Science.gov

Sample records for solar system binaries

  1. Solar System binaries

    NASA Astrophysics Data System (ADS)

    Noll, Keith S.

    The discovery of binaries in each of the major populations of minor bodies in the solar system is propelling a rapid growth of heretofore unattainable physical information. The availability of mass and density constraints for minor bodies opens the door to studies of internal structure, comparisons with meteorite samples, and correlations between bulk-physical and surface-spectral properties. The number of known binaries is now more than 70 and is growing rapidly. A smaller number have had the extensive followup observations needed to derive mass and albedo information, but this list is growing as well. It will soon be the case that we will know more about the physical parameters of objects in the Kuiper Belt than has been known about asteroids in the Main Belt for the last 200 years. Another important aspect of binaries is understanding the mechanisms that lead to their formation and survival. The relative sizes and separations of binaries in the different minor body populations point to more than one mechanism for forming bound pairs. Collisions appear to play a major role in the Main Belt. Rotational and/or tidal fission may be important in the Near Earth population. For the Kuiper Belt, capture in multi-body interactions may be the preferred formation mechanism. However, all of these conclusions remain tentative and limited by observational and theoretical incompleteness. Observational techniques for identifying binaries are equally varied. High angular resolution observations from space and from the ground are critical for detection of the relatively distant binaries in the Main Belt and the Kuiper Belt. Radar has been the most productive method for detection of Near Earth binaries. Lightcurve analysis is an independent technique that is capable of exploring phase space inaccessible to direct observations. Finally, spacecraft flybys have played a crucial paradigm-changing role with discoveries that unlocked this now-burgeoning field.

  2. Orbital coplanarity in solar-type binary systems: Implications for planetary system formation and detection

    NASA Technical Reports Server (NTRS)

    Hale, Alan

    1994-01-01

    The equatorial inclinations of solar-type stars within visual binary systems are computed by combining v sin i measurements with rotational period information, or with expected rotational velocities based upon the age of the star in question. These inclinations are then compared with the orbital inclinations of the systems to test the alignment between the equatorial and orbital planes, and how the tendency for or against coplanarity varies as a function of parameters such as spectral type, separation, eccentricity, etc. The results are extended to planetary systems in order to determine the appropriateness of basing planetary search strategies upon a parent star's equatorial inclination, and to address issues in planetary system formation and evolution, including the stability of planetary orbits within binary systems. During the course of this project new or improved v sin i measurements are made for over 30 solar-type stars within binary systems, and (for the purposes of the study) tentative orbits are computed for thirteen long-period systems. The results suggest that approximate coplanarity between the equatorial and orbital planes exists solar-type binary systems with separations less than 30-40 AU. The coplanarity tendency, as well as this 'critical separation,' is not significantly affected by most of the other parameters studied. The one significant exception occurs with hierarchical multiple systems, where noncoplanarity may exist at relatively small separations. If it is assumed that planetary distances in our solar system are typical, the results suggest there is no reason to expect planets to orbit in planes significantly different from that of the parent star's equator, in turn suggesting that planetary formation models and search strategies dependent upon this assumption are valid from this standpoint. The results also suggest that noncoplanarity between the components of a binary system is not a significant issue in addressing the stability of

  3. Searching for Solar System Wide Binaries with Pan-STARRS-1

    NASA Astrophysics Data System (ADS)

    Holman, Matthew J.; Protopapas, P.; Tholen, D. J.

    2007-10-01

    Roughly 60% of the observing time of the Pan-STARRS-1 (PS1) telescope will be dedicated to a "3pi steradian" survey with an observing cadence that is designed for the detection of near-Earth asteroids and slow-moving solar system bodies. Over this course of its 3.5 year cience mission, this unprecedented survey will discover nearly every asteroid, Trojan, Centaur, long-period comet, short-period comet, and trans-neptunian object (TNO) brighter than magnitude R=23. This census will be used to address a large number of questions regarding the physical and dynamical properties of the various small body populations of the solar system. Roughly 1-2% of TNOs are wide binaries with companions at separations greater than 1 arcsec and brightness differences less than 2 magnitudes (Kern & Elliot 2006; Noll et al 2007). These can be readily detected by PS1; we will carry out such a search with PS1 data. To do so, we will modify the Pan-STARRS Moving Object Processing System (MOPS) such that it will associate the components of resolved or marginally resolved binaries, link such pairs of detections obtained at different epochs, and the estimate the relative orbit of the binary. We will also determine the efficiency with which such binaries are detected as a function of the binary's relative orbit and the relative magnitudes of the components. Based on an estimated 7000 TNOs that PS1 will discover, we anticipate finding 70-140 wide binaries. The PS1 data, 60 epochs over three years, is naturally suited to determining the orbits of these objects. Our search will accurately determine the binary fraction for a variety of subclasses of TNOs.

  4. Thermal phase diagram of acetamide-benzoic acid and benzoic acid-phthalimide binary systems for solar thermal applications

    NASA Astrophysics Data System (ADS)

    Kumar, Rohitash; Kumar, Ravindra; Dixit, Ambesh

    2016-05-01

    Thermal properties of Acetamide (AM) - Benzoic acid (BA) and Benzoic acid (BA) - Phthalimide (PM) binary eutectic systems are theoretically calculated using thermodynamic principles. We found that the binary systems of AM-BA at 67.6 : 32.4 molar ratio, BA-PM at 89.7 : 10.3 molar ratio form eutectic mixtures with melting temperatures ~ 54.5 °C and 114.3 °C respectively. Calculated latent heat of fusion for these eutectic mixtures are 191 kJ/kg and 146.5 kJ/kg respectively. These melting temperatures and heat of fusions of these eutectic mixtures make them suitable for thermal energy storage applications in solar water heating and solar cooking systems.

  5. The Frozen Earth: Binary Scattering Events and the Fate of the Solar System

    NASA Astrophysics Data System (ADS)

    Laughlin, Gregory; Adams, Fred C.

    2000-06-01

    Planetary systems that encounter passing stars can experience severe orbital disruption, and the efficiency of this process is enhanced when the impinging systems are binary pairs rather than single stars. Using a Monte Carlo approach to perform more than 200,000 Nbody integrations, we examine the ramifications of this scattering process for the long-term prospects of our own Solar System. After statistical processing of the results, we estimate an overall probability of order 2×10 -5 that Earth will find its orbit seriously disrupted prior to the emergence of a runaway greenhouse effect driven by the Sun's increasing luminosity. This estimate includes both direct disruption events and scattering processes that seriously alter the orbits of the jovian planets, which force severe changes upon the Earth's orbit. Our set of scattering experiments gives a number of other results. For example, there is about 1 chance in 2 million that Earth will be captured into orbit around another star before the onset of a runaway greenhouse effect. In addition, the odds of Neptune doubling its eccentricity are only one part in several hundred. We then examine the consequences of Earth being thrown into deep space. The surface biosphere would rapidly shut down under conditions of zero insolation, but the Earth's radioactive heat is capable of maintaining life deep underground, and perhaps in hydrothermal vent communities, for some time to come. Although unlikely for Earth, this scenario may be common throughout the universe, since many environments where liquid water could exist (e.g., Europa and Callisto) must derive their energy from internal (rather than external) heating.

  6. The Earth-Moon system as a typical binary in the Solar System

    NASA Astrophysics Data System (ADS)

    Ipatov, S.

    2014-07-01

    In recent years new arguments in favor of the formation of solid planetesimals by contraction of rarefied preplanetesimals (RPPs) have been found. It is often considered that masses of some RPPs can correspond to masses of solid bodies of diameter about 1000 km. [1] showed that in the vortices launched by the Rossby wave instability in the borders of the dead zone, the solids quickly achieve critical densities and undergo gravitational collapse into protoplanetary embryos in the mass range 0.1-0.6M_E (where M_E is the mass of the Earth). [2] and [3] supposed that transneptunian binaries were formed from RPPs. It was shown in [2] that the angular momenta acquired at collisions of RPPs moving in circular heliocentric orbits could have the same values as the angular momenta of discovered transneptunian and asteroid binaries. [4] obtained that the angular momenta used in [3] as initial data in calculations of the contraction of RPPs leading to formation of transneptunian binaries could be acquired at collisions of two RPPs moving in circular heliocentric orbits. I supposed that the fraction of RPPs collided with other RPPs during their contraction can be about the fraction of small bodies of diameter d>100 km with satellites (among all such small bodies), i.e., it can be about 0.3 for objects formed in the transneptunian belt. The model of collisions of RPPs explains negative angular momenta of some observed binaries, as about 20 percent of collisions of RPPs moving in circular heliocentric orbits lead to retrograde rotation. Note that if all RPPs got their angular momenta at their formation without mutual collisions, then the angular momenta of small bodies without satellites and those with satellites could be similar (but actually they differ considerably). Most of rarefied preasteroids could turn into solid asteroids before they collided with other preasteroids. Some present asteroids can be debris of larger solid bodies, and the formation of many binaries with

  7. A Solar-type Stellar Companion to a Deep Contact Binary in a Quadruple System

    NASA Astrophysics Data System (ADS)

    Zhou, X.; Qian, S.-B.; Zhang, J.; Jiang, L.-Q.; Zhang, B.; Kreiner, J.

    2016-02-01

    The four-color (B, V, Rc, Ic) light curves of V776 Cas are presented and analyzed using the Wilson-Devinney method. It is discovered that V776 Cas is an early F-type (F2V) overcontact binary with a very high contact degree (f = 64.6%) and an extremely low-mass ratio (q = 0.130), which indicate that it is at the final evolutionary stage of cool short-period binaries. The mass of the primary and secondary stars are calculated to be M1 = 1.55(±0.04) M⊙, M2 = 0.20(±0.01) M⊙. V776 Cas is supposed to be formed from an initially detached binary system via the loss of angular momentum due to the magnetic wind. The initial masses of the present primary and secondary components are calculated to be M1i = 0.86(±0.10) M⊙ and M2i = 2.13(±0.04) M⊙. The observed-calculated curve exhibits a cyclic period variation, which is due to the light-travel time effect caused by the presence of a third component with a period of 23.7 years. The mass of the third component is estimated to be M3 = 1.04(±0.03) M⊙ and the orbital inclination of the third component is calculated to be i‧ = 33.°1. The distance of the binary system to the mass center of the triple system is calculated to be {a}12\\prime = 3.45 AU. The presence of the close-in tertiary component may play an important role in the formation and evolution of this binary system by drawing angular momentum from the central system.

  8. A Mechanistic Understanding of a Binary Additive System to Synergistically Boost Efficiency in All-Polymer Solar Cells

    PubMed Central

    Kim, Yu Jin; Ahn, Sunyong; Wang, Dong Hwan; Park, Chan Eon

    2015-01-01

    All-polymer solar cells are herein presented utilizing the PBDTTT-CT donor and the P(NDI2OD-T2) acceptor with 1,8-diiodooctane (DIO) and 1-chloronaphthalene (CN) binary solvent additives. A systematic study of the polymer/polymer bulk heterojunction photovoltaic cells processed from the binary additives revealed that the microstructures and photophysics were quite different from those of a pristine system. The combination of DIO and CN with a DIO/CN ratio of 3:1 (3 vol% DIO, 1 vol% CN and 96 vol% o-DCB) led to suitable penetrating polymer networks, efficient charge generation and balanced charge transport, which were all beneficial to improving the efficiency. This improvement is attributed to increase in power conversion efficiency from 2.81% for a device without additives to 4.39% for a device with the binary processing additives. A detailed investigation indicates that the changes in the polymer:polymer interactions resulted in the formation of a percolating nasnoscale morphology upon processing with the binary additives. Depth profile measurements with a two-dimensional grazing incidence wide-angle X-ray scattering confirm this optimum phase feature. Furthermore impedance spectroscopy also finds evidence for synergistically boosting the device performance. PMID:26658472

  9. A Mechanistic Understanding of a Binary Additive System to Synergistically Boost Efficiency in All-Polymer Solar Cells

    NASA Astrophysics Data System (ADS)

    Kim, Yu Jin; Ahn, Sunyong; Wang, Dong Hwan; Park, Chan Eon

    2015-12-01

    All-polymer solar cells are herein presented utilizing the PBDTTT-CT donor and the P(NDI2OD-T2) acceptor with 1,8-diiodooctane (DIO) and 1-chloronaphthalene (CN) binary solvent additives. A systematic study of the polymer/polymer bulk heterojunction photovoltaic cells processed from the binary additives revealed that the microstructures and photophysics were quite different from those of a pristine system. The combination of DIO and CN with a DIO/CN ratio of 3:1 (3 vol% DIO, 1 vol% CN and 96 vol% o-DCB) led to suitable penetrating polymer networks, efficient charge generation and balanced charge transport, which were all beneficial to improving the efficiency. This improvement is attributed to increase in power conversion efficiency from 2.81% for a device without additives to 4.39% for a device with the binary processing additives. A detailed investigation indicates that the changes in the polymer:polymer interactions resulted in the formation of a percolating nasnoscale morphology upon processing with the binary additives. Depth profile measurements with a two-dimensional grazing incidence wide-angle X-ray scattering confirm this optimum phase feature. Furthermore impedance spectroscopy also finds evidence for synergistically boosting the device performance.

  10. A Mechanistic Understanding of a Binary Additive System to Synergistically Boost Efficiency in All-Polymer Solar Cells.

    PubMed

    Kim, Yu Jin; Ahn, Sunyong; Wang, Dong Hwan; Park, Chan Eon

    2015-12-11

    All-polymer solar cells are herein presented utilizing the PBDTTT-CT donor and the P(NDI2OD-T2) acceptor with 1,8-diiodooctane (DIO) and 1-chloronaphthalene (CN) binary solvent additives. A systematic study of the polymer/polymer bulk heterojunction photovoltaic cells processed from the binary additives revealed that the microstructures and photophysics were quite different from those of a pristine system. The combination of DIO and CN with a DIO/CN ratio of 3:1 (3 vol% DIO, 1 vol% CN and 96 vol% o-DCB) led to suitable penetrating polymer networks, efficient charge generation and balanced charge transport, which were all beneficial to improving the efficiency. This improvement is attributed to increase in power conversion efficiency from 2.81% for a device without additives to 4.39% for a device with the binary processing additives. A detailed investigation indicates that the changes in the polymer:polymer interactions resulted in the formation of a percolating nasnoscale morphology upon processing with the binary additives. Depth profile measurements with a two-dimensional grazing incidence wide-angle X-ray scattering confirm this optimum phase feature. Furthermore impedance spectroscopy also finds evidence for synergistically boosting the device performance.

  11. HUBBLE HUNTS DOWN BINARY OBJECTS AT FRINGE OF OUR SOLAR SYSTEM

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope snapped pictures of a double system of icy bodies in the Kuiper Belt. This composite picture shows the apparent orbit of one member of the pair. In reality, the objects, called 1998 WW31, revolve around a common center of gravity, like a pair of waltzing skaters. This picture shows the motion of one member of the duo [the six faint blobs] relative to the other [the large white blob]. The blue oval represents the orbital path. Astronomers assembled this picture from six separate exposures, taken from July to September 2001, December 2001, and January to February 2002. Astronomers used the Hubble telescope to study the orbit of this binary system. They then used that information to determine other characteristics of the duo, such as their total mass, and their orbital period (the time it takes them to orbit each other). Credit: NASA and C. Veillet (Canada-France-Hawaii Telescope)

  12. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  13. A new insight into the Galactic potential: A simple secular model for the evolution of binary systems in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Correa-Otto, J. A.; Calandra, M. F.; Gil-Hutton, R. A.

    2017-03-01

    Context. Among the main effects that the Milky Way exerts in binary systems, the Galactic tide is the only one that is not probabilistic and can be deduced from a potential. Therefore, it is possible to perform an analysis of the global structure of the phase space of binary systems in the solar neighbourhood using the Galactic potential. Aims: The aim of this work is to obtain a simple model to study the collisionless dynamical evolution of generic wide binaries systems in the solar neighbourhood. Methods: Through an averaging process, we reduced the three-dimensional potential of the Galaxy to a secular one-degree of freedom model. The accuracy of this model was tested by comparing its predictions with numerical simulations of the exact equations of motion of a two-body problem disturbed by the Galaxy. Results: Using the one-degree of freedom model, we developed a detailed dynamical study, finding that the secular Galactic tide period changes as a function of the separation of the pair, which also gives a dynamical explanation for the arbitrary classification between "wide" and "tight" binaries. Moreover, the secular phase space for a generic gravitationally bound pair is similar to the dynamical structure of a Lidov-Kozai resonance, but surprisingly this structure is independent of the masses and semimajor axis of the binary system. Thus, the Galactic potential is able to excite the initially circular orbit of binary systems to high values of eccentricity, which has important implications for studies of binary star systems (with and without exoplanets), comets, and Oort cloud objects.

  14. Binary Stars with Components of Solar Type: 25 Orbits and System Masses

    NASA Astrophysics Data System (ADS)

    Docobo, J. A.; Ling, J. F.

    2009-10-01

    Revised orbits and system masses are presented for the following 25 visual double stars: WDS 00593-0040 (A 1902), WDS 00596-0111 (A 1903 AB), WDS 01023+0552 (A 2003), WDS 01049+3649 (A 1515), WDS 01234+5809 (STF 115 AB), WDS 02399+0009 (A 1928), WDS 03310+2937 (A 983), WDS 06573-3530 (I 65), WDS 07043-0303 (A 519), WDS 08267+2432 (A 1746 BC), WDS 10585+1711 (A 2375), WDS 11308+4117 (STT 234), WDS 15370+6426 (HU 1168), WDS 16044-1122 (STF 1998 AB), WDS 16283-1613 (RST 3950), WDS 17324+2848 (A 352), WDS 18466+3821 (HU 1191), WDS 19039+2642 (A 2992), WDS 19055+3352(HU 940), WDS 19282-1209 (SCJ 22), WDS 19487+1504 (A 1658), WDS 22400+0113 (A 2099), WDS 23506-5142 (SLR 14), WDS 23518-0637 (A 2700), and WDS 23529-0309 (FIN 359). In all of these systems, at least one component is of solar type. Total system masses were calculated in each case from the orbital period and semiaxis major together with the Hipparcos parallax, except in the cases for which there are no Hipparcos data or when these values are not precise. Other orbital and physical properties of these stars are also discussed. This paper is the second of three collating the revised double star orbits we have calculated in the past 15 yr.

  15. DISCOVERY OF A RED GIANT WITH SOLAR-LIKE OSCILLATIONS IN AN ECLIPSING BINARY SYSTEM FROM KEPLER SPACE-BASED PHOTOMETRY

    SciTech Connect

    Hekker, S.; Debosscher, J.; De Ridder, J.; Aerts, C.; Van Winckel, H.; Beck, P. G.; Blomme, J.; Huber, D.; Hidas, M. G.; Stello, D.; Bedding, T. R.; Gilliland, R. L.; Christensen-Dalsgaard, J.; Kjeldsen, H.; Brown, T. M.; Borucki, W. J.; Koch, D.; Jenkins, J. M.; Pigulski, A.

    2010-04-20

    Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in an eclipsing binary observed with the NASA Kepler satellite. We compute stellar parameters of the red giant from spectra and the asteroseismic mass and radius from the oscillations. Although only one eclipse has been observed so far, we can already determine that the secondary is a main-sequence F star in an eccentric orbit with a semi-major axis larger than 0.5 AU and orbital period longer than 75 days.

  16. Improvement of N-phthaloylchitosan based gel polymer electrolyte in dye-sensitized solar cells using a binary salt system.

    PubMed

    Yusuf, S N F; Azzahari, A D; Selvanathan, V; Yahya, R; Careem, M A; Arof, A K

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I2) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, JSC of 17.29mAcm(-2), open circuit voltage, VOC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD.

  17. Asteroseismic estimate of helium abundance of a solar analog binary system

    SciTech Connect

    Verma, Kuldeep; Antia, H. M.; Faria, João P.; Monteiro, Mário J. P. F. G.; Basu, Sarbani; Mazumdar, Anwesh; Appourchaux, Thierry; Chaplin, William J.; García, Rafael A.

