weigh from 900-1200 kg each, and required the development of specialized lifting and dolly devices to permit their assembly, manipulation and testing. The GRO is intended a{s a tool for studying discrete celestial objects such as black holes, neutron stars and other gamma-ray emitting objects, scanning for nucleosynthesis processes, mapping the Galaxy and other, high energy galaxies in terms of gamma rays, searching for cosmological effects and observing gamma ray bursts. The instruments will be sensitive from the upper end mof X-rya wavelengths to the highest energies possible. Details of the hardware and performance specifications of each of the instruments are discussed.

Risk of Adverse Health and Performance Effects of Celestial Dust Exposure

NASA Technical Reports Server (NTRS)

Scully, Robert R.; Meyers, Valerie E.

2015-01-01

Crew members can be directly exposed to celestial dust in several ways. After crew members perform extravehicular activities (EVAs), they may introduce into the habitat dust that will have collected on spacesuits and boots. Cleaning of the suits between EVAs and changing of the Environmental Control Life Support System filters are other operations that could result in direct exposure to celestial dusts. In addition, if the spacesuits used in exploration missions abrade the skin, as current EVA suits have, then contact with these wounds would provide a source of exposure. Further, if celestial dusts gain access to a suit's interior, as was the case during the Apollo missions, the dust could serve as an additional source of abrasions or enhance suit-induced injuries. When a crew leaves the surface of a celestial body and returns to microgravity, the dust that is introduced into the return vehicle will "float," thus increasing the opportunity for ocular and respiratory injury. Because the features of the respirable fraction of lunar dusts indicate they could be toxic to humans, NASA conducted several studies utilizing lunar dust simulants and authentic lunar dust to determine the unique properties of lunar dust that affect physiology, assess the dermal and ocular irritancy of the dust, and establish a permissible exposure limit for episodic exposure to airborne lunar dust during missions that would involve no more than 6 months stay on the lunar surface. Studies, with authentic lunar soils from both highland (Apollo 16) and mare (Apollo17) regions demonstrated that the lunar soil is highly abrasive to a high fidelity model of human skin. Studies of lunar dust returned during the Apollo 14 mission from an area of the moon in which the soils were comprised of mineral constituents from both major geological regions (highlands and mares regions) demonstrated only minimal ocular irritancy, and pulmonary toxicity that was less than the highly toxic terrestrial crystalline silica (Permissible Exposure Limit [PEL] 0.05 mg/m3) but more toxic than the nuisance dust titanium dioxide (TiO2 [PEL 5.0 mg/m3]). A PEL for episodic exposure to airborne lunar dust during a six-month stay on the lunar surface was established, in consultation with an independent, extramural panel of expert pulmonary toxicologists, at 0.3 mg/m3. The PEL provided for lunar dust is limited to the conditions and exposure specified therefore additional research remains to be accomplished with lunar dust to further address the issues of activation, address other areas of more unique lunar geology (Glotch et al., 2010; Greenhagen et al., 2010), examine potential toxicological effects of inhaled or ingested dust upon other organ systems, such cardiovascular, nervous systems, and examine effects of acute exposure to massive doses of dust such as may occur during off-nominal situations. Work to support the establishment of PELs for Martian dust and dusts of asteroids remains to be accomplished. The literature that describes health effects of exposure to toxic terrestrial dusts provides substantial basis for concern that prolonged exposure to respirable celestial dust could be detrimental to human health. Celestial bodies where a substantial portion of the dust is in the respirable range or where the dusts have large reactive surface areas or contain transition metals or volatile organics, represent greater risks of adverse effects from exposure to the dust. It is possible that in addition to adverse effects to the respiratory system, inhalation and ingestion of celestial dusts could pose risks to other systems

NASA Awards Chandra X-Ray Observatory Follow-On Contract

NASA Astrophysics Data System (ADS)

2003-08-01

NASA has awarded a contract to the Smithsonian Astrophysical Observatory in Cambridge, Mass., to provide science and operational support for the Chandra X-ray Observatory, one of the world's most powerful tools to better understand the structure and evolution of the universe. The contract will have a period of performance from August 31, 2003, through July 31, 2010, with an estimated value of 373 million. It is a follow-on contract to the existing contract with Smithsonian Astrophysical Observatory that has provided science and operations support to the Observatory since its launch in July 1999. At launch the intended mission life was five years. As a result of Chandra's success, NASA extended the mission from five to 10 years. The value of the original contract was 289 million. The follow-on contract with the Smithsonian Astrophysical Observatory will continue through the 10-year mission. The contract type is cost reimbursement with no fee. The contract covers mission operations and data analysis, which includes the observatory operations, science data processing and the general and guaranteed time observer (astronomer) support. The observatory operations tasks include monitoring the health and status of the observatory and developing and up linking the observation sequences during Chandra's communication coverage periods. The science data processing tasks include the competitive selection, planning, and coordination of science observations with the general observers and processing and delivery of the resulting scientific data. There are approximately 200 to 250 observing proposals selected annually out of about 800 submitted, with a total amount of observing time of about 20 million seconds. Chandra has exceeded expectations of scientists, giving them unique insight into phenomena light years away, such as exotic celestial objects, matter falling into black holes, and stellar explosions. X-ray astronomy can only be performed from space because Earth's atmosphere blocks X-rays from reaching the surface. The Chandra Observatory travels one-third of the way to the moon during its orbit around the Earth every 64 hours. At its highest point, Chandra's highly elliptical, or egg- shaped, orbit is 200 times higher than that of its visible- light-gathering sister, the Hubble Space Telescope. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. For information about NASA on the Internet, visit: http://www.nasa.gov For information about the Chandra X-ray Observatory on the Internet, visit: http://chandra.harvard.edu and http://chandra.nasa.gov

Review on the Celestial Sphere Positioning of FITS Format Image Based on WCS and Research on General Visualization

NASA Astrophysics Data System (ADS)

Song, W. M.; Fan, D. W.; Su, L. Y.; Cui, C. Z.

2017-11-01

Calculating the coordinate parameters recorded in the form of key/value pairs in FITS (Flexible Image Transport System) header is the key to determine FITS images' position in the celestial system. As a result, it has great significance in researching the general process of calculating the coordinate parameters. By combining CCD related parameters of astronomical telescope (such as field, focal length, and celestial coordinates in optical axis, etc.), astronomical images recognition algorithm, and WCS (World Coordinate System) theory, the parameters can be calculated effectively. CCD parameters determine the scope of star catalogue, so that they can be used to build a reference star catalogue by the corresponding celestial region of astronomical images; Star pattern recognition completes the matching between the astronomical image and reference star catalogue, and obtains a table with a certain number of stars between CCD plane coordinates and their celestial coordinates for comparison; According to different projection of the sphere to the plane, WCS can build different transfer functions between these two coordinates, and the astronomical position of image pixels can be determined by the table's data we have worked before. FITS images are used to carry out scientific data transmission and analyze as a kind of mainstream data format, but only to be viewed, edited, and analyzed in the professional astronomy software. It decides the limitation of popular science education in astronomy. The realization of a general image visualization method is significant. FITS is converted to PNG or JPEG images firstly. The coordinate parameters in the FITS header are converted to metadata in the form of AVM (Astronomy Visualization Metadata), and then the metadata is added to the PNG or JPEG header. This method can meet amateur astronomers' general needs of viewing and analyzing astronomical images in the non-astronomical software platform. The overall design flow is realized through the java program and tested by SExtractor, WorldWide Telescope, picture viewer, and other software.

Celestial ephemerides in an expanding universe

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei M.

2012-09-01

The post-Newtonian theory of motion of celestial bodies and propagation of light was instrumental in conducting the critical experimental tests of general relativity and in building the astronomical ephemerides of celestial bodies in the Solar System with unparalleled precision. The cornerstone of the theory is the postulate that the Solar System is gravitationally isolated from the rest of the Universe and the background spacetime is asymptotically flat. The present article extends this theoretical concept and formulates the principles of celestial dynamics of particles and light moving in the gravitational field of a localized astronomical system embedded to the expanding Friedmann-Lemaître-Robertson-Walker universe. We formulate the precise mathematical concept of the Newtonian limit of Einstein’s field equations in the conformally flat Friedmann-Lemaître-Robertson-Walker spacetime and analyze the geodesic motion of massive particles and light in this limit. We prove that by doing conformal spacetime transformations, one can reduce the equations of motion of particles and light to the classical form of the Newtonian theory. However, the time arguments in the equations of motion of particles and light differ from each other in terms being proportional to the Hubble constant H. This leads to the important conclusion that the equations of light propagation used currently by space navigation centers for fitting range and Doppler-tracking observations of celestial bodies are missing some terms of the cosmological origin that are proportional to the Hubble constant H. We also analyze the effect of the cosmological expansion on motion of electrons in atoms. We prove that the Hubble expansion does not affect the atomic frequencies and hence does not affect the atomic time scale used in the creation of astronomical ephemerides. We derive the cosmological correction to the light travel time equation and argue that its measurement opens an exciting opportunity to determine the local value of the Hubble constant H in the Solar System independently of cosmological observations.

Global Velocities from VLBI

NASA Technical Reports Server (NTRS)

Ma, Chopo; Gordon, David; MacMillan, Daniel

1999-01-01

Precise geodetic Very Long Baseline Interferometry (VLBI) measurements have been made since 1979 at about 130 points on all major tectonic plates, including stable interiors and deformation zones. From the data set of about 2900 observing sessions and about 2.3 million observations, useful three-dimensional velocities can be derived for about 80 sites using an incremental least-squares adjustment of terrestrial, celestial, Earth rotation and site/session-specific parameters. The long history and high precision of the data yield formal errors for horizontal velocity as low as 0.1 mm/yr, but the limitation on the interpretation of individual site velocities is the tie to the terrestrial reference frame. Our studies indicate that the effect of converting precise relative VLBI velocities to individual site velocities is an error floor of about 0.4 mm/yr. Most VLBI horizontal velocities in stable plate interiors agree with the NUVEL-1A model, but there are significant departures in Africa and the Pacific. Vertical precision is worse by a factor of 2-3, and there are significant non-zero values that can be interpreted as post-glacial rebound, regional effects, and local disturbances.

The chaotic "sculpting" of the Solar System

NASA Astrophysics Data System (ADS)

Tsiganis, K.

2006-01-01

The orbits of the large celestial bodies in our Solar System are stable for very long times, as can be shown by numerical simulation. This gives the erroneous impression of perpetual stability of the system. It is only when we study the orbital distribution of the numerous minor bodies in the Solar System that we discover the rich variety of complex dynamical processes that have in fact shaped our system. During the last decade, enormous progress has been made, in understanding the evolution of the system over the last ~3.9 Gy. However, it also became clear that, in order to unveil its behaviour during the first ~700 million years of its lifetime, we have to find convincing explanations for observations that appear as details of its dynamical architecture. In the following we are going to show how the two best known - and up to now unexplained - observations in the Solar System, namely (i) the heavily cratered surface of the Moon and (ii) the elliptic (and not circular) motion of the planets, lead us to the discovery of the chaotic sculpting of the Solar System [1]-[3].

Celestial Software Scratches More Than the Surface

NASA Technical Reports Server (NTRS)

2005-01-01

While NASA is preparing to send humans back to the Moon by 2020 and then eventually to Mars, the average person can explore the landscapes of these celestial bodies much sooner, without the risk and training, and without even leaving the comfort of home. Geological data and imagery collected from NASA missions are enabling anybody with computer access to virtually follow the footsteps of Apollo astronauts who walked on the Moon or trace the tracks of the exploration rovers currently on Mars.

Use of Reference Frames for Interplanetary Navigation at JPL

NASA Technical Reports Server (NTRS)

Heflin, Michael; Jacobs, Chris; Sovers, Ojars; Moore, Angelyn; Owen, Sue

2010-01-01

Navigation of interplanetary spacecraft is typically based on range, Doppler, and differential interferometric measurements made by ground-based telescopes. Acquisition and interpretation of these observations requires accurate knowledge of the terrestrial reference frame and its orientation with respect to the celestial frame. Work is underway at JPL to reprocess historical VLBI and GPS data to improve realizations of the terrestrial and celestial frames. Improvements include minimal constraint alignment, improved tropospheric modeling, better orbit determination, and corrections for antenna phase center patterns.

Proceedings of the Symposium on Military Space Communications and Operations Held at USAF Academy, Colorado on 2-4 August 1983

DTIC Science & Technology

1983-08-04

IS CURRERTLY OFF; TRANSMITSTHE COM TO TURHE AN N; WAITS FO Procedures are valuable because they provide hCGMDTOTR PROPTION AN POCSSI OELAS...legal and Other Celestial Bodies ,!/ was a regime which has been created by brilliant accomplishment of the world international treaties. These legal...difficulty posed by some controversial provisions in the Agreement Governing the Activities of States on the Moon and Other Celestial Bodies and the

Thirty Years After Jack Eddy at the Big Horn Medicine Wheel

NASA Astrophysics Data System (ADS)

Merriot, Ivy

2017-01-01

In the thirty years since John (Jack) Eddy’s work on the Big Horn Medicine Wheel, attention to the astronomy of medicine wheels went from high to low, with the lowest moment occurring during the ”welcome” talk of the Oxford IX International Archaeoastronomy (ISAAC) conference in Lima, Peru in 2011 when the wall-size projected image of the Big Horn Wheel carried a thick black “X” across its face. The alignments proposed by Eddy in 1974 and by Robinson in the 1980s have been reviewed and analyzed at the Wheel on Medicine Mountain in situ under bitter cold, clear dark nights at 10,000 feet altitude. Research was conducted using naked eye skywatching, transit surveying, and a Meade Cassegraine 8” electronic telescope. Along with this “review” of 20th century research, new research was conducted Wheel causing the second decade of the 21st century to bring new physical evidence and historical information for consideration.New research at the Big Horn Medicine Wheel gives evidence that the Wheel “mirrors” the night and daytime sky by creating a sky “grid” by its design made of basement and surface stones. The Wheel’s stone design mirrors the precession of the equinoxes by showing positions of all major pole stars over the full precessional cycle. Its twenty-eight sections are useful in the same way the twenty-eight sectioned Stations of the Moon star charts were useful in ancient and historical times. This manner of dividing the sky for tracking celestial objects holds celestial markers in constant position over millennia. This occurs because the Wheel’s center represents the Sun’ ecliptic north pole. Star charts that use the ecliptic pole do not need constant mathematical computation to keep up with current declinations and right ascensions. The Wheel’s twenty-eight sectioned sky chart keeps the same Dec and RA for celestial positions for thousands of years and will more quickly alert the observer to changes due to proper motion than will our current Polaris-dependant Dec-RA system in use.

NASA's Great Observatories Celebrate the International Year of Astronomy

NASA Technical Reports Server (NTRS)

2009-01-01

[figure removed for brevity, see original site] Click on the image for larger version

In 1609, Galileo improved the newly invented telescope, turned it toward the heavens, and revolutionized our view of the universe. In celebration of the 400th anniversary of this milestone, 2009 has been designated as the International Year of Astronomy.

Today, NASA's Great Observatories are continuing Galileo's legacy with stunning images and breakthrough science from the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory.

While Galileo observed the sky using visible light seen by the human eye, technology now allows us to observe in many wavelengths, including Spitzer's infrared view and Chandra's view in X-rays. Each wavelength region shows different aspects of celestial objects and often reveals new objects that could not otherwise be studied.

This image of the spiral galaxy Messier 101 is a composite of views from Spitzer, Hubble, and Chandra. The red color shows Spitzer's view in infrared light. It highlights the heat emitted by dust lanes in the galaxy where stars can form. The yellow color is Hubble's view in visible light. Most of this light comes from stars, and they trace the same spiral structure as the dust lanes. The blue color shows Chandra's view in X-ray light. Sources of X-rays include million-degree gas, exploded stars, and material colliding around black holes.

Such composite images allow astronomers to see how features seen in one wavelength match up with those seen in another wavelength. It's like seeing with a camera, night vision goggles, and X-ray vision all at once.

In the four centuries since Galileo, astronomy has changed dramatically. Yet our curiosity and quest for knowledge remain the same. So, too, does our wonder at the splendor of the universe.

The International Year of Astronomy Great Observatories Image Unveiling is supported by the NASA Science Mission Directorate Astrophysics Division. The project is a collaboration between the Space Telescope Science Institute, the Spitzer Science Center, and the Chandra X-ray Center.

The Russian-Ukrainian Observatories Network for the European Astronomical Observatory Route Project

NASA Astrophysics Data System (ADS)

Andrievsky, S. M.; Bondar, N. I.; Karetnikov, V. G.; Kazantseva, L. V.; Nefedyev, Y. A.; Pinigin, G. I.; Pozhalova, Zh. A.; Rostopchina-Shakhovskay, A. N.; Stepanov, A. V.; Tolbin, S. V.

2011-09-01

In 2004,the Center of UNESCO World Heritage has announced a new initiative "Astronomy & World Heritage" directed for search and preserving of objects,referred to astronomy,its history in a global value,historical and cultural properties. There were defined a strategy of thematic programme "Initiative" and general criteria for selecting of ancient astronomical objects and observatories. In particular, properties that are situated or have significance in relation to celestial objects or astronomical events; representations of sky and/or celestial bodies and astronomical events; observatories and instruments; properties closely connected with the history of astronomy. In 2005-2006,in accordance with the program "Initiative", information about outstanding properties connected with astronomy have been collected.In Ukraine such work was organized by astronomical expert group in Nikolaev Astronomical Observatory. In 2007, Nikolaev observatory was included to the Tentative List of UNESCO under # 5116. Later, in 2008, the network of four astronomical observatories of Ukraine in Kiev,Crimea, Nikolaev and Odessa,considering their high authenticities and integrities,was included to the Tentative List of UNESCO under # 5267 "Astronomical Observatories of Ukraine". In 2008-2009, a new project "Thematic Study" was opened as a successor of "Initiative". It includes all fields of astronomical heritage from earlier prehistory to the Space astronomy (14 themes in total). We present the Ukraine-Russian Observatories network for the "European astronomical observatory Route project". From Russia two observatories are presented: Kazan Observatory and Pulkovo Observatory in the theme "Astronomy from the Renaissance to the mid-twentieth century".The description of astronomical observatories of Ukraine is given in accordance with the project "Thematic study"; the theme "Astronomy from the Renaissance to the mid-twentieth century" - astronomical observatories in Kiev,Nikolaev and Odessa; the theme "Contemporary Astronomy" - Crimean Astrophysical Observatory. Also on the basis of collaboration between Ukraine and Russia the Russian-Ukrainian network of astronomical observatories was organized. The participation in Paris conference, on September 20-22, will be a good opportunity to present and to discuss some questions of selection, protection and preparation of Russian-Ukrainian -network to the List of UNESCO within the topic of the Project "Route of European astronomical observatories ".