    2014-08-01

    16 Cyg A and B are among the brightest stars observed by Kepler. What makes these stars more interesting is that they are solar analogs. 16 Cyg A and B exhibit solar-like oscillations. In this work we use oscillation frequencies obtained using 2.5 yr of Kepler data to determine the current helium abundance of these stars. For this we use the fact that the helium ionization zone leaves a signature on the oscillation frequencies and that this signature can be calibrated to determine the helium abundance of that layer. By calibrating the signature of the helium ionization zone against models of known helium abundance, the helium abundance in the envelope of 16 Cyg A is found to lie in the range of 0.231 to 0.251 and that of 16 Cyg B lies in the range of 0.218 to 0.266.

  18. Can binary stars test solar models?

    NASA Technical Reports Server (NTRS)

    Popper, D. M.; Ulrich, R. K.

    1986-01-01

    The position in the H-R diagram of the approximately solar-mass component of the Hyades eclipsing binary, HD 27130, is compared with the predictions of stellar structure theory. The stellar models are calibrated by matching a model with the solar heavy element composition and age to the solar radius and luminosity. The comparison to the Hyades binary then is a test of the prediction that the initial solar luminosity was only about 0.7 times the present solar luminosity. The agreement is satisfactory, lending a measure of confidence to the solar model employed, provided that the initial helium abundance of the Hyades stars is not greater than that of the sun and is not less by more than about 0.03 in Y. Unless the model is grossly incorrect, the inference of Stromgren, Olsen, and Gustafsson (1982) from the 'Hyades anomaly' in intermediate-band photometry that Y(Hyades) is less than Y(solar) by 0.1 or 0.15 is rejected by the observed properties of HD 27130.

  19. Terrestrial Planet Formation in Binary Star Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.; Quintana, E. V.; Adams, F. C.; Chambers, J. E.

    2006-01-01

    Most stars reside in binary/multiple star systems; however, previous models of planet formation have studied growth of bodies orbiting an isolated single star. Disk material has been observed around one or both components of various young close binary star systems. If planets form at the right places within such disks, they can remain dynamically stable for very long times. We have simulated the late stages of growth of terrestrial planets in both circumbinary disks around 'close' binary star systems with stellar separations ($a_B$) in the range 0.05 AU $\\le a_B \\le$ 0.4 AU and binary eccentricities in the range $0 \\le e \\le 0.8$ and circumstellar disks around individual stars with binary separations of tens of AU. The initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and around individual stars in the Alpha Centauri system (Quintana et al. 2002, A.J., 576, 982); giant planets analogous to Jupiter and Saturn are included if their orbits are stable. The planetary systems formed around close binaries with stellar apastron distances less than or equal to 0.2 AU with small stellar eccentricities are very similar to those formed in the Sun-Jupiter-Saturn, whereas planetary systems formed around binaries with larger maximum separations tend to be sparser, with fewer planets, especially interior to 1 AU. Likewise, when the binary periastron exceeds 10 AU, terrestrial planets can form over essentially the entire range of orbits allowed for single stars with Jupiter-like planets, although fewer terrestrial planets tend to form within high eccentricity binary systems. As the binary periastron decreases, the radial extent of the terrestrial planet systems is reduced accordingly. When the periastron is 5 AU, the formation of Earth-like planets near 1 AU is compromised.

  20. Solar Systems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  1. The Ruinous Influence of Close Binary Companions on Planetary Systems

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Ireland, Michael; Mann, Andrew; Huber, Daniel; Dupuy, Trent J.

    2017-01-01

    The majority of solar-type stars are found in binary systems, and the dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of nearly 500 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. We super-resolve some binary systems to projected separations of under 5 AU, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. When the binary population is parametrized with a semimajor axis cutoff a cut and a suppression factor inside that cutoff S bin, we find with correlated uncertainties that inside acut = 47 +59/-23 AU, the planet occurrence rate in binary systems is only Sbin = 0.34 +0.14/-0.15 times that of wider binaries or single stars. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion.

  2. Evolution of Close Binary Systems

    SciTech Connect

    Yakut, K; Eggleton, P

    2005-01-24

    We collected data on the masses, radii, etc. of three classes of close binary stars: low-temperature contact binaries (LTCBs), near-contact binaries (NCBs), and detached close binaries (DCBs). They restrict themselves to systems where (1) both components are, at least arguably, near the Main Sequence, (2) the periods are less than a day, and (3) there is both spectroscopic and photometric analysis leading to reasonably reliable data. They discuss the possible evolutionary connections between these three classes, emphasizing the roles played by mass loss and angular momentum loss in rapidly-rotating cool stars.

  3. Modular Solar Electric Power (MSEP) Systems (Presentation)

    SciTech Connect

    Hassani, V.

    2000-06-18

    This presentation discusses the development and deployment of Modular Solar Electric Power (MSEP) systems, the feasibility of application of existing binary power cycles to solar trough technology, and identification of next action items.

  4. Surprisingly Rapid Orbital Evolution: A Compendium of Solar Type Binaries

    NASA Astrophysics Data System (ADS)

    Samec, Ronald George

    2015-08-01

    Solar type binaries are believed to be undergoing steady but slow angular momentum losses due to magnetic braking (Réville et al. 2015, Jiang et al. 2014) as stellar winds leave radially away on semi-rigid (out to the Alfvén radius) bipolar field lines: There is an outward radial flow of ions along the rotating magnetic fields. This is happening simultaneously as the gravitationally locked binary rotates about its center of mass. The stream of ions spiral outward resulting in a resistant torque, causing a decay in the orbital radius along with a period decrease due to Kepler’s laws. My past studies have included more than 25 binaries that appear to be undergoing magnetic braking. I have extended the number of systems to 75+ in this group by perusing the literature of modern precision synthetic light curve studies. Several interesting facts arise including their surprisingly rapid orbital evolution, much faster than would be suggested by the theory. Further results are presented in this study.

  5. Stardust findings favor not only the planetary origin of comets but the underlying close-binary cosmogony of the Solar System as well

    NASA Astrophysics Data System (ADS)

    Drobyshevski, Edward M.

    2008-09-01

    We analyze findings of the Stardust mission that brought to the Earth dust from the 81P/Wild 2 coma. Just as the data obtained in the Deep Impact mission to 9P/Tempel 1, they are at odds with the universally accepted condensation/sublimation comet paradigm. They fit rather well to the approach assuming ejection of nuclei of short-period comets from Moon-like bodies of the type of Galilean satellites in rare (six to seven events in 4.5 aeons) global explosions of their massive icy envelopes saturated by 2H 2 + O 2, products of the electrolysis of ice. This approach offers an explanation, in particular, for the jet activity of comets, which is sustained by combustion of the 2H 2 + O 2 + organics mixture ignited and complemented by the solar radiation. Combustion accounts also for other observations, in particular, the presence in the dust of products of high-temperature (800-900 K) metamorphism. The presence of minerals forming at still higher temperatures (˜1400-2000 K), just as the undoubtedly planetary origin of some long-period comets arriving from the joint planeto-cometary cloud beyond Neptune, forces one, however, to invoke the close-binary cosmogony of the Solar System, which three decades ago predicted the existence of such a cloud (in the recent decade, this prediction has been substantiated by the discovery there of many dwarf planets). This cosmogony is based on the modern understanding of the processes involved in the formation of multiple stellar systems and of their gas-dynamic evolution. It considers the Jupiter-Sun system as the limiting case of a binary star and uses it as a basis for explanation of all the known observations and for prediction of the new ones to come. It provides a plausible explanation, in particular, for both the origin and capture by the Earth of the Moon as a high-temperature condensate and the formation of the Galilean satellites, which also contain inclusions of refractory minerals in the ices of their envelopes.

  6. STAR HOPPERS: PLANET INSTABILITY AND CAPTURE IN EVOLVING BINARY SYSTEMS

    SciTech Connect

    Kratter, Kaitlin M.; Perets, Hagai B.

    2012-07-01

    Many planets are observed in stellar binary systems, and their frequency may be comparable to that of planetary systems around single stars. Binary stellar evolution in such systems influences the dynamical evolution of the resident planets. Here, we study the evolution of a single planet orbiting one star in an evolving binary system. We find that stellar evolution can trigger dynamical instabilities that drive planets into chaotic orbits. This instability leads to planet-star collisions, exchange of the planet between the binary stars ('star hoppers'), and ejection of the planet from the system. The means by which planets can be recaptured is similar to the pull-down capture mechanism for irregular solar system satellites. Because planets often suffer close encounters with the primary on the asymptotic giant branch, captures during a collision with the stellar envelope are also possible for more massive planets. Such capture could populate the habitable zone around white dwarfs.

  7. Planetary Formation and Dynamics in Binary Systems

    NASA Astrophysics Data System (ADS)

    Xie, J. W.

    2013-01-01

    As of today, over 500 exoplanets have been detected since the first exoplanet was discovered around a solar-like star in 1995. The planets in binaries could be common as stars are usually born in binary or multiple star systems. Although current observations show that the planet host rate in multiple star systems is around 17%, this fraction should be considered as a lower limit because of noticeable selection effects against binaries in planet searches. Most of the current known planet-bearing binary systems are S-types, meaning the companion star acts as a distant satellite, typically orbiting the inner star-planet system over 100 AU away. Nevertheless, there are four systems with a smaller separation of 20 AU, including the Gamma Cephei, GJ 86, HD 41004, and HD 196885. In addition to the planets in circumprimary (S-type) orbits discussed above, planets in circumbinary (P-type) orbits have been found in only two systems. In this thesis, we mainly study the planet formation in the S-type binary systems. In chapter 1, we first summarize current observational facts of exoplanets both in single-star and binary systems, then review the theoretical models of planet formation, with special attention to the application in binary systems. Perturbative effects from stellar companions render the planet formation process in binary systems even more complex than that in single-star systems. The perturbations from a binary companion can excite planetesimal orbits, and increase their mutual impact velocities to the values that might exceed their escape velocity or even the critical velocity for the onset of eroding collisions. The intermediate stage of the formation process---from planetesimals to planetary embryos---is thus the most problematic. In the following chapters, we investigate whether and how the planet formation goes through such a problematic stage. In chapter 2, we study the effects of gas dissipation on the planetesimals' mutual accretion. We find that in a

  8. A solar twin in the eclipsing binary LL Aquarii

    NASA Astrophysics Data System (ADS)

    Graczyk, D.; Smolec, R.; Pavlovski, K.; Southworth, J.; Pietrzyński, G.; Maxted, P. F. L.; Konorski, P.; Gieren, W.; Pilecki, B.; Taormina, M.; Suchomska, K.; Karczmarek, P.; Górski, M.; Wielgórski, P.; Anderson, R. I.

    2016-10-01

    Aims: In the course of a project to study eclipsing binary stars in vinicity of the Sun, we found that the cooler component of LL Aqr is a solar twin candidate. This is the first known star with properties of a solar twin existing in a non-interacting eclipsing binary, offering an excellent opportunity to fully characterise its physical properties with very high precision. Methods: We used extensive multi-band, archival photometry and the Super-WASP project and high-resolution spectroscopy obtained from the HARPS and CORALIE spectrographs. The spectra of both components were decomposed and a detailed LTE abundance analysis was performed. The light and radial velocity curves were simultanously analysed with the Wilson-Devinney code. The resulting highly precise stellar parameters were used for a detailed comparison with PARSEC, MESA, and GARSTEC stellar evolution models. Results: LL Aqr consists of two main-sequence stars (F9 V + G3 V) with masses of M1 = 1.1949 ± 0.0007 and M2 = 1.0337 ± 0.0007 M⊙, radii R1 = 1.321 ± 0.006 and R2 = 1.002 ± 0.005 R⊙, temperatures T1 = 6080 ± 45 and T2 = 5703 ± 50 K and solar chemical composition [M/H] = 0.02 ± 0.05. The absolute dimensions, radiative and photometric properties, and atmospheric abundances of the secondary are all fully consistent with being a solar twin. Both stars are cooler by about 3.5σ or less metal abundant by 5σ than predicted by standard sets of stellar evolution models. When advanced modelling was performed, we found that full agreement with observations can only be obtained for values of the mixing length and envelope overshooting parameters that are hard to accept. The most reasonable and physically justified model fits found with MESA and GARSTEC codes still have discrepancies with observations but only at the level of 1σ. The system is significantly younger that the Sun, with an age between 2.3 Gyr and 2.7 Gyr, which agrees well with the relatively high lithium abundance of the secondary, A

  9. Solar Energy: Solar System Economics.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system economics is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies.…

  10. Close binary neutron star systems

    NASA Astrophysics Data System (ADS)

    Marronetti, Pedro

    1999-12-01

    We present a method to calculate solutions to the initial value problem in (3 + 1) general relativity corresponding to binary neutron-star systems (BNS) in irrotational quasi-equilibrium orbits. The initial value equations are solved using a conformally flat spatial metric tensor. The stellar fluid dynamics corresponds to that of systems with zero vorticity in the inertial reference frame. Irrotational systems like the ones analyzed in the present work are likely to resemble the final stages of the evolution of neutron-star binaries, thus providing insights on the inspiral process. The fluid velocity is derived from the gradient of a scalar potential. A numerical program was developed to solve the elliptic equations for the metric fields and the fluid velocity potential. We discuss the different numerical techniques employed to achieve high resolution across the stellar volume, as well as the methods used to find solutions to the Poisson-like equations with their corresponding boundary conditions. We present sequences of quasi-stable circular orbits which conserve baryonic mass. These sequences mimic the time evolution of the inspiral and are obtained without solving the complex evolution equations. They also provide sets of initial value data for future time evolution codes, which should be valid very close to the final merger. We evaluate the emission of gravitational radiation during the evolution through multipole expansions methods.

  11. Formation and Evolution of Binary Systems Containing Collapsed Stars

    NASA Technical Reports Server (NTRS)

    Rappaport, Saul; West, Donald (Technical Monitor)

    2003-01-01

    This research includes theoretical studies of the formation and evolution of five types of interacting binary systems. Our main focus has been on developing a number of comprehensive population synthesis codes to study the following types of binary systems: (i) cataclysmic variables (#3, #8, #12, #15), (ii) low- and intermediate-mass X-ray binaries (#13, #20, #21), (iii) high-mass X-ray binaries (#14, #17, #22), (iv) recycled binary millisecond pulsars in globular clusters (#5, #10, #ll), and (v) planetary nebulae which form in interacting binaries (#6, #9). The numbers in parentheses refer to papers published or in preparation that are listed in this paper. These codes take a new unified approach to population synthesis studies. The first step involves a Monte Carlo selection of the primordial binaries, including the constituent masses, and orbital separations and eccentricities. Next, a variety of analytic methods are used to evolve the primary star to the point where either a dynamical episode of mass transfer to the secondary occurs (the common envelope phase), or the system evolves down an alternate path. If the residual core of the primary is greater than 2.5 solar mass, it will evolve to Fe core collapse and the production of a neutron star and a supernova explosion. In the case of systems involving neutron stars, a kick velocity is chosen randomly from an appropriate distribution and added to the orbital dynamics which determine the state of the binary system after the supernova explosion. In the third step, all binaries which commence stable mass transfer from the donor star (the original secondary in the binary system) to the compact object, are followed with a detailed binary evolution code. Finally, we include all the relevant dynamics of the binary system. For example, in the case of LMXBs, the binary system, with its recoil velocity from the supernova explosion, is followed in time through its path in the Galactic potential. For our globular cluster

  12. Efficiency enhancement in dye sensitized solar cells using gel polymer electrolytes based on a tetrahexylammonium iodide and MgI2 binary iodide system.

    PubMed

    Bandara, T M W J; Dissanayake, M A K L; Jayasundara, W J M J S R; Albinsson, I; Mellander, B-E

    2012-06-28

    Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, based on PAN host polymers and mixture of salts tetrahexylammonium iodide (Hex4N(+)I(-)) and MgI2, were prepared by incorporating ethylene carbonate and propylene carbonate as plasticizers. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrolyte containing 120% Hex4N(+)I(-) with respect to weight of PAN and without MgI2 showed the highest conductivity out of the compositions studied, 2.5 × 10(-3) S cm(-1) at 25 °C, and a glass transition at -102.4 °C. However, the electrolyte containing 100% Hex4N(+)I(-) and 20% MgI2 showed the best solar cell performance highlighting the influence of the cation on the performance of the cell. The predominantly ionic behaviour of the electrolytes was established from the dc polarization data and all the electrolytes exhibit iodide ion transport. Seven different solar cells were fabricated employing different electrolyte compositions. The best cell using the electrolyte with 100% Hex4N(+)I(-) and 20% MgI2 with respect to PAN weight showed 3.5% energy conversion efficiency and 8.6 mA cm(-2) short circuit current density.

  13. Dynamical fate of wide binaries in the solar neighborhood

    SciTech Connect

    Weinberg, M.D.; Shapiro, S.L.; Wasserman, I.

    1987-01-01

    An analytical model is presented for the evolution of wide binaries in the Galaxy. The study is pertinent to the postulated solar companion, Nemesis, which may disturb the Oort cloud and cause catastrophic comet showers to strike the earth every 26 Myr. Distant gravitational encounters are modeled by Fokker-Planck coefficients for advection and diffusion of the orbital binding energy. It is shown that encounters with passing stars cause a diffusive evolution of the binding energy and semimajor axis. Encounters with subclumps in giant molecular clouds disrupt orbits to a degree dependent on the cumulative number of stellar encounters. The time scales of the vents and the limitations of scaling laws used are discussed. Results are provided from calculations of galactic distribution of wide binaries and the evolution of wide binary orbits. 38 references.

  14. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    SciTech Connect

    Weinberg, Nevin N.; Arras, Phil; Quataert, Eliot; Burkart, Josh

    2012-06-01

    We study the excitation and damping of tides in close binary systems, accounting for the leading-order nonlinear corrections to linear tidal theory. These nonlinear corrections include two distinct physical effects: three-mode nonlinear interactions, i.e., the redistribution of energy among stellar modes of oscillation, and nonlinear excitation of stellar normal modes by the time-varying gravitational potential of the companion. This paper, the first in a series, presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism we present is applicable to binaries containing stars, planets, and/or compact objects, we focus on non-rotating solar-type stars with stellar or planetary companions. Our primary results include the following: (1) The linear tidal solution almost universally used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited internal gravity waves in solar-type stars are nonlinearly unstable to parametric resonance for companion masses M' {approx}> 10-100 M{sub Circled-Plus} at orbital periods P Almost-Equal-To 1-10 days. The nearly static 'equilibrium' tidal distortion is, however, stable to parametric resonance except for solar binaries with P {approx}< 2-5 days. (2) For companion masses larger than a few Jupiter masses, the dynamical tide causes short length scale waves to grow so rapidly that they must be treated as traveling waves, rather than standing waves. (3) We show that the global three-wave treatment of parametric instability typically used in the astrophysics literature does not yield the fastest-growing daughter modes or instability threshold in many cases. We find a form of parametric instability in which a single parent wave excites a very large number of daughter waves (N Almost-Equal-To 10{sup 3}[P/10 days] for a solar-type star) and drives them as a single coherent unit with

  15. Orbital Architectures of Planet-Hosting Binary Systems

    NASA Astrophysics Data System (ADS)

    Dupuy, Trent J.; Kratter, Kaitlin M.

    2016-01-01

    We present the first results from our Keck AO astrometric monitoring of Kepler Prime Mission planet-hosting binary systems. Observational biases in exoplanet discovery have long left the frequency, properties, and provenance of planets in most binary systems largely unconstrained. Recent results from our ongoing survey of a volume-limited sample of Kepler planet hosts indicate that binary companions at solar-system scales of 20-100 AU suppress the occurrence of planetary systems at a rate of 30-100%. However, some planetary systems do survive in binaries, and determining these systems' orbital architectures is key to understanding why. As a demonstration of this new approach to testing ideas of planet formation, we present a detailed analysis of the triple star system Kepler-444 (HIP 94931) that hosts five Ganymede- to Mars-sized planets. By combining our high-precision astrometry with radial velocities from HIRES we discover a highly eccentric stellar orbit that would have made this a seemingly hostile site for planet formation. This either points to an extremely robust and efficient planet formation mechanism or a rare case of favorable initial conditions. Such broader implications will be addressed by determining orbital architectures for our larger statistical sample of Kepler planet-hosting systems that have stellar companions on solar system scales.