Astrometry of Solar System Objects with Gaia

NASA Astrophysics Data System (ADS)

Hestroffer, Daniel J.; Arenou, Frederic; Desmars, Josselin; Robert, Vincent; Thuillot, William; Arlot, Jean-Eudes; Carry, Benoit; David, Pedro; Eggl, Siegfried; Fabricius, Claus; Kudryashova, Maria; Lainey, Valery; Spoto, Federica; Tanga, Paolo; Gaia DPAC

2016-10-01

The Gaia ESA space mission will provide astrometric observations of a large number of celestial bodies, with unprecedented accuracy, and in an homogenous reference frame (to become the optical ICRF). The Gaia satellite is monitoring regularly the whole celestial sphere, with one complete scan in about 6month, down to approximately magnitude V≤20.7. It will provide after its nominal lifetime, (5 years, 2014-2019) about 70 astrometric points for several hundred thousands of solar system objects, asteroids from the Near-Earth region to Centaurs and bright TNOs, as well as planetary satellites and comets. The highly precise astrometric and photometric data is bound to lead to huge advances in the science of small Small Solar System Bodies (e.g. Tanga et al. 2016 P\\&SS, Hestroffer et al. 2014 COSPAR #40 ; Mignard et al. 2007 EMP).The first Gaia data release (GDR#1) is foreseen for Q3-2016 and will provide highly precise positions of selected stars down to mag V≈20. While solar system objets data is foreseen for the next data release (in 2017), science of Solar System will also highly benefit from the Gaia stellar catalogue. We will present the status of the satellite and Gaia mission, and details on the stellar data that will be published in this GDR#1. We discuss the catalogue content, number of stars, parameters and precisions, and the process of cross-matching and validation. We also touch upon the construction of combined Tycho-Gaia TGAS catalogue.A Gaia data daily processing is devoted to the identification of Solar System Objects. During this process the detection of new (or critical) objects arises and leads to the triggering of scientific alerts to be found on the web gaiafunsso.imcce.fr. We have also set up an international follow-up network called Gaia-FUN-SSO to validate the detection in space. For this goal, in case of detection the observational data must be sent to the MPC by the observers. Besides, Gaia should benefit for the classical astrometric reduction, for future as well as for past observations, which is part of the NAROO project (Robert et al. 2015 A&A). We will also touch upon the next releases steps, and the SSO data from Gaia observations that will be published.

Expected Improvements in VLBI Measurements of the Earth's Orientation

NASA Technical Reports Server (NTRS)

Ma, Chopo

2003-01-01

Measurements of the Earth s orientation since the 1970s using space geodetic techniques have provided a continually expanding and improving data set for studies of the Earth s structure and the distribution of mass and angular momentum. The accuracy of current one-day measurements is better than 100 microarcsec for the motion of the pole with respect to the celestial and terrestrial reference frames and better than 3 microsec for the rotation around the pole. VLBI uniquely provides the three Earth orientation parameters (nutation and UTI) that relate the Earth to the extragalactic celestial reference frame. The accuracy and resolution of the VLBI Earth orientation time series can be expected to improve substantially in the near future because of refinements in the realization of the celestial reference frame, improved modeling of the troposphere and non-linear station motions, larger observing networks, optimized scheduling, deployment of disk-based Mark V recorders, full use of Mark IV capabilities, and e-VLBI. More radical future technical developments will be discussed.

Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

NASA Astrophysics Data System (ADS)

Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

2016-01-01

High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

On the Origin of the Spin of Planets and Stars and its Connection with Gravitomagnetism

NASA Astrophysics Data System (ADS)

Elbeze, Alexandre Chaloum

2012-06-01

The origin of the spin of planets and stars is, to a certain extent, still unexplained. In general, we attribute their rotation to the swirl of their constituent primitive gases. In this paper, we try to show that the rotation of celestial bodies depends only on their mass, apparent radius and tilt of their spin axes. We reach this conclusion within the framework of gravitomagnetism, implied by the Einstein's general relativity theory (GR). Our results show that it might possible, in principle, to calculate the mass of spinning objects by measuring their apparent radius, the speed of rotation and the tilt of the axis of rotation.

Reevaluation of lunar and Martian spectra in the mid-IR region.

PubMed

Plendl, J N; Plendl, H S

1982-12-15

A reference point method has been developed to correct infrared spectra from the moon and other celestial objects for selective absorption in the earth's atmosphere. The method is applied to lunar spectra that were obtained 2.3 km above sea level within the two atmospheric IR windows. The results indicate that SiO(2) and Al(2)O(3) are major mineral constituents in the four large surface areas analyzed in agreement with the localized probings at spacecraft landing sites. In addition, IR spectra from Martian dust clouds that were observed from the Mariner 9 spacecraft are examined. The principal sources of radiation in this case appear to be Al(2)O(3) and sulfur.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

The fairing for Deep Space 1 nears the top of the Mobile Service Tower before being attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

NASA's Deep Space 1 spacecraft waits in the Payload Hazardous Servicing Facility for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1150

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility (PHSF) attach a solar panel to Deep Space 1. The payload is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1050

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1051

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1073

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- Workers watch as the fairing for Deep Space 1 is lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1074

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- The fairing for Deep Space 1 nears the top of the Mobile Service Tower before being attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1072

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- The fairing for Deep Space 1 is raised upright before being lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc933

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers ready NASA’s Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc931

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- NASA’s Deep Space 1 spacecraft waits in the Payload Hazardous Servicing Facility for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc934

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers ready NASA’s Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1049

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

HIFOGS: Its design, operations and calibration

NASA Astrophysics Data System (ADS)

Witteborn, Fred C.; Cohen, Martin; Bregman, Jesse D.; Heere, Karen R.; Greene, Thomas P.; Wooden, Diane H.

The High-efficiency, Infrared Faint Object Grating Spectrometer (HIFOGS) provides spectral coverage of selectable portions of the 3 to 18 micron range at resolving powers from 00 to 1000 using 120 Si/Bi detectors. Additional coverage to 30 microns is provided by a bank of 32 Si:P detectors. Selectable apertures, gratings and band-pass filters provide flexibility to this system. Software for operation of HIFOGS and reduction of the data runs on a MacIntosh computer. HIFOGS has been used to establish celestial flux standards using 3 independent approaches: comparison to star models, comparisons to asteroid models and comparisons to laboratory blackbodies. These standards are expected to have wide application in astronomical thermal-infrared spectroscopy.

Two odometers in honeybees?

PubMed

Dacke, M; Srinivasan, M V

2008-10-01

Although several studies have examined how honeybees gauge and report the distance and direction of a food source to their nestmates, relatively little is known about how this information is combined to obtain a representation of the position of the food source. In this study we manipulate the amount of celestial compass information available to the bee during flight, and analyse the encoding of spatial information in the waggle dance as well as in the navigation of the foraging bee. We find that the waggle dance encodes information about the total distance flown to the food source, even when celestial compass cues are available only for a part of the journey. This stands in contrast to how a bee gauges distance flown when it navigates back to a food source that it already knows. When bees were trained to find a feeder placed at a fixed distance in a tunnel in which celestial cues were partially occluded and then tested in a tunnel that was fully open to the sky, they searched for the feeder at a distance that corresponds closely to the distance that was flown under the open sky during the training. Thus, when navigating back to a food source, information about distance travelled is disregarded when there is no concurrent input from the celestial compass. We suggest that bees may possess two different odometers - a 'community' odometer that is used to provide information to nestmates via the dance, and a 'personal' odometer that is used by an experienced individual to return to a previously visited source.

Radio Telescopes' Precise Measurements Yield Rich Scientific Payoffs

NASA Astrophysics Data System (ADS)

2008-01-01

Having the sharpest pictures always is a big advantage, and a sophisticated radio-astronomy technique using continent-wide and even intercontinental arrays of telescopes is yielding extremely valuable scientific results in a wide range of specialties. That's the message delivered to the American Astronomical Society's meeting in Austin, Texas, by Mark Reid of the Harvard-Smithsonian Center for Astrophysics, a leading researcher in the field of ultra-precise astronomical position measurements. Very Long Baseline Interferometry provides extremely high precision that can extend use of the parallax technique to many more celestial objects. Parallax is a direct means of measuring cosmic distances by detecting the slight shift in an object’s apparent position in the sky caused by Earth’s orbital motion. Credit: Bill Saxton, NRAO/AUI/NSF "Using radio telescopes, we are measuring distances and motions of celestial bodies with unprecedented accuracy. That's helping us better understand many processes ranging from star formation to the scale of the entire Universe," Reid said. The observing technique, called Very Long Baseline Interferometry (VLBI), was pioneered in 1967, but has come into continuous use only in the past 10-15 years. The National Science Foundation's Very Long Baseline Array (VLBA), a system of 10 radio-telescope antennas ranging from Hawaii to the Caribbean, was dedicated in 1993. There are other VLBI systems in Europe and Asia, and large radio telescopes around the world cooperate regularly to increase sensitivity. VLBI observations routinely produce images hundreds of times more detailed than those made at visible-light wavelengths by the Hubble Space Telescope. Several groups of researchers from across the globe use the VLBA to study stellar nurseries in our own Milky Way Galaxy and measure distances to regions where new stars are forming. The key has been to improve measurement accuracy to a factor of a hundred times better than that produced by the highly successful Hipparcos satellite. Using small clouds of gas in star-forming regions that strongly amplify radio waves, called cosmic masers, the astronomers measured the tiny shift in the object's position in the sky caused by the Earth's orbit around the sun. This, in turn, yielded highly-accurate distances by the simple surveying technique of triangulation, the "gold standard" of distance measuring techniques available to astronomers. Dr. Mark Reid Dr. Mark Reid Credit: CfA Click image for high-resolution file (1.02 MB) "Knowing the distance accurately means we also know the luminosities, masses and ages of the young stars much more accurately, and that is vital to understanding how star formation works," Reid said. In addition, he pointed out, the VLBA observations have shown the motions of the young stars in the Milky Way are much more complicated than simple circular motion. Massive young stars appear to be born orbiting the Milky Way considerably slower than older stars. "This might be explained by the interaction of giant molecular clouds, the ultimate sites of massive star formation, as they "surf" spiral density waves in the Milky Way." An international team of scientists led by Reid has used VLBI to detect the slight change in apparent position of the object at the Milky Way's center caused by our Solar System's orbit around that center. "It takes our Solar System more than 200 million years to circle the center of our Galaxy, and yet we can detect that motion in only a couple weeks with the VLBA -- truly astounding!" Reid said. The VLBA studies of the Galactic Center have shown that an object called Sagittarius A* is at the exact gravitational center of our Galaxy. That means, the scientists say, that the object must be incredibly massive. "The VLBA measurements, combined with infrared observations of stellar orbits around this object, provide overwhelming evidence that it's a supermassive black hole," Reid explained. "These observations are also going to make it possible to re-define the coordinate system used to map the entire Galaxy," Reid added. Looking farther outward, astronomers achieved a longstanding goal of measuring the spin of another galaxy. In 2005, Reid and his colleagues measured both the rotational spin and the motion in space of the galaxy M33, nearly 2.4 million light-years from Earth. Astronomers in the 1920s had attempted such a feat, but their results were not accurate enough. "This achievement had to wait for the VLBA," Reid said. This and subsequent work has put strong limits on the amount of unseen "dark matter" around the giant Andromeda galaxy, which M33 orbits. A continuing goal is to use VLBI observations to measure the orbits of these and other galaxies within the Local Group of galaxies to which our own Milky Way belongs. VLBA The Very Long Baseline Array (VLBA), the National Radio Astronomy Observatory’s continent-wide radio-telescope system. The VLBA provides the greatest resolving power, or ability to see detail, of any instrument in astronomy. Credit: NRAO/AUI/NSF In 1999, astronomers set a new standard for a distance measurement outside the Local Group of galaxies when they used the VLBA to make a direct geometric distance measurement to a galaxy called NGC 4258, 23.5 million light-years from Earth. That measurement, accurate to within 7 percent, caused other scientists to revise their indirect-measurement techniques for the rest of the Universe. The NGC 4258 distance was calculated by measuring the motion of masers in a disk of gas containing water molecules and orbiting a supermassive black hole at the galaxy's center. "Now, other galaxies are being observed in hopes of extending direct distance measurement even farther out in the Universe," Reid said. "One candidate, called UGC 3789, at a distance of about 160 million light-years, will be measured with about 10 percent accuracy. Our goal is to further improve these measurements and to measure 5 to 10 other galaxies in order to determine the Hubble constant (the expansion rate of the Universe) to 3 percent accuracy. This would put limits on key parameters of the dark energy that apparently is accelerating the expansion of the Universe," Reid added. The kind of accurate measurement of distances and motions that VLBI observations provide can benefit numerous other areas of astronomy, Reid pointed out. For example, the distances to pulsars have been measured directly with the VLBA, yielding better understanding of their characteristics. The technique also could reveal planets circling some nearby stars. "Anytime you can do something as dramatic as improving measurement accuracy by a hundredfold, you're bound to get a great scientific payoff," Reid said. "We're looking forward to exciting new results in the coming years," he added. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Very Large Array Retooling for 21st-Century Science

NASA Astrophysics Data System (ADS)

2008-02-01

An international project to make the world's most productive ground-based telescope 10 times more capable has reached its halfway mark and is on schedule to provide astronomers with an extremely powerful new tool for exploring the Universe. The National Science Foundation's Very Large Array (VLA) radio telescope now has half of its giant, 230-ton dish antennas converted to use new, state-of-the-art digital electronics to replace analog equipment that has served since the facility's construction during the 1970s. VLA and Radio Galaxy VLA Antennas Getting Modern Electronics To Meet New Scientific Challenges CREDIT: NRAO/AUI/NSF Click on image for more information, higher-resolution files "We're taking a facility that has made landmark discoveries in astronomy for three decades and making it 10 times more powerful, at a cost that's a fraction of its total value, by replacing outdated technology with modern equipment," said Mark McKinnon, project manager for the Expanded VLA (EVLA). Rick Perley, EVLA project scientist, added: "When completed in 2012, the EVLA will be 10 times more sensitive, cover more frequencies, and provide far greater analysis capabilities than the current VLA. In addition, it will be much simpler to use, making its power available to a wider range of scientists." The EVLA will give scientists new power and flexibility to meet the numerous challenges of 21st-Century astrophysics. The increased sensitivity will reveal the earliest epochs of galaxy formation, back to within a billion years of the Big Bang, or 93 percent of the look-back time to the beginning of the Universe. It will have the resolution to peer deep into the dustiest star-forming clouds, imaging protoplanetary disks around young stars on scales approaching that of the formation of terrestrial planets. The EVLA will provide unique capabilities to study magnetic fields in the Universe, to image regions near massive black holes, and to systematically track changes in transient objects such as supernovae and fast-moving jets from massive, compact objects such as neutron stars and black holes. Authorized by Congress in 1972, the VLA was constructed during the 1970s and dedicated in 1980. Astronomers began using it for research even before its completion. To date, nearly 2,500 scientists from around the world have used the VLA for more than 13,000 observing projects. More than 200 Ph.D dissertations have been based on data obtained from VLA observations. The VLA's discoveries have ranged from finding water ice on Mercury, the closest planet to the Sun, to revealing details of the complex region surrounding the black hole at the core of our own Milky Way Galaxy, to providing surprising evidence that a distant galaxy had already formed and produced stars prolifically less than a billion years after the Big Bang. Half, or fourteen, of the VLA's inventory of 28, 25-meter-diameter dish antennas now have been converted to the new, digital configuration. The antennas collect faint radio waves emitted by celestial objects. Data from all the antennas are brought to a central, special-purpose computing machine, called a correlator, to be combined into a form that allows scientists to produce detailed, high-quality images of the astronomical objects under investigation. This entire system for collecting, transmitting and analyzing the cosmic radio signals is being replaced for the EVLA. New, more sensitive radio receivers will cover the entire frequency range of 1-50 GHz. A 1970s-era waveguide system gives way to a modern, fiber-optic system that dramatically increases the amount of data that can be delivered from the antenna to the correlator. Finally, a new, state-of-the-art correlator - a special-purpose supercomputer - is being built by Canadian scientists and engineers. This correlator will easily handle the increased data flow, offers much greater observing flexibility, and provides vastly expanded capabilities for analyzing the data to gain scientific insight about the astronomical objects. "We're leapfrogging several generations of technological progress to make the EVLA a completely modern, 21st-Century scientific facility," said Fred K.Y. Lo, NRAO Director. Construction work on the EVLA began in 2001. The project costs 93.75 million in U.S. dollars - 58.7 million in new direct funding from the National Science Foundation, 1.75 million from Mexico, 17 million from Canada in the form of the new correlator, and 16.3 million in the form of labor from existing staff at the NRAO. The current value of the VLA infrastructure on which the EVLA is being built is estimated at 300 million. "The EVLA project is giving us 10 times the VLA's capability at one-third the cost of the current facility," McKinnon pointed out. To provide the improved scientific capabilities, the EVLA will boast some impressive technical feats. For example, the fiber-optic data transmission system will carry as much information instantaneously as the entire current U.S. internet. The EVLA receiving system will be so sensitive that it could detect the weak radio transmission from a cell phone at the distance of Jupiter - half a billion miles away. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

On the asteroid hazard

NASA Astrophysics Data System (ADS)

Eneev, T. M.; Akhmetshin, R. Z.; Efimov, G. B.

2012-04-01

The concept of "space patrol" is considered, aimed at discovering and cataloging the majority of celestial bodies that constitute a menace for the Earth [1, 2]. The scheme of "optical barrier" formed by telescopes of the space patrol is analyzed, requirements to the observation system are formulated, and some schemes of sighting the optical barrier region are suggested (for reliable detection of the celestial bodies approaching the Earth and for determination of their orbits). A comparison is made of capabilities of electro-jet engines and traditional chemical engines for arrangement of patrol spacecraft constellation in the Earth's orbit.

On a celestial occurrence recorded in the hagiography of St. Vladimir

NASA Astrophysics Data System (ADS)

Banjević, Boris

2002-04-01

There were recorded a number of celestial occurrences in Serbian early history. Amongst them are a few appearances of comets. One except from Bible bearing on life of king David, relating to a phenomenon that might be interpreted as a comet, is in some way similar to the quotation from the hagiography of St. Vladimir. There is possibility that Halley's comet was observed at some time. This affects the chronology of the reign of St. Vladimir by about 11 years. This author thinks that it was in the summer 989 AD.

Comparison of Measured Galactic Background Radiation at L-Band with Model

NASA Technical Reports Server (NTRS)

LeVine, David M.; Abraham, Saji; Kerr, Yann H.; Wilson, William J.; Skou, Niels; Sobjaerg, Sten

2004-01-01

Radiation from the celestial sky in the spectral window at 1.413 GHz is strong and an accurate accounting of this background radiation is needed for calibration and retrieval algorithms. Modern radio astronomy measurements in this window have been converted into a brightness temperature map of the celestial sky at L-band suitable for such applications. This paper presents a comparison of the background predicted by this map with the measurements of several modern L-band remote sensing radiometer Keywords-Galactic background, microwave radiometry; remote sensing;

The Southern Hemisphere VLBI experiment

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

Preston, R.A.; Meier, D.L.; Louie, A.P.

1989-07-01

Six radio telescopes were operated as the first Southern Hemisphere VLBI array in April and May 1982. Observations were made at 2.3 and 8.4 GHz. This array provided VLBI modeling and hybrid imaging of celestial radio sources in the Southern Hemisphere, high-accuracy VLBI geodesy between Southern Hemisphere sites, and subarcsecond radio astrometry of celestial sources south of declination -45 deg. The goals and implementation of the array are discussed, the methods of modeling and hybrid image production are explained, and the VLBI structure of the sources that were observed is summarized. 36 refs.

General Methodology for Designing Spacecraft Trajectories

NASA Technical Reports Server (NTRS)

Condon, Gerald; Ocampo, Cesar; Mathur, Ravishankar; Morcos, Fady; Senent, Juan; Williams, Jacob; Davis, Elizabeth C.

2012-01-01

A methodology for designing spacecraft trajectories in any gravitational environment within the solar system has been developed. The methodology facilitates modeling and optimization for problems ranging from that of a single spacecraft orbiting a single celestial body to that of a mission involving multiple spacecraft and multiple propulsion systems operating in gravitational fields of multiple celestial bodies. The methodology consolidates almost all spacecraft trajectory design and optimization problems into a single conceptual framework requiring solution of either a system of nonlinear equations or a parameter-optimization problem with equality and/or inequality constraints.

Celestial Mechanics: from the bases of the past to the challenges of the future

NASA Astrophysics Data System (ADS)

de Melo, C. F.; Prado, A. F. B. A.; Macau, E. E. N.; Winter, O. C.; Gomes, V. M.

2015-10-01

This special issue of Journal of Physics: Conference Series brings a set of 31 papers presented in the Brazilian Colloquium on Orbital Dynamics (CBDO), held on December 1 - 5, 2014, in the city of Águas de Lindoia, Brazil. CBDO is a traditional and important scientific meeting in the areas of Theoretical and Applied Celestial Mechanics. The meeting takes place every two years, when researchers from South America and also guests from other continents present their works and discuss the paths trodden by the space sciences.

Space Telescope Systems Description Handbook

NASA Technical Reports Server (NTRS)

Carter, R. E.

1985-01-01

The objective of the Space Telescope Project is to orbit a high quality optical 2.4-meter telescope system by the Space Shuttle for use by the astronomical community in conjunction with NASA. The scientific objectives of the Space Telescope are to determine the constitution, physical characteristics, and dynamics of celestial bodies; the nature of processes which occur in the extreme physical conditions existing in stellar objects; the history and evolution of the universe; and whether the laws of nature are universal in the space-time continuum. Like ground-based telescopes, the Space Telescope was designed as a general-purpose instrument, capable of utilizing a wide variety of scientific instruments at its focal plane. This multi-purpose characteristic will allow the Space Telescope to be effectively used as a national facility, capable of supporting the astronomical needs for an international user community and hence making contributions to man's needs. By using the Space Shuttle to provide scientific instrument upgrading and subsystems maintenance, the useful and effective operational lifetime of the Space Telescope will be extended to a decade or more.

A celestial gamma-ray foreground due to the albedo of small solar system bodies and a remote probe of the interstellar cosmic ray spectrum

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

Moskalenko, Igor V.; Porter, Troy A.; Digel, Seth W.

2007-12-17

We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and Kuiper Belt strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. If detected, the {gamma}-ray emission by the Mainmore » Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic, especially near the Galactic center and for signals at high Galactic latitudes, such as the extragalactic {gamma}-ray emission. Additionally, it can be used to probe the spectrum of CR nuclei at close-to-interstellar conditions, and the mass spectrum of small bodies in the Main Belt and Kuiper Belt. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center.« less

Stonehenge: A Simple and Accurate Predictor of Lunar Eclipses

NASA Astrophysics Data System (ADS)

Challener, S.

1999-12-01

Over the last century, much has been written about the astronomical significance of Stonehenge. The rage peaked in the mid to late 1960s when new computer technology enabled astronomers to make the first complete search for celestial alignments. Because there are hundreds of rocks or holes at Stonehenge and dozens of bright objects in the sky, the quest was fraught with obvious statistical problems. A storm of controversy followed and the subject nearly vanished from print. Only a handful of these alignments remain compelling. Today, few astronomers and still fewer archaeologists would argue that Stonehenge served primarily as an observatory. Instead, Stonehenge probably served as a sacred meeting place, which was consecrated by certain celestial events. These would include the sun's risings and settings at the solstices and possibly some lunar risings as well. I suggest that Stonehenge was also used to predict lunar eclipses. While Hawkins and Hoyle also suggested that Stonehenge was used in this way, their methods are complex and they make use of only early, minor, or outlying areas of Stonehenge. In contrast, I suggest a way that makes use of the imposing, central region of Stonehenge; the area built during the final phase of activity. To predict every lunar eclipse without predicting eclipses that do not occur, I use the less familiar lunar cycle of 47 lunar months. By moving markers about the Sarsen Circle, the Bluestone Circle, and the Bluestone Horseshoe, all umbral lunar eclipses can be predicted accurately.

The Green Bank North Celestial Cap Pulsar Survey. III. 45 New Pulsar Timing Solutions

NASA Astrophysics Data System (ADS)

Lynch, Ryan S.; Swiggum, Joseph K.; Kondratiev, Vlad I.; Kaplan, David L.; Stovall, Kevin; Fonseca, Emmanuel; Roberts, Mallory S. E.; Levin, Lina; DeCesar, Megan E.; Cui, Bingyi; Cenko, S. Bradley; Gatkine, Pradip; Archibald, Anne M.; Banaszak, Shawn; Biwer, Christopher M.; Boyles, Jason; Chawla, Pragya; Dartez, Louis P.; Day, David; Ford, Anthony J.; Flanigan, Joseph; Hessels, Jason W. T.; Hinojosa, Jesus; Jenet, Fredrick A.; Karako-Argaman, Chen; Kaspi, Victoria M.; Leake, Sean; Lunsford, Grady; Martinez, José G.; Mata, Alberto; McLaughlin, Maura A.; Noori, Hind Al; Ransom, Scott M.; Rohr, Matthew D.; Siemens, Xavier; Spiewak, Renée; Stairs, Ingrid H.; van Leeuwen, Joeri; Walker, Arielle N.; Wells, Bradley L.

2018-06-01

We provide timing solutions for 45 radio pulsars discovered by the Robert C. Byrd Green Bank Telescope. These pulsars were found in the Green Bank North Celestial Cap pulsar survey, an all-GBT-sky survey being carried out at a frequency of 350 {MHz}. We include pulsar timing data from the Green Bank Telescope and Low Frequency Array. Our sample includes five fully recycled millisecond pulsars (MSPs, three of which are in a binary system), a new relativistic double neutron star system, an intermediate-mass binary pulsar, a mode-changing pulsar, a 138 ms pulsar with a very low magnetic field, and several nulling pulsars. We have measured two post-Keplerian parameters and thus the masses of both objects in the double neutron star system. We also report a tentative companion mass measurement via Shapiro delay in a binary MSP. Two of the MSPs can be timed with high precision and have been included in pulsar timing arrays being used to search for low-frequency gravitational waves, while a third MSP is a member of the black widow class of binaries. Proper motion is measurable in five pulsars, and we provide an estimate of their space velocity. We report on an optical counterpart to a new black widow system and provide constraints on the optical counterparts to other binary MSPs. We also present a preliminary analysis of nulling pulsars in our sample. These results demonstrate the scientific return of long timing campaigns on pulsars of all types.

HIPPARCOS satellite: Aeritalia involvement and system test activities and results

NASA Astrophysics Data System (ADS)

Strim, B.; Cugno, W.; Morsillo, G.

In 1989 the European Space Agency is scheduled to launch HIPPARCOS on a 2.5-year mission that will revolutionize the state of astronomy. This is the first satellite to be dedicated to astrometry, a branch of astronomy that deals with the position of celestial objects and their motion in space. With an accuracy impossible to achieve from Earth, HIPPARCOS will make position, trigonometric parallax and proper motion measurements of some 100.000 pre-selected stars. The data will be used to calculate each star's distance and motion, providing astronomers with an unprecedented map of the heavens. In the end, the HIPPARCOS mission is expected to reveal surprisingly new insight into theories of stellar evolution, as well as into the nature of our galaxy and the universe. The program has been awarded to the MESH industrial consortium for definition, development and production. The French firm MATRA (prime contractor) and the AERITALIA SPACE SYSTEMS GROUP (major co-contractor) share program responsibility. AERITALIA is in charge of the spacecraft or "service module". This is the structural platform for the telescope payload and provides all subsystem services including thermal control, data handling, telecommunications, electrical power distribution, power generation, attitude and orbit control, and apogee kick motor. AERITALIA is responsible for the procurement of all spacecraft subsystems for which it directs the activities of a multinational team of subcontractors. In addition, it is in charge of the satellite's final assembly, integration and testing, as well as for the procurement of all ground support equipment for satellite testing. HIPPARCOS stands for HIgh Precision PARallax COllecting Satellite. Its name is also intended to honor the Greek astronomer Hipparchus (190-120 BC) who compiled the first star catalog and who first used trigonometric parallax to calculate the distance to the moon. (Parallax is the apparent shift in a celestial body's position in the sky when observed from two different points, for example, from two different points in the Earth's orbit around the sun. Distance can be calculated using parallax measurements). The satellite payload is a Schmidt reflecting telescope with two openings 58 degrees apart. The design allows stars in two different parts of the sky to be observed at the same time. Internally, the two fields of view are combined and the angular separation between pairs of stars - one star from each field of view - is recorded. Over the 2.5-year life of the HIPPARCOS mission, millions of such measurements between star pairs as faint as magnitude 13 will be made covering the entire celestial sphere. The data will be compiled into the HIPPARCOS catalog. The accuracy of these measurements for most of the stars is expected to be within 0.002 arcsec, an improvement of about a factor of 20 over ground-based observations. A second experiment, called TYCHO, will collect position and photometric data on about 400.000 stars. Although less accurate than the main experiment, TYCHO will provide astronomers with a reference catalog for a large number of stars. Both the HIPPARCOS and TYCHO star catalogs are expected to be available to the worldwide astronomical community by around 1994. The launch weight of HIPPORCOS is 1.140 kg. It will be put into geostationary orbit by an Ariane rocket. Purpose of the present paper is to put the spotlight on the system tests performed on the Satellite Structural Thermal Model STM, the Engineering Model EM and to summarize the main results so far obtained. A description of the System and Spacecraft design to better understand the mission and system requirements is also presented.

Using machine learning techniques to automate sky survey catalog generation

NASA Technical Reports Server (NTRS)

Fayyad, Usama M.; Roden, J. C.; Doyle, R. J.; Weir, Nicholas; Djorgovski, S. G.

1993-01-01

We describe the application of machine classification techniques to the development of an automated tool for the reduction of a large scientific data set. The 2nd Palomar Observatory Sky Survey provides comprehensive photographic coverage of the northern celestial hemisphere. The photographic plates are being digitized into images containing on the order of 10(exp 7) galaxies and 10(exp 8) stars. Since the size of this data set precludes manual analysis and classification of objects, our approach is to develop a software system which integrates independently developed techniques for image processing and data classification. Image processing routines are applied to identify and measure features of sky objects. Selected features are used to determine the classification of each object. GID3* and O-BTree, two inductive learning techniques, are used to automatically learn classification decision trees from examples. We describe the techniques used, the details of our specific application, and the initial encouraging results which indicate that our approach is well-suited to the problem. The benefits of the approach are increased data reduction throughput, consistency of classification, and the automated derivation of classification rules that will form an objective, examinable basis for classifying sky objects. Furthermore, astronomers will be freed from the tedium of an intensely visual task to pursue more challenging analysis and interpretation problems given automatically cataloged data.

Reconsidering the advantages of the three-dimensional representation of the interferometric transform for imaging with non-coplanar baselines and wide fields of view

NASA Astrophysics Data System (ADS)

Smith, D. M. P.; Young, A.; Davidson, D. B.

2017-07-01

Radio telescopes with baselines that span thousands of kilometres and with fields of view that span tens of degrees have been recently deployed, such as the Low Frequency Array, and are currently being developed, such as the Square Kilometre Array. Additionally, there are proposals for space-based instruments with all-sky imaging capabilities, such as the Orbiting Low Frequency Array. Such telescopes produce observations with three-dimensional visibility distributions and curved image domains. In most work to date, the visibility distribution has been converted to a planar form to compute the brightness map using a two-dimensional Fourier transform. The celestial sphere is faceted in order to counter pixel distortion at wide angles, with each such facet requiring a unique planar form of the visibility distribution. Under the above conditions, the computational and storage complexities of this approach can become excessive. On the other hand, when using the direct Fourier transform approach, which maintains the three-dimensional shapes of the visibility distribution and celestial sphere, the non-coplanar visibility component requires no special attention. Furthermore, as the celestial samples are placed directly on the curved surface of the celestial sphere, pixel distortion at wide angles is avoided. In this paper, a number of examples illustrate that under these conditions (very long baselines and very wide fields of view) the costs of the direct Fourier transform may be comparable to (or even lower than) methods that utilise the two-dimensional fast Fourier transform.

Dynamics of a vertical flight in the stationary gravitational field of a celestial body: Post-newtonian corrections and gravitational redshift

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

Imshennik, V. S., E-mail: imshennik@itep.r

2010-04-15

The standard problem of a radial motion of test particles in the stationary gravitational field of a spherically symmetric celestial body is solved and is used to determine the time features of this motion. The problem is solved for the equations of motion of general relativity (GR), and the time features are obtained in the post-Newtonian approximation, with linear GR corrections proportional to r{sub g}/r and {beta}{sup 2} (in the solution being considered, they are of the same order of smallness) being taken rigorously into account. Total times obtained by integrating the time differentials along the trajectories of motion aremore » considered as the time features in question. It is shown that, for any parameters of the motion, the proper time (which corresponds to watches comoving with a test particle) exceeds the time of watches at rest (watches at the surface of the celestial body being considered). The mass and the radius of the celestial body, as well as the initial velocity of the test particle, serve as arbitrary parameters of the motion. The time difference indicated above implies a leading role of the gravitational redshift, which decreases somewhat because of the opposite effect of the Doppler shift. The results are estimated quantitatively for the important (from the experimental point of view) case of vertical flights of rockets starting from the Earth's surface. In this case, the GR corrections, albeit being extremely small (a few microseconds for several hours of the flight), aremeasurable with atomic (quantum) watches.« less

A New Precession Formula

NASA Astrophysics Data System (ADS)

Fukushima, Toshio

2003-07-01

We adapt J. G. Williams' expression of the precession and nutation using the 3-1-3-1 rotation to an arbitrary inertial frame of reference. The modified formulation avoids a singularity caused by finite pole offsets near the epoch. By adopting the planetary precession formula numerically determined from DE405 and by using a recent theory of the forced nutation of the nonrigid Earth by Shirai & Fukishima, we analyze the celestial pole offsets observed by VLBI for 1979-2000 and determine the best-fit polynomials of the lunisolar precession angles. We then translate the results into classical precession quantities and evaluate the difference due to the difference in the ecliptic definition. The combination of these formulae and the periodic part of the Shirai-Fukishima nutation theory serves as a good approximation of the precession-nutation matrix in the International Celestial Reference Frame. As a by-product, we determine the mean celestial pole offset at J2000.0 as X0=-(17.12+/-0.01) mas and Y0=-(5.06+/-0.02) mas. Also, we estimate the speed of general precession in longitude at J2000.0 as p=5028.7955"+/-0.0003" per Julian century, the mean obliquity at J2000.0 in the inertial sense as (ɛ0)I=84381.40621"+/-0.00001" and in the rotational sense as (ɛ0)R=84381.40955"+/-0.00001", and the dynamical flattening of Earth as Hd=(3.2737804+/-0.0000003)×10-3. Furthermore, we establish a fast way to compute the precession-nutation matrix and provide a best-fit polynomial of an angle to specify the mean Celestial Ephemeris Origin.

ESA is hot on the trail of Geminga

NASA Astrophysics Data System (ADS)

XMM-Newton image of Geminga showing the discovery of the twi hi-res Size hi-res: 68 kb Credits: ESA XMM-Newton image of Geminga showing the discovery of the twin tails This image was captured by the EPIC camera on board the satellite. The motion of Geminga across the sky is indicated, showing that the tails are trailing the neutron star. The scale bar corresponds to a distance of 1.5 million million kilometres at the distance of Geminga. Computer models of the shock wave created by Geminga hi-res Size hi-res: 522 kb Credits: Patrizia Caraveo Computer models of the shockwave created by Geminga Computer models of the shockwave created by Geminga show that the best matches to the data occur if the neutron star is travelling virtually across our line of sight. These correspond to the inclinations of less than 30 degrees. A neutron star measures only 20-30 kilometres across and is the dense remnant of an exploded star. Geminga is one of the closest to Earth, at a distance of about 500 light-years. Most neutron stars emit radio emissions, appearing to pulsate like a lighthouse, but Geminga is 'radio-quiet'. It does, however, emit huge quantities of pulsating gamma rays making it one of the brightest gamma-ray sources in the sky. Geminga is the only example of a successfully identified gamma-ray source from which astronomers have gained significant knowledge. It is 350 000 years old and ploughs through space at 120 kilometres per second. Its route creates a shockwave that compresses the gas of the interstellar medium and its naturally embedded magnetic field by a factor of four. Patrizia Caraveo, Instituto di Astrofisica Spaziale e Fisica Cosmica, Milano, Italy, and her colleagues (at CESR, France, ESO and MPE, Germany) have calculated that the tails are produced because highly energetic electrons become trapped in this enhanced magnetic field. As the electrons spiral inside the magnetic field, they emit the X-rays seen by XMM-Newton. The electrons themselves are created close to the neutron star. Geminga’s breathless rotation rate - once every quarter of a second - creates an extraordinary environment in which electrons and positrons, their antimatter counterparts, can be accelerated to extraordinarily high energies. At such energies, they become powerful high-energy gamma-ray producers. Astronomers had assumed that all the electrons would be converted into gamma rays. However, the discovery of the tails proves that some do find escape routes from the maelstrom. “It is astonishing that such energetic electrons succeed in escaping to create these tails,” says Caraveo, “The tail electrons have an energy very near to the maximum energy achievable in the environment of Geminga.” The tails themselves are the bright edges of the three-dimensional shockwave sculpted by Geminga. Such shockwaves are a bit like the wake of a ship travelling across the ocean. Using a computer model, the team has estimated that Geminga is travelling almost directly across our line of sight. Studies of Geminga could not be more important. The majority of known gamma-ray sources in the Universe have yet to be identified with known classes of celestial objects. Some astronomers believe that a sizeable fraction of them may be Geminga-like radio-quiet neutron stars. Certainly, the family of radio-quiet neutron stars, discovered through their X-ray emission, is continuously growing. Currently, about a dozen objects are known but only Geminga has a pair of tails! Note for editors During the search to track down this elusive celestial object, a co-author on the paper, Giovanni Bignami, named Geminga almost 30 years ago. He was Principal Investigator of XMM-Newton's EPIC camera from 1987 to1997 and is now Director of the Centre d'Etude Spatiale des Rayonnements (CESR). Geminga was first glimpsed as a mysterious source of gamma rays, coming from somewhere in the constellation Gemini by NASA's SAS-2 spacecraft in 1973. While searching to pin down its exact location and nature, Bignami named it Geminga because it was a 'Gemini gamma-ray source'. As an astronomer in Milan, Italy, he was also aware that in his native dialect 'gh'è minga' means 'it is not there', which he found amusing. It was also remarkably apt, for it was not until 1993 that he succeeded in finally 'seeing' and therefore pinpointing Geminga, using optical wavelengths. While it lacked radio emissions, the pulsating X-ray and gamma-ray emissions meant Geminga could only be a new class of radio-quiet neutron star. The original paper was published yesterday, 24 July 2003, on Science Express, a feature of Science Online.

A Long Journey of Mathematics and Astronomy in Romania

NASA Astrophysics Data System (ADS)

Stavinschi, Magda

2010-10-01

Bucharest Astronomical Observatory celebrated recently its centenary. Its founders were all mathematicians or, better said, astronomers specialized in celestial mechanics. Their first doctoral theses were defended at Sorbonne, in the second half of the 19th century, under the guidance of the greatest specialists of the time. After they returned home, they continued what they had begun in Paris, namely celestial mechanics. The instruments they ordered and the first programmes of astronomical observations had an increasingly closer relation to mathematics, as they referred to astrometry and especially to stellar catalogues. Naturally, there were also astrophysical concerns, timid ones in the beginning, and then ever larger, especially beginning with the International Geophysical Year. The evolution of world astronomy, as well as that of Romania, seems to be following but one direction: astrophysics. The truth is that astrometry and celestial mechanics continue to lie at the basis of all astrophysical researches, actually in an entirely new and modern form. The astrometry schools recently organized, the new astrometry textbooks, as well as the IAU working groups dedicated to modern astrometry prove that the long journey of mathematics and astronomy is not over yet.

Numerical analysis of seismic events distributions on the planetary scale and celestial bodies astrometrical parameters

NASA Astrophysics Data System (ADS)

Bulatova, Dr.