  16. Orbital Architectures of Planet-Hosting Binary Systems

    NASA Astrophysics Data System (ADS)

    Dupuy, Trent; Kratter, Kaitlin M.; Kraus, Adam; Isaacson, Howard T.; Mann, Andrew; Ireland, Michael; Howard, Andrew; Huber, Daniel

    2015-12-01

    We present the first results from our Keck AO astrometric monitoring of Kepler planet-hosting binary systems. Observational biases in exoplanet discovery have long left the frequency, properties, and provenance of planets in most binary systems largely unconstrained. Recent results from our ongoing survey of a volume-limited sample of Kepler planet hosts indicate that binary companions at solar-system scales of 20-100 AU suppress the occurrence of planetary systems at a rate of 30-100%. However, some planetary systems do survive in binaries, and determining these systems' orbital architectures is key to understanding why. As a demonstration of this new approach to testing ideas of planet formation, we present a detailed analysis of the triple star system Kepler-444 (HIP 94931) that hosts five Ganymede- to Mars-sized planets. By combining our high-precision astrometry with radial velocities from HIRES and computational dynamical modeling, we discover an unexpected orbital architecture for this multi-planet, triple-star system. Finally, we preview results from our full statistical sample, such as tests of coplanarity between binary and planet orbits in single versus multi-planet systems.

  17. KIC 7177553: A QUADRUPLE SYSTEM OF TWO CLOSE BINARIES

    SciTech Connect

    Lehmann, H.; Borkovits, T.; Rappaport, S. A.; Ngo, H.; Mawet, D.; Csizmadia, Sz.; Forgács-Dajka, E. E-mail: borko@electra.bajaobs.hu E-mail: hngo@caltech.edu E-mail: szilard.csizmadia@dlr.de

    2016-03-01

    KIC 7177553 was observed by the Kepler satellite to be an eclipsing eccentric binary star system with an 18-day orbital period. Recently, an eclipse timing study of the Kepler binaries has revealed eclipse timing variations (ETVs) in this object with an amplitude of ∼100 s and an outer period of 529 days. The implied mass of the third body is that of a super-Jupiter, but below the mass of a brown dwarf. We therefore embarked on a radial velocity (RV) study of this binary to determine its system configuration and to check the hypothesis that it hosts a giant planet. From the RV measurements, it became immediately obvious that the same Kepler target contains another eccentric binary, this one with a 16.5-day orbital period. Direct imaging using adaptive optics reveals that the two binaries are separated by 0.″4 (∼167 AU) and have nearly the same magnitude (to within 2%). The close angular proximity of the two binaries and very similar γ velocities strongly suggest that KIC 7177553 is one of the rare SB4 systems consisting of two eccentric binaries where at least one system is eclipsing. Both systems consist of slowly rotating, nonevolved, solar-like stars of comparable masses. From the orbital separation and the small difference in γ velocity, we infer that the period of the outer orbit most likely lies in the range of 1000–3000 yr. New images taken over the next few years, as well as the high-precision astrometry of the Gaia satellite mission, will allow us to set much narrower constraints on the system geometry. Finally, we note that the observed ETVs in the Kepler data cannot be produced by the second binary. Further spectroscopic observations on a longer timescale will be required to prove the existence of the massive planet.

  18. Solar electric systems

    SciTech Connect

    Warfield, G.

    1984-01-01

    Electricity from solar sources is the subject. The state-of-the-art of photovoltaics, wind energy and solar thermal electric systems is presented and also a broad range of solar energy activities throughout the Arab world is covered. Contents, abridged: Solar radiation fundamentals. Basic theory solar cells. Solar thermal power plants. Solar energy activities at the scientific research council in Iraq. Solar energy program at Kuwait Institute for Scientific Research. Prospects of solar energy for Egypt. Non-conventional energy in Syria. Wind and solar energies in Sudan. Index.

  19. Solar System Sleuth

    NASA Astrophysics Data System (ADS)

    Ryden, Barbara

    2005-11-01

    One of the great astronomers of the last century, Gerhard Peter Kuiper, was born 100 years ago this year. He is considered the father of modern planetary science and an expert on binary and white dwarf stars. Kuiper was recruited by Otto Struve to the Yerkes Observatory and used the 82-inch Telescope at McDonald Observatory for groundbreaking studies of Mars and the giant moons in the outer solar system. Later, he became the founding director of the Lunar and Planetary Laboratory at the University of Arizona. Kuiper predicted that a vast number of asteroid-like objects lie beyond the orbit of Pluto; this was later substantiated and called the Kuiper Belt. Late in life, Kuiper pioneered the use of infrared telescopes and instruments aboard aircraft and the NASA's original flying observatory was named the Kuiper Airborne Observatory in his honor.

  20. Terrestrial Planet Formation in Binary Star Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Quintana, Elisa V.; Chambers, John; Duncan, Martin J.; Adams, Fred

    2003-01-01

    Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets within binary star systems, using a new, ultrafast, symplectic integrator that we have developed for this purpose. We show that the late stages of terrestrial planet formation can indeed take place in a wide variety of binary systems and we have begun to delineate the range of parameter space for which this statement is true. Results of our initial simulations of planetary growth around each star in the alpha Centauri system and other 'wide' binary systems, as well as around both stars in very close binary systems, will be presented.

  1. Terrestrial Planet Formation in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Quintana, Elisa V.; Lissauer, Jack J.

    More than half of all main sequence stars, and an even larger fraction of pre-main sequence stars, reside in binary or multiple systems (Duquennoy and Mayor 1991; Mathieu et al. 2000). The presence of planet-forming material has been indirectly observed around one or both components of some young binaries, and (Mathieu et al. 2000) numerical simulations of the formation of binary stars suggest that disks form within these systems, as well (Bodenheimer et al. 2000). Terrestrial planets and the cores of giant planets are thought to form by an accretion process within a disk of dust and gas (Safronov 1969; Lissauer 1993), and therefore may be common in binary star systems. In this chapter, we present the results from numerical simulations of the final stages of terrestrial planet formation around one or both stars of a binary.

  2. Planet Formation in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Martin, Rebecca

    About half of observed exoplanets are estimated to be in binary systems. Understanding planet formation and evolution in binaries is therefore essential for explaining observed exoplanet properties. Recently, we discovered that a highly misaligned circumstellar disk in a binary system can undergo global Kozai-Lidov (KL) oscillations of the disk inclination and eccentricity. These oscillations likely have a significant impact on the formation and orbital evolution of planets in binary star systems. Planet formation by core accretion cannot operate during KL oscillations of the disk. First, we propose to consider the process of disk mass transfer between the binary members. Secondly, we will investigate the possibility of planet formation by disk fragmentation. Disk self gravity can weaken or suppress the oscillations during the early disk evolution when the disk mass is relatively high for a narrow range of parameters. Thirdly, we will investigate the evolution of a planet whose orbit is initially aligned with respect to the disk, but misaligned with respect to the orbit of the binary. We will study how these processes relate to observations of star-spin and planet orbit misalignment and to observations of planets that appear to be undergoing KL oscillations. Finally, we will analyze the evolution of misaligned multi-planet systems. This theoretical work will involve a combination of analytic and numerical techniques. The aim of this research is to shed some light on the formation of planets in binary star systems and to contribute to NASA's goal of understanding of the origins of exoplanetary systems.

  3. Stability of multiplanet systems in binaries

    NASA Astrophysics Data System (ADS)

    Marzari, F.; Gallina, G.

    2016-10-01

    Context. When exploring the stability of multiplanet systems in binaries, two parameters are normally exploited: the critical semimajor axis ac computed by Holman & Wiegert (1999, AJ, 117, 621) within which planets are stable against the binary perturbations, and the Hill stability limit Δ determining the minimum separation beyond which two planets will avoid mutual close encounters. Both these parameters are derived in different contexts, i.e. Δ is usually adopted for computing the stability limit of two planets around a single star while ac is computed for a single planet in a binary system. Aims: Our aim is to test whether these two parameters can be safely applied in multiplanet systems in binaries or if their predictions fail for particular binary orbital configurations. Methods: We have used the frequency map analysis (FMA) to measure the diffusion of orbits in the phase space as an indicator of chaotic behaviour. Results: First we revisited the reliability of the empirical formula computing ac in the case of single planets in binaries and we find that, in some cases, it underestimates by 10-20% the real outer limit of stability and it does not account for planets trapped in resonance with the companion star well beyond ac. For two-planet systems, the value of Δ is close to that computed for planets around single stars, but the level of chaoticity close to it substantially increases for smaller semimajor axes and higher eccentricities of the binary orbit. In these configurations ac also begins to be unreliable and non-linear secular resonances with the stellar companion lead to chaotic behaviour well within ac, even for single planet systems. For two planet systems, the superposition of mean motion resonances, either mutual or with the binary companion, and non-linear secular resonances may lead to chaotic behaviour in all cases. We have developed a parametric semi-empirical formula determining the minimum value of the binary semimajor axis, for a given

  4. The Evolution of Compact Binary Star Systems.

    PubMed

    Postnov, Konstantin A; Yungelson, Lev R

    2014-01-01

    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

  5. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Calibrated in kilowatt hours per square meter, the solar counter produced by Dodge Products, Inc. provides a numerical count of the solar energy that has accumulated on a surface. Solar energy sensing, measuring and recording devices in corporate solar cell technology developed by Lewis Research Center. Customers for their various devices include architects, engineers and others engaged in construction and operation of solar energy facilities; manufacturers of solar systems or solar related products, such as glare reducing windows; and solar energy planners in federal and state government agencies.

  6. Mass flow in close binary systems

    NASA Technical Reports Server (NTRS)

    Kondo, Y.; Mccluskey, G. E.

    1976-01-01

    The manner of mass flow in close binary systems is examined with a special view to the role of the so-called critical Roche (or Jacobian) lobe, taking into consideration relevant physical conditions such as radiation pressure that may affect the restricted three-body problem treatment. The mass does not necessarily flow from component one to component two through the L1 point to form a gaseous ring surrounding the latter. These considerations are applied to X-ray binaries with early-type optical components, such as Cyg X-1 (HDE 226868) and 3U 1700 - 37 (HD 153919). In the two bright close binary systems Beta Lyr and UW CMa, which are believed to be undergoing dynamic mass transfer, recent Copernicus observations show that the gas giving rise to the prominent ultraviolet emission lines surrounds the entire binary system rather than merely component two. Implications of these observations are also discussed.

  7. A candidate sub-parsec supermassive binary black hole system.

    PubMed

    Boroson, Todd A; Lauer, Tod R

    2009-03-05

    The role of mergers in producing galaxies, together with the finding that most large galaxies harbour black holes in their nuclei, implies that binary supermassive black hole systems should be common. Here we report that the quasar SDSS J153636.22+044127.0 is a plausible example of such a system. This quasar shows two broad-line emission systems, separated in velocity by 3,500 km s(-1). A third system of unresolved absorption lines has an intermediate velocity. These characteristics are unique among known quasars. We interpret this object as a binary system of two black holes, having masses of 10(7.3) and 10(8.9) solar masses separated by approximately 0.1 parsec with an orbital period of approximately 100 years.

  8. Planetary nebula progenitors that swallow binary systems

    NASA Astrophysics Data System (ADS)

    Soker, Noam

    2016-01-01

    I propose that some irregular messy planetary nebulae (PNe) owe their morphologies to triple-stellar evolution where tight binary systems evolve inside and/or on the outskirts of the envelope of asymptotic giant branch (AGB) stars. In some cases, the tight binary system can survive, in others, it is destroyed. The tight binary system might break up with one star leaving the system. In an alternative evolution, one of the stars of the broken-up tight binary system falls towards the AGB envelope with low specific angular momentum, and drowns in the envelope. In a different type of destruction process, the drag inside the AGB envelope causes the tight binary system to merge. This releases gravitational energy within the AGB envelope, leading to a very asymmetrical envelope ejection, with an irregular and messy PN as a descendant. The evolution of the triple-stellar system can be in a full common envelope evolution or in a grazing envelope evolution. Both before and after destruction (if destruction takes place), the system might launch pairs of opposite jets. One pronounced signature of triple-stellar evolution might be a large departure from axisymmetrical morphology of the descendant PN. I estimate that about one in eight non-spherical PNe is shaped by one of these triple-stellar evolutionary routes.

  9. Solar tracking system

    DOEpatents

    Okandan, Murat; Nielson, Gregory N.

    2016-07-12

    Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

  10. Solar ADEPT: Efficient Solar Energy Systems

    SciTech Connect

    2011-01-01

    Solar ADEPT Project: The 7 projects that make up ARPA-E's Solar ADEPT program, short for 'Solar Agile Delivery of Electrical Power Technology,' aim to improve the performance of photovoltaic (PV) solar energy systems, which convert the sun's rays into electricity. Solar ADEPT projects are integrating advanced electrical components into PV systems to make the process of converting solar energy to electricity more efficient.

  11. Stacking Analysis of Binary Systems with HAWC

    NASA Astrophysics Data System (ADS)

    Brisbois, Chad; HAWC Collaboration

    2017-01-01

    Detecting binary systems at TeV energies is an important problem because only a handful of such systems are currently known. The nature of such systems is typically thought to be composed of a compact object and a massive star. The TeV emission from these systems does not obviously correspond to emission in GeV or X-ray, where many binary systems have previously been found. This study focuses on a stacking method to detect TeV emission from LS 5039, a known TeV binary, to test its efficacy in HAWC data. Stacking is a widely employed method for increasing signal to noise ratio in optical astronomy, but has never been attempted previously with HAWC. HAWC is an ideal instrument to search for TeV binaries, because of its wide field of view and high uptime. Applying this method to the entire sky may allow HAWC to detect binary sources of very short or very long periods not sensitive to current analyses. NSF, DOE, Los Alamos, Michigan Tech, CONACyt, UNAM, BUAP.

  12. The Impact of Stellar Multiplicity on Planetary Systems. I. The Ruinous Influence of Close Binary Companions

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Ireland, Michael J.; Huber, Daniel; Mann, Andrew W.; Dupuy, Trent J.

    2016-07-01

    The dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of 382 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. Among the full sample of 506 candidate binary companions to KOIs, we super-resolve some binary systems to projected separations of <5 au, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. For a field binary population, we should have found 58 binary companions with projected separation ρ < 50 au and mass ratio q > 0.4 we instead only found 23 companions (a 4.6σ deficit), many of which must be wider pairs that are only close in projection. When the binary population is parametrized with a semimajor axis cutoff a cut and a suppression factor inside that cutoff S bin, we find with correlated uncertainties that inside {a}{cut}={47}-23+59 au, the planet occurrence rate in binary systems is only {S}{bin}={0.34}-0.15+0.14 times that of wider binaries or single stars. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion.

  13. On the Habitability of Planets in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Pilat-Lohinger, E.; Eggl, S.; Gyergyovits, M.

    2012-04-01

    The discovery of more and more extra-solar planets in and around binary star systems cause questions concerning the determination of the classical habitable zone (HZ). We present calculations of the radiative and gravitational perturbations of two stars on a terrestrial planet moving in the HZ in different binary - planet configurations. Two types of planetary motion will be considered, i.e. S-type motion (or circumprimary motion) where the planet orbits one star only and P-type (or circumbinary motion) where the binary revolves inside the planet's orbit. It was found that the HZ in S-type configurations tend to be gravitationally dominated, the radiative input due to the second star is negligible compared to its dynamical influence causing secular changes in the eccentricity of the planets. This alters the amount of incident radiation significantly. In P-type configurations the radiation estimates can be determined on shorter time-scales. The radiation amplitude depends on the eccentricity of the binary in both configurations. Finally we present time independent analytical estimates about the habitability of a terrestrial planet in the HZ of a binary star system as shown by Eggl et al.(2012). This work was financed by the Austrian Science Fonds (FWF) P22603-N16 and AS11608-N16 and S.Eggl was financed by the University of Vienna (Forschungsstipendium 2012). Ref.: Eggl, S., Pilat-Lohinger, E., Gerogakarakos, N., Gyergyovits, M. and Funk, B., "Habitable Zones in S-Type Binary Star Systems", ApJ, submitted.

  14. Solar system positioning system

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I.; Chui, Talso

    2006-01-01

    Power-rich spacecraft envisioned in Prometheus initiative open up possibilities for long-range high-rate communication. A constellation of spacecraft on orbits several A.U. from the Sun, equipped with laser transponders and precise clocks can be configured to measure their mutual distances to within few cm. High on-board power can create substantial non-inertial contribution to the spacecraft trajectory. We propose to alleviate this contribution by employing secondary ranging to a passive daughter spacecraft. Such constellation can form the basis of it navigation system capable of providing position information anywhere in the soIar system with similar accuracy. Apart from obvious Solar System exploration implications, this system can provide robust reference for GPS and its successors.

  15. Tidal evolution in close binary systems.

    NASA Technical Reports Server (NTRS)

    Kopal, Z.

    1972-01-01

    Mathematical outline of the theory of tidal evolution in close binary systems of secularly constant total momentum. Following a general outline of the problem the basic expressions for the energy and momenta of close binaries consisting of components of arbitrary internal structure are established, and the maximum and minimum values of the energy (kinetic and potential) which such systems can attain for a given amount of total momentum are investigated. These results are compared with the actual facts encountered in binaries with components whose internal structure (and, therefore, rotational momenta) are known from evidence furnished by the observed rates of apsidal advance. The results show that all such systems whether of detached or semidetached type - disclose that more than 99% of their total momenta are stored in the orbital momentum. The sum of the rotational momenta of the constituent components amounts to less than 1% of the total -a situation characteristic of a state close to the minimum energy for given total momentum.

  16. The evolution of ultrashort period binary systems

    NASA Technical Reports Server (NTRS)

    Nelson, L. A.; Rappaport, S. A.; Joss, P. C.

    1986-01-01

    A discussion is presented concerning the results of detailed evolutionary calculations in which a very low mass and hydrogen-depleted semiattached binary star containing a collapsed object can reach an exceptionally short orbital period while sustaining a relatively high mass transfer rate. The observed properties of such systems can be understood under the assumption that they contain moderately to severely hydrogen-defficient secondary stars that are neither fully degenerate nor burning He. It is noted that for extremely hydrogen-depleted stars, the assumption of chemical homogeneity becomes untenable. Attention is given to the binary systems 4U 1626-67, 4U 1916-05, and G61-29.

  17. EFFECTS OF ROTATIONALLY INDUCED MIXING IN COMPACT BINARY SYSTEMS WITH LOW-MASS SECONDARIES AND IN SINGLE SOLAR-TYPE STARS

    SciTech Connect

    Chatzopoulos, E.; Robinson, Edward L.; Wheeler, J. Craig

    2012-08-20

    Many population synthesis and stellar evolution studies have addressed the evolution of close binary systems in which the primary is a compact remnant and the secondary is filling its Roche lobe, thus triggering mass transfer. Although tidal locking is expected in such systems, most studies have neglected the rotationally induced mixing that may occur. Here we study the possible effects of mixing in mass-losing stars for a range of secondary star masses and metallicities. We find that tidal locking can induce rotational mixing prior to contact and thus affect the evolution of the secondary star if the effects of the Spruit-Tayler dynamo are included both for angular momentum and chemical transport. Once contact is made, the effect of mass transfer tends to be more rapid than the evolutionary timescale, so the effects of mixing are no longer directly important, but the mass-transfer strips matter to inner layers that may have been affected by the mixing. These effects are enhanced for secondaries of 1-1.2 M{sub Sun} and for lower metallicities. We discuss the possible implications for the paucity of carbon in the secondaries of the cataclysmic variable SS Cyg and the black hole candidate XTE J1118+480 and for the progenitor evolution of Type Ia supernovae. We also address the issue of the origin of blue straggler stars in globular and open clusters. We find that for models that include rotation consistent with that observed for some blue straggler stars, evolution is chemically homogeneous. This leads to tracks in the H-R diagram that are brighter and bluer than the non-rotating main-sequence turn-off point. Rotational mixing could thus be one of the factors that contribute to the formation of blue stragglers.

  18. Gravitational wave background from binary systems

    SciTech Connect

    Rosado, Pablo A.