2012-04-01

Modern research in the domains of Earth sciences is developing from the descriptions of each individual natural phenomena to the systematic complex research in interdisciplinary areas. For studies of its kind in the form numerical analysis of three-dimensional (3D) systems, the author proposes space-time Technology (STT), based on a Ptolemaic geocentric system, consist of two modules, each with its own coordinate system: (1) - 3D model of a Earth, the coordinates of which provides databases of the Earth's events (here seismic), and (2) - a compact model of the relative motion of celestial bodies in space - time on Earth known as the "Method of a moving source" (MDS), which was developed in MDS (Bulatova, 1998-2000) for the 3D space. Module (2) was developed as a continuation of the geocentric Ptolemaic system of the world, built on the astronomical parameters heavenly bodies. Based on the aggregation data of Space and Earth Sciences, systematization, and cooperative analysis, this is an attempt to establish a cause-effect relationship between the position of celestial bodies (Moon, Sun) and Earth's seismic events.

Anomalous celestial polarization caused by forest fire smoke: why do some insects become visually disoriented under smoky skies?

NASA Astrophysics Data System (ADS)

Hegedüs, Ramón; Åkesson, Susanne; Horváth, Gábor

2007-05-01

The effects of forest fire smoke on sky polarization and animal orientation are practically unknown. Using full-sky imaging polarimetry, we therefore measured the celestial polarization pattern under a smoky sky in Fairbanks, Alaska, during the forest fire season in August 2005. It is quantitatively documented here that the celestial polarization, a sky attribute that is necessary for orientation of many polarization-sensitive animal species, above Fairbanks on 17 August 2005 was in several aspects anomalous due to the forest fire smoke: (i) The pattern of the degree of linear polarization p of the reddish smoky sky differed considerably from that of the corresponding clear blue sky. (ii) Due to the smoke, p of skylight was drastically reduced (pmax≤14%, paverage≤8%). (iii) Depending on wavelength and time, the Arago, Babinet, and Brewster neutral points of sky polarization had anomalous positions. We suggest that the disorientation of certain insects observed by Canadian researchers under smoky skies during the forest fire season in August 2003 in British Columbia was the consequence of the anomalous sky polarization caused by the forest fire smoke.

New Horizons Corrects Its Course in the Kuiper Belt

NASA Image and Video Library

2017-12-11

The New Horizons spacecraft is about 300 million miles (483 million kilometers) from 2014 MU69, the Kuiper Belt object it will encounter on Jan. 1, 2019. https://photojournal.jpl.nasa.gov/catalog/PIA22188

Space Activities for the Visually Impaired

NASA Astrophysics Data System (ADS)

Ries, J. G.; Baguio, M.

2005-12-01

To a visually impaired person celestial objects or concepts of space exploration are likely to be more abstract than to other people, but they encounter news about the universe through their daily life. A partnership between Texas Space Grant Consortium, The University of Texas at Austin, and the Texas School for the Blind and Visually Impaired provided the opportunity to assist visually impaired students increase their understanding of astronomy and space science. The activities helped visually impaired students activity engage in inquiry-based, hands-on astronomy activities. The experiences provided during the educator workshops, adapted instructional classroom activities, and tactile learning aids will be shared in the hopes that others may be able to incorporate these lessons into their regular teaching activities.

Saturn Apollo Program

NASA Image and Video Library

1972-04-27

The Apollo 16 Command Module splashed down in the Pacific Ocean on April 27, 1972 after an 11-day moon exploration mission. The sixth manned lunar landing mission, the Apollo 16 (SA-511), carrying three astronauts: Mission Commander John W. Young, Command Module pilot Thomas K. Mattingly II, and Lunar Module pilot Charles M. Duke, lifted off on April 16, 1972. The Apollo 16 continued the broad-scale geological, geochemical, and geophysical mapping of the Moon’s crust, begun by the Apollo 15, from lunar orbit. This mission marked the first use of the Moon as an astronomical observatory by using the ultraviolet camera/spectrograph which photographed ultraviolet light emitted by Earth and other celestial objects. The Lunar Roving Vehicle, developed by the Marshall Space Flight Center, was also used.

Saturn Apollo Program

NASA Image and Video Library

1972-04-18

This view of the back side of the Moon was captured by the Apollo 16 mission crew. The sixth manned lunar landing mission, the Apollo 16 (SA-511), carrying three astronauts: Mission Commander John W. Young, Command Module pilot Thomas K. Mattingly II, and Lunar Module pilot Charles M. Duke, lifted off on April 16, 1972. The Apollo 16 continued the broad-scale geological, geochemical, and geophysical mapping of the Moon’s crust, begun by the Apollo 15, from lunar orbit. This mission marked the first use of the Moon as an astronomical observatory by using the ultraviolet camera/spectrograph which photographed ultraviolet light emitted by Earth and other celestial objects. The Lunar Roving Vehicle, developed by the Marshall Space Flight Center, was also used. The mission ended on April 27, 1972.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

The fairing for Deep Space 1 is raised upright before being lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Evolutionary models of interstellar chemistry

NASA Technical Reports Server (NTRS)

Prasad, Sheo S.

1987-01-01

The goal of evolutionary models of interstellar chemistry is to understand how interstellar clouds came to be the way they are, how they will change with time, and to place them in an evolutionary sequence with other celestial objects such as stars. An improved Mark II version of an earlier model of chemistry in dynamically evolving clouds is presented. The Mark II model suggests that the conventional elemental C/O ratio less than one can explain the observed abundances of CI and the nondetection of O2 in dense clouds. Coupled chemical-dynamical models seem to have the potential to generate many observable discriminators of the evolutionary tracks. This is exciting, because, in general, purely dynamical models do not yield enough verifiable discriminators of the predicted tracks.

Experiment T002: Manual navigation sightings

NASA Technical Reports Server (NTRS)

Smith, D.

1971-01-01

Navigation-type measurements through the window of the stabilized Gemini 12 spacecraft by the use of a hand-held sextant are reported. The major objectives were as follows: (1) to evaluate the ability of the crewmen to make accurate navigational measurements by the use of simple instruments in an authentic space flight environment; (2) to evaluate the operational feasibility of the measurement techniques by the use of the pressure suit with the helmet off and with the helmet on and the visor closed; (3) to evaluate operational problems associated with the spacecraft environment; and (4) to validate ground based simulation techniques by comparison of the inflight results with base line data obtained by the pilot by the use of simulators and celestial targets from ground based observatories.

System definition phase and acquisition phase project plan for Small Astronomy Satellite SAS-D

NASA Technical Reports Server (NTRS)

1971-01-01

The objective of the SAS-D project is to conduct spectral distribution studies of celestial ultraviolet sources using an Explorer-class spacecraft launched by a Delta vehicle into a geosynchronous orbit in the last half of 1975. The telescope system is intended for use by guest astronomers for a major portion of the total observing time. The concept of the overall system, designed to resemble functionally the operation of a ground-based observatory, should maximize the usefulness of the instrument to the astronomical community by limiting the amount of special instruction needed to use the spaceborne telescope. The SAS-D mission will obtain information on what stars, nebulae, and galaxies are and how they develop.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers watch as the fairing for Deep Space 1 is lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers check the position of the fairing for Deep Space 1 as it reaches the top of the Mobile Service Tower where it will be attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers ready NASA's Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers look over NASA's Deep Space 1 spacecraft before prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers maneuver NASA's Deep Space 1 spacecraft into place for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers move NASA's Deep Space 1 spacecraft into another room in the Payload Hazardous Servicing Facility for prelaunch processing . Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Science and Technology Review June 2006

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

Radousky, H

2006-04-20

This month's issue has the following articles: (1) Maintaining Excellence through Intellectual Vitality--Commentary by Cherry A. Murray; (2) Next-Generation Scientists and Engineers Tap Lab's Resources--University of California Ph.D. candidates work with Livermore scientists and engineers to conduct fundamental research as part of their theses; (3) Adaptive Optics Provide a Clearer View--The Center for Adaptive Optics is sharpening the view of celestial objects and retinal cells; (4) Wired on the Nanoscale--A Lawrence Fellow at Livermore is using genetically engineered viruses to create nanostructures such as tiny gold wires; and (5) Too Hot to Handle--Livermore scientists couple carbon-cycle and climate models tomore » predict the global effects of depleting Earth's fossil-fuel supply.« less

KSC-98pc1053

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, is lifted into place above the flame trench at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1052

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, is lifted into place above the surface of Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc936

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers maneuver NASA’s Deep Space 1 spacecraft into place for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1075

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- Workers check the position of the fairing for Deep Space 1 as it reaches the top of the Mobile Service Tower where it will be attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc937

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers look over NASA’s Deep Space 1 spacecraft before prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1151

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- A technician in the Payload Hazardous Servicing Facility (PHSF) places a paper signed by workers in the PHSF inside a compartment in Deep Space 1. The payload is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc932

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers remove the protective covering from NASA’s Deep Space 1 spacecraft in the Payload Hazardous Servicing Facility at KSC to prepare it for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc935

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers move NASA’s Deep Space 1 spacecraft into another room in the Payload Hazardous Servicing Facility for prelaunch processing . Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1154

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- In the Payload Hazardous Servicing Facility, workers maneuver Deep Space 1 into place to attach the solar panels. Deep Space 1 is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

Integration of planetary protection activities

NASA Technical Reports Server (NTRS)

Race, Margaret S.

1995-01-01

For decades, NASA has been concerned about the protection of planets and other solar system bodies from biological contamination. Its policies regarding biological contamination control for outbound and inbound planetary spacecraft have evolved to focus on three important areas: (1) the preservation of celestial objects and the space environment; (2) protection of Earth from extraterrestrial hazards; and (3) ensuring the integrity of its scientific investigations. Over the years as new information has been obtained from planetary exploration and research, planetary protection parameters and policies have been modified accordingly. The overall focus of research under this cooperative agreement has been to provide information about non-scientific and societal factors related to planetary protection and use it in the planning and implementation phases of future Mars sample return missions.

Automatic Recognition of Object Names in Literature

NASA Astrophysics Data System (ADS)

Bonnin, C.; Lesteven, S.; Derriere, S.; Oberto, A.

2008-08-01

SIMBAD is a database of astronomical objects that provides (among other things) their bibliographic references in a large number of journals. Currently, these references have to be entered manually by librarians who read each paper. To cope with the increasing number of papers, CDS develops a tool to assist the librarians in their work, taking advantage of the Dictionary of Nomenclature of Celestial Objects, which keeps track of object acronyms and of their origin. The program searches for object names directly in PDF documents by comparing the words with all the formats stored in the Dictionary of Nomenclature. It also searches for variable star names based on constellation names and for a large list of usual names such as Aldebaran or the Crab. Object names found in the documents often correspond to several astronomical objects. The system retrieves all possible matches, displays them with their object type given by SIMBAD, and lets the librarian make the final choice. The bibliographic reference can then be automatically added to the object identifiers in the database. Besides, the systematic usage of the Dictionary of Nomenclature, which is updated manually, permitted to automatically check it and to detect errors and inconsistencies. Last but not least, the program collects some additional information such as the position of the object names in the document (in the title, subtitle, abstract, table, figure caption...) and their number of occurrences. In the future, this will permit to calculate the 'weight' of an object in a reference and to provide SIMBAD users with an important new information, which will help them to find the most relevant papers in the object reference list.

Guide star targeting success for the HEAO-B observatory

NASA Technical Reports Server (NTRS)

Farrenkopf, R. L.; Hoffman, D. P.

1977-01-01

The statistics associated with the successful selection and acquisition of guide stars as attitude benchmarks for use in reorientation maneuvers of the HEAO-B observatory are considered as a function of the maneuver angle, initial attitude uncertainties, and the pertinent celestial region. Success likelihoods in excess of 0.99 are predicted assuming anticipated gyro and star tracker error sources. The maneuver technique and guide star selection constraints are described in detail. The results presented are specialized numerically to the HEAO-B observatory. However, the analytical techniques developed are considered applicable to broader classes of spacecraft requiring celestial targeting.

Evaluation of optical data for Mars approach navigation.

NASA Technical Reports Server (NTRS)

Jerath, N.

1972-01-01

Investigation of several optical data types which can be obtained from science and engineering instruments normally aboard interplanetary spacecraft. TV cameras are assumed to view planets or satellites and stars for celestial references. Also, spacecraft attitude sensors are assumed to yield celestial references. The investigation of approach phases of typical Mars missions showed that the navigation accuracy was greatly enhanced with the addition of optical data to radio data. Viewing stars and the planet Mars was found most advantageous ten days before Mars encounter, and viewing Deimos or Phobos and stars was most advantageous within ten days of encounter.

The bee's map of the e-vector pattern in the sky.

PubMed

Rossel, S; Wehner, R

1982-07-01

It has long been known that bees can use the pattern of polarized light in the sky as a compass cue even if they can see only a small part of the whole pattern. How they solve this problem has remained enigmatic. Here we show that the bees rely on a generalized celestial map that is used invariably throughout the day. We reconstruct this map by analyzing the navigation errors made by bees to which single e-vectors are displayed. In addition, we demonstrate how the bee's celestial map can be derived from the e-vector patterns in the sky.

Gaia, Helios, Selene and Ouranos: the three principal celestial bodies and the sky in the ancient Greek cosmogony

NASA Astrophysics Data System (ADS)

Theodossiou, Efstratios; Manimanis, Vassilios N.; Dimitrijević, Milan S.; Mantarakis, Petros

In this article we consider the role of the three principal celestial bodies, the Earth (Gaia), the Sun (Helios) and the Moon (Selene), as well as the Sky (Ouranos) in the ancient Greek cosmogony. This is done by the analysis of antique Greek texts like Orphic Hymns and the literary remains of the writers and philosophers like Aeschylus, (Pseudo) Apollodorus, Apollonius Rhodius, Aristotle, Euripides, Hesiod, Homer, Hyginus, Nonnus, Pausanias, Pindar and Sophocles, as well as by the analysis of texts of Roman writers like Cicero, Ovid and Pliny.

The HEAO-A Scanning Modulation Collimator instrument

NASA Technical Reports Server (NTRS)

Roy, A.; Ballas, J.; Jagoda, N.; Mckinnon, P.; Ramsey, A.; Wester, E.

1977-01-01

The Scanning Modulation Collimator X-ray instrument for the HEAO-A satellite was designed to measure celestial radiation in the range between 1 and 15 KeV and to resolve, and correlate, the position of X-ray sources with visible light sources on the celestial sphere to within 5 arc seconds. The positional accuracy is made possible by mechanical collimation of the X-ray sources viewed by the instrument. High sensitivity is provided from two systems each containing four gas filled proportional counters followed by preamplification, signal summing, pulse height analysis, pulse shape discrimination, X-ray event accumulators and telemetry processing electronics.

The IAA Cosmic Study 'Protecting the Environment of Celestial Bodies'

NASA Astrophysics Data System (ADS)

Rettberg, Petra; Hofmann, Mahulena; Williamson, Mark

The study group tasked with producing this International Academy of Astronautics (IAA) `Cosmic Study' on Protecting the Environment of Celestial Bodies was formed under the aus-pices of IAA Commission V (Space Policy, Law Economy). The members of the international, multidisciplinary team assembled to undertake the Study accept, as a premise, the Planetary Protection Policy guidelines developed by COSPAR, which differentiate the degree of protec-tion according to the type of space activity and the celestial body under investigation (such that fly-by missions have less stringent requirements than lander missions, while Mars is `better protected' than the Moon). However, this Study goes deliberately beyond the interpretation of `Planetary Protection' as a set of methods for protecting the planets from biological con-tamination and extends consideration to the geophysical, industrial and cultural realms. The Study concludes that, from the perspective of current and future activities in outer space, present measures aimed at protecting the space environment are insufficient. Deficiencies in-clude a lack of suitable in-situ methods of chemical and biological detection and the absence of a systematic record of radioactive contaminants. Other issues identified by the Study include an insufficient legal framework, a shortage of effective economic tools and a lack of political will to address these concerns. It is expected that new detection methods under development, and the resultant increase in microbiological knowledge of the planetary surfaces, will lead to changes in the COSPAR planetary protection guidelines and bioburden limits. It is important, however, that any new approaches should not hamper future exploration and exploitation of celestial bodies more than absolutely necessary. The Study addresses the need to find a balance between protection and freedom of action. From a legal perspective, the Study concludes that a general consensus on protection of the environment of the Moon and other celestial bodies should be sought among spacefaring states, while the question of new laws and regulations should be deliberated in the UN and scientific organisations. In doing so, it is recommended that experience in formulating the Antarctic Treaty System and other terrestrial environmen-tal accords should be taken into account. In general terms, it is expected that the majority of space activities would remain untouched by any future policies and regulations, to ensure that space exploration and exploitation remains open to future generations. But this philosophy brings with it a responsibility to protect the freedoms of those future generations from the ill-conceived practices of the present. As a result, activities that threaten the environments of celestial bodies, and our cultural heritage, should be identified, mitigated and discouraged (either by policy or by law).

Infrared fine-structure line diagnostics of shrouded active galactic nuclei

NASA Technical Reports Server (NTRS)

Voit, G. M.

1993-01-01

Far-infrared spectroscopy of celestial objects will improve dramatically in the coming decade, allowing astronomers to use fine-structure line emission to probe photoionized regions obscured in the optical band by thick clouds of dust. The ultraluminous far-IR galaxies revealed by IRAS, quasar-like in luminosity but smothered in molecular gas, probably conceal either immense starbursts or luminous active nuclei. In both scenarios, these objects ought to produce copious infrared fine-structure emission with several lines comparable to H(beta) in luminosity. This paper shows how these lines, if detected, can be used to determine the electron densities and far-IR obscurations of shrouded photoionized regions and to constrain the shape and ionization parameter of the ionizing spectra. The presence of (Ne V) emission in particular will distinguish shrouded AGN's from shrouded starbursts. Since all active galaxies photoionize at least some surrounding material, these diagnostics can also be applied to active galaxies in general and will aid in studying how an active nucleus interacts with the interstellar medium of its host galaxy.

Radiation-induced rotation of small celestial bodies

NASA Technical Reports Server (NTRS)

Misconi, N. Y.; Oliver, John; Mzariegos, Roberto

1992-01-01

The rotation was studied of particles in a simulated space environment via a technique known as Laser Particle Levitation. The combination of both a high vacuum and optical laser levitation to negate the effects of Earth's gravity, simulate the space environment. The rotation mechanism under study is known as the 'Windmill Effect,' which is a spin mechanism that suggests that the interaction of the photon field from a star with the surface irregularities of cosmic dust will cause them to spin due to the imbalance in the directionality of the scattered photons which necessitates a non-zero angular momentum. This conclusion is based on the random nature of the orientation of the sites of surface irregularities. The general object is to study the behavior of particles in orbits around the Earth, both natural and man made, as well as interplanetary and circumstellar particles. To meet this objective, an apparatus was constructed which was designed to allow optical levitation in a vacuum.

Astronomical Context of Georgian Folklore

NASA Astrophysics Data System (ADS)

Jijelava1, Badri; Holbrook, Jarita; Simonia, Irakli

2016-10-01

Objectives: The religious Ancient megalithic monuments are accordingly o/riente to the ancient Gods - The Sun, Moon, luminaries. The aim of this work to research the ethnographic data, current folklore and based on the results, harmonize the ancient Gods and the orientations of the religious megalithic complexes. Methods/Statistical Analysis: We harmonized the ethnographical, folklore and historical information and restoration of ancient celestial sphere (using special astronomy application) and identified the correlations between the some acronychal or helical rising/set of luminaries and orientations of megalithic objects. Such connections are stored in a folklore. Findings: This technique of investigations gives us more clear understanding of ancient universe. Using this method, we can receive additional information about the ancient Gods - Luminaries, clarify current mythology, date the megalithic complex. Application/Improvements: This method of investigation - Harmonization cultural astronomy and archae or astronomy with the archeological investigations will be more fruitful, because it gives us reliable information concerning the ancient culture, ancient religion and ancient people.

ESA's high-energy observatories spot doughnut-shaped cloud with a black-hole filling

NASA Astrophysics Data System (ADS)

2004-07-01

hi-res Size hi-res: 7265 KB Credits: ESA, V. Beckmann (GSFC) Doughnut-shaped cloud surrounds black hole This artist's impression shows the thick dust torus that astronomers believe surrounds supermassive black holes and their accretion discs, like the one harboured in the nucleus of the spiral galaxy NGC 4388. When the torus is seen `edge-on’ as in this case, the visible light emitted by the accretion disc is partially blocked. However, the sharp X-ray and gamma-ray eyes of XMM-Newton and Integral can peer through the thick dust and see how the energy released by the accretion disc interacts with and is absorbed by the torus. Black holes are objects so compact and with gravity so strong that not even light can escape from them. Scientists think that `supermassive’ black holes are located in the cores of most galaxies, including our Milky Way galaxy. They can contain the mass of thousands of millions of suns, confined within a region no larger than our Solar System. They appear to be surrounded by a hot, thin disk of accreting gas and, farther out, the thick doughnut-shaped torus. Depending on the inclination of the torus, it can hide the black hole and the hot accretion disc from the line of sight. Galaxies in which a torus blocks the light from the central accretion disc are called `Seyfert 2’ types and are usually faint to optical telescopes. Another theory, however, is that these galaxies appear rather faint because the central black hole is not actively accreting gas and the disc surrounding it is therefore faint. An international team of astronomers led by Dr Volker Beckmann, Goddard Space Flight Center (Greenbelt, USA) has studied one of the nearest objects of this type, a spiral galaxy called NGC 4388, located 65 million light years away in the constellation Virgo. Since NGC 4388 is relatively close, and therefore unusually bright for its class, it is easier to study. Astronomers often study black holes that are aligned face-on, thus avoiding the enshrouding torus. However, Beckmann's group took the path less trodden and studied the central black hole by peering through the torus. With XMM-Newton and Integral, they could detect some of the X-rays and gamma rays, emitted by the accretion disc, which partially penetrate the torus. "By peering right into the torus, we see the black hole phenomenon in a whole new light, or lack of light, as the case may be here," Beckmann said. Beckmann's group saw how different processes around a black hole produce light at different wavelengths. For example, some of the gamma rays produced close to the black hole get absorbed by iron atoms in the torus and are re-emitted at a lower energy. This in fact is how the scientists knew they were seeing `reprocessed’ light farther out. Also, because of the line of sight towards NGC 4388, they knew this iron was from a torus on the same plane as the accretion disk, and not from gas clouds `above’ or `below’ the accretion disk. This new view through the haze has provided valuable insight into the relationship between the black hole, its accretion disc and the doughnut, and supports the torus model in several ways. Gas in the accretion disc close to the black hole reaches high speeds and temperatures (over 100 million degrees, hotter than the Sun) as it races toward the void. The gas radiates predominantly at high energies, in the X-ray wavelengths. According to Beckmann, this light is able to escape the black hole because it is still outside of its border, but ultimately collides with matter in the torus. Some of it is absorbed; some of it is reflected at different wavelengths, like sunlight penetrating a cloud; and the very energetic gamma rays pierce through. "This torus is not as dense as a real doughnut or a true German Krapfen, but it is far hotter - up to a thousand degrees - and loaded with many more calories," Beckmann said. The new observations also pinpoint the origin of the high-energy emission from NGC 4388. While the lower-energy X-rays seen by XMM-Newton appear to come from a diffuse emission, far away from the black hole, the higher-energy X-rays detected by Integral are directly related to the black hole activity. The team could infer the doughnut’s structure and its distance from the black hole by virtue of light that was either reflected or completely absorbed. The torus itself appears to be several hundred light years from the black hole, although the observation could not gauge its diameter, from inside to outside. The result marks the clearest observation of an obscured black hole in X-ray and gamma-ray `colours’, a span of energy nearly a million times wider than the window of visible light, from red to violet. Multi-wavelength studies are increasingly important to understanding black holes, as already demonstrated earlier this year. In May 2004, the European project known as the Astrophysical Virtual Observatory, in which ESA plays a major role, found 30 supermassive black holes that had previously escaped detection behind masking dust clouds. Note for editors This result will appear on The Astrophysical Journal. Besides Volker Beckmann, the author list includes Neil Gehrels, Pascal Favre, Roland Walter, Thierry Courvoisier, Pierre-Olivier Petrucci and Julien Malzac. For more information about the Astrophysical Virtual Observatory programme and how it has allowed European scientists to discover a number of previously hidden black holes, see: http://www.spacetelescope.org/news/html/heic0409.html More about Integral The International Gamma Ray Astrophysics Laboratory (Integral) is the first space observatory that can simultaneously observe celestial objects in gamma rays, X-rays and visible light. Integral was launched on a Russian Proton rocket on 17 October 2002 into a highly elliptical orbit around Earth. Its principal targets include regions of the galaxy where chemical elements are being produced and compact objects, such as black holes. More information on Integral can be found at: http://www.esa.int/esaSC/SEM9P5374OD_0_spk.html More about XMM-Newton XMM-Newton can detect more X-ray sources than any previous observatory and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket from French Guiana. It is expected to return data for a decade. XMM-Newton’s high-tech design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects. More information on XMM-Newton can be found at: http://www.esa.int/esaSC/SEMM8IGHZTD_1_spk.html

Development of management objectives for waterfowl and shorebirds within the Mississippi Alluvial Valley

USGS Publications Warehouse

Loesch, C.R.; Twedt, D.J.; Tripp, K.; Hunter, W.C.; Woodrey, M.S.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry

2000-01-01

The goal of the Lower Mississippi Valley Joint Venture of the North American Waterfowl Management Plan is to provide sufficient habitat to support 4.3 million wintering ducks and 1.0 million wintering geese annually. Under the assumption that the amount of foraging habitat is the primary limitation to supporting waterfowl population goals in the Mississippi Alluvial Valley (MAV), a habitat objective to make available 285,000 ha of waterfowl foraging habitat is divided among seven states. This habitat objective is further divided between public and private ownership and among three habitat types: Bottomland hardwood forest, moist-soil sites, and agricultural fields. Management objectives for shorebirds within the MAV which provide foraging habitat for 0.5 million shorebirds during their southward migration have been tentatively established. Several as yet unverified assumptions were used in establishing these objectives; consequently, we caution that the objectives are subject to revision as the assumptions are tested. We assumed that 0.5 million shorebirds move through the MAV during late summer and fall, each foraging for an average of 10 days. During this migration period, foraging shorebirds are assumed to require sufficient forage to gain 1 g of biomass per day, in addition to their basal metabolic needs. Given an invertebrate food supply that provides 17.6 kj ? g-1, we calculated that an average 45 g shorebird requires about 8 g of invertebrate forage per day. Further assuming that each ha of managed shorebird habitat can provide 20 kg of invertebrate food resources available to shorebirds, we extrapolated a need for 2000 ha of shorebird foraging habitat. We suggest that the bulk of this foraging habitat be provided on public lands and that it be distributed throughout the MAV.

Massive Gas Cloud Speeding Toward Collision With Milky Way

NASA Astrophysics Data System (ADS)

2008-01-01

"The leading edge of this cloud is already interacting with gas from our Galaxy," said Felix J. Lockman, of the National Radio Astronomy Observatory (NRAO), leader of a team of astronomers who used the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to study the object. The scientists presented their findings to the American Astronomical Society's meeting in Austin, Texas. The cloud, called Smith's Cloud, after the astronomer who discovered it in 1963, contains enough hydrogen to make a million stars like the Sun. Eleven thousand light-years long and 2,500 light-years wide, it is only 8,000 light-years from our Galaxy's disk. It is careening toward our Galaxy at more than 150 miles per second, aimed to strike the Milky Way's disk at an angle of about 45 degrees. "This is most likely a gas cloud left over from the formation of the Milky Way or gas stripped from a neighbor galaxy. When it hits, it could set off a tremendous burst of star formation. Many of those stars will be very massive, rushing through their lives quickly and exploding as supernovae. Over a few million years, it'll look like a celestial New Year's celebration, with huge firecrackers going off in that region of the Galaxy," Lockman said. When Smith's Cloud was first discovered, and for decades after, the available images did not have enough detail to show whether the cloud was part of the Milky Way, something being blown out of the Milky Way, or something falling in. Lockman and his colleagues used the GBT to make an extremely detailed study of hydrogen in Smith's Cloud. Their observations included nearly 40,000 individual pointings of the giant telescope to cover the cloud with unprecedented sensitivity and resolution. Smith's Cloud is about 15 degrees long in the sky, 30 times the width of the full moon. "If you could see this cloud with your eyes, it would be a very impressive sight in the night sky," Lockman said. "From tip to tail it would cover almost as much sky as the Orion constellation. But as far as we know it is made entirely of gas -- no one has found a single star in it." The detailed GBT study dramatically changed the astronomers' understanding of the cloud. Its velocity shows that it is falling into the Milky Way, not leaving it, and the new data show that it is plowing up Milky Way gas before it as it falls. "Its shape, somewhat similar to that of a comet, indicates that it's already hitting gas in our Galaxy's outskirts," Lockman said. "It is also feeling a tidal force from the gravity of the Milky Way and may be in the process of being torn apart. Our Galaxy will get a rain of gas from this cloud, then in about 20 to 40 million years, the cloud's core will smash into the Milky Way's plane," Lockman explained.

A recurrent neural network for classification of unevenly sampled variable stars

NASA Astrophysics Data System (ADS)

Naul, Brett; Bloom, Joshua S.; Pérez, Fernando; van der Walt, Stéfan

2018-02-01

Astronomical surveys of celestial sources produce streams of noisy time series measuring flux versus time (`light curves'). Unlike in many other physical domains, however, large (and source-specific) temporal gaps in data arise naturally due to intranight cadence choices as well as diurnal and seasonal constraints1-5. With nightly observations of millions of variable stars and transients from upcoming surveys4,6, efficient and accurate discovery and classification techniques on noisy, irregularly sampled data must be employed with minimal human-in-the-loop involvement. Machine learning for inference tasks on such data traditionally requires the laborious hand-coding of domain-specific numerical summaries of raw data (`features')7. Here, we present a novel unsupervised autoencoding recurrent neural network8 that makes explicit use of sampling times and known heteroskedastic noise properties. When trained on optical variable star catalogues, this network produces supervised classification models that rival other best-in-class approaches. We find that autoencoded features learned in one time-domain survey perform nearly as well when applied to another survey. These networks can continue to learn from new unlabelled observations and may be used in other unsupervised tasks, such as forecasting and anomaly detection.

Seven-year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Planets and Celestial Calibration Sources

NASA Astrophysics Data System (ADS)

Weiland, J. L.; Odegard, N.; Hill, R. S.; Wollack, E.; Hinshaw, G.; Greason, M. R.; Jarosik, N.; Page, L.; Bennett, C. L.; Dunkley, J.; Gold, B.; Halpern, M.; Kogut, A.; Komatsu, E.; Larson, D.; Limon, M.; Meyer, S. S.; Nolta, M. R.; Smith, K. M.; Spergel, D. N.; Tucker, G. S.; Wright, E. L.

2011-02-01

We present WMAP seven-year observations of bright sources which are often used as calibrators at microwave frequencies. Ten objects are studied in five frequency bands (23-94 GHz): the outer planets (Mars, Jupiter, Saturn, Uranus, and Neptune) and five fixed celestial sources (Cas A, Tau A, Cyg A, 3C274, and 3C58). The seven-year analysis of Jupiter provides temperatures which are within 1σ of the previously published WMAP five-year values, with slightly tighter constraints on variability with orbital phase (0.2% ± 0.4%), and limits (but no detections) on linear polarization. Observed temperatures for both Mars and Saturn vary significantly with viewing geometry. Scaling factors are provided which, when multiplied by the Wright Mars thermal model predictions at 350 μm, reproduce WMAP seasonally averaged observations of Mars within ~2%. An empirical model is described which fits brightness variations of Saturn due to geometrical effects and can be used to predict the WMAP observations to within 3%. Seven-year mean temperatures for Uranus and Neptune are also tabulated. Uncertainties in Uranus temperatures are 3%-4% in the 41, 61, and 94 GHz bands; the smallest uncertainty for Neptune is 8% for the 94 GHz band. Intriguingly, the spectrum of Uranus appears to show a dip at ~30 GHz of unidentified origin, although the feature is not of high statistical significance. Flux densities for the five selected fixed celestial sources are derived from the seven-year WMAP sky maps and are tabulated for Stokes I, Q, and U, along with polarization fraction and position angle. Fractional uncertainties for the Stokes I fluxes are typically 1% to 3%. Source variability over the seven-year baseline is also estimated. Significant secular decrease is seen for Cas A and Tau A: our results are consistent with a frequency-independent decrease of about 0.53% per year for Cas A and 0.22% per year for Tau A. We present WMAP polarization data with uncertainties of a few percent for Tau A. Where appropriate, WMAP results are compared against previous findings in the literature. With an absolute calibration uncertainty of 0.2%, WMAP data are a valuable asset for calibration work. WMAP is the result of a partnership between Princeton University and NASA's Goddard Space Flight Center. Scientific guidance is provided by the WMAP Science Team.

SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP ) OBSERVATIONS: PLANETS AND CELESTIAL CALIBRATION SOURCES

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

Weiland, J. L.; Odegard, N.; Hill, R. S.

2011-02-01

We present WMAP seven-year observations of bright sources which are often used as calibrators at microwave frequencies. Ten objects are studied in five frequency bands (23-94 GHz): the outer planets (Mars, Jupiter, Saturn, Uranus, and Neptune) and five fixed celestial sources (Cas A, Tau A, Cyg A, 3C274, and 3C58). The seven-year analysis of Jupiter provides temperatures which are within 1{sigma} of the previously published WMAP five-year values, with slightly tighter constraints on variability with orbital phase (0.2% {+-} 0.4%), and limits (but no detections) on linear polarization. Observed temperatures for both Mars and Saturn vary significantly with viewing geometry.more » Scaling factors are provided which, when multiplied by the Wright Mars thermal model predictions at 350 {mu}m, reproduce WMAP seasonally averaged observations of Mars within {approx}2%. An empirical model is described which fits brightness variations of Saturn due to geometrical effects and can be used to predict the WMAP observations to within 3%. Seven-year mean temperatures for Uranus and Neptune are also tabulated. Uncertainties in Uranus temperatures are 3%-4% in the 41, 61, and 94 GHz bands; the smallest uncertainty for Neptune is 8% for the 94 GHz band. Intriguingly, the spectrum of Uranus appears to show a dip at {approx}30 GHz of unidentified origin, although the feature is not of high statistical significance. Flux densities for the five selected fixed celestial sources are derived from the seven-year WMAP sky maps and are tabulated for Stokes I, Q, and U, along with polarization fraction and position angle. Fractional uncertainties for the Stokes I fluxes are typically 1% to 3%. Source variability over the seven-year baseline is also estimated. Significant secular decrease is seen for Cas A and Tau A: our results are consistent with a frequency-independent decrease of about 0.53% per year for Cas A and 0.22% per year for Tau A. We present WMAP polarization data with uncertainties of a few percent for Tau A. Where appropriate, WMAP results are compared against previous findings in the literature. With an absolute calibration uncertainty of 0.2%, WMAP data are a valuable asset for calibration work.« 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 objects. The brown dwarfs are the faintest objects in the image. Surveying the cluster's central region, the Hubble telescope spied brown dwarfs with masses equaling 10 to 80 Jupiters. Researchers think there may be less massive brown dwarfs that are beyond the limits of Hubble's vision. The near-infrared image was taken Jan. 17, 1998. Two near-infrared filters were used to obtain information on the colors of the stars at two wavelengths (1.1 and 1.6 microns). The Trapezium picture is 1 light-year across. This composite image was made from a 'mosaic' of nine separate, but adjoining images. In this false-color image, blue corresponds to warmer, more massive stars, and red to cooler, less massive stars and brown dwarfs, and stars that are heavily obscured by dust. The visible-light data were taken in 1994 and 1995. Credits for near-infrared image: NASA; K.L. Luhman (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.); and G. Schneider, E. Young, G. Rieke, A. Cotera, H. Chen, M. Rieke, R. Thompson (Steward Observatory, University of Arizona, Tucson, Ariz.) Credits for visible-light picture: NASA, C.R. O'Dell and S.K. Wong (Rice University)

Those astronomers crazy about the skies, or the story of the observation of double stars

NASA Astrophysics Data System (ADS)

Ling, J. F.

2015-05-01

Those astronomers crazy about the skies are people who have dedicated their lives, often their fortunes, to the research and study of double stars, enigmatic star systems that like to play hide and seek while dancing a mysterious waltz. Many efforts have been made to collect the wonderful golden harvest that celestial fields provide. Starting with Sir William Herschel, organist and brilliant astronomer who documented their orbital motions, the Struve clan who undertook the first census, the Anglican priest who discovered authentic celestial jewels and all the way to current international research teams using the greatest telescopes, they all searched with the same passion. They all went beyond the mere spectacle of the eternity of these pairs, seeking the Philosopher's Stone, the secret of stellar alchemy and the means to break down the wall that imprisons our knowledge. This book is the Spanish translation of the original French text written by Paul Couteau, one of the foremost authorities on the subject. No one better than him to immerse us into the knowledge of these objects, both scientifically and historically. Despite the 25 years since its publication, the text has not lost relevance. The story never dies and the attraction that still elicits has been one of the reasons to provide readers with this Spanish translation. In addition, we have included a chapter written by Josefina F. Ling. This version, published by the Department of Publications and Scientific Communications at the University of Santiago de Compostela and partially funded by the Spanish Society of Astronomy, has an initial print of 500 copies.

VizieR Online Data Catalog: Radio fluxes of 195 ICRF2-Gaia transfer sources (Le Bail+, 2016)

NASA Astrophysics Data System (ADS)

Le Bail, K.; Gipson, J. M.; Gordon, D.; MacMillan, D. S.; Behrend, D.; Thomas, C. C.; Bolotin, S.; Himwich, W. E.; Baver, K. D.; Corey, B. E.; Titus, M.; Bourda, G.; Charlot, P.; Collioud, A.

2016-07-01

The second realization of the International Celestial Reference Frame (ICRF2) is based on Very Long Baseline Interferometry (VLBI) data at radio frequencies in X band and S band. The European Space Agency's Gaia mission, launched on 2013 December 19, started routine scientific operations in 2014 July. By scanning the whole sky, it is expected to observe ~500000 Quasi Stellar Objects in the optical domain. This means that, in the future, two extragalactic celestial reference frames, at two different frequency domains, will coexist. It will thus be important to align them very accurately. In 2012, the Laboratoire d'Astrophysique de Bordeaux (LAB) selected 195 sources from ICRF2 that will be observed by Gaia and should be suitable for aligning the radio and optical frames: they are called ICRF2-Gaia transfer sources. The LAB submitted a proposal to the International VLBI Service (IVS) to regularly observe these ICRF2-Gaia transfer sources at the same rate as Gaia observes them in the optical realm, e.g., roughly once a month. Of the 195 sources, all but one have been successfully observed in the 12 months prior to 2015 September 01. Table1 lists the 195 ICRF2-Gaia transfer sources. Beginning in 2003 June, the Goddard VLBI group developed a program to purposefully monitor when sources were observed and to increase the observations of "under-observed" sources. In 2013 March, we added all 195 ICRF2-Gaia transfer sources to the IVS source monitoring program with an observation target of 12 successful sessions per year. (1 data file).

Comet/Asteroid Protection System (CAPS): A Space-Based System Concept for Revolutionizing Earth Protection and Utilization of Near-Earth Objects

NASA Technical Reports Server (NTRS)

Mazanek, Daniel D.; Roithmayr, Carlos M.; Antol, Jeffrey; Kay-Bunnell, Linda; Werner, Martin R.; Park, Sang-Young; Kumar, Renjith R.