    2011-10-15

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter {Omega}(f), commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, {Omega}(f) is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the frequencies of all existing and planned detectors. A semi-analytical formula for {Omega}(f) is derived in the case of stellar binaries (containing white dwarfs, neutron stars or stellar-mass black holes). Besides a realistic expectation of the level of background, upper and lower limits are given, to account for the uncertainties in some astrophysical parameters such as binary coalescence rates. One interesting result concerns all current and planned ground-based detectors (including the Einstein Telescope). In their frequency range, the background of binaries is resolvable and only sporadically present. In other words, there is no stochastic background of binaries for ground-based detectors.

  19. Binary optics at Hughes Danbury Optical Systems

    NASA Technical Reports Server (NTRS)

    Logue, James; Power, Michael

    1993-01-01

    An overview of binary optics development at Hughes Danbury Optical Systems is presented. Design software used for mask design is presented. A brief discussion of fabrication follows. Two examples of actual projects are used to highlight the discussion: (1) a large aspheric lens; and (2) a set of grating and lenslet arrays.

  20. Solar energy systems cost

    SciTech Connect

    Lavender, J.A.

    1980-01-01

    Five major areas of work currently being pursued in the United States in solar energy which will have a significant impact on the world's energy situation in the future are addressed. The five significant areas discussed include a technical description of several solar technologies, current and projected cost of the selected solar systems, and cost methodologies which are under development. In addition, sensitivity considerations which are unique to solar energy systems and end user applications are included. A total of six solar technologies - biomass, photovoltaics, wind, ocean thermal energy conversion (OTEC), solar thermal, and industrial process heat (IPH) have been included in a brief technical description to present the variety of systems and their techncial status. System schematics have been included of systems which have been constructed, are currently in the detail design and test stage of development, or are of a conceptual nature.

  1. Binary Cepheids: Separations and Mass Ratios in 5 Solar Mass Binaries

    DTIC Science & Technology

    2013-10-01

    material: color figures 1. INTRODUCTION Binary-star studies are valuable for what they provide directly (e.g., stellar masses), as well as for the...the high stellar density in the cluster, this could be a chance alignment. 3.2.2. Approximate Orbital Periods We used the angular separations in Table...subsequent evolution of the system will be drastically altered. For Cepheids we have a good estimation of where this effect sets in. Z Lac—not in our sample

  2. BROWN DWARF BINARIES FROM DISINTEGRATING TRIPLE SYSTEMS

    SciTech Connect

    Reipurth, Bo; Mikkola, Seppo E-mail: Seppo.Mikkola@utu.fi

    2015-04-15

    Binaries in which both components are brown dwarfs (BDs) are being discovered at an increasing rate, and their properties may hold clues to their origin. We have carried out 200,000 N-body simulations of three identical stellar embryos with masses drawn from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions within the cloud core, while accreting using Bondi–Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. In order to illustrate 200,000 end-states of such dynamical evolution with accretion, we introduce the “triple diagnostic diagram,” which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations, and statistical properties are derived. The separation distribution function is in good correspondence with observations, showing a steep rise at close separations, peaking around 13 AU and declining more gently, reaching zero at separations greater than 200 AU. Unresolved BD triple systems may appear as wider BD binaries. Mass ratios are strongly peaked toward unity, as observed, but this is partially due to the initial assumptions. Eccentricities gradually increase toward higher values, due to the lack of viscous interactions in the simulations, which would both shrink the orbits and decrease their eccentricities. Most newborn triple systems are unstable and while there are 9209 ejected BD binaries at 1 Myr, corresponding to about 4% of the 200,000 simulations, this number has grown to

  3. Brown Dwarf Binaries from Disintegrating Triple Systems

    NASA Astrophysics Data System (ADS)

    Reipurth, Bo; Mikkola, Seppo

    2015-04-01

    Binaries in which both components are brown dwarfs (BDs) are being discovered at an increasing rate, and their properties may hold clues to their origin. We have carried out 200,000 N-body simulations of three identical stellar embryos with masses drawn from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions within the cloud core, while accreting using Bondi-Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. In order to illustrate 200,000 end-states of such dynamical evolution with accretion, we introduce the “triple diagnostic diagram,” which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations, and statistical properties are derived. The separation distribution function is in good correspondence with observations, showing a steep rise at close separations, peaking around 13 AU and declining more gently, reaching zero at separations greater than 200 AU. Unresolved BD triple systems may appear as wider BD binaries. Mass ratios are strongly peaked toward unity, as observed, but this is partially due to the initial assumptions. Eccentricities gradually increase toward higher values, due to the lack of viscous interactions in the simulations, which would both shrink the orbits and decrease their eccentricities. Most newborn triple systems are unstable and while there are 9209 ejected BD binaries at 1 Myr, corresponding to about 4% of the 200,000 simulations, this number has grown to

  4. THE AGE AND STELLAR PARAMETERS OF THE PROCYON BINARY SYSTEM

    SciTech Connect

    Liebert, James; Arnett, David; Fontaine, Gilles; Young, Patrick A.; Williams, Kurtis A. E-mail: darnett@as.arizona.edu E-mail: pyoung.3@asu.edu

    2013-05-20

    The Procyon AB binary system (orbital period 40.838 yr, a newly refined determination) is near and bright enough that the component radii, effective temperatures, and luminosities are very well determined, although more than one possible solution to the masses has limited the claimed accuracy. Preliminary mass determinations for each component are available from Hubble Space Telescope imaging, supported by ground-based astrometry and an excellent Hipparcos parallax; we use these for our preferred solution for the binary system. Other values for the masses are also considered. We have employed the TYCHO stellar evolution code to match the radius and luminosity of the F5 IV-V primary star to determine the system's most likely age as 1.87 {+-} 0.13 Gyr. Since prior studies of Procyon A found its abundance indistinguishable from solar, the solar composition of Asplund, Grevesse, and Sauval (Z = 0.014) is assumed for the Hertzsprung-Russell diagram fitting. An unsuccessful attempt to fit using the older solar abundance scale of Grevesse and Sauval (Z = 0.019) is also reported. For Procyon B, 11 new sequences for the cooling of non-DA white dwarfs have been calculated to investigate the dependences of the cooling age on (1) the mass, (2) core composition, (3) helium layer mass, and (4) heavy-element opacities in the helium envelope. Our calculations indicate a cooling age of 1.19 {+-} 0.11 Gyr, which implies that the progenitor mass of Procyon B was 2.59{sub -0.26}{sup +0.44} M{sub Sun }. In a plot of initial versus final mass of white dwarfs in astrometric binaries or star clusters (all with age determinations), the Procyon B final mass lies several {sigma} below a straight line fit.

  5. The Age and Stellar Parameters of the Procyon Binary System

    NASA Astrophysics Data System (ADS)

    Liebert, James; Fontaine, Gilles; Young, Patrick A.; Williams, Kurtis A.; Arnett, David

    2013-05-01

    The Procyon AB binary system (orbital period 40.838 yr, a newly refined determination) is near and bright enough that the component radii, effective temperatures, and luminosities are very well determined, although more than one possible solution to the masses has limited the claimed accuracy. Preliminary mass determinations for each component are available from Hubble Space Telescope imaging, supported by ground-based astrometry and an excellent Hipparcos parallax; we use these for our preferred solution for the binary system. Other values for the masses are also considered. We have employed the TYCHO stellar evolution code to match the radius and luminosity of the F5 IV-V primary star to determine the system's most likely age as 1.87 ± 0.13 Gyr. Since prior studies of Procyon A found its abundance indistinguishable from solar, the solar composition of Asplund, Grevesse, and Sauval (Z = 0.014) is assumed for the Hertzsprung-Russell diagram fitting. An unsuccessful attempt to fit using the older solar abundance scale of Grevesse & Sauval (Z = 0.019) is also reported. For Procyon B, 11 new sequences for the cooling of non-DA white dwarfs have been calculated to investigate the dependences of the cooling age on (1) the mass, (2) core composition, (3) helium layer mass, and (4) heavy-element opacities in the helium envelope. Our calculations indicate a cooling age of 1.19 ± 0.11 Gyr, which implies that the progenitor mass of Procyon B was 2.59_{-0.26}^{+0.44} M ⊙. In a plot of initial versus final mass of white dwarfs in astrometric binaries or star clusters (all with age determinations), the Procyon B final mass lies several σ below a straight line fit.

  6. Transit Timing Variations In Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Sansone, Eric; Haghighipour, N.

    2012-01-01

    We present the results of a study of the effect of a stellar companion on the transit timing variations (TTV) of a planetary system. The purpose of our study is to determine the ranges of the orbital elements of a secondary star for which the amplitude of a currently existing TTV is enhanced. We chose the system of Kepler 9 as this system represents the first planetary system detected by the transit timing variation method, and studied its TTVs by considering a hypothetical secondary star in this system. By varying the mass, semi-major axis, and eccentricity of the fictitious binary companion, we tested the stability of the known planets Kepler-9c and Kepler-9b and identified the region of the parameter-space for which the binary planetary system would be stable. We calculated TTVs for the two planets of the system for different values of the orbital elements of the secondary star and calculated its difference with the system's already existing TTVs. Results of our study indicate that the effect of the binary companion is significant only when the secondary star is in a highly eccentric orbit and/or the planets of the system are within the range of Super-Earth or terrestrial sizes. This work was funded by the National Science Foundation in the form of a Research Experience for Undergraduates program at the University of Hawaii at Manoa.

  7. Solar System Dynamics

    NASA Astrophysics Data System (ADS)

    Murray, Carl D.; Dermott, Stanley F.

    2000-02-01

    Preface; 1. Structure of the solar system; 2. The two-body problem; 3. The restricted three-body problem; 4. Tides, rotation and shape; 5. Spin-orbit coupling; 6. The disturbing function; 7. Secular perturbations; 8. Resonant perturbations; 9. Chaos and long-term evolution; 10. Planetary rings; Appendix A. Solar system data; Appendix B. Expansion of the disturbing function; Index.

  8. Homemade Solar Systems

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Through the use of NASA Tech Briefs, Peter Kask, was able to build a solarized domestic hot water system. Also by applying NASA's solar energy design information, he was able to build a swimming pool heating system with minimal outlay for materials.

  9. Solar photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Forney, R. G.

    1978-01-01

    The Department of Energy's photovoltaic program is outlined. The main objective of the program is the development of low cost reliable terrestrial photovoltaic systems. A second objective is to foster widespread use of the system in residential, industrial and commercial application. The system is reviewed by examining each component; silicon solar cell, silicon solar cell modules, advanced development modules and power systems. Cost and applications of the system are discussed.

  10. Formation of Binaries from Triple Systems

    PubMed Central

    Szebehely, Victor

    1972-01-01

    The dynamical behavior of three masses moving under their mutual gravitational attraction in a plane is investigated by a systematic series of numerical experiments. It is shown that in 73% of the cases, a triple system disintegrates in less than 150 time units (corresponding to about 150 crossing times), and a binary is formed with the third star that escapes at hyperbolic velocity. The average time for disintegration is of the order of 109 years for triple stellar systems, as well as for triple galaxies. The statistics of the escaping masses show that the escaping mass is usually, but not always, the smallest in the system. A simple equation, giving the balance between the negative energy stored in the binary and the positive energy necessary for escape, explains the results qualitatively. PMID:16591978

  11. Parabolic solar systems

    NASA Astrophysics Data System (ADS)

    Parsons, W. L., IV; Goetchius, W.

    The further development of parabolic solar collectors to increase their efficiency and simplify their operation was the prime objective of this research project. Three primary objectives were pursued. The first of these was to investigate the simplest and most efficient techniques to build and mass-produce parabolic solar collectors. The second objective was to further develop and simplify absorber tubes used to collect and transfer the solar energy. Absorber tubes represented a significant area of this research project. The third objective was to develop accurate, low cost, and durable tracking systems for solar collectors. Solar tracking systems are covered including several schematic representations of various systems and designs. The testing systems and associated mechanisms for the designs discussed in this report are described.

  12. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    SciTech Connect

    Haghighipour, Nader; Kaltenegger, Lisa

    2013-11-10

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results.

  13. Solar Electric System

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Heat Pipe Technology, Inc. undertook the development of a PV system that could bring solar electricity to the individual home at reasonable cost. His system employs high efficiency PV modules plus a set of polished reflectors that concentrate the solar energy and enhance the output of the modules. Dinh incorporated a sun tracking system derived from space tracking technology. It automatically follows the sun throughout the day and turns the modules so that they get maximum exposure to the solar radiation, further enhancing the system efficiency.

  14. Residential Solar Systems.

    ERIC Educational Resources Information Center

    Fulkerson, Dan

    This publication contains student and teacher instructional materials for a course in residential solar systems. The text is designed either as a basic solar course or as a supplement to extend student skills in areas such as architectural drafting, air conditioning and refrigeration, and plumbing. The materials are presented in four units…

  15. Pulsars in binary systems: probing binary stellar evolution and general relativity.

    PubMed

    Stairs, Ingrid H

    2004-04-23

    Radio pulsars in binary orbits often have short millisecond spin periods as a result of mass transfer from their companion stars. They therefore act as very precise, stable, moving clocks that allow us to investigate a large set of otherwise inaccessible astrophysical problems. The orbital parameters derived from high-precision binary pulsar timing provide constraints on binary evolution, characteristics of the binary pulsar population, and the masses of neutron stars with different mass-transfer histories. These binary systems also test gravitational theories, setting strong limits on deviations from general relativity. Surveys for new pulsars yield new binary systems that increase our understanding of all these fields and may open up whole new areas of physics, as most spectacularly evidenced by the recent discovery of an extremely relativistic double-pulsar system.

  16. Solar Energy: Solar System Design Fundamentals.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system design fundamentals is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy…

  17. Subsystems in Nearby Solar-type Wide Binaries

    NASA Astrophysics Data System (ADS)

    Tokovinin, Andrei; Hartung, Markus; Hayward, Thomas L.

    2010-08-01

    We conducted a deep survey of resolved subsystems among wide binaries with solar-type components within 67 pc of the Sun. Images of 61 stars in the K and H bands were obtained with the Near-Infrared Coronagraphic Imager adaptive-optics instrument on the 8 m Gemini-South telescope. Our maximum detectable magnitude difference is about 5 mag and 7.8 mag at 0farcs15 and 0farcs9 separations, respectively. This enables a complete census of subsystems with stellar companions in the projected separation range from 5 to 100 AU. Out of seven such companions found in our sample, only one was previously known. We determine that the fraction of subsystems with projected separations above 5 AU is 0.12 ± 0.04 and that the distribution of their mass ratio is flat, with a power-law index of 0.2 ± 0.5. Comparing this with the properties of closer spectroscopic subsystems (separations below 1 AU), it appears that the mass-ratio distribution does not depend on the separation. The frequency of subsystems in the separation ranges below 1 AU and between 5 and 100 AU is similar, about 0.15. Unbiased statistics of multiplicity higher than 2, advanced by this work, provide constraints on star formation theory. Based on observations obtained at the Gemini Observatory (Program ID GS-2009B-Q-49), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  18. Solar energy collection system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1977-01-01

    An improved solar energy collection system, having enhanced energy collection and conversion capabilities, is delineated. The system is characterized by a plurality of receivers suspended above a heliostat field comprising a multiplicity of reflector surfaces, each being adapted to direct a concentrated beam of solar energy to illuminate a target surface for a given receiver. A magnitude of efficiency, suitable for effectively competing with systems employed in collecting and converting energy extracted from fossil fuels, is indicated.

  19. Stellivore extraterrestrials? Binary stars as living systems

    NASA Astrophysics Data System (ADS)

    Vidal, Clément

    2016-11-01

    We lack signs of extraterrestrial intelligence (ETI) despite decades of observation in the whole electromagnetic spectrum. Could evidence be buried in existing data? To recognize ETI, we first propose criteria discerning life from non-life based on thermodynamics and living systems theory. Then we extrapolate civilizational development to both external and internal growth. Taken together, these two trends lead to an argument that some existing binary stars might actually be ETI. Since these hypothetical beings feed actively on stars, we call them "stellivores". I present an independent thermodynamic argument for their existence, with a metabolic interpretation of interacting binary stars. The jury is still out, but the hypothesis is empirically testable with existing astrophysical data.

  20. Solar system fault detection

    DOEpatents

    Farrington, Robert B.; Pruett, Jr., James C.

    1986-01-01

    A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

  1. Solar system fault detection

    DOEpatents

    Farrington, R.B.; Pruett, J.C. Jr.

    1984-05-14

    A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

  2. Fragmentary Solar System History

    NASA Technical Reports Server (NTRS)

    Marti, Kurt

    1997-01-01

    The objective of this research is an improved understanding of the early solar system environment and of the processes involved in the nebula and in the evolution of solid bodies. We present results of our studies on the isotopic signatures in selected primitive solar system objects and on the evaluation of the cosmic ray records and of inferred collisional events. Furthermore, we report data of trapped martian atmospheric gases in meteorites and the inferred early evolution of Mars' atmosphere.

  3. Utilizing Energy Transfer in Binary and Ternary Bulk Heterojunction Organic Solar Cells.

    PubMed

    Feron, Krishna; Cave, James M; Thameel, Mahir N; O'Sullivan, Connor; Kroon, Renee; Andersson, Mats R; Zhou, Xiaojing; Fell, Christopher J; Belcher, Warwick J; Walker, Alison B; Dastoor, Paul C

    2016-08-17

    Energy transfer has been identified as an important process in ternary organic solar cells. Here, we develop kinetic Monte Carlo (KMC) models to assess the impact of energy transfer in ternary and binary bulk heterojunction systems. We used fluorescence and absorption spectroscopy to determine the energy disorder and Förster radii for poly(3-hexylthiophene-2,5-diyl), [6,6]-phenyl-C61-butyric acid methyl ester, 4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl]squaraine (DIBSq), and poly(2,5-thiophene-alt-4,9-bis(2-hexyldecyl)-4,9-dihydrodithieno[3,2-c:3',2'-h][1,5]naphthyridine-5,10-dione). Heterogeneous energy transfer is found to be crucial in the exciton dissociation process of both binary and ternary organic semiconductor systems. Circumstances favoring energy transfer across interfaces allow relaxation of the electronic energy level requirements, meaning that a cascade structure is not required for efficient ternary organic solar cells. We explain how energy transfer can be exploited to eliminate additional energy losses in ternary bulk heterojunction solar cells, thus increasing their open-circuit voltage without loss in short-circuit current. In particular, we show that it is important that the DIBSq is located at the electron donor-acceptor interface; otherwise charge carriers will be trapped in the DIBSq domain or excitons in the DIBSq domains will not be able to dissociate efficiently at an interface. KMC modeling shows that only small amounts of DIBSq (<5% by weight) are needed to achieve substantial performance improvements due to long-range energy transfer.

  4. The New Solar System

    NASA Astrophysics Data System (ADS)

    Beatty, J. Kelly; Collins Petersen, Carolyn; Chaikin, Andrew

    1999-01-01

    As the definitive guide for the armchair astronomer, The New Solar System has established itself as the leading book on planetary science and solar system studies. Incorporating the latest knowledge of the solar system, a distinguished team of researchers, many of them Principal Investigators on NASA missions, explain the solar system with expert ease. The completely-revised text includes the most recent findings on asteroids, comets, the Sun, and our neighboring planets. The book examines the latest research and thinking about the solar system; looks at how the Sun and planets formed; and discusses our search for other planetary systems and the search for life in the solar system. In full-color and heavily-illustrated, the book contains more than 500 photographs, portrayals, and diagrams. An extensive set of tables with the latest characteristics of the planets, their moon and ring systems, comets, asteroids, meteorites, and interplanetary space missions complete the text. New to this edition are descriptions of collisions in the solar system, full scientific results from Galileo's mission to Jupiter and its moons, and the Mars Pathfinder mission. For the curious observer as well as the student of planetary science, this book will be an important library acquisition. J. Kelly Beatty is the senior editor of Sky & Telescope, where for more than twenty years he has reported the latest in planetary science. A renowned science writer, he was among the first journalists to gain access to the Soviet space program. Asteroid 2925 Beatty was named on the occasion of his marriage in 1983. Carolyn Collins Petersen is an award-winning science writer and co-author of Hubble Vision (Cambridge 1995). She has also written planetarium programs seen at hundreds of facilities around the world. Andrew L. Chaikin is a Boston-based science writer. He served as a research geologist at the Smithsonian Institution's Center for Earth and Planetary Studies. He is a contributing editor to

  5. Discovering the Solar System

    NASA Astrophysics Data System (ADS)

    Jones, Barrie W.

    1999-04-01

    Discovering the Solar System Barrie W. Jones The Open University, Milton Keynes, UK Discovering the Solar System is a comprehensive, up-to-date account of the Solar System and of the ways in which the various bodies have been investigated and modelled. The approach is thematic, with sequences of chapters on the interiors of planetary bodies, on their surfaces, and on their atmospheres. Within each sequence there is a chapter on general principles and processes followed by one or two chapters on specific bodies. There is also an introductory chapter, a chapter on the origin of the Solar System, and a chapter on asteroids, comets and meteorites. Liberally illustrated with diagrams, black and white photographs and colour plates, Discovering the Solar System also features: * tables of essential data * question and answers within the text * end of section review questions with answers and comments Discovering the Solar System is essential reading for all undergraduate students for whom astronomy or planetary science are components of their degrees, and for those at a more advanced level approaching the subject for the first time. It will also be of great interest to non-specialists with a keen interest in astronomy. A small amount of scientific knowledge is assumed plus familiarity with basic algebra and graphs. There is no calculus. Praise for this book includes: ".certainly qualifies as an authoritative text. The author clearly has an encyclopedic knowledge of the subject." Meteorics and Planetary Science ".liberally doused with relevant graphs, tables, and black and white figures of good quality." EOS, Transactions of the American Geophysical Union ".one of the best books on the Solar System I have seen. The general accuracy and quality of the content is excellent." Journal of the British Astronomical Association

  6. New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems

    NASA Astrophysics Data System (ADS)

    Bluhm, P.; Jones, M. I.; Vanzi, L.; Soto, M. G.; Vos, J.; Wittenmyer, R. A.; Drass, H.; Jenkins, J. S.; Olivares, F.; Mennickent, R. E.; Vučković, M.; Rojo, P.; Melo, C. H. F.

    2016-10-01

    We report the discovery of 24 spectroscopic binary companions to giant stars. We fully constrain the orbital solution for 6 of these systems. We cannot unambiguously derive the orbital elements for the remaining stars because the phase coverage is incomplete. Of these stars, 6 present radial velocity trends that are compatible with long-period brown dwarf companions. The orbital solutions of the 24 binary systems indicate that these giant binary systems have a wide range in orbital periods, eccentricities, and companion masses. For the binaries with restricted orbital solutions, we find a range of orbital periods of between ~97-1600 days and eccentricities of between ~0.1-0.4. In addition, we studied the metallicity distribution of single and binary giant stars. We computed the metallicity of a total of 395 evolved stars, 59 of wich are in binary systems. We find a flat distribution for these binary stars and therefore conclude that stellar binary systems, and potentially brown dwarfs, have a different formation mechanism than planets. This result is confirmed by recent works showing that extrasolar planets orbiting giants are more frequent around metal-rich stars. Finally, we investigate the eccentricity as a function of the orbital period. We analyzed a total of 130 spectroscopic binaries, including those presented here and systems from the literature. We find that most of the binary stars with periods ≲30 days have circular orbits, while at longer orbital periods we observe a wide spread in their eccentricities. Based on observations collected at La Silla - Paranal Observatory under programs IDs IDs 085.C-0557, 087.C.0476, 089.C-0524, 090.C-0345, 096.A-9020 and through the Chilean Telescope Time under programs IDs CN2012A-73, CN2012B-47, CN2013A-111, CN2013B-51, CN2014A-52 and CN2015A-48.

  7. Evolution of close binary systems: Observational aspects

    NASA Technical Reports Server (NTRS)

    Plavec, M. J.

    1981-01-01

    Detached close binary systems define the main sequence band satisfactorily, but very little is known about the masses of giants and supergiants. High dispersion international ultraviolet explorer satellite observations promise an improvement, since blue companions are now frequently found to late type supergiants. Mu Sagittaril and in particular Xi Aurigae are discussed in more detail. The barium star abundance anomaly appears to be due to mass transfer in interacting systems. The symbiotic stars are another type of binary systems containing late type giants; several possible models for the hotter star and for the type of interaction are discussed. The W Serpentis stars appear to be Algols in the rapid phase of mass transfer, but a possible link relating them to the symbiotics is also indicated. Evidence of hot circumstellar plasmas has now been found in several ordinary Algols; there may exist a smooth transition between very quiescent Algols and the W Serpentis stars. Beta Lyrae is discussed in the light of new spectrophotometric results.

  8. Radio emission from RS CVn binary systems

    SciTech Connect

    Doiron, D.J.

    1984-01-01

    The RS CVn binary stellar systems UX Ari, HR 1099, AR Lac, HR 5110, II Peg, lambda And, and SZ Psc were investigated by use of radio interferometry during the period from July 1982 through August 1983. Interferometry took two forms: Very Large Array (VLA) observations and Very Long Baseline Interferometry (VLBI). The VLA observations determined the characteristic polarization and flux behavior of the centimeter wavelength radio emission. The observed spectral index was near zero during quiescent periods, rising to between 0.5 and 1.0 during active periods. No net linear polarization is observed to a limit of 1.7%. This is expected since the Faraday depth of thermal electrons deduced from x-ray observations is approx. 10/sup 5/. Circular polarization is observed to be less than 20% at all frequencies often with a helicity reversal between 1.6 GHz and 5 GHz. The VLBI observations have shown that the brightness temperatures are often T/sub B/ approx.> 10/sup 10/ /sup 0/K and size sources smaller than or comparable to the overall size of the binary system. These data are consistent with incoherent gyrosynchrotron emission from mildly relativistic electrons which are optically thick to their own radiation at 1.6 GHz and optically thin at 5 GHz and above. The spectral behavior suggests that the radio emission is due to a power-law distribution of electrons.

  9. Solar energy collection system

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1979-01-01

    A fixed, linear, ground-based primary reflector having an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus reflector primary. The primary reflector may be constructed by a process utilizing well known freeway paving machinery. The solar energy absorber is preferably a fluid transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency.

  10. A detached binary system BK Pegasi

    NASA Astrophysics Data System (ADS)

    Demircan, Osman; Kaya, Yalcin; Tufekcioglu, Zeki

    1994-12-01

    The UBV photometry of the detached F-type eclipsing binary BK Pegasi is presented. The light curve solution by a simple spherical model assumption suggests that a slightly hotter, larger and more luminous primary was eclipsed during the primary minimum. Combined with the radial velocity curves in Popper (1983), it was used to determine anew the system's parameters. The age and the metal abundance of the system were estimated as (3.3 +/- 0.2) x 109 yr and z = 0.028 +/- 0.003 from a comparison with the new grids of stellar models and the isochrones by Schaller et al. (1993). The distance of the system was estimated as 290 pc.

  11. Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. VI. A Giant Planet and a Brown Dwarf Candidate in a Close Binary System HD 87646

    NASA Astrophysics Data System (ADS)

    Ma, Bo; Ge, Jian; Wolszczan, Alex; Muterspaugh, Matthew W.; Lee, Brian; Henry, Gregory W.; Schneider, Donald P.; Martín, Eduardo L.; Niedzielski, Andrzej; Xie, Jiwei; Fleming, Scott W.; Thomas, Neil; Williamson, Michael; Zhu, Zhaohuan; Agol, Eric; Bizyaev, Dmitry; Nicolaci da Costa, Luiz; Jiang, Peng; Martinez Fiorenzano, A. F.; González Hernández, Jonay I.; Guo, Pengcheng; Grieves, Nolan; Li, Rui; Liu, Jane; Mahadevan, Suvrath; Mazeh, Tsevi; Nguyen, Duy Cuong; Paegert, Martin; Sithajan, Sirinrat; Stassun, Keivan; Thirupathi, Sivarani; van Eyken, Julian C.; Wan, Xiaoke; Wang, Ji; Wisniewski, John P.; Zhao, Bo; Zucker, Shay

    2016-11-01

    We report the detections of a giant planet (MARVELS-7b) and a brown dwarf (BD) candidate (MARVELS-7c) around the primary star in the close binary system, HD 87646. To the best of our knowledge, it is the first close binary system with more than one substellar circumprimary companion that has been discovered. The detection of this giant planet was accomplished using the first multi-object Doppler instrument (KeckET) at the Sloan Digital Sky Survey (SDSS) telescope. Subsequent radial velocity observations using the Exoplanet Tracker at the Kitt Peak National Observatory, the High Resolution Spectrograph at the Hobby Eberley telescope, the “Classic” spectrograph at the Automatic Spectroscopic Telescope at the Fairborn Observatory, and MARVELS from SDSS-III confirmed this giant planet discovery and revealed the existence of a long-period BD in this binary. HD 87646 is a close binary with a separation of ˜22 au between the two stars, estimated using the Hipparcos catalog and our newly acquired AO image from PALAO on the 200 inch Hale Telescope at Palomar. The primary star in the binary, HD 87646A, has {T}{eff} = 5770 ± 80 K, log g = 4.1 ± 0.1, and [Fe/H] = -0.17 ± 0.08. The derived minimum masses of the two substellar companions of HD 87646A are 12.4 ± 0.7 {M}{Jup} and 57.0 ± 3.7 {M}{Jup}. The periods are 13.481 ± 0.001 days and 674 ± 4 days and the measured eccentricities are 0.05 ± 0.02 and 0.50 ± 0.02 respectively. Our dynamical simulations show that the system is stable if the binary orbit has a large semimajor axis and a low eccentricity, which can be verified with future astrometry observations.

  12. Solar-heating system

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report describes solar modular domestic-hot-water and space-heating system intended for use in small single family dwelling where roof-mounted collectors are not feasible. Contents include design, performance, and hardware specifications for assembly, installation, operation, and maintenance of system.

  13. Binary stars.

    PubMed

    Paczynacuteski, B

    1984-07-20

    Most stars in the solar neighborhood are either double or multiple systems. They provide a unique opportunity to measure stellar masses and radii and to study many interesting and important phenomena. The best candidates for black holes are compact massive components of two x-ray binaries: Cygnus X-1 and LMC X-3. The binary radio pulsar PSR 1913 + 16 provides the best available evidence for gravitational radiation. Accretion disks and jets observed in close binaries offer a very good testing ground for models of active galactic nuclei and quasars.

  14. Baby Solar System

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Grady, Carol

    2012-01-01

    What did our solar system look like in its infancy,...... when the planets were forming? We cannot travel back in time to take an image of the early solar system, but in principle we can have the next best thing: images of infant planetary systems around Sun-like stars with ages of 1 to 5 million years, the time we think it took for the giant planets to form. Infant exoplanetary systems are critically important because they can help us understand how our solar system fits within the context of planet formation in general. More than 80% of stars are born with gas- and dust-rich disks, and thus have the potential to form planets. Through many methods we have identified more than 760 planetary systems around middle-aged stars like the Sun, but many of these have architectures that look nothing like our solar system. Young planetary systems are important missing links between various endpoints and may help us understand how and when these differences emerge. Well-known star-forming regions in Taurus, Scorpius. and Orion contain stars that could have infant planetary systems. But these stars are much more distant than our nearest neighbors such as Alpha Centauri or Sirius, making it extremely challenging to produce clear images of systems that can reveal signs of recent planet formation, let alone reveal the planets themselves. Recently, a star with the unassuming name LkCa 15 may have given us our first detailed "baby picture" of a young planetary system similar to our solar system. Located about 450 light-years away in the Taurus starforming region. LkCa 15 has a mass comparable to the Sun (0.97 solar mass) and an age of l to 5 million years, comparable to the time at which Saturn and perhaps Jupiter formed. The star is surrounded by a gas-rich disk similar in structure to the one in our solar system from which the planets formed. With new technologies and observing strategies, we have confirmed suspicions that LkCa 15's disk harbors a young planetary system.

  15. RS CVn binaries: Testing the solar-stellar dynamo connection

    NASA Technical Reports Server (NTRS)

    Dempsey, R.

    1995-01-01

    We have used the Extreme Ultraviolet Explorer satellite to study the coronal emission from the EUV-bright RS CVn binaries Sigma2 CrB, observed February 10-21, 1994, and II Peg, observed October 1-5, 1993. We present time-resolved and integrated EUV short-, medium-, and long-wavelength spectra for these binaries. Sigma2 CrB shows significant first-order emission features in the long-wavelength region. The coronal emission distributions and electron densities are estimated for those active coronae dominated by high temperature plasma.

  16. Conjugating binary systems for spacecraft thermal control

    NASA Technical Reports Server (NTRS)

    Grodzka, Philomena G.; Dean, William G.; Sisk, Lori A.; Karu, Zain S.

    1989-01-01

    The materials search was directed to liquid pairs which can form hydrogen bonds of just the right strength, i.e., strong enough to give a high heat of mixing, but weak enough to enable phase change to occur. The cursory studies performed in the area of additive effects indicate that Conjugating Binary (CB) performance can probably be fine-tuned by this means. The Fluid Loop Test Systems (FLTS) tests of candidate CBs indicate that the systems Triethylamine (TEA)/water and propionaldehyde/water show close to the ideal, reversible behavior, at least initially. The Quick Screening Tests QSTs and FLTS tests, however, both suffer from rather severe static due either to inadequate stirring or temperature control. Thus it is not possible to adequately evaluate less than ideal CB performers. Less than ideal performers, it should be noted, may have features that make them better practical CBs than ideal performers. Improvement of the evaluation instrumentation is thus indicated.

  17. Solar System Dynamics

    NASA Technical Reports Server (NTRS)

    Wisdom, Jack

    2002-01-01

    In these 18 years, the research has touched every major dynamical problem in the solar system, including: the effect of chaotic zones on the distribution of asteroids, the delivery of meteorites along chaotic pathways, the chaotic motion of Pluto, the chaotic motion of the outer planets and that of the whole solar system, the delivery of short period comets from the Kuiper belt, the tidal evolution of the Uranian arid Galilean satellites, the chaotic tumbling of Hyperion and other irregular satellites, the large chaotic variations of the obliquity of Mars, the evolution of the Earth-Moon system, and the resonant core- mantle dynamics of Earth and Venus. It has introduced new analytical and numerical tools that are in widespread use. Today, nearly every long-term integration of our solar system, its subsystems, and other solar systems uses algorithms that was invented. This research has all been primarily Supported by this sequence of PGG NASA grants. During this period published major investigations of tidal evolution of the Earth-Moon system and of the passage of the Earth and Venus through non-linear core-mantle resonances were completed. It has published a major innovation in symplectic algorithms: the symplectic corrector. A paper was completed on non-perturbative hydrostatic equilibrium.

  18. SAGE III L2 Solar Event Species Profiles (Binary)

    Atmospheric Science Data Center

    2016-06-14

    ... Search and Order:  Earthdata Search   FTP Access:  Data Pool V3  |  Data Pool V4 Parameters:  Aerosol ... Search Additional Info:  Data Format: Big Endian/IEEE Binary; Avg Size in MB: 0.044 SCAR-B Block:  ...

  19. Planetary system disruption by Galactic perturbations to wide binary stars.

    PubMed

    Kaib, Nathan A; Raymond, Sean N; Duncan, Martin

    2013-01-17

    Nearly half the exoplanets found within binary star systems reside in very wide binaries with average stellar separations greater than 1,000 astronomical units (one astronomical unit (AU) being the Earth-Sun distance), yet the influence of such distant binary companions on planetary evolution remains largely unstudied. Unlike their tighter counterparts, the stellar orbits of wide binaries continually change under the influence of the Milky Way's tidal field and impulses from other passing stars. Here we report numerical simulations demonstrating that the variable nature of wide binary star orbits dramatically reshapes the planetary systems they host, typically billions of years after formation. Contrary to previous understanding, wide binary companions may often strongly perturb planetary systems, triggering planetary ejections and increasing the orbital eccentricities of surviving planets. Although hitherto not recognized, orbits of giant exoplanets within wide binaries are statistically more eccentric than those around isolated stars. Both eccentricity distributions are well reproduced when we assume that isolated stars and wide binaries host similar planetary systems whose outermost giant planets are scattered beyond about 10 AU from their parent stars by early internal instabilities. Consequently, our results suggest that although wide binaries eventually remove the most distant planets from many planetary systems, most isolated giant exoplanet systems harbour additional distant, still undetected planets.

  20. Effect of Blend Composition on Binary Organic Solar Cells Using a Low Band Gap Polymer.

    PubMed

    Wright, Matthew; Lin, Rui; Tayebjee, Murad J Y; Yang, Xiaohan; Veettil, Binesh Puthen; Wen, Xiaoming; Uddin, Ashraf

    2015-03-01

    This report investigates the influence of the solution blend composition of binary bulk heterojunction organic solar cells composed of poly(2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl)-4H- cyclopenta[2,1-b:3,4-b'dithiophene-2,6-diy

  1. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    SciTech Connect

    Kaltenegger, Lisa; Haghighipour, Nader

    2013-11-10

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886.

  2. The New Solar System

    ERIC Educational Resources Information Center

    Wilkinson, John

    2009-01-01

    Since 2006, the details of bodies making up our solar system have been revised. This was largely as a result of new discoveries of a number of planet-like objects beyond the orbit of Pluto. The International Astronomical Union redefined what constituted a planet and established two new classifications--dwarf planets and plutoids. As a result, the…

  3. Probing the Solar System

    ERIC Educational Resources Information Center

    Wilkinson, John

    2013-01-01

    Humans have always had the vision to one day live on other planets. This vision existed even before the first person was put into orbit. Since the early space missions of putting humans into orbit around Earth, many advances have been made in space technology. We have now sent many space probes deep into the Solar system to explore the planets and…

  4. Solar System Remote Sensing

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This volume contains abstracts that have been accepted for presentation at the symposium on Solar System Remote Sensing, September 20-21, 2002, in Pittsburgh, Pennsylvania. Administration and publications support for this meeting were provided by the staff of the Publications and Program Services Departments at the Lunar and Planetary Institute.

  5. N-Body Integrators for Planets in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Chambers, John E.

    The discovery of planets orbiting in binary star systems represents an exciting new field of astrophysics. The stability of planetary orbits in binary systems can only be addressed analytically in special cases, so most researchers have studied stability using long-term N-body integrations of test particles, examining binary systems with a range of masses and orbits (e.g. Wiegert and Holman 1997; Haghighipour and Wiegert 1999; Haghighipour 2006). This has led to a good understanding of the likely regions of stability and instability in binary systems. Integrators can also been used to study the more complex problem of several finite-mass planets orbiting in a binary system, where interactions between the planets are significant. However, at the time of writing, this problem has been explored in less detail than the test-particle case, and we still lack a general theory for the stability of these systems.

  6. Evolution of the symbiotic binary system AG Dranconis

    NASA Technical Reports Server (NTRS)

    Mikolajewska, Joanna; Kenyon, Scott J; Mikolajewski, Maciej; Garcia, Michael R.; Polidan, Ronald S.

    1995-01-01

    We present an analysis of new and archival photometric and spectroscopic observations of the symbiotic star AG Draconis. This binary has undergone several 1 - 3 mag optical and ultraviolet eruptions during the past 15 years. Our combination of optical and ultraviolet spectroscopic data allow a more complete analysis of this system than in previous papers. AG Dra is composed of a K-type bright giant M(sub g) approximately 1.5 solar mass) and a hot, compact star M(sub h approximatelly 0.4 - 0.6 solar mass) embedded in a dense, low metallicity nebula. The hot component undergoes occasional thermonuclear runaways that produce 2 - 3 mag optical/ultraviolet eruptions. During these eruptions, the hot component develops a low velocity wind that quenches x-ray emission from the underlying hot white dwarf. The photoionized nebula changes its volume by a factor of 5 throughout an eruptin cycle. The K bright giant occults low ionization emission lines during superior conjunctions at all outburst phases but does not occult high ionization lines in outburst (and perhaps quiescence). This geometry and the component masses suggest a system inclination of i approximately 30 deg - 45 deg.