2002-01-01

There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS is a future spacebased system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This paper provides a summary of CAPS and discusses several key areas and technologies that are being investigated.

Kuiper Belt Objects of different sizes and average densities: thermal evolution scenarios and modern structure of matter

NASA Astrophysics Data System (ADS)

Shchuko, O. B.; Shchuko, S. D.; Kartashov, D.; Orosei, R.

2012-04-01

Thermal evolution of accretion-formed Kuiper Belt Objects (KBOs) with modern sizes from 200 to 2000 km and average densities from 1100 to 3200 kg/m3 has been studied by mathematical simulation methods. The values range of physical parameters of the accretion material and ultimate radionuclide content, securing KBO existence at present, have been found. The solid dust material of protosolar cloud fringe regions and fine-fractured H2O condensate in the form of amorphous ice are considered to have been the building matter for these objects. This material was represented by small dust particles of different chemical and mineralogical composition, embedded with radionuclides 238U, 235U, 232Th, 40K providing the sources of radiogenic heat. H2O condensate secured the presence of amorphous ice in the forming body's matter. Radiogenic heat leads to H2O phase transitions which define a body's interior matter differentiation. The radionuclide content at the initial time of the body formation determined the dynamically changing degree of the interior matter differentiation at different KBO depths for the whole period from the initial up to the present time. For the models of the celestial objects considered, the dynamically changing boundaries of spherically symmetric regions with different degree of matter differentiation have been determined.

Spectroscopy - so what?

NASA Astrophysics Data System (ADS)

Stanley, Matthew

2010-07-01

The development of astronomical spectroscopy allowed amazing achievements in investigating the composition and motion of celestial bodies. But even beyond specific measurements and results, the fruitfulness and practice of spectroscopy had important ramifications on a more abstract level. This paper will discuss ways in which spectroscopy inspired or boosted new theories of the atom, life, and the Universe; redrew the boundaries among scientific disciplines; demonstrated the unity of terrestrial and celestial physical laws; changed what counted as scientific knowledge; and even revealed divine mysteries. Scientists and science writers from the first half-century of astronomical spectroscopy will be discussed, including James Clerk Maxwell, William Crookes, John Tyndall, Agnes Clerke, William Huggins and Norman Lockyer.

Spectroscopy - so what?

NASA Astrophysics Data System (ADS)

Stanley, Matthew

2010-01-01

The development of astronomical spectroscopy allowed amazing achievements in investigating the composition and motion of celestial bodies. But even beyond specific measurements and results, the fruitfulness and practice of spectroscopy had important ramifications on a more abstract level. This paper will discuss ways in which spectroscopy inspired or boosted new theories of the atom, life, and the universe; redrew the boundaries among scientific disciplines; demonstrated the unity of terrestrial and celestial physical laws; changed what counted as scientific knowledge; and even revealed divine mysteries. Scientists and science writers from the first half-century of astronomical spectroscopy will be discussed, including James Clerk Maxwell, William Thomson (Lord Kelvin), John Tyndall, Agnes Clerke, William Huggins, and Norman Lockyer.

Difference method to search for the anisotropy of primary cosmic radiation

NASA Astrophysics Data System (ADS)

Pavlyuchenko, V. P.; Martirosov, R. M.; Nikolskaya, N. M.; Erlykin, A. D.

2018-01-01

The original difference method used in the search for an anisotropy of primary cosmic radiation at the knee region of its energy spectrum is considered. Its methodical features and properties are analyzed. It is shown that this method, in which properties of particle fluxes (rather than an intensity) are investigated, is stable against random experimental errors and allows one to separate anomalies connected with the laboratory coordinate system from anomalies in the celestial coordinate system. The method uses the multiple scattering of charged particles in the magnetic fields of the Galaxy to study the whole celestial sphere, including the regions outside the line of sight of the installation.

Refraction effects of atmosphere on geodetic measurements to celestial bodies

NASA Technical Reports Server (NTRS)

Joshi, C. S.

1973-01-01

The problem is considered of obtaining accurate values of refraction corrections for geodetic measurements of celestial bodies. The basic principles of optics governing the phenomenon of refraction are defined, and differential equations are derived for the refraction corrections. The corrections fall into two main categories: (1) refraction effects due to change in the direction of propagation, and (2) refraction effects mainly due to change in the velocity of propagation. The various assumptions made by earlier investigators are reviewed along with the basic principles of improved models designed by investigators of the twentieth century. The accuracy problem for various quantities is discussed, and the conclusions and recommendations are summarized.

Semi-analytical integration of the Earth's precession-nutation based on the GCRS coordinates of the CIP unit vector

NASA Astrophysics Data System (ADS)

Capitaine, N.; Folgueira, M.

2012-12-01

In a previous paper (Capitaine et al. 2006), referred here as Paper I, we demonstrated the possibility of integrating the Earth's rotational motion in terms of the coordinates (X, Y ) of the celestial intermediate pole (CIP) unit vector in the Geocentric celestial reference system (GCRS). Here, we report on the approach that has been followed for solving the equations in the case of an axially symmetric rigid Earth and the semi-analytical (X, Y ) solution obtained from the expression of the external torque acting on the Earth derived from the most complete semi-analytical solutions for the Earth, Moon and planets.

Deep data fusion method for missile-borne inertial/celestial system

NASA Astrophysics Data System (ADS)

Zhang, Chunxi; Chen, Xiaofei; Lu, Jiazhen; Zhang, Hao

2018-05-01

Strap-down inertial-celestial integrated navigation system has the advantages of autonomy and high precision and is very useful for ballistic missiles. The star sensor installation error and inertial measurement error have a great influence for the system performance. Based on deep data fusion, this paper establishes measurement equations including star sensor installation error and proposes the deep fusion filter method. Simulations including misalignment error, star sensor installation error, IMU error are analyzed. Simulation results indicate that the deep fusion method can estimate the star sensor installation error and IMU error. Meanwhile, the method can restrain the misalignment errors caused by instrument errors.

Method and System for Gamma-Ray Localization Induced Spacecraft Navigation Using Celestial Gamma-Ray Sources

NASA Technical Reports Server (NTRS)

Hisamoto, Chuck (Inventor); Arzoumanian, Zaven (Inventor); Sheikh, Suneel I. (Inventor)

2015-01-01

A method and system for spacecraft navigation using distant celestial gamma-ray bursts which offer detectable, bright, high-energy events that provide well-defined characteristics conducive to accurate time-alignment among spatially separated spacecraft. Utilizing assemblages of photons from distant gamma-ray bursts, relative range between two spacecraft can be accurately computed along the direction to each burst's source based upon the difference in arrival time of the burst emission at each spacecraft's location. Correlation methods used to time-align the high-energy burst profiles are provided. The spacecraft navigation may be carried out autonomously or in a central control mode of operation.

The Celestial Bodies in Traditional Armenian Nuptial Songs of Praise

NASA Astrophysics Data System (ADS)

Tigranyan, Marianna

2016-12-01

The universe and its structure have occupied people's minds since the beginning of time. The myths and legends of the ancient cultures are replete with tales about the myriad celestial bodies, planets and stars. Back then, the Ancient Sumerians were phenomenally successful in astronomy; their extensive knowledge is effectively used by astronomers today. The deities were featured as heavenly bodies and were eulogized and revered by the peoples of the Ancient World. At Armenian wedding ceremonies, the groom - traditionally the Crown wearer - was often likened to the Sun, and the bride to the Moon, or sometimes Venus. The newly-married couple was glorified by delightful songs of praise.

How Galileo and Kepler Countered Aristotle's Cosmological Errors

NASA Astrophysics Data System (ADS)

Gingerich, O.

2009-08-01

Aristotle made two major common sense assumptions that ultimately had to be refuted to open the way to modern science. One was the dichotomy between celestial and terrestrial. The other was the separation of astronomy from physics. Galileo, particularly with his examination of the moon in the Sidereus nuncius, was a pioneer in destroying the first assumption, while Kepler, whose Astronomia nova was subtitled ``based on causes, or celestial physics,'' broke the stranglehold of the second. The importance of these fundamental contributions toward establishing the nature of modern science, which paved the way for Isaac Newton, is often overshadowed by their more specific contributions in optics or mechanics.

Design, fabrication and performance of two grazing incidence telescopes for celestial extreme ultraviolet astronomy

NASA Technical Reports Server (NTRS)

Lampton, M.; Cash, W.; Malina, R. F.; Bowyer, S.

1977-01-01

The design and performance of grazing incidence telescopes for celestial extreme ultraviolet (EUV) astronomy are described. The telescopes basically consist of a star tracker, collimator, grazing incidence mirror, vacuum box lid, vacuum housing, filters, a ranicon detector, an electronics box, and an aspect camera. For the survey mirror a Wolter-Schwarzschild type II configuration was selected. Diamond-turning was used for mirror fabrication, a technique which machines surfaces to the order of 10 microns over the required dimensions. The design of the EUV spectrometer is discussed with particular reference to the optics for a primarily spectroscopic application and the fabrication of the f/10 optics.

An analytical model for the celestial distribution of polarized light, accounting for polarization singularities, wavelength and atmospheric turbidity

NASA Astrophysics Data System (ADS)

Wang, Xin; Gao, Jun; Fan, Zhiguo; Roberts, Nicholas W.

2016-06-01

We present a computationally inexpensive analytical model for simulating celestial polarization patterns in variable conditions. We combine both the singularity theory of Berry et al (2004 New J. Phys. 6 162) and the intensity model of Perez et al (1993 Sol. Energy 50 235-245) such that our single model describes three key sets of data: (1) the overhead distribution of the degree of polarization as well as the existence of neutral points in the sky; (2) the change in sky polarization as a function of the turbidity of the atmosphere; and (3) sky polarization patterns as a function of wavelength, calculated in this work from the ultra-violet to the near infra-red. To verify the performance of our model we generate accurate reference data using a numerical radiative transfer model and statistical comparisons between these two methods demonstrate no significant difference in almost all situations. The development of our analytical model provides a novel method for efficiently calculating the overhead skylight polarization pattern. This provides a new tool of particular relevance for our understanding of animals that use the celestial polarization pattern as a source of visual information.

Exogeoconservation: Protecting geological heritage on celestial bodies

NASA Astrophysics Data System (ADS)

Matthews, Jack J.; McMahon, Sean

2018-08-01

Geoconservation is an increasingly widely adopted theoretical, practical and administrative approach to the protection of geological and geomorphological features of special scientific, functional, historic, cultural, aesthetic, or ecological value. Protected sites on Earth include natural rocky outcrops, shorelines, river banks, and landscapes, as well as human-made structures such as road cuts and quarries exposing geological phenomena. However, geoconservation has rarely been discussed in the context of other rocky and icy planets, rings, moons, dwarf planets, asteroids, or comets, which present extraordinarily diverse, beautiful, and culturally, historically and scientifically important geological phenomena. Here we propose to adapt geoconservation strategies for protecting the geological heritage of these celestial bodies, and introduce the term 'exogeoconservation' and other associated terms for this purpose. We argue that exogeoconservation is acutely necessary for the scientific exploration and responsible stewardship of celestial bodies, and suggest how this might be achieved and managed by means of international protocols. We stress that such protocols must be sensitive to the needs of scientific, industrial, and other human activities, and not unduly prohibitive. However, with space exploration and exploitation likely to accelerate in coming decades, it is increasingly important that an internationally agreed, holistic framework be developed for the protection of our common 'exogeoheritage'.

Harbour seals (Phoca vitulina) can steer by the stars.

PubMed

Mauck, Björn; Gläser, Nele; Schlosser, Wolfhard; Dehnhardt, Guido

2008-10-01

Offshore orientation in marine mammals is still a mystery. For visual orientation during night-time foraging and travelling in the open seas, seals cannot rely on distant terrestrial landmarks, and thus might use celestial cues as repeatedly shown for nocturnally migrating birds. Although seals detect enough stars to probably allow for astronavigation, it was unclear whether they can orient by the night sky. The widely accepted cognitive mechanism for bird night-time orientation by celestial cues is a time-independent star compass with learned geometrical star configurations used to pinpoint north as the rotational centre of the starry sky while there is no conclusive evidence for a time-compensated star compass or true star navigation. Here, we present results for two harbour seals orienting in a custom made swimming planetarium. Both seals learned to highly accurately identify a lodestar out of a pseudo-randomly oriented, realistic projection of the northern hemisphere night sky. Providing the first evidence for star orientation capability in a marine mammal, our seals' outstanding directional precision would allow them to steer by following lodestars of learned star courses, a celestial orientation mechanism that has been known to be used by Polynesian navigators but has not been considered for animals yet.

Dung beetles use the Milky Way for orientation.

PubMed

Dacke, Marie; Baird, Emily; Byrne, Marcus; Scholtz, Clarke H; Warrant, Eric J

2013-02-18

When the moon is absent from the night sky, stars remain as celestial visual cues. Nonetheless, only birds, seals, and humans are known to use stars for orientation. African ball-rolling dung beetles exploit the sun, the moon, and the celestial polarization pattern to move along straight paths, away from the intense competition at the dung pile. Even on clear moonless nights, many beetles still manage to orientate along straight paths. This led us to hypothesize that dung beetles exploit the starry sky for orientation, a feat that has, to our knowledge, never been demonstrated in an insect. Here, we show that dung beetles transport their dung balls along straight paths under a starlit sky but lose this ability under overcast conditions. In a planetarium, the beetles orientate equally well when rolling under a full starlit sky as when only the Milky Way is present. The use of this bidirectional celestial cue for orientation has been proposed for vertebrates, spiders, and insects, but never proven. This finding represents the first convincing demonstration for the use of the starry sky for orientation in insects and provides the first documented use of the Milky Way for orientation in the animal kingdom. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Need for Medical Geology in Space Exploration: Implications for the Journey to Mars and Beyond

NASA Technical Reports Server (NTRS)

Harrington, A. D.; Zeigler, R. A.; McCubbin, F. M.

2018-01-01

The previous manned missions to the Moon represent milestones in human ingenuity, perseverance, and intellectual curiosity. They also highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust "storm" generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness". It was further reported that the allergic response to the dust worsened with each exposure. The lower gravity environment exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. However, even then the returned samples could also put the Curators, technicians, and scientists at risk during processing and examination.

Motions of Celestial Bodies; Computer simulations

NASA Astrophysics Data System (ADS)

Butikov, Eugene

2014-10-01

This book is written for a wide range of graduate and undergraduate students studying various courses in physics and astronomy. It is accompanied by the award winning educational software package 'Planets and Satellites' developed by the author. This text, together with the interactive software, is intended to help students learn and understand the fundamental concepts and the laws of physics as they apply to the fascinating world of the motions of natural and artificial celestial bodies. The primary aim of the book is the understanding of the foundations of classical and modern physics, while their application to celestial mechanics is used to illustrate these concepts. The simulation programs create vivid and lasting impressions of the investigated phenomena, and provide students and their instructors with a powerful tool which enables them to explore basic concepts that are difficult to study and teach in an abstract conventional manner. Students can work with the text and software at a pace they can enjoy, varying parameters of the simulated systems. Each section of the textbook is supplied with questions, exercises, and problems. Using some of the suggested simulation programs, students have an opportunity to perform interesting mini-research projects in physics and astronomy.

Differentiated Instructional Strategies on Space Education for Sustained Capacity Building of Underprivileged School Students

NASA Astrophysics Data System (ADS)

Ghosh, Sumit

2016-07-01

Although innovations in space education were introduced in many developing countries with good intentions, too many changes and challenges in the existing system have often penalized those who needed them the most. Consequently, the students and teachers in the underprivileged schools face isolation, neglect and coupled with inadequate pedagogic attention, poor infrastructure and insufficient resources, inadvertently suffer. Surprisingly, these deprived school students possess cognitive capabilities of comprehending nature. One of the most compelling situations in Indian school education is that the syllabus is often modified haphazardly without the necessary groundwork and infrastructure to implement it. Apparently, there has neither been teaching nor learning on applied knowledge. Despite the growth in communication and technology applications in space education, inequalities continue to exist in developing countries. In our present society many crucial services are provided by space and it becomes imperative that students have a comprehensive knowledge of space and space based technologies. To realize these objectives, we have adopted a comprehensive and holistic capacity building mechanism which incorporates differentiated instructional strategy on teaching space education in underprivileged schools. Because differentiation and scaffolding techniques yield similar instructional goals, we have blended together both the approaches to the point of being indistinguishable and this proved successful. Initiation was done through the setting up of an Astronomy Club in a backward area in Hyderabad and necessary infrastructure was provided by one of the authors. A state of the art audio-visual room with LCD Projector for ICT mode of presentations of various astronomy and space topics, having a seating capacity of 50 students is in place. A laptop, printer and Wi-Fi connection exists. In addition, visual charts on various celestial phenomena and objects, inspirational portraits of important personalities who have contributed in this field are displayed. No astronomy session can be complete without night sky observations. To provide real time observational environment, an Alt-Azimuth mounted Reflecting astronomical Telescope with variety of eyepieces, Barlow lens, filters; a high powered Astro-Binoculars with tripod; spectrometer; sky atlas with charts; CCD camera; other observing aids etc ., were purchased with the generous contributions from the AGM foundation. When a membership drive to this club was initiated, it is needless to say, a tumultuous response was received from students and teachers as well as the local community members showing enthusiasm to join the club. Till date we have carried out night sky programs as well as important celestial events observations for all the stake holders. Not only we have been successful in enhancing the knowledge and skills of the deprived students but also elicited the general public on the various misconceptions and superstitious beliefs that are still prevalent with certain celestial occurrences in the country. Our endeavor has rekindled the student's interest for science; particularly space sciences so much so that, they have volunteered to take up space science based courses for their future higher education programs.

Analyzing the Formation of Ultra-compact Dwarfs through Stellar Populations

NASA Astrophysics Data System (ADS)

Seshadri, Anish; Wang, Carolyn; Romanowsky, Aaron J.; Martin-navarro, Ignacio

2017-01-01

Since their discovery in 1999, ultra-compact dwarfs (UCDs) have been the subjects of intense study. Their small size, yet tremendous mass, brings into question their place among celestial objects. Are they galaxies or globular clusters? The answer to this question could come from analyzing how they formed. Thus, the goal of this project is to test one of the theories for the formation of UCDs, the theory of tidal stripping.This project approaches the issue by looking at dwarf galaxies currently in the process of stripping to understand formation history. Over twenty such dwarf galaxies were identified and their stellar populations analyzed. Using modeling techniques on spectroscopic and photometric data, the age, metallicity, and color of each object was identified. By objectively categorizing each object into a stage of evolution in the process of tidal stripping, a virtual timeline was built for the formation of UCDs. Data for each object were plotted vs. stage of formation, with pristine dwarfs and UCDs signifying the endpoints. Trends in the data revealed a natural progression over all stages of evolution, showing that tidally stripped dwarfs likely represent an intermediate stage in the formation of UCDs.This research was supported by NSF Grant AST-1515084. Most of this work was carried out by high school students working under the auspices of the Science Internship Program at UC Santa Cruz.

Observation of Galactic Sources of Very High Energy γ-RAYS with the Magic Telescope

NASA Astrophysics Data System (ADS)

Bartko, H.

The MAGIC telescope with its 17m diameter mirror is today the largest operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on the Canary Island La Palma, at an altitude of 2200 m above sea level, as part of the Roque de los Muchachos European Northern Observatory. The MAGIC telescope detects celestial very high energy γ-radiation in the energy band between about 50 GeV and 10 TeV. Since the autumn of 2004 MAGIC has been taking data routinely, observing various objects, like supernova remnants (SNRs), γ-ray binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We briefly describe the observational strategy, the procedure implemented for the data analysis, and discuss the results of observations of Galactic Sources.