  7. NASA's Solar System Exploration Program

    NASA Technical Reports Server (NTRS)

    Robinson, James

    2005-01-01

    A viewgraph presentation describing NASA's Solar System Exploration Program is shown. The topics include: 1) Solar System Exploration with Highlights and Status of Programs; 2) Technology Drivers and Plans; and 3) Summary

  8. Future solar system missions

    NASA Technical Reports Server (NTRS)

    Briggs, Geoffrey A.

    1990-01-01

    NASA's planetary exploration program is discussed, with emphasis on strategy, namely, exploration of all three main classes of solar system bodies (the terrestrial planets, the outer giants and their moons, and the primitive small bodies). Planning of an extensive search for other planetary systems is focused on the application of various approaches to ultra-high precision astrometry and the possible use of a space-based coronagraphic telescope. Program strategy and lunar and Mars outpost precursor missions are illustrated.

  9. The Evolution of Compact Binary Star Systems.

    PubMed

    Postnov, Konstantin A; Yungelson, Lev R

    2006-01-01

    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars - compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.

  10. Asteroid Systems: Binaries, Triples, and Pairs

    NASA Astrophysics Data System (ADS)

    Margot, J.-L.; Pravec, P.; Taylor, P.; Carry, B.; Jacobson, S.

    In the past decade, the number of known binary near-Earth asteroids has more than quadrupled and the number of known large main-belt asteroids with satellites has doubled. Half a dozen triple asteroids have been discovered, and the previously unrecognized populations of asteroid pairs and small main-belt binaries have been identified. The current observational evidence confirms that small (≲20 km) binaries form by rotational fission and establishes that the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect powers the spin-up process. A unifying paradigm based on rotational fission and post-fission dynamics can explain the formation of small binaries, triples, and pairs. Large (>~20 km) binaries with small satellites are most likely created during large collisions.

  11. XZ And a semidetached asynchronous binary system

    NASA Astrophysics Data System (ADS)

    Manzoori, Davood

    2016-05-01

    In this work the light curves (LCs) solutions along with the radial velocity curve of the semidetached binary systemXZ And are presented using the PHOEBE program(ver 0.31a). Absolute parameters of the stellar components were then determined, enabling us to discuss structure and evolutionary status of the system. The analysis indicates that the primary is a non-synchronous (i.e., F1 = 3.50 ± 0.01) Main Sequence (MS) star and the secondary is a bit more evolved, and fills its Roche critical surface. In addition, times of minima data (" O - C curve") were analyzed. Apart from an almost parabolic variation in the general trend of O - C data, which was attributed to a mass transfer from the secondary with the rate ˙2 = (9.52 ± 0.41) × 10-10 M ⊙ yr-1; two cyclic variations with mean periods of 34.8 ± 2.4 and 23.3 ± 3.0 yr, modulating the orbital period, were found, which were attributed to a third body orbiting around the system, and magnetic activity cycle effect, respectively.

  12. Solar System Voyage

    NASA Astrophysics Data System (ADS)

    Brunier, Serge

    2002-11-01

    In the last few decades, the exploration of our solar system has revealed fascinating details about the worlds that lie beyond our Earth. This lavishly illustrated book invites the reader on a journey through the solar system. After locating our planetary system in the Universe, Brunier describes the Sun and its planets, the large satellites, asteroids, and comets. Photographs and information taken from the latest space missions allow readers to experience spectacular scenes: the lunar plains scarred by asteroid impacts, the frozen deserts of Mars and Europa, the continuously erupting volcanoes of Io and the giant geysers of Triton, the rings of Saturn and the clouds of Venus and Titan, and the powerful crash of the comet Shoemaker-Levy into Jupiter. Inspired by the extraordinary photographs and incisive text, readers of Solar System Voyage will gain a greater appreciation of the hospitable planet we call home. Serge Brunier is chief editor of the journal Ciel et Espace, a photojournalist, and the author of many nonfiction books aimed at both specialists and the general public. His previous books include Space Odyssey (Cambridge, 2002), Glorious Eclipses with Jean-Pierre Luminet (Cambridge, 2000), and Majestic Universe (Cambridge, 1999).

  13. ANALYSIS OF THE MOTION OF AN EXTRASOLAR PLANET IN A BINARY SYSTEM

    SciTech Connect

    Plávalová, Eva; Solovaya, Nina A. E-mail: solov@sai.msu.ru

    2013-11-01

    More than 10% of extra-solar planets (EPs) orbit in a binary or multiple stellar system. We investigated the motion of planets revolving in binary systems in the case of the three-body problem. We carried out an analysis of the motion of an EP revolving in a binary system with the following conditions: (1) a planet in a binary system revolves around one of the components (parent star); (2) the distance between the star's components is greater than that between the parent star and the orbiting planet (ratio of the semi-major axes is a small parameter); and (3) the mass of the planet is smaller than the mass of the stars, but is not negligible. The Hamiltonian of the system without short periodic terms was used. We expanded the Hamiltonian in terms of the Legendre polynomial and truncated after the second-order term, depending on only one angular variable. In this case, the solution of the system was obtained and the qualitative analysis of the motion was produced. We have applied this theory to real EPs and compared to the numerical integration. Analyses of the possible regions of motion are presented. It is shown that stable and unstable motions of EPs are possible. We applied our calculations to two binary systems hosting an EP and calculated the possible values for their unknown orbital elements.

  14. On solar system nomenclature

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1976-01-01

    Arguments in support of naming topographic features on other solar system objects after human beings other than astronomers are outlined. In particular, it is important to make sure that the end result will be a nonprovincial distribution of nationalities, epochs, and occupations, a distribution that future generations can be proud of. A more consistent scheme for Jovian satellite nomenclature is proposed which consistently maintains the tradition of naming Jovian satellites after prominent consorts.

  15. Fixed solar collection system

    SciTech Connect

    Tipton, H.R.

    1984-07-31

    A fixed solar energy collector system has facing panels of different size forming a Vee-shaped trough open at its base and supporting a plurality of highly reflective convex reflectors strategically disposed upon said panels in reflective relationship to a plurality of Fresnel lenses positioned at the base of the trough. A suitable reflector, disposed beneath the Fresnel lenses, directs the reflected energy to a heat-needy target.

  16. Are the orbital poles of binary stars in the solar neighbourhood anisotropically distributed?

    NASA Astrophysics Data System (ADS)

    Agati, J.-L.; Bonneau, D.; Jorissen, A.; Soulié, E.; Udry, S.; Verhas, P.; Dommanget, J.

    2015-02-01

    We test whether or not the orbital poles of the systems in the solar neighbourhood are isotropically distributed on the celestial sphere. The problem is plagued by the ambiguity on the position of the ascending node. Of the 95 systems closer than 18 pc from the Sun with an orbit in the 6th Catalogue of Orbits of Visual Binaries, the pole ambiguity could be resolved for 51 systems using radial velocity collected in the literature and CORAVEL database or acquired with the HERMES/Mercator spectrograph. For several systems, we can correct the erroneous nodes in the 6th Catalogue of Orbits and obtain new combined spectroscopic/astrometric orbits for seven systems [WDS 01083+5455Aa,Ab; 01418+4237AB; 02278+0426AB (SB2); 09006+4147AB (SB2); 16413+3136AB; 17121+4540AB; 18070+3034AB]. We used of spherical statistics to test for possible anisotropy. After ordering the binary systems by increasing distance from the Sun, we computed the false-alarm probability for subsamples of increasing sizes, from N = 1 up to the full sample of 51 systems. Rayleigh-Watson and Beran tests deliver a false-alarm probability of 0.5% for the 20 systems closer than 8.1 pc. To evaluate the robustness of this conclusion, we used a jackknife approach, for which we repeated this procedure after removing one system at a time from the full sample. The false-alarm probability was then found to vary between 1.5% and 0.1%, depending on which system is removed. The reality of the deviation from isotropy can thus not be assessed with certainty at this stage, because only so few systems are available, despite our efforts to increase the sample. However, when considering the full sample of 51 systems, the concentration of poles toward the Galactic position l = 46.0°, b = 37°, as observed in the 8.1 pc sphere, totally vanishes (the Rayleigh-Watson false-alarm probability then rises to 18%). Tables 1-3 and Appendices are available in electronic form at http://www.aanda.org† Deceased October 1, 2014.

  17. Metallicity dependence of Type Ib/c and IIb supernova progenitors in binary systems

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-Chul

    Type Ib/c supernovae (SNe Ib/c) are characterized by the lack of prominent hydrogen lines in thespectra, implying that their progenitors have lost most of their hydrogen envelopes by the time of the iron corecollapse. Binary interactions provide an important evolutionary chanel for SNe Ib/c, and recent observations indicatethat the inferred ejecta masses of SNe Ibc are more consistent with the prediction of the binary scenario than that ofthe single star scenario that invokes mass loss as the key evolutionary factor for SNe Ib/c progenitors. So far,theoretical predictions on the detailed properties of SNe Ib/c progenitors in binary systems have been made mostlywith models using solar metallicity. However, unlike the single star scenario, where SNe Ib/c are expected only forsufficiently high metallicity, hydrogen-deficent SN progenitors can be produced via binary interactions at anymetallicity. In this talk, I will discuss theoretical predictions on the metallicity dependence of the SNe Ib/c progenitorstructure, based on evolutionary models of massive binary stars. Sepefically, I will address how the ejecta masses ofSNe Ib and Ic and the ratio of SN Ib/c to SN IIb as well as SN Ib to SN Ic would systematically change as a function ofmetallicity, and which new types of SNe are expected in binary systems at low metallicity.

  18. Metallicity dependence of Type Ib/c and IIb supernova progenitors in binary systems

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-CHul

    2015-08-01

    Type Ib/c supernovae (SNe Ib/c) are characterized by the lack of prominent hydrogen lines in the spectra, implying that their progenitors have lost most of their hydrogen envelopes by the time of the iron core collapse. Binary interactions provide an important evolutionary chanel for SNe Ib/c, and recent observations indicate that the inferred ejecta masses of SNe Ibc are more consistent with the prediction of the binary scenario than that of the single star scenario that invokes mass loss as the key evolutionary factor for SNe Ib/c progenitors. So far, theoretical predictions on the detailed properties of SNe Ib/c progenitors in binary systems have been made mostly with models using solar metallicity. However, unlike the single star scenario, where SNe Ib/c are expected only for sufficiently high metallicity, hydrogen-deficent SN progenitors can be produced via binary interactions at any metallicity. In this talk, I will discuss theoretical predictions on the metallicity dependence of the SNe Ib/c progenitor structure, based on evolutionary models of massive binary stars. Sepefically, I will address how the ejecta masses of SNe Ib and Ic and the ratio of SN Ib/c to SN IIb as well as SN Ib to SN Ic would systematically change as a function of metallicity, and which new types of SNe are expected in binary systems at low metallicity.

  19. Close encounters of the third-body kind. [intruding bodies in binary star systems

    NASA Technical Reports Server (NTRS)

    Davies, M. B.; Benz, W.; Hills, J. G.

    1994-01-01

    We simulated encounters involving binaries of two eccentricities: e = 0 (i.e., circular binaries) and e = 0.5. In both cases the binary contained a point mass of 1.4 solar masses (i.e., a neutron star) and a 0.8 solar masses main-sequence star modeled as a polytrope. The semimajor axes of both binaries were set to 60 solar radii (0.28 AU). We considered intruders of three masses: 1.4 solar masses (a neutron star), 0.8 solar masses (a main-sequence star or a higher mass white dwarf), and 0.64 solar masses (a more typical mass white dwarf). Our strategy was to perform a large number (40,000) of encounters using a three-body code, then to rerun a small number of cases with a three-dimensional smoothed particle hydrodynamics (SPH) code to determine the importance of hydrodynamical effects. Using the results of the three-body runs, we computed the exchange across sections, sigma(sub ex). From the results of the SPH runs, we computed the cross sections for clean exchange, denoted by sigma(sub cx); the formation of a triple system, denoted by sigma(sub trp); and the formation of a merged binary with an object formed from the merger of two of the stars left in orbit around the third star, denoted by sigma(sub mb). For encounters between either binary and a 1.4 solar masses neutron star, sigma(sub cx) approx. 0.7 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 0.3 sigma(sub ex). For encounters between either binary and the 0.8 solar masses main-sequence star, sigma(sub cx) approx. 0.50 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 1.0 sigma(sub ex). If the main sequence star is replaced by a main-sequence star of the same mass, we have sigma(sub cx) approx. 0.5 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 1.6 sigma(sub ex). Although the exchange cross section is a sensitive function of intruder mass, we see that the cross section to produce merged binaries is roughly independent of intruder mass. The merged binaries produced have semi

  20. DETECTION OF LOW-MASS-RATIO STELLAR BINARY SYSTEMS

    SciTech Connect

    Gullikson, Kevin; Dodson-Robinson, Sarah

    2013-01-01

    O- and B-type stars are often found in binary systems, but the low binary mass-ratio regime is relatively unexplored due to observational difficulties. Binary systems with low mass ratios may have formed through fragmentation of the circumstellar disk rather than molecular cloud core fragmentation. We describe a new technique sensitive to G- and K-type companions to early B stars, a mass ratio of roughly 0.1, using high-resolution, high signal-to-noise spectra. We apply this technique to a sample of archived VLT/CRIRES observations of nearby B stars in the CO bandhead near 2300 nm. While there are no unambiguous binary detections in our sample, we identify HIP 92855 and HIP 26713 as binary candidates warranting follow-up observations. We use our non-detections to determine upper limits to the frequency of FGK stars orbiting early B-type primaries.

  1. Solar Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  2. Solar Powered Refrigeration System

    NASA Astrophysics Data System (ADS)

    Ewert, Michael K.; Bergeron, David J., III

    2002-09-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  3. Terrestrial solar thermionic energy conversion systems concept

    NASA Technical Reports Server (NTRS)

    Shimada, K.; Swerdling, M.

    1975-01-01

    Results obtained from studies of a (1) solar concentrator, (2) solar energy receiver - thermionic converter system, and (3) solar thermionic topping system are described. Peripheral subsystems, which are required for any solar energy conversion system, are also discussed.

  4. The Planet in the HR 7162 Binary System Discovered by PHASES Astrometry

    NASA Astrophysics Data System (ADS)

    Muterspaugh, Matthew W.; Lane, B. F.; Konacki, M.; Burke, B. F.; Colavita, M. M.; Shao, M.; Hartkopf, W. I.; Boss, A. P.; O'Connell, J.; Fekel, F. C.; Wiktorowicz, S. J.

    2011-01-01

    The now-completed Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) used phase-referenced long-baseline interferometry to monitor 51 binary systems with 35 micro-arcsecond measurement precision, resulting in the high-confidence detection of a planet in the HR 7162 system. The 1.5 Jupiter mass planet is in a 2 AU orbit around one of the stars, whereas the binary itself has a separation of only 19 AU. Despite the close stellar companion, this configuration is expected to be stable, based on dynamic simulations. In the context of our solar system, this is analogous to a Jovian planet just outside of Mars' orbit, with a second star at the distance of Uranus. If this configuration were present during the period of planet formation, the complex gravitational environment created by the stars would seem to disrupt planet formation mechanisms that require long times to complete (thousands of years or more). While it is possible the arrangement resulted from the planet being formed in another environment (a single star or wider binary) after which the system reached its current state via dynamic interactions (star-planet exchange with a binary, or the binary orbit shrinking by interacting with a passing star), the frequency of such interactions is very low. Because the PHASES search only had the sensitivity to rule out Jovian mass companions in 11 of our 51 systems, yet one such system was found, the result indicates either extreme luck or that there is a high frequency of 20 AU binaries hosting planets. The latter interpretation is supported by previous detections of planets in 5-6 additional 20 AU binaries in other surveys (though with less control over the statistics for determining frequency of occurrence). Thus, there is observational support suggesting that a mechanism for rapid Jovian planet formation occurs in nature.

  5. Solar system plasma waves

    NASA Technical Reports Server (NTRS)

    Gurnett, Donald A.

    1995-01-01

    An overview is given of spacecraft observations of plasma waves in the solar system. In situ measurements of plasma phenomena have now been obtained at all of the planets except Mercury and Pluto, and in the interplanetary medium at heliocentric radial distances ranging from 0.29 to 58 AU. To illustrate the range of phenomena involved, we discuss plasma waves in three regions of physical interest: (1) planetary radiation belts, (2) planetary auroral acceleration regions and (3) the solar wind. In each region we describe examples of plasma waves that are of some importance, either due to the role they play in determining the physical properties of the plasma, or to the unique mechanism involved in their generation.

  6. Planetesimal Accretion in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Marzari, F.; Scholl, H.

    2000-11-01

    Planetesimal accretion in close binary systems is a complex process for the gravitational perturbations of the companion star on the planetesimal orbits. These perturbations excite high eccentricities that can halt the accumulation process of planetesimals into planets also in those regions around the star where stable planetary orbits would eventually be possible. However, the evolution of a planetesimal swarm is also affected by collisions and gas drag. In particular, gas drag combined with the secular perturbations of the secondary star forces a strong alignment of all the planetesimal periastra. Since periastra are also coupled to eccentricities via the secular perturbations of the companion, the orbits of the planetesimals, besides all being aligned, also have very close values of eccentricity. This orbital ``phasing'' strongly reduces the contribution of the eccentricity to the relative velocities between planetesimals, and the impact speeds are dominated by the Keplerian shear: accretion becomes possible. This behavior is not limited to small planetesimals but also affects bodies as large as 100 km in diameter. The effects of gas drag are in fact enhanced by the presence of the constant forced component in the orbital eccentricity of the planetesimals. We describe analytically the periastron alignment by using the secular equations developed by Heppenheimer, and we test the prediction of the theory with a numerical code that integrates the orbits of a swarm of planetesimals perturbed by gas drag and collisions. The gas density is assumed to decrease outward, and the collisions are modeled as inelastic. Our computations are focused on the α Centauri system, which is a good candidate for terrestrial planets as we will show. The impact velocities between planetesimals of different sizes are computed at progressively increasing distances from the primary star and are compared with estimates for the maximum velocity for accretion. According to our simulations in

  7. Early Solar System Chronology

    NASA Astrophysics Data System (ADS)

    McKeegan, K. D.; Davis, A. M.

    2003-12-01

    Chondritic Meteorites as Probes of Early Solar System EvolutionThe evolutionary sequence involved in the formation of relatively low-mass stars, such as the Sun, has been delineated in recent years through impressive advances in astronomical observations at a variety of wavelengths, combined with improved numerical and theoretical models of the physical processes thought to occur during each stage. From the models and the observational statistics, it is possible to infer in a general way how our solar system ought to have evolved through the various stages from gravitational collapse of a fragment of a molecular cloud to the accretion of planetary-sized bodies (e.g., Cameron, 1995; Alexander et al., 2001; Shu et al., 1987; André et al., 2000; see Chapters 1.04, 1.17, and 1.20). However, the details of these processes remain obscured, literally from an astronomical perspective, and the dependence of such models on various parameters requires data to constrain the specific case of our solar system's origin.Fortunately, the chondritic meteorites sample aspects of this evolution. The term "chondrite" (or chondritic) was originally applied to meteorites bearing chondrules, which are approximately millimeter-sized solidified melt droplets consisting largely of mafic silicate minerals and glass commonly with included metal or sulfide. However, the meaning of chondritic has been expanded to encompass all extraterrestrial materials that are "primitive," i.e., are undifferentiated samples having nearly solar elemental composition. Thus, the chondrites represent a type of cosmic sediment, and to a first approximation can be thought of as "hand samples" of the condensable portion of the solar nebula. The latter is a general term referring to the phase(s) of solar system evolution intermediate between molecular cloud collapse and planet formation. During the nebular phase, the still-forming Sun was an embedded young-stellar object (YSO) enshrouded by gas and dust, which was

  8. Advanced Solar Power Systems

    NASA Technical Reports Server (NTRS)

    Atkinson, J. H.; Hobgood, J. M.

    1984-01-01

    The Advanced Solar Power System (ASPS) concentrator uses a technically sophisticated design and extensive tooling to produce very efficient (80 to 90%) and versatile energy supply equipment which is inexpensive to manufacture and requires little maintenance. The advanced optical design has two 10th order, generalized aspheric surfaces in a Cassegrainian configuration which gives outstanding performance and is relatively insensitive to temperature changes and wind loading. Manufacturing tolerances also have been achieved. The key to the ASPS is the direct absorption of concentrated sunlight in the working fluid by radiative transfers in a black body cavity. The basic ASPS design concepts, efficiency, optical system, and tracking and focusing controls are described.

  9. Solar system exploration

    NASA Technical Reports Server (NTRS)

    Chapman, Clark R.; Ramlose, Terri (Editor)

    1989-01-01

    The goal of planetary exploration is to understand the nature and development of the planets, as illustrated by pictures from the first two decades of spacecraft missions and by the imaginations of space artists. Planets, comets, asteroids, and moons are studied to discover the reasons for their similarities and differences and to find clues that contain information about the primordial process of planet origins. The scientific goals established by the National Academy of Sciences as the foundation of NASA's Solar System Exploration Program are covered: to determine the nature of the planetary system, to understand its origin and evolution, the development of life on Earth, and the principles that shape present day Earth.

  10. Solar-System Ephemeris Toolbox

    NASA Technical Reports Server (NTRS)

    Walker, Charles F.

    2005-01-01

    NASA s Jet Propulsion Laboratory (JPL) generates planetary and lunar ephemeris data and FORTRAN routines that allow users to obtain state data for the Sun, the moon, and the planets. The JPL Solar System Ephemeris Toolbox, developed at Kennedy Space Center, is a set of functions that provides the same functionality in the MATLAB computing environment along with some additional capabilities. The toolbox can be used interactively via a graphical user interface (GUI), or individual functions can be called from the MATLAB command prompt or other MATLAB scripts and functions. The toolbox also includes utility functions to define and perform coordinate transformation (e.g., mean-of-date, true-of-date, J2000) that are common in the use of these ephemerides. An attached README file guides the user through the process of constructing binary ephemeris files, verifying correct installation, and using functions to extract state data. This process also can be performed using the GUI. Help from each toolbox function is available through MATLAB s "help" function. Many of the functions in the toolbox are MATLAB equivalents of the JPL-written FORTRAN programs and subroutines used for the same purposes. A novice can use the GUI to extract state data, while a more experienced user can use the functions directly, as needed, in his/her applications. The toolbox has been tested using MATLAB Releases 13 an

  11. Solar thermal power system

    DOEpatents

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  12. Solar heating system

    DOEpatents

    Schreyer, James M.; Dorsey, George F.

    1982-01-01

    An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

  13. Improved solar heating systems

    DOEpatents

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  14. KOI-3278: a self-lensing binary star system.

    PubMed

    Kruse, Ethan; Agol, Eric

    2014-04-18

    Over 40% of Sun-like stars are bound in binary or multistar systems. Stellar remnants in edge-on binary systems can gravitationally magnify their companions, as predicted 40 years ago. By using data from the Kepler spacecraft, we report the detection of such a "self-lensing" system, in which a 5-hour pulse of 0.1% amplitude occurs every orbital period. The white dwarf stellar remnant and its Sun-like companion orbit one another every 88.18 days, a long period for a white dwarf-eclipsing binary. By modeling the pulse as gravitational magnification (microlensing) along with Kepler's laws and stellar models, we constrain the mass of the white dwarf to be ~63% of the mass of our Sun. Further study of this system, and any others discovered like it, will help to constrain the physics of white dwarfs and binary star evolution.

  15. Outer Solar System Nomenclature

    NASA Technical Reports Server (NTRS)

    Owen, Tobias C.

    1998-01-01

    The Principal Investigator's responsibilities on this grant fell into two categories according to his participation. In the nomenclature work of the International Astronomical Union (IAU). Owen is chair of the Task Group for the Outer Solar System. He is also a member of the IAU's Working Group on Planetary and Satellite Nomenclature (WGPSN) which is composed of the chairs of the several Task Groups plus the presidents of two IAU Commissions and several outside consultants. The WGPSN is presided over by its President, Professor Kaare Aksnes from the Rosseland Institute for Theoretical Astrophysics in Oslo, Norway.

  16. The chemical evolution of the solar neighbourhood: the effect of binaries

    NASA Astrophysics Data System (ADS)

    De Donder, E.; Vanbeveren, D.

    2002-03-01

    In this paper we compute the time evolution of the elements ( 4He, 12C, 14N, 16O, 20Ne, 24Mg, 28Si, 32S, 40Ca and 56Fe) and of the supernova rates in the solar neighbourhood by means of a galactic chemical evolutionary code that includes in detail the evolution of both single and binary stars. Special attention is payed to the formation of black holes. Our main conclusions: in order to predict the galactic time evolution of the different types of supernovae, it is essential to compute in detail the evolution of the binary population, the observed time evolution of carbon is better reproduced by a galactic model where the effect is included of a significant fraction of intermediate mass binaries, massive binary mass exchange provides a possible solution for the production of primary nitrogen during the very early phases of galactic evolution, chemical evolutionary models with binaries or without binaries but with a detailed treatment of the SN Ia progenitors predict very similar age-metallicity relations and very similar G-dwarf distributions whereas the evolution of the yields as function of time of the elements 4He, 16O, 20Ne, 24Mg, 28Si, 32S and 40Ca differ by no more than a factor of two or three, the observed time evolution of oxygen is best reproduced when most of the oxygen produced during core helium burning in ALL massive stars serves to enrich the interstellar medium. This can be used as indirect evidence that (massive) black hole formation in single stars and binary components is always preceded by a supernova explosion.

  17. The evolution of highly compact binary stellar systems in globular clusters

    NASA Technical Reports Server (NTRS)

    Krolik, J. H.; Meiksin, A.; Joss, P. C.

    1984-01-01

    A highly compact binary represents a system which is composed of a collapsed object (degenerate dwarf, neutron star, or black hole) in orbit with a low-mass (equal to or less than 0.5 solar mass) secondary star. Matter may be transferred from the secondary to the collapsed star due to the decay of the orbit resulting from the emission of gravitational radiation. The present investigation has the objective to study quantitatively the evolution of highly compact binaries in globular cluster cores, subject to the interplay of gravitational radiation and collisions with field stars. The investigation is exploratory in nature. The numerical methods employed are based on the techniques developed by Rappaport et al. (1982). It is found that occasional close encounters with field stars strongly dominate the evolution of highly compact binaries in dense globular cluster cores. Attention is given to the applicability of the findings to observations of X-ray sources and cataclysmic variables.

  18. Solar System Visualizations

    NASA Technical Reports Server (NTRS)

    Brown, Alison M.

    2005-01-01

    Solar System Visualization products enable scientists to compare models and measurements in new ways that enhance the scientific discovery process, enhance the information content and understanding of the science results for both science colleagues and the public, and create.visually appealing and intellectually stimulating visualization products. Missions supported include MER, MRO, and Cassini. Image products produced include pan and zoom animations of large mosaics to reveal the details of surface features and topography, animations into registered multi-resolution mosaics to provide context for microscopic images, 3D anaglyphs from left and right stereo pairs, and screen captures from video footage. Specific products include a three-part context animation of the Cassini Enceladus encounter highlighting images from 350 to 4 meter per pixel resolution; Mars Reconnaissance Orbiter screen captures illustrating various instruments during assembly and testing at the Payload Hazardous Servicing Facility at Kennedy Space Center; and an animation of Mars Exploration Rover Opportunity's 'Rub al Khali' panorama where the rover was stuck in the deep fine sand for more than a month. This task creates new visualization products that enable new science results and enhance the public's understanding of the Solar System and NASA's missions of exploration.

  19. Our Solar System's Cousin?

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This artist's concept illustrates two planetary systems -- 55 Cancri (top) and our own. Blue lines show the orbits of planets, including the dwarf planet Pluto in our solar system. The 55 Cancri system is currently the closest known analogue to our solar system, yet there are some fundamental differences.

    The similarities begin with the stars themselves, which are about the same mass and age. Both stars also host big families of planets. Our solar system has eight planets, while 55 Cancri has five, making it the record-holder for having the most known exoplanets. In fact, 55 Cancri could have additional planets, possibly even rocky ones that are too small to be seen with current technologies. All of the planets in the two systems have nearly circular orbits.

    In addition, both planetary systems have giant planets in their outer regions. The giant located far away from 55 Cancri is four times the mass of our Jupiter, and completes one orbit every 14 years at a distance of five times that between Earth and the sun (about 868 million kilometers or 539 million miles). Our Jupiter completes one orbit around the sun every 11.9 years, also at about five times the Earth-sun distance (778 million kilometers or 483 million miles). Fifty-five Cancri is still the only known star besides ours with a planet in a distant Jupiter-like orbit. Both systems also contain inner planets that are less massive than their outer planets.

    The differences begin with the planets' masses. The planets orbiting 55 Cancri are all larger than Earth, and represent a 'souped-up' version of our own solar system. In fact, this is the first star that boasts more giant planets than our sun!

    The arrangement of the planetary systems is also different. The inner four planets of 55 Cancri are all closer to the star than Earth is to the sun. The closest, about the mass of Uranus, whips around the star in just under three days at a distance of approximately 5.6 million kilometers (3

  20. Binary Star Systems and Extrasolar Planets: The PHASES Search for Planets in Binaries

    NASA Astrophysics Data System (ADS)

    Muterspaugh, M. W.; PTI: Palomar Testbed Interferometer Collaboration; PHASES Team

    2005-12-01

    A new observing method has been developed to perform very high precision differential astrometry on bright binary stars with separations in the range of 0.1-1.0 arcseconds. Typical measurement precisions over an hour of integration are on the order of 10 micro-arcseconds, enabling one to look for perturbations to the Keplerian orbit that would indicate the presence of additional components to the system. This is used as the basis for a new program to find extrasolar planets. The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) is a search for giant planets orbiting either star in 50 binary systems. The goal of this search is to detect or rule out planets in the systems observed and thus place limits on any enhancements of planet formation in binaries. It is also used to measure fundamental properties of the stars comprising the binary, such as masses and distances, useful for constraining stellar models at the 10-3 level. This work is funded in part by a Michelson Graduate Fellowship, the California Institute of Technology Astronomy Department, and the National Aeronautics and Space Administration under Grant No. NNG05GJ58G issued through the Terrestrial Planet Finder Foundation Science Program.

  1. Selective Morphology Control of Bulk Heterojunction in Polymer Solar Cells Using Binary Processing Additives.

    PubMed

    Jung, Yen-Sook; Yeo, Jun-Seok; Kim, Nam-Koo; Lee, Sehyun; Kim, Dong-Yu

    2016-11-09

    We report the effect of binary additives on the fabrication of polymer solar cells (PSCs) based on a bulk heterojunction (BHJ) system. The combination of 1,8-diiodooctane (DIO), a high-boiling and selective solvent, for fullerene derivatives and poly(dimethylsiloxane) (PDMS) precursor, a nonvolatile insulating additive, affords complementary functions on the effective modulation of BHJ morphology. It was found that DIO and PDMS precursor each play different roles in the control of BHJ morphology, and thus, the power conversion efficiency (PCE) can be further enhanced to 7.6% by improving the fill factor (FF) from 6.8% compared to that achieved using a conventional device employing only a DIO additive. In the BHJ of the active layer, DIO suppressed the large phase separation of PBDTTT-CF and PC71BM while allowing the formation of continuous polymer networks in the donor polymer through phase separation of the PDMS precursor and BHJ components. The appropriate amount of PDMS precursor does not disturb charge transport in the BHJ despite having insulating properties. In addition, the dependence of photovoltaic parameters on different light intensities reveals that the charge recombination in the device with DIO and PDMS precursor decreases compared to that achieved using the device with only DIO.

  2. Milankovitch cycles of terrestrial planets in binary star systems

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan

    2016-12-01

    The habitability of planets in binary star systems depends not only on the radiation environment created by the two stars, but also on the perturbations to planetary orbits and rotation produced by the gravitational field of the binary and neighbouring planets. Habitable planets in binaries may therefore experience significant perturbations in orbit and spin. The direct effects of orbital resonances and secular evolution on the climate of binary planets remain largely unconsidered. We present latitudinal energy balance modelling of exoplanet climates with direct coupling to an N-Body integrator and an obliquity evolution model. This allows us to simultaneously investigate the thermal and dynamical evolution of planets orbiting binary stars, and discover gravito-climatic oscillations on dynamical and secular time-scales. We investigate the Kepler-47 and Alpha Centauri systems as archetypes of P- and S-type binary systems, respectively. In the first case, Earth-like planets would experience rapid Milankovitch cycles (of order 1000 yr) in eccentricity, obliquity and precession, inducing temperature oscillations of similar periods (modulated by other planets in the system). These secular temperature variations have amplitudes similar to those induced on the much shorter time-scale of the binary period. In the Alpha Centauri system, the influence of the secondary produces eccentricity variations on 15 000 yr time-scales. This produces climate oscillations of similar strength to the variation on the orbital time-scale of the binary. Phase drifts between eccentricity and obliquity oscillations creates further cycles that are of order 100 000 yr in duration, which are further modulated by neighbouring planets.

  3. The Evolutionary Outcomes of Expansive Binary Asteroid Systems

    NASA Astrophysics Data System (ADS)

    McMahon, Jay W.

    2016-10-01

    Singly synchronous binary asteroid systems have several evolutionary end-states, which depend heavily on the BYORP effect. In the case of expansive BYORP, the binary system could evolve to become a wide asynchronous binary system (Jacobson, et al 2014), or the system could expand far enough to become disrupted to form a heliocentric pair (Vokrouhlicky et al 2008). Cuk et al (2011) found that upon expanding the secondary will quickly become asynchronous, and will end up re-establishing synchronous rotation with the opposite attitude, causing the binary orbit to subsequently contract. The distinction between these outcomes depends on whether the secondary asteroid stays synchronized, which keeps the BYORP effect active and the orbit expanding. As the orbit expands, the secondary libratation will expand, and the libration will also causes large variations in the binary orbit due to the elongation of the secondary. If the eccentricity and libration are bound to small enough values the system can expand significantly. This work discusses the stability of the libration and orbital motion as a binary expands from a wide variety of simulation runs with various parameters. We investigate how the strength of tides and BYORP change the stability of the librational motion; an important factor is the speed of BYORP expansion as slower expansion allows tides to have a more stabilizing effect. We also investigate the effect of heliocentric orbit semimajor axis and eccentricity. We find that resonances between the coupled orbit-libration frequencies and the heliocentric orbit cause instability in the binary orbit eccentricity which produces a strong preference for wide binary production, especially amongst retrograde binary systems. This instability also becomes stronger with large heliocentric eccentricities. Prograde binaries are more stable and can possible grow to become asteroid pairs. We find that even in the presence of tides, reestablishment of synchronous spin into a

  4. Magnetised winds in single and binary star systems

    NASA Astrophysics Data System (ADS)

    Johnstone, Colin

    2016-07-01

    Stellar winds are fundamentally important for the stellar magnetic activity evolution and for the immediate environment surrounding their host stars. Ionised winds travel at hundreds of km/s, impacting planets and clearing out large regions around the stars called astropheres. Winds influence planets in many ways: for example, by compressing the magnetosphere and picking up atmospheric particles, they can cause significant erosion of a planetary atmosphere. By removing angular momentum, winds cause the rotation rates of stars to decrease as they age. This causes the star's magnetic dynamo to decay, leading to a significant decay in the star's levels of X-ray and extreme ultraviolet emission. Despite their importance, little is currently known about the winds of other Sun-like stars. Their small mass fluxes have meant that no direct detections have so far been possible. What is currently known has either been learned indirectly or through analogies with the solar wind. In this talk, I will review what is known about the properties and evolution of the winds of other Sun-like stars. I will also review wind dynamics in binary star systems, where the winds from both stars impact each other, leading to shocks and compression regions.

  5. Solar system to scale

    NASA Astrophysics Data System (ADS)

    Gerwig López, Susanne

    2016-04-01

    One of the most important successes in astronomical observations has been to determine the limit of the Solar System. It is said that the first man able to measure the distance Earth-Sun with only a very slight mistake, in the second century BC, was the wise Greek man Aristarco de Samos. Thanks to Newtońs law of universal gravitation, it was possible to measure, with a little margin of error, the distances between the Sun and the planets. Twelve-year old students are very interested in everything related to the universe. However, it seems too difficult to imagine and understand the real distances among the different celestial bodies. To learn the differences among the inner and outer planets and how far away the outer ones are, I have considered to make my pupils work on the sizes and the distances in our solar system constructing it to scale. The purpose is to reproduce our solar system to scale on a cardboard. The procedure is very easy and simple. Students of first year of ESO (12 year-old) receive the instructions in a sheet of paper (things they need: a black cardboard, a pair of scissors, colored pencils, a ruler, adhesive tape, glue, the photocopies of the planets and satellites, the measurements they have to use). In another photocopy they get the pictures of the edge of the sun, the planets, dwarf planets and some satellites, which they have to color, cut and stick on the cardboard. This activity is planned for both Spanish and bilingual learning students as a science project. Depending on the group, they will receive these instructions in Spanish or in English. When the time is over, the students bring their works on their cardboard to the class. They obtain a final mark: passing, good or excellent, depending on the accuracy of the measurements, the position of all the celestial bodies, the asteroids belts, personal contributions, etc. If any of the students has not followed the instructions they get the chance to remake it again properly, in order not

  6. A quintuple star system containing two eclipsing binaries

    NASA Astrophysics Data System (ADS)

    Rappaport, S.; Lehmann, H.; Kalomeni, B.; Borkovits, T.; Latham, D.; Bieryla, A.; Ngo, H.; Mawet, D.; Howell, S.; Horch, E.; Jacobs, T. L.; LaCourse, D.; Sódor, Á.; Vanderburg, A.; Pavlovski, K.

    2016-10-01

    We present a quintuple star system that contains two eclipsing binaries. The unusual architecture includes two stellar images separated by 11 arcsec on the sky: EPIC 212651213 and EPIC 212651234. The more easterly image (212651213) actually hosts both eclipsing binaries which are resolved within that image at 0.09 arcsec, while the westerly image (212651234) appears to be single in adaptive optics (AO), speckle imaging, and radial velocity (RV) studies. The `A' binary is circular with a 5.1-d period, while the `B' binary is eccentric with a 13.1-d period. The γ velocities of the A and B binaries are different by ˜10 km s-1. That, coupled with their resolved projected separation of 0.09 arcsec, indicates that the orbital period and separation of the `C' binary (consisting of A orbiting B) are ≃65 yr and ≃25 au, respectively, under the simplifying assumption of a circular orbit. Motion within the C orbit should be discernible via future RV, AO, and speckle imaging studies within a couple of years. The C system (i.e. 212651213) has an RV and proper motion that differ from that of 212651234 by only ˜1.4 km s-1 and ˜3 mas yr-1. This set of similar space velocities in three dimensions strongly implies that these two objects are also physically bound, making this at least a quintuple star system.

  7. SEARCHING FOR BINARY Y DWARFS WITH THE GEMINI MULTI-CONJUGATE ADAPTIVE OPTICS SYSTEM (GeMS)

    SciTech Connect

    Opitz, Daniela; Tinney, C. G.; Faherty, Jacqueline K.; Sweet, Sarah; Gelino, Christopher R.; Kirkpatrick, J. Davy

    2016-03-01

    The NASA Wide-field Infrared Survey Explorer (WISE) has discovered almost all the known members of the new class of Y-type brown dwarfs. Most of these Y dwarfs have been identified as isolated objects in the field. It is known that binaries with L- and T-type brown dwarf primaries are less prevalent than either M-dwarf or solar-type primaries, they tend to have smaller separations and are more frequently detected in near-equal mass configurations. The binary statistics for Y-type brown dwarfs, however, are sparse, and so it is unclear if the same trends that hold for L- and T-type brown dwarfs also hold for Y-type ones. In addition, the detection of binary companions to very cool Y dwarfs may well be the best means available for discovering even colder objects. We present results for binary properties of a sample of five WISE Y dwarfs with the Gemini Multi-Conjugate Adaptive Optics System. We find no evidence for binary companions in these data, which suggests these systems are not equal-luminosity (or equal-mass) binaries with separations larger than ∼0.5–1.9 AU. For equal-mass binaries at an age of 5 Gyr, we find that the binary binding energies ruled out by our observations (i.e., 10{sup 42} erg) are consistent with those observed in previous studies of hotter ultra-cool dwarfs.