Neutron star evolution and emission

NASA Astrophysics Data System (ADS)

Epstein, R. I.; Edwards, B. C.; Haines, T. J.

1997-01-01

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.

X-ray Optics Development at MSFC

NASA Technical Reports Server (NTRS)

Sharma, Dharma P.

2017-01-01

Development of high resolution focusing telescopes has led to a tremendous leap in sensitivity, revolutionizing observational X-ray astronomy. High sensitivity and high spatial resolution X-ray observations have been possible due to use of grazing incidence optics (paraboloid/hyperboloid) coupled with high spatial resolution and high efficiency detectors/imagers. The best X-ray telescope flown so far is mounted onboard Chandra observatory launched on July 23,1999. The telescope has a spatial resolution of 0.5 arc seconds with compatible imaging instruments in the energy range of 0.1 to 10 keV. The Chandra observatory has been responsible for a large number of discoveries and has provided X-ray insights on a large number of celestial objects including stars, supernova remnants, pulsars, magnetars, black holes, active galactic nuclei, galaxies, clusters and our own solar system.

Double layers and circuits in astrophysics

NASA Technical Reports Server (NTRS)

Alfven, H.

1986-01-01

A simple circuit is applied to the energizing of auroral particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the Sun's axis which may give radiations detectable from Earth. Double layers in space should be classified as a new type of celestial object. It is suggested that X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). The way the most used textbooks in astrophysics treat concepts like double layers, critical velocity, pinch effects and circuits was studied. It is found that students using these textbooks remain essentially ignorant of even the existence of these, although some of the phenomena were discovered 50 yr ago.

An intelligent ground operator support system

NASA Technical Reports Server (NTRS)

Goerlach, Thomas; Ohlendorf, Gerhard; Plassmeier, Frank; Bruege, Uwe

1994-01-01

This paper presents first results of the project 'Technologien fuer die intelligente Kontrolle von Raumfahrzeugen' (TIKON). The TIKON objective was the demonstration of feasibility and profit of the application of artificial intelligence in the space business. For that purpose a prototype system has been developed and implemented for the operation support of the Roentgen Satellite (ROSAT), a scientific spacecraft designed to perform the first all-sky survey with a high-resolution X-ray telescope and to investigate the emission of specific celestial sources. The prototype integrates a scheduler and a diagnosis tool both based on artificial intelligence techniques. The user interface is menu driven and provides synoptic displays for the visualization of the system status. The prototype has been used and tested in parallel to an already existing operational system.

The first stage of Boeing's Delta 7326 arrives at Pad 17A, CCAS, in preparation for the Deep Space 1

NASA Technical Reports Server (NTRS)

1998-01-01

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers remove the protective covering from NASA's Deep Space 1 spacecraft in the Payload Hazardous Servicing Facility at KSC to prepare it for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Real-time detection of optical transients with RAPTOR

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

Borozdin, K. N.; Brumby, Steven P.; Galassi, M. C.

2002-01-01

Fast variability of optical objects is an interesting though poorly explored subject in modern astronomy. Real-time data processing and identification of transient, celestial events in the images is very important, for such study as it allows rapid follow-up with more sensitive instruments, We discuss an approach which we have chosen for the RAPTOR project which is a pioneering close-loop system combining real-time transient detection with rapid follow-up. Our data processing pipeline is able to identify and localize an optical transient within seconds after the observation. We describe the challenges we met, solutions we found and some results obtained in ourmore » search for fast optical transients. The software pipeline we have developed for RAPTOR can easily be applied to the data from other experiments.« less

Close encounters with PHOBOS

NASA Astrophysics Data System (ADS)

Zakharov, A. V.

1988-07-01

Aspects of the Soviet mission to Phobos are examined, including the objectives of the mission, the spapcecraft, experiments, and landers. Past Mars research and unanswered questions concerning Mars and its satellites are discussed. The spacecraft is expected to reach Mars in early 1989 and to observe the planet from two orbits, coming as close as 500 km from the surface, before moving into a third path close to Phobos. After studying the Phobos terrain from above, the craft will jettison one or two small long-duration automated landers, which will perform surface experiments, including work on celestial mechanics, the history of the Phobos orbit, surface composition, and mechanical properties. In addition to studying Phobos and Mars, the craft will examine the interplanetary medium, make observations of the Sun, and possibly study Deimos.

Twist-induced guidance in coreless photonic crystal fiber: A helical channel for light.

PubMed

Beravat, Ramin; Wong, Gordon K L; Frosz, Michael H; Xi, Xiao Ming; Russell, Philip St J

2016-11-01

A century ago, Einstein proposed that gravitational forces were the result of the curvature of space-time and predicted that light rays would deflect when passing a massive celestial object. We report that twisting the periodically structured "space" within a coreless photonic crystal fiber creates a helical channel where guided modes can form despite the absence of any discernible core structure. Using a Hamiltonian optics analysis, we show that the light rays follow closed spiral or oscillatory paths within the helical channel, in close analogy with the geodesics of motion in a two-dimensional gravitational field. The mode diameter shrinks, and its refractive index rises, as the twist rate increases. The birefringence, orbital angular momentum, and dispersion of these unusual modes are explored.

KSC-98pc1152

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility (PHSF) place a rolled-up document inside Deep Space 1. The paper was signed by the workers in the PHSF. Deep Space 1 is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1071

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- Arriving in the early morning hours at Pad 17A, Cape Canaveral Air Station, the fairing for Deep Space 1 is lifted from the truck before being raised to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1153

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Through the open panel of Deep Space 1 can be seen the rolled-up document (on the left) signed by the workers in the Payload Hazardous Servicing Facility. Deep Space 1 is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1382

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- Lighting up the launch pad, a Boeing Delta II (7326) rocket propels Deep Space 1 through the morning clouds after liftoff from Launch Complex 17A, Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

The development of the imaging polarimeter's polarizer on the basis of the polarizing film

NASA Astrophysics Data System (ADS)

Vidmachenko, A. P.; Ivanov, Yu. S.; Syniavskyi, I. I.

2015-07-01

Work has begun on the developing of the scientific equipment "Spectrometer polarimeter", which is planned as one of five devices that form part of the Russian-Ukrainian space experiment "Planetary Monitoring". The devices are designed to form images of celestial objects in the focal plane of a planetary telescope (PT-600) and to register spectral and polarimetric information on gas and aerosol composition of the atmospheres of planets and physics and chemical properties of the surface layers of atmosphereless astronomical bodies. A model of a polarizer based on the use of polarizing films has been designed. This model can be used in the spectrometer-polarimeter. The results of the investigation of the polarizer in the spectral range 420-850 nm are given.

Evidence for black holes.

PubMed

Begelman, Mitchell C

2003-06-20

Black holes are common objects in the universe. Each galaxy contains large numbers-perhaps millions-of stellar-mass black holes, each the remnant of a massive star. In addition, nearly every galaxy contains a supermassive black hole at its center, with a mass ranging from millions to billions of solar masses. This review discusses the demographics of black holes, the ways in which they interact with their environment, factors that may regulate their formation and growth, and progress toward determining whether these objects really warp spacetime as predicted by the general theory of relativity.

The first Messenger data supporting main theses of the wave planetology

NASA Astrophysics Data System (ADS)

Kochemasov, G. G.

2008-09-01

The first fundamental statement of the wave planetology [1-6 & others] is about ubiquity of tectonic dichotomy. All celestial bodies move, as it was established by I. Kepler, in non-round but elliptical orbits. This means that they all notwithstanding their sizes, masses, physical states and chemical compositions have alternating increasing and decreasing accelerations producing forces (Newton: F = m·a) warping celestial bodies. This wave warping rotating bodies (but all bodies rotate!) is decomposed into four orthogonal and diagonal directions of standing waves. An interference of these directions gives tectonic blocks of three kinds: uplifting (+), subsiding (-) and neutral (0). The block sizes depend on warping wavelengths. The fundamental wave long 2πR (R - a body radius) is present in all bodies thus making one hemisphere rising and the opposite one falling (more precise relation is 1/3 to 2/3 or 2/3 to 1/3). A geometrical proof of this relation is given in [6] where two famous tectonic dichotomies of Earth and Mars were explained by one wave reason. This ubiquitous phenomenon was described as the first theorem of the wave planetology: "Celestial bodies are dichotomous". There are many examples proving it among planets, satellites and asteroids, even Sun is dichotomous. But up to recent time the studied partially Mercury's surface was not a good example of this phenomenon as not fully visible Caloris basin didn't show its real dimension. Now, after the Messenger flyby we know that it is about 1500 km in diameter, that is about 1/3 of the Mercury's diameter and the rule is not violated. The third theorem of the wave planetary tectonics states: "Celestial bodies are granular". This means that celestial bodies are warped by individual waves lengths of which are inversely proportional to their orbital frequencies: higher frequency - finer granules, lower frequency - larger granules (Fig. 1). Observations fully support it not only in sense of granules diameters but also in granules amplitudes reflected in planetary relief range. It increases with the solar distances: Venus ~14, Earth ~20, Mars ~28-30 km. Without good topography on Mercury we theoretically assumed that this planet's relief range must be significantly lower (3-6 km) just to not violate the observed sequence (Fig. 2). The Messenger's measurements show that the real range does not exceed ~5 km. (small vertical relief differentiation is accompanied by small petrological differentiation expressed by a low albedo range, Fig. 2). One of Mercury's surprises is Caloris basin. Basins on planetary surfaces are normally lowlands filled with denser material (basalts for the terrestrial planets). Subsiding tectonic blocks - depressions - basins - occupying narrower and narrower space must be contracted, squeezed, wrinkled, rippled. This is confirmed in many occasions. But in the case of Caloris there is an extension confirmed by concentric and radial cracks. Uplifting and extending basin is a consequence of the wave tectonics. Waves have two phases (up and down) and a period after which the phases change. That is why initially subsided block - basin now (it started maybe a few milliards or hundreds millions years ago: the larger block - the longer wave phase period) experiences uplifting with extension. Is it the only case in the Solar system? Quite not. And Earth is a good example. Its southern mainly oceanic (thus subsided) hemisphere is filled with basalts, what is normal for planetary depressions. But precise geodynamic measurements show that the southern hemisphere increases lengths of its parallels that is expending. This dynamics is confirmed by widening modern planetary rifts in Atlantic, Indian ocean, Pacific in the southern direction and around Antarctic ("Southern" ocean) - a kind of the radial-concentric structure. A geochemical anomaly in oceanic basalts of this region ("DUPAL" anomaly after S.R. Hart, 1984) is characterized by relatively high Rb/Sr, Th/Pb, Th/U - a continental (uplifting) trend related to potassium enrichment. P. Castillo (1988) correlates this the largest mantle geochemical anomaly with a zone of decreased seismic velocities in the lower mantle - again decreased densities are tied to uplifting. The majority of hotspots are above the low velocity regions. Mesozoic continental flood basalts of the southern hemisphere (the Ferrar magmatic province) are low-Ti and high in Si, Rb/Sr, 87Sr/86Sr (initial 0. 707 - 0. 713)[7]. So, the shrunk planet due to cooling and important loss of volatiles [8] is no exception from the regular row of planets structurized by wave warping according to their solar distances.

Skylore of the Indigenous Peoples of Northern Eurasia

NASA Astrophysics Data System (ADS)

Frank, Roslyn M.

This chapter examines the skylore of the indigenous peoples of northern Eurasia, paying particular attention to the commonalities found among them as well as the differences. Special attention is placed on the motif of the Cosmic Hunt and its diverse manifestations across the study area as well as on the oral nature of the celestial beliefs of these groups. The stars of a variety of "Western" constellation figures are implicated in the narratives and in some cases are clearly utilized in social practice for celestial navigation. The role played by the underlying hunter-gatherer mode of subsistence in shaping their cultural conceptualizations, their skyscapes, and the overarching cosmology of these peoples is also addressed.

Compact optics for high resolution spectroscopy of celestial x-ray sources

NASA Astrophysics Data System (ADS)

Cash, W.; Lillie, C.; McEntaffer, R.; Zhang, W.

2011-05-01

The astronomy community has never flown a celestial source spectrograph that can resolve natural line widths in absorption the way the ultraviolet community since OAO-3 Copernicus in 1972. Yet there is important science to be mined there, and right now there are now missions on track to pursue it. We present a modified off-plane grating spectrograph design that will support high resolution (λ/δλ ~ 4000) in the soft x-ray band with a high packing density that will enable a modest cost space mission. We discuss the design for the WHIMEx mission which was proposed as an Explorer earlier this year with the goal of detecting high temperature oxygen in the Intergalactic Medium.

Archaeoastronomy and Calendar Cities

NASA Astrophysics Data System (ADS)

Campion, Nicholas

2016-02-01

The use of astronomy for collective purposes, both religious and political, is apparent in the earliest astronomical records, from the evidence for Palaeolithic lunar calendars to megalithic monuments and Mesopotamian celestial-omen reports. This paper will consider the application of the heavens to the organisation of the ‘Cosmic State’, the human polity modelled on the assumption of a close relationship between society on the one hand and planetary and stellar patterns on the other. I will also examine the foundation of Baghdad within the tradition of celestial town planning and argue that the city may be seen as a ‘talisman’, designed to connect heaven to Earth and ensure peace, stability and political success by harmonising time and space.

The Cosmology Gallery: Unity through diversity in a vast and awe-inspiring universe.

NASA Astrophysics Data System (ADS)

Goldsmith, John

2011-06-01

Scientists, artists, religious and cultural leaders have come together to create the Cosmology Gallery at the Gravity Discovery Centre (GDC) located 70 km north of Perth, Western Australia. The Cosmology Gallery exhibitions include the multicultural cosmology artworks, Celestial Visions astronomical photography exhibition and the Timeline of the Universe. The multicultural cosmology artworks are new artworks inspired by Australian Indigenous, Christian, Buddhist, Islamic, Hindu, scientific and technological perspectives of the universe. The Celestial Visions exhibition features astronomical events above famous landmarks, including Stonehenge and the Pyramids. The AUD 400,000+ project was funded by Lotterywest, Western Australia and the Cosmology Gallery was officially opened in July 2008 by the Premier of Western Australia.

Determination of celestial bodies orbits and probabilities of their collisions with the Earth

NASA Astrophysics Data System (ADS)

Medvedev, Yuri; Vavilov, Dmitrii

In this work we have developed a universal method to determine the small bodies orbits in the Solar System. In the method we consider different planes of body’s motion and pick up which is the most appropriate. Given an orbit plane we can calculate geocentric distances at time of observations and consequence determinate all orbital elements. Another technique that we propose here addresses the problem of estimation probability of collisions celestial bodies with the Earth. This technique uses the coordinate system associated with the nominal osculating orbit. We have compared proposed technique with the Monte-Carlo simulation. Results of these methods exhibit satisfactory agreement, whereas, proposed method is advantageous in time performance.

A Mechanical Principle for Acquisition of useful Power on a Celestial Body Through Utilisation of its Planetary Precession

NASA Astrophysics Data System (ADS)

Vulkov, K.

In consequence of the phenomenon of planetary precession there emerges a possibility for acquisition of power through utilisation of the rotary motions in the universe. The idea is to acquire useful power on the working shaft of a properly designed machine installed on a celestial body (planet), at the expense of the motional energy of the latter. Strange as it may appear, this is possible if only the regulation of the machine be brought in line with the parameters of the precession. The principle of action of such a planetary engine, including an energy balance, is put forward in the present paper.

Orientations of the Villas at Tylissos on Crete and their Relationships to the Minoan Calendar

NASA Astrophysics Data System (ADS)

Henriksson, Göran; Blomberg, Mary

2015-05-01

The two Late Minoan I villas at Tylissos and an unknown earlier building at the site show similar relationships to the celestial bodies that we have encountered at all of the Minoan buildings that we have studied. They had orientations to celestial events relevant to the calendar, such as sunrise or sunset at the equinoxes and the solstices, and the heliacal risings and settings of bright stars. We also re-encountered the phenomenon that different places marked the beginning of one or more solar months, which suggests that certain months had special relevance for specific places, as if to honor a god or goddess or some other special event for that particular place. In addition, the orientations of the two Late Minoan I villas at Tylissos share the same complexity that we have met at two other sites, where diagonal lines were used to create shadows when marking the parts of the calendar that were specific for Tylissos. It now seems clear that an element of Minoan cosmology insisted on a close connection between their places on earth and the celestial sphere. It was the custom for the Mycenaeans and the Greeks, who later inhabited the island, to honor their deities in special months, and we may find the roots of this custom among the Minoans.

Time-Dependent Selection of an Optimal Set of Sources to Define a Stable Celestial Reference Frame

NASA Technical Reports Server (NTRS)

Le Bail, Karine; Gordon, David

2010-01-01

Temporal statistical position stability is required for VLBI sources to define a stable Celestial Reference Frame (CRF) and has been studied in many recent papers. This study analyzes the sources from the latest realization of the International Celestial Reference Frame (ICRF2) with the Allan variance, in addition to taking into account the apparent linear motions of the sources. Focusing on the 295 defining sources shows how they are a good compromise of different criteria, such as statistical stability and sky distribution, as well as having a sufficient number of sources, despite the fact that the most stable sources of the entire ICRF2 are mostly in the Northern Hemisphere. Nevertheless, the selection of a stable set is not unique: studying different solutions (GSF005a and AUG24 from GSFC and OPA from the Paris Observatory) over different time periods (1989.5 to 2009.5 and 1999.5 to 2009.5) leads to selections that can differ in up to 20% of the sources. Observing, recording, and network improvement are some of the causes, showing better stability for the CRF over the last decade than the last twenty years. But this may also be explained by the assumption of stationarity that is not necessarily right for some sources.

On the foundations of general relativistic celestial mechanics

NASA Astrophysics Data System (ADS)

Battista, Emmanuele; Esposito, Giampiero; Dell'Agnello, Simone

2017-09-01

Towards the end of nineteenth century, Celestial Mechanics provided the most powerful tools to test Newtonian gravity in the solar system and also led to the discovery of chaos in modern science. Nowadays, in light of general relativity, Celestial Mechanics leads to a new perspective on the motion of satellites and planets. The reader is here introduced to the modern formulation of the problem of motion, following what the leaders in the field have been teaching since the nineties, in particular, the use of a global chart for the overall dynamics of N bodies and N local charts describing the internal dynamics of each body. The next logical step studies in detail how to split the N-body problem into two sub-problems concerning the internal and external dynamics, how to achieve the effacement properties that would allow a decoupling of the two sub-problems, how to define external-potential-effacing coordinates and how to generalize the Newtonian multipole and tidal moments. The review paper ends with an assessment of the nonlocal equations of motion obtained within such a framework, a description of the modifications induced by general relativity on the theoretical analysis of the Newtonian three-body problem, and a mention of the potentialities of the analysis of solar-system metric data carried out with the Planetary Ephemeris Program.

Polarized light use in the nocturnal bull ant, Myrmecia midas.

PubMed

Freas, Cody A; Narendra, Ajay; Lemesle, Corentin; Cheng, Ken

2017-08-01

Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant, Myrmecia midas . We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1-2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts.

A Ka-Band Celestial Reference Frame with Applications to Deep Space Navigation

NASA Technical Reports Server (NTRS)

Jacobs, Christopher S.; Clark, J. Eric; Garcia-Miro, Cristina; Horiuchi, Shinji; Sotuela, Ioana

2011-01-01

The Ka-band radio spectrum is now being used for a wide variety of applications. This paper highlights the use of Ka-band as a frequency for precise deep space navigation based on a set of reference beacons provided by extragalactic quasars which emit broadband noise at Ka-band. This quasar-based celestial reference frame is constructed using X/Ka-band (8.4/32 GHz) from fifty-five 24-hour sessions with the Deep Space Network antennas in California, Australia, and Spain. We report on observations which have detected 464 sources covering the full 24 hours of Right Ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the international standard S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of approximately 200 micro-arcsec in alpha cos(delta) and approximately 300 micro-arcsec in delta. There is evidence for systematic errors at the 100 micro-arcsec level. Known errors include limited SNR, lack of instrumental phase calibration, tropospheric refraction mis-modeling, and limited southern geometry. The motivation for extending the celestial reference frame to frequencies above 8 GHz is to access more compact source morphology for improved frame stability and to support spacecraft navigation for Ka-band based NASA missions.

Method based on artificial excitation of characteristic radiation by an electron beam for remote X-ray spectral elemental analysis of surface rocks on atmosphereless celestial bodies

NASA Astrophysics Data System (ADS)

Kolesnikov, E. K.

2016-11-01

This article, like our previous one [1], is devoted to advanced space technology concepts. It evaluates the potential for developing active systems to conduct a remote elemental analysis of surface rocks on an atmosphereless celestial body. The analysis is based on the spectrometry of characteristic X-rays (CXR) artificially excited in the surface soil layer. It has been proposed to use an electron beam injected from aboard a spacecraft orbiting the celestial body (or moving in a flyby trajectory) to excite the CXR elements contained in surface rocks. The focus is on specifying technical requirements to the parameters of payloads for a global mapping of the composition of lunar rocks from aboard of a low-orbiting lunar satellite. This article uses the results obtained in [2], our first study that shows the potential to develop an active system for a remote elemental analysis of lunar surface rocks using the above method. Although there has been interest in our research on the part of leading national academic institutions and space technology developers in the Soviet Union, the studies were discontinued because of the termination of the Soviet lunar program and the completion of the American Apollo program.

Polarized light use in the nocturnal bull ant, Myrmecia midas

PubMed Central

Lemesle, Corentin; Cheng, Ken

2017-01-01

Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant, Myrmecia midas. We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1−2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts. PMID:28879002

NICER Mission Overview, Status, and GO opportunities

NASA Astrophysics Data System (ADS)

Gendreau, Keith C.

2018-01-01

The Neutron Interior Composition Explorer (NICER) was launched in June 2017 to the International Space Station (ISS) where it is studying the time-domain X-ray sky. NICER consists of a collection of X-ray concentrators, silicon drift detectors, an optical bench, and pointing system that together provide a large collection area in the soft (0.2-12 keV) X-ray bandpass. NICER time-stamps individual X-ray photons to an absolute precision of better than 100 nanoseconds while providing moderate CCD-like energy resolution. Since installation, NICER has observed over 100 celestial targets including neutron stars and other objects. The NICER team accepts target of opportunity (TOO) requests for consideration. In addition, NICER will be demonstrating the use of some millisecond pulsars as navigational beacons. NICER will complete its baseline mission in January 2019 with data beginning to be made public in January 2018. Conditional on the status of its baseline science objectives, NICER will be open to a guest observer program with first round proposals due in mid 2018 for observations beginning in 2019.

Computational algorithms dealing with the classical and statistical mechanics of celestial scale polymers in space elevator technology

NASA Astrophysics Data System (ADS)

Knudsen, Steven; Golubovic, Leonardo

Prospects to build Space Elevator (SE) systems have become realistic with ultra-strong materials such as carbon nano-tubes and diamond nano-threads. At cosmic length-scales, space elevators can be modeled as polymer like floppy strings of tethered mass beads. A new venue in SE science has emerged with the introduction of the Rotating Space Elevator (RSE) concept supported by novel algorithms discussed in this presentation. An RSE is a loopy string reaching into outer space. Unlike the classical geostationary SE concepts of Tsiolkovsky, Artsutanov, and Pearson, our RSE exhibits an internal rotation. Thanks to this, objects sliding along the RSE loop spontaneously oscillate between two turning points, one of which is close to the Earth whereas the other one is in outer space. The RSE concept thus solves a major problem in SE technology which is how to supply energy to the climbers moving along space elevator strings. The investigation of the classical and statistical mechanics of a floppy string interacting with objects sliding along it required development of subtle computational algorithms described in this presentation

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies

PubMed Central

Grob, Robin; Fleischmann, Pauline N.; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance—presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system. PMID:29184487

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies.

PubMed

Grob, Robin; Fleischmann, Pauline N; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance-presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system.

How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation.

PubMed

Pomozi, I; Horváth, G; Wehner, R

2001-09-01

One of the biologically most important parameters of the cloudy sky is the proportion P of the celestial polarization pattern available for use in animal navigation. We evaluated this parameter by measuring the polarization patterns of clear and cloudy skies using 180 degrees (full-sky) imaging polarimetry in the red (650 nm), green (550 nm) and blue (450 nm) ranges of the spectrum under clear and partly cloudy conditions. The resulting data were compared with the corresponding celestial polarization patterns calculated using the single-scattering Rayleigh model. We show convincingly that the pattern of the angle of polarization (e-vectors) in a clear sky continues underneath clouds if regions of the clouds and parts of the airspace between the clouds and the earth surface (being shady at the position of the observer) are directly lit by the sun. The scattering and polarization of direct sunlight on the cloud particles and in the air columns underneath the clouds result in the same e-vector pattern as that present in clear sky. This phenomenon can be exploited for animal navigation if the degree of polarization is higher than the perceptual threshold of the visual system, because the angle rather than the degree of polarization is the most important optical cue used in the polarization compass. Hence, the clouds reduce the extent of sky polarization pattern that is useful for animal orientation much less than has hitherto been assumed. We further demonstrate quantitatively that the shorter the wavelength, the greater the proportion of celestial polarization that can be used by animals under cloudy-sky conditions. As has already been suggested by others, this phenomenon may solve the ultraviolet paradox of polarization vision in insects such as hymenopterans and dipterans. The present study extends previous findings by using the technique of 180 degrees imaging polarimetry to measure and analyse celestial polarization patterns.

NuSTAR: system engineering and modeling challenges in pointing reconstruction for a deployable x-ray telescope

NASA Astrophysics Data System (ADS)

Harp, D. Isaiah; Liebe, Carl Christian; Craig, William; Harrison, Fiona; Kruse-Madsen, Kristin; Zoglauer, Andreas

2010-07-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will make the first sensitive images of the sky in the high energy X-ray band (6 - 80 keV). The NuSTAR observatory consists of two co-aligned grazing incidence hard X-ray telescopes with a ~10 meter focal length, achieved by the on-orbit extension of a deployable mast. A principal science objective of the mission is to locate previously unknown high-energy X-ray sources to an accuracy of 10 arcseconds (3-sigma), sufficient to uniquely identify counterparts at other wavelengths. In order to achieve this, a star tracker and laser metrology system are an integral part of the instrument; in conjunction, they will determine the orientation of the optics bench in celestial coordinates and also measure the flexures in the deployable mast as it responds to the varying on-orbit thermal environment, as well as aerodynamic and control torques. The architecture of the NuSTAR system for solving the attitude and aspect problems differs from that of previous X-ray telescopes, which did not require ex post facto reconstruction of the instantaneous observatory alignment on-orbit. In this paper we describe the NuSTAR instrument metrology system architecture and implementation, focusing on the systems engineering challenges associated with validating the instantaneous transformations between focal plane and celestial coordinates to within the required accuracy. We present a mathematical solution to photon source reconstruction, along with a detailed error budget that relates component errors to science performance. We also describe the architecture of the instrument simulation software being used to validate the end-to-end performance model.

Monthly gravity field solutions based on GRACE observations generated with the Celestial Mechanics Approach

NASA Astrophysics Data System (ADS)

Meyer, Ulrich; Jäggi, Adrian; Beutler, Gerhard

2012-09-01

The main objective of the Gravity Recovery And Climate Experiment (GRACE) satellite mission consists of determining the temporal variations of the Earth's gravity field. These variations are captured by time series of gravity field models of limited resolution at, e.g., monthly intervals. We present a new time series of monthly models, which was computed with the so-called Celestial Mechanics Approach (CMA), developed at the Astronomical Institute of the University of Bern (AIUB). The secular and seasonal variations in the monthly models are tested for statistical significance. Calibrated errors are derived from inter-annual variations. The time-variable signal can be extracted at least up to degree 60, but the gravity field coefficients of orders above 45 are heavily contaminated by noise. This is why a series of monthly models is computed up to a maximum degree of 60, but only a maximum order of 45. Spectral analysis of the residual time-variable signal shows a distinctive peak at a period of 160 days, which shows up in particular in the C20 spherical harmonic coefficient. Basic filter- and scaling-techniques are introduced to evaluate the monthly models. For this purpose, the variability over the oceans is investigated, which serves as a measure for the noisiness of the models. The models in selected regions show the expected seasonal and secular variations, which are in good agreement with the monthly models of the Helmholtz Centre Potsdam, German Research Centre for Geosciences (GFZ). The results also reveal a few small outliers, illustrating the necessity for improved data screening. Our monthly models are available at the web page of the International Centre for Global Earth Models (ICGEM).

Impact of quasar proper motions on the alignment between the International Celestial Reference Frame and the Gaia reference frame

NASA Astrophysics Data System (ADS)

Liu, J.-C.; Malkin, Z.; Zhu, Z.

2018-03-01

The International Celestial Reference Frame (ICRF) is currently realized by the very long baseline interferometry (VLBI) observations of extragalactic sources with the zero proper motion assumption, while Gaia will observe proper motions of these distant and faint objects to an accuracy of tens of microarcseconds per year. This paper investigates the difference between VLBI and Gaia quasar proper motions and it aims to understand the impact of quasar proper motions on the alignment of the ICRF and Gaia reference frame. We use the latest time series data of source coordinates from the International VLBI Service analysis centres operated at Goddard Space Flight Center (GSF2017) and Paris observatory (OPA2017), as well as the Gaia auxiliary quasar solution containing 2191 high-probability optical counterparts of the ICRF2 sources. The linear proper motions in right ascension and declination of VLBI sources are derived by least-squares fits while the proper motions for Gaia sources are simulated taking into account the acceleration of the Solar system barycentre and realistic uncertainties depending on the source brightness. The individual and global features of source proper motions in GSF2017 and OPA2017 VLBI data are found to be inconsistent, which may result from differences in VLBI observations, data reduction and analysis. A comparison of the VLBI and Gaia proper motions shows that the accuracies of the components of rotation and glide between the two systems are 2-4 μas yr- 1 based on about 600 common sources. For the future alignment of the ICRF and Gaia reference frames at different wavelengths, the proper motions of quasars must necessarily be considered.

Kilohoku Ho`okele Wa`a : Astronomy of the Hawaiian Navigators

NASA Astrophysics Data System (ADS)

Slater, Stephanie; Slater, Timothy F.; Baybayan, Kalepa C.

2016-01-01

This poster provides an introduction to the astronomy of the Hawaiian wayfinders, Kilohoku Ho`okele Wa`a. Rooted in a legacy of navigation across the Polynesian triangle, wayfinding astronomy has been part of a suite of skills that allows navigators to deliberately hop between the small islands of the Pacific, for thousands of years. Forty years ago, in one manifestation of the Hawaiian Renaissance, our teachers demonstrated that ancient Hawaiians were capable of traversing the wide Pacific to settle and trade on islands separated by thousands of miles. Today those same mentors train a new generation of navigators, making Hawaiian voyaging a living, evolving, sustainable endeavor. This poster presents two components of astronomical knowledge that all crewmen, but particularly those in training to become navigators, learn early in their training. Na Ohana Hoku, the Hawaiian Star Families constitute the basic units of the Hawaiian sky. In contrast to the Western system of 88 constellations, Na Ohana Hoku divides the sky into four sections that each run from the northern to the southern poles. This configuration reduces cognitive load, allowing the navigator to preserve working memory for other complex tasks. In addition, these configurations of stars support the navigator in finding and generatively using hundreds of individual, and navigationally important pairs of stars. The Hawaiian Star Compass divides the celestial sphere into a directional system that uses 32 rather than 8 cardinal points. Within the tropics, the rising and setting of celestial objects are consistent within the Hawaiian Star Compass, providing for extremely reliable direction finding. Together, Na Ohana Hoku and the Hawaiian Star Compass provide the tropical navigator with astronomical assistance that is not available to, and would have been unknown to Western navigators trained at higher latitudes.

Kilohoku Ho`okele Wa`a : Astronomy of the Modern Hawaiian Wayfinders

NASA Astrophysics Data System (ADS)

Ha`o, Celeste; Dye, Ahia G.; Slater, Stephanie J.; Slater, Timothy F.; Baybayan, Kalepa

2015-08-01

This paper provides an introduction to Kilohoku Ho`okele Wa`a, the astronomy of the Hawaiian wayfinders. Rooted in a legacy of navigation across the Polynesian triangle, wayfinding astronomy has been part of a suite of skills that allows navigators to deliberately hop between the small islands of the Pacific, for thousands of years. Forty years ago, in one manifestation of the Hawaiian Renaissance, our teachers demonstrated that ancient Hawaiians were capable of traversing the wide Pacific to settle and trade on islands separated by thousands of miles. Today those same mentors train a new generation of navigators, making Hawaiian voyaging a living, evolving, sustainable endeavor. This paper presents two components of astronomical knowledge that all crewmen, but particularly those in training to become navigators, learn early in their training. Na Ohana Hoku, the Hawaiian Star Families constitute the basic units of the Hawaiian sky. In contrast to the Western system of 88 constellations, Na Ohana Hoku divides the sky into four sections that each run from the northern to the southern poles. This configuration reduces cognitive load, allowing the navigator to preserve working memory for other complex tasks. In addition, these configurations of stars support the navigator in finding and generatively using hundreds of individual, and navigationally important pairs of stars. The Hawaiian Star Compass divides the celestial sphere into a directional system that uses 32 rather than 8 cardinal points. Within the tropics, the rising and setting of celestial objects are consistent within the Hawaiian Star Compass, providing for extremely reliable direction finding. Together, Na Ohana Hoku and the Hawaiian Star Compass provide the tropical navigator with astronomical assistance that is not available to, and would have been unknown to Western navigators trained at higher latitudes.

Systematic analysis of funding awarded for mycology research to institutions in the UK, 1997–2010

PubMed Central

Head, Michael G; Fitchett, Joseph R; Atun, Rifat; May, Robin C

2014-01-01

Objectives Fungal infections cause significant global morbidity and mortality. We have previously described the UK investments in global infectious disease research, and here our objective is to describe the investments awarded to UK institutions for mycology research and outline potential funding gaps in the UK portfolio. Design Systematic analysis. Setting UK institutions carrying out infectious disease research. Primary and secondary outcome measures Primary outcome is the amount of funding and number of studies related to mycology research. Secondary outcomes are describing the investments made to specific fungal pathogens and diseases, and also the type of science along the R&D value chain. Methods We systematically searched databases and websites for information on research studies from public and philanthropic funding institutions awarded between 1997 and 2010, and highlighted the mycology-related projects. Results Of 6165 funded studies, we identified 171 studies related to mycology (total investment £48.4 million, 1.9% of all infection research, with mean annual funding £3.5 million). Studies related to global health represented 5.1% of this funding (£2.4 million, compared with 35.6% of all infectious diseases). Leading funders were the Biotechnology and Biological Sciences Research Council (£14.8 million, 30.5%) and Wellcome Trust (£12.0 million, 24.7%). Preclinical studies received £42.2 million (87.3%), with clinical trials, intervention studies and implementation research in total receiving £6.2 million (12.7%). By institution, University of Aberdeen received most funding (£16.9 million, 35%). Studies investigating antifungal resistance received £1.5 million (3.2%). Conclusions There is little translation of preclinical research into clinical trials or implementation research in spite of substantial disease burden globally, and there are few UK institutions that carry out significant quantities of mycology research of any type. In the context of global health and the burden of disease in low-income countries, more investment is required for mycology research. PMID:24413353

Observations of VHE γ-Ray Sources with the MAGIC Telescope

NASA Astrophysics Data System (ADS)

Bartko, H.

2008-10-01

The MAGIC telescope with its 17m diameter mirror is today the largest operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on the Canary Island La Palma, at an altitude of 2200m above sea level, as part of the Roque de los Muchachos European Northern Observatory. The MAGIC telescope detects celestial very high energy γ-radiation in the energy band between about 50 GeV and 10 TeV. Since Autumn of 2004 MAGIC has been taking data routinely, observing various objects like supernova remnants (SNRs), γ-ray binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We briefly describe the observational strategy, the procedure implemented for the data analysis, and discuss the results for individual sources. An outlook to the construction of the second MAGIC telescope is given.

n/a

NASA Image and Video Library

1962-04-27

The Apollo 16 Command Module splashed down in the Pacific Ocean on April 27, 1972 after an 11-day moon exploration mission. The 3-man crew is shown here aboard the rescue ship, USS Horton. From left to right are: Mission Commander John W. Young, Lunar Module pilot Charles M. Duke, and Command Module pilot Thomas K. Mattingly II. The sixth manned lunar landing mission, the Apollo 16 (SA-511) lifted off on April 16, 1972. The Apollo 16 mission continued the broad-scale geological, geochemical, and geophysical mapping of the Moon’s crust, begun by the Apollo 15, from lunar orbit. This mission marked the first use of the Moon as an astronomical observatory by using the ultraviolet camera/spectrograph which photographed ultraviolet light emitted by Earth and other celestial objects. The Lunar Roving Vehicle, developed by the Marshall Space Flight Center, was also used.

PHOTOMETRY OF VARIABLE STARS FROM DOME A, ANTARCTICA: RESULTS FROM THE 2010 OBSERVING SEASON

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

Wang, Lingzhi; Zhu, Zonghong; Macri, Lucas M.

We present results from a season of observations with the Chinese Small Telescope ARray, obtained over 183 days of the 2010 Antarctic winter. We carried out high-cadence time-series aperture photometry of 9125 stars with i ∼< 15.3 mag located in a 23 deg{sup 2} region centered on the south celestial pole. We identified 188 variable stars, including 67 new objects relative to our 2008 observations, thanks to broader synoptic coverage, a deeper magnitude limit, and a larger field of view. We used the photometric data set to derive site statistics from Dome A. Based on two years of observations, wemore » find that extinction due to clouds at this site is less than 0.1 and 0.4 mag during 45% and 75% of the dark time, respectively.« less

Search for dark matter WIMPs using upward through-going muons in Super-Kamiokande

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

Desai, S.; Earl, M.; Kearns, E.

2004-10-15

We present the results of indirect searches for Weakly Interacting Massive Particles (WIMPs), with 1679.6 live days of data from the Super-Kamiokande detector using neutrino-induced upward through-going muons. The search is performed by looking for an excess of high energy muon neutrinos from WIMP annihilations in the Sun, the core of the Earth, and the Galactic Center, as compared to the number expected from the atmospheric neutrino background. No statistically significant excess was seen. We calculate the flux limits in various angular cones around each of the above celestial objects. We obtain conservative model-independent upper limits on the WIMP-nucleon crossmore » section as a function of WIMP mass, and compare these results with the corresponding results from direct dark matter detection experiments.« less

OSO-7 Orbiting Solar Observatory program

NASA Technical Reports Server (NTRS)

1972-01-01

The seventh Orbiting Solar Observatory (OSO-7) in the continuing series designed to gather solar and celestial data that cannot be obtained from the earth's surface is described. OSO-7 was launched September 29, 1971. It has been highly successful in returning scientific data giving new and important information about solar flare development, coronal temperature variations, streamer dynamics of plasma flow, and solar nuclear processes. OSO-7 is expected to have sufficient lifetime to permit data comparisons with the Skylab A mission during 1973. The OSO-7 is a second generation observatory. It is about twice as large and heavy as its predecessors, giving it considerably greater capability for scientific measurements. This report reviews mission objectives, flight history, and scientific experiments; describes the observatory; briefly compares OSO-7 with the first six OSO's; and summarizes the performance of OSO-7.