  8. Searching for Binary Y Dwarfs with the Gemini Multi-conjugate Adaptive Optics System (GeMS)

    NASA Astrophysics Data System (ADS)

    Opitz, Daniela; Tinney, C. G.; Faherty, Jacqueline K.; Sweet, Sarah; Gelino, Christopher R.; Kirkpatrick, J. Davy

    2016-03-01

    The NASA Wide-field Infrared Survey Explorer (WISE) has discovered almost all the known members of the new class of Y-type brown dwarfs. Most of these Y dwarfs have been identified as isolated objects in the field. It is known that binaries with L- and T-type brown dwarf primaries are less prevalent than either M-dwarf or solar-type primaries, they tend to have smaller separations and are more frequently detected in near-equal mass configurations. The binary statistics for Y-type brown dwarfs, however, are sparse, and so it is unclear if the same trends that hold for L- and T-type brown dwarfs also hold for Y-type ones. In addition, the detection of binary companions to very cool Y dwarfs may well be the best means available for discovering even colder objects. We present results for binary properties of a sample of five WISE Y dwarfs with the Gemini Multi-Conjugate Adaptive Optics System. We find no evidence for binary companions in these data, which suggests these systems are not equal-luminosity (or equal-mass) binaries with separations larger than ˜0.5-1.9 AU. For equal-mass binaries at an age of 5 Gyr, we find that the binary binding energies ruled out by our observations (i.e., 1042 erg) are consistent with those observed in previous studies of hotter ultra-cool dwarfs.

  9. Wind in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2010-01-01

    As an astronomy instructor I am always looking for commonly experienced Earthly phenomena to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote short "TPT" articles on frost and precipitation. The present article is on winds in the solar system. A windy day or storm might…

  10. Exploration of the solar system

    NASA Technical Reports Server (NTRS)

    Henderson, A., Jr.; Grey, J.

    1974-01-01

    A sourcebook of information on the solar system and the technology used for its exploration is presented. An outline of the potential achievements of solar system exploration is given along with a course of action which maximizes the rewards to mankind.

  11. FIRST PRECISION LIGHT CURVE ANALYSIS OF THE NEGLECTED EXTREME MASS RATIO SOLAR-TYPE BINARY HR BOOTIS

    SciTech Connect

    Samec, Ronald G.; Benkendorf, Barry; Dignan, James B.; Robb, Russell; Kring, James; Faulkner, Danny R.

    2015-04-15

    HR Bootis is a neglected binary that is found to be a solar-type (G2V) extreme mass ratio binary (EMRB). It was discovered by Hanley and Shapley in 1940. Surprisingly, little has been published in the intervening years. In 1999 it was characterized by a 0.31587 day orbital period. Since that time it has been observed by various observers who have determined ∼20 timings of minimum light over the past ∼15,000 orbits. Our observations in 2012 represent the first precision curves in the BVR{sub c}I{sub c} Johnson–Cousins wavelength bands. The light curves have rather low amplitudes, averaging some 0.5 magnitudes, yet they exhibit total eclipses, which is typical of the rare group of solar-type EMRBs. An improved linear ephemeris was computed along with a quadratic ephemeris showing a decaying orbit, which indicates magnetic breaking may be occurring. The light curve solution reveals that HR Boo is a contact system with a somewhat low 21% Roche-lobe fill-out but a mass ratio of q = 4.09 (0.2444), which defines it as an EMRB. Two spots, both hot, were allowed to iterate to fit the light curve asymmetries. Their radii are 32° and 16°. Both are high-latitude polar spots indicative of strong magnetic activity. The shallow contact yet nearly equal component temperatures makes it an unusual addition to this group.

  12. Relating binary-star planetary systems to central configurations

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri

    2016-11-01

    Binary-star exoplanetary systems are now known to be common, for both wide and close binaries. However, their orbital evolution is generally unsolvable. Special cases of the N-body problem which are in fact completely solvable include dynamical architectures known as central configurations. Here, I utilize recent advances in our knowledge of central configurations to assess the plausibility of linking them to coplanar exoplanetary binary systems. By simply restricting constituent masses to be within stellar or substellar ranges characteristic of planetary systems, I find that (i) this constraint reduces by over 90 per cent the phase space in which central configurations may occur, (ii) both equal-mass and unequal-mass binary stars admit central configurations, (iii) these configurations effectively represent different geometrical extensions of the Sun-Jupiter-Trojan-like architecture, (iv) deviations from these geometries are no greater than 10°, and (v) the deviation increases as the substellar masses increase. This study may help restrict future stability analyses to architectures which resemble exoplanetary systems, and might hint at where observers may discover dust, asteroids and/or planets in binary-star systems.

  13. Solar Power System Design for the Solar Probe+ Mission

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Schmitz, Paul C.; Kinnison, James; Fraeman, Martin; Roufberg, Lew; Vernon, Steve; Wirzburger, Melissa

    2008-01-01

    Solar Probe+ is an ambitious mission proposed to the solar corona, designed to make a perihelion approach of 9 solar radii from the surface of the sun. The high temperature, high solar flux environment makes this mission a significant challenge for power system design. This paper summarizes the power system conceptual design for the solar probe mission. Power supplies considered included nuclear, solar thermoelectric generation, solar dynamic generation using Stirling engines, and solar photovoltaic generation. The solar probe mission ranges from a starting distance from the sun of 1 AU, to a minimum distance of about 9.5 solar radii, or 0.044 AU, from the center of the sun. During the mission, the solar intensity ranges from one to about 510 times AM0. This requires power systems that can operate over nearly three orders of magnitude of incident intensity.

  14. On the Possibility of Habitable Trojan Planets in Binary Star Systems.

    PubMed

    Schwarz, Richard; Funk, Barbara; Bazsó, Ákos

    2015-12-01

    Approximately 60% of all stars in the solar neighbourhood (up to 80% in our Milky Way) are members of binary or multiple star systems. This fact led to the speculations that many more planets may exist in binary systems than are currently known. To estimate the habitability of exoplanetary systems, we have to define the so-called habitable zone (HZ). The HZ is defined as a region around a star where a planet would receive enough radiation to maintain liquid water on its surface and to be able to build a stable atmosphere. We search for new dynamical configurations-where planets may stay in stable orbits-to increase the probability to find a planet like the Earth.

  15. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A waste water treatment plant in Wilton, Maine, where sludge is converted to methane gas, and Monsanto Company's Environmental Health Laboratory in St. Louis Missouri, where more than 200 solar collectors provide preheating of boiler feed water for laboratory use are representative of Grumman's Sunstream line of solar energy equipment. This equipment was developed with technology from NASA's Apollo lunar module program.

  16. The formation and evolution of eccentric binary systems

    NASA Astrophysics Data System (ADS)

    Davis, Philip

    2014-09-01

    Observations are revealing a host of post-mass-transfer binary systems in significantly eccentric orbits, most notably Barium stars [1] and subdwarf-B + main-sequence systems [2]. Their formation is very puzzling in light of the fact that tidal forces efficiently circularise the orbit. Using our state-of-the-art binary stellar evolution code BINSTAR [3], we explore the formation and evolution of eccentric binary systems within the framework of the osculating orbital theory. This scheme describes, in a physically realistic manner, the perturbing forces acting on the orbit arising from mass transfer [4]. Results are presented, showing the impact of wind losses and Roche lobe overflow on the orbital separation and eccentricity for a range of initial stellar and binary parameters. As an interesting case study, we also discuss a promising formation channel for the eccentric white dwarf + main-sequence binary IP Eri [5], which invokes a tidally enhanced wind-loss mechanism. Our approach reproduces the observed system parameters remarkably well [6]. [1] Jorissen A., 1999, IAU Symposium, 191, 437 [2] Vos et al., 2013, A&A, 559, 54 [3] Siess L. et al., 2012, A&A, 550, 100 [4] Hadjidemetriou J., 1969, Ap&SS, 3, 330 [5] Merle et al., 2014, A&A, in press (arXiv:1405.4669) [6] Siess L., Davis P. J., Jorissen A., 2014, A&A, 565, A57

  17. Constraining the orbits of young binary systems with ALMA

    NASA Astrophysics Data System (ADS)

    Nogueira, Natasha; Jensen, Eric L. N.; Akeson, Rachel L.

    2017-01-01

    Measuring the orbits of young binary systems can provide the stars' individual stellar masses as well as insight into the dynamical effects they should have on each others' protoplanetary disks. As a byproduct of our ALMA observations of disks in young binary systems, we are able to measure precise relative separations of binaries with separations of 0.22--0.35 arcsec (~ 30--50 AU at the distance of the Taurus star-forming region). Most of these systems were first resolved in the early 1990s, so our epoch 2015 observations add an additional point in the orbit that is 20--25 years after the discovery epoch. While this coverage does not yet yield a definitive orbit, the extended coverage allows improved constraints on the binary orbital parameters. We present updated orbital constraints on a number of young binary systems, including XZ Tau, GH Tau, GN Tau, IS Tau, V955 Tau, and JH 112.This work makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00150.S. and ADS/JAO.ALMA#2013.1.00105.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  18. Dipole gravitational radiation in Rosen's theory of gravity - Observable effects in the binary system PSR 1913+16

    NASA Technical Reports Server (NTRS)

    Will, C. M.; Eardley, D. M.

    1977-01-01

    It is shown that Rosen's (1973) bimetric theory of gravity predicts the emission of dipole gravitational radiation from binary systems containing neutron stars, such as the binary pulsar PSR 1913+16, which causes rapid changes in orbital period. The theory also predicts sizable corrections to masses inferred from orbital data and periastron-shift data. It is demonstrated that this prediction is inconsistent with the observed upper limit on period changes unless the system consists of two neutron stars whose masses differ by less than 0.3 solar mass, or a neutron star of mass less than 0.4 solar mass and a companion which must be a rapidly rotating white dwarf or a helium main-sequence star. Because Rosen's theory is in agreement with all solar-system experiments to date, this represents a feasible test of its viability.

  19. Obtaining gravitational waves from inspiral binary systems using LIGO data

    NASA Astrophysics Data System (ADS)

    Antelis, Javier M.; Moreno, Claudia

    2017-01-01

    The discovery of the astrophysical events GW150926 and GW151226 has experimentally confirmed the existence of gravitational waves (GW) and has demonstrated the existence of binary stellar-mass black hole systems. This finding marks the beginning of a new era that will reveal unexpected features of our universe. This work presents a basic insight to the fundamental theory of GW emitted by inspiral binary systems and describes the scientific and technological efforts developed to measure these waves using the interferometer-based detector called LIGO. Subsequently, the work presents a comprehensive data analysis methodology based on the matched filter algorithm, which aims to recovery GW signals emitted by inspiral binary systems of astrophysical sources. This algorithm was evaluated with freely available LIGO data containing injected GW waveforms. Results of the experiments performed to assess detection accuracy showed the recovery of 85% of the injected GW.

  20. Contrasting performance of donor-acceptor copolymer pairs in ternary blend solar cells and two-acceptor copolymers in binary blend solar cells.

    PubMed

    Khlyabich, Petr P; Rudenko, Andrey E; Burkhart, Beate; Thompson, Barry C

    2015-02-04

    Here two contrasting approaches to polymer-fullerene solar cells are compared. In the first approach, two distinct semi-random donor-acceptor copolymers are blended with phenyl-C61-butyric acid methyl ester (PC61BM) to form ternary blend solar cells. The two poly(3-hexylthiophene)-based polymers contain either the acceptor thienopyrroledione (TPD) or diketopyrrolopyrrole (DPP). In the second approach, semi-random donor-acceptor copolymers containing both TPD and DPP acceptors in the same polymer backbone, termed two-acceptor polymers, are blended with PC61BM to give binary blend solar cells. The two approaches result in bulk heterojunction solar cells that have the same molecular active-layer components but differ in the manner in which these molecular components are mixed, either by physical mixing (ternary blend) or chemical "mixing" in the two-acceptor (binary blend) case. Optical properties and photon-to-electron conversion efficiencies of the binary and ternary blends were found to have similar features and were described as a linear combination of the individual components. At the same time, significant differences were observed in the open-circuit voltage (Voc) behaviors of binary and ternary blend solar cells. While in case of two-acceptor polymers, the Voc was found to be in the range of 0.495-0.552 V, ternary blend solar cells showed behavior inherent to organic alloy formation, displaying an intermediate, composition-dependent and tunable Voc in the range from 0.582 to 0.684 V, significantly exceeding the values achieved in the two-acceptor containing binary blend solar cells. Despite the differences between the physical and chemical mixing approaches, both pathways provided solar cells with similar power conversion efficiencies, highlighting the advantages of both pathways toward highly efficient organic solar cells.

  1. Electrical Resistivity of Ten Selected Binary Alloy Systems.

    DTIC Science & Technology

    1981-04-01

    alloys --* Aluminum Alloys --*Copper alloys --*Gold alloys --*Nickel Alloys --*Silver alloys --*Iron alloys --*Palladium alloys ... aluminum -magnesium, and copper-zinc) are given for 27 compositions: 0 (pure element).* For aluminum -copper, aluninu.-eagnes tur, end copper-zinc alloy ...available data and infor- mation. The ten binary alloy systems selected are the systems of aluminum - copper, aluminum -magnesium, copper-gold,

  2. Outer Solar System Nomenclature

    NASA Technical Reports Server (NTRS)

    Owen, Tobias C.; Grant, John (Technical Monitor)

    2003-01-01

    This grant has supported work by T. Owen and B. A. Smith on planetary and satellite nomenclature, carried out under the general auspices of the International Astronomical Union (IAU). The IAU maintains a Working Group on Planetary and Satellite Nomenclature (WGPSN) whose current chair is Prof.Kaare Aksnes of the Rosseland Institute for Theoretical Astrophysics in Oslo, Norway. Both Owen and Smith are members of the WGPSN; Owen as chair of the Outer Solar System Task Group, and Smith as chair of the Mars Task Group. The major activity during the last grant period (2002) was the approval of several new names for features on Mars by Smith's group and features on Jovian satellites plus new names for satellites of Jupiter, Saturn and Uranus by Owen's group. Much of this work was accomplished by e-mail exchanges, but the new nomenclature was formally discussed and approved at a meeting of the WGPSN held in conjunction with the Division for Planetary Sciences meeting in Birmingham, Alabama in October 2002.

  3. Astrometric solar system anomalies

    SciTech Connect

    Nieto, Michael Martin; Anderson, John D

    2009-01-01

    There are at least four unexplained anomalies connected with astrometric data. perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. next, a secular change in the astronomical unit AU is definitely a concern. It is increasing by about 15 cm yr{sup -1}. The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions. Some astronomers and physicists are convinced this effect is of concern, but many others are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon's orbit. Here again, an increase is expected from tidal friction in both the Earth and Moon. However, there is a reported unexplained increase that is significant at the three-sigma level. It is produent to suspect that all four anomalies have mundane explanations, or that one or more anomalies are a result of systematic error. Yet they might eventually be explained by new physics. For example, a slightly modified theory of gravitation is not ruled out, perhaps analogous to Einstein's 1916 explanation for the excess precession of Mercury's perihelion.

  4. Galaxy and the solar system

    SciTech Connect

    Smoluchowski, R.; Bahcall, J.M.; Matthews, M.S.

    1986-01-01

    The solar-Galactic neighborhood, massive interstellar clouds and other Galactic features, the Oort cloud, perturbations of the solar system, and the existence and stability of a solar companion star are examined in chapters based on contributions to a conference held in Tucson, AZ during January 1985. The individual topics addressed include: the Galactic environment of the solar system; stars within 25 pc of the sun; the path of the sun in 100 million years; the local velocity field in the last billion years; interstellar clouds near the sun; and evidence for a local recent supernova. Also considered are: dynamic influence of Galactic tides and molecular clouds on the Oort cloud; cometary evidence for a solar companion; dynamical interactions between the Oort cloud and the Galaxy; geological periodicities and the Galaxy; giant comets and the Galaxy; dynamical evidence for Planet X; evolution of the solar system in the presence of a solar companion star; mass extinctions, crater ages, and comet showers; evidence for Nemesis, a solar companion star.

  5. Space solar power systems

    NASA Technical Reports Server (NTRS)

    Toliver, C.

    1977-01-01

    Studies were done on the feasibility of placing a solar power station called POwersat, in space. A general description of the engineering features are given as well as a brief discussion of the economic considerations.

  6. Analyzing Age-Rotation-Activity Relationships in Wide Binary Systems

    NASA Astrophysics Data System (ADS)

    Walton Clarke, Riley; Davenport, James R. A.

    2017-01-01

    We present an analysis of flare activity among equal mass wide binary pairs using a combination of value-added data sets from the NASA Kepler mission. Wide binary twins form from the same molecular cloud and are therefore coeval, making them ideal benchmarks for stellar evolution and formation studies. This implies that their magnetic activity should decay at the same rate, causing a similar decrease in flare activity over time. The first data set is the list of known wide binary candidates in the Kepler field, and contains pairs of stars that have similar proper motions. We then crossmatch these systems with data on relative flare luminosity for ~200,000 stars in the original Kepler field, provided by an automated flare-finding algorithm. This combined data set allows us to compare flare activity, mass, and pair separation between stars in binary pairs. We preliminarily find that the flare rates for these stars do not show strong correlation, indicating either a large intrinsic scatter in the flare rate as these stars age, or that the formation mechanism of wide binaries somehow affects their dynamo evolution. As a goal for future development of this work, we hope to compare flare rates with gyrochronology in these key systems.

  7. Temperature and brightness distribution in the components of binary systems

    NASA Astrophysics Data System (ADS)

    Barman, S. K.

    1993-03-01

    From the theoretical model of a binary system for gravity darkening (Barman 1991), the temperature and brightness distributions along the surface of the components have been calculated using the third and fourth orders of the ratio (r/R) in the tidal potentials created by the secondary components, where r is radial distance and R the distance between the centers of gravities of the binary stars. Results of both distributions have been presented in seven figures. On analyzing the results, it has been suggested that if the expansion technique be used to calculate the combined potentials and related matters e.g. the temperature and brightness distributions of a binary system, one should at least consider the fourth order of the ratio (r/R).

  8. Solar Radiation Alert System

    DTIC Science & Technology

    2005-07-01

    the earth’s atmosphere at high geomagnetic latitudes were calculated for the solar proton event of 20 January 2005. The event started at 06:50...excluding them does not significantly affect the calculated dose rates. The data are available in near real-time from the file transfer protocol (ftp...form a com- plete spectrum used to calculate effective doses in Step 9. A piecewise-continuous spectrum is needed because during solar proton events

  9. Solar Thermal Electricity Generating System

    NASA Astrophysics Data System (ADS)

    Mishra, Sambeet; Tripathy, Pratyasha

    2012-08-01

    A Solar Thermal Electricity generating system also known as Solar Thermal Power plant is an emerging renewable energy technology, where we generate the thermal energy by concentrating and converting the direct solar radiationat medium/high temperature (300∫C ñ 800∫C). The resulting thermal energy is then used in a thermodynamic cycleto produce electricity, by running a heat engine, which turns a generator to make electricity. Solar thermal power is currently paving the way for the most cost-effective solar technology on a large scale and is heading to establish a cleaner, pollution free and secured future. Photovoltaic (PV) and solar thermal technologies are two main ways of generating energy from the sun, which is considered the inexhaustible source of energy. PV converts sunlight directly into electricity whereas in Solar thermal technology, heat from the sun's rays is concentrated to heat a fluid, whose steam powers a generator that produces electricity. It is similar to the way fossil fuel-burning power plants work except that the steam is produced by the collected heat rather than from the combustion of fossil fuels. In order to generate electricity, five major varieties of solar thermal technologies used are:* Parabolic Trough Solar Electric Generating System (SEGS).* Central Receiver Power Plant.* Solar Chimney Power Plant.* Dish Sterling System.* Solar Pond Power Plant.Most parts of India,Asia experiences a clear sunny weather for about 250 to 300 days a year, because of its location in the equatorial sun belt of the earth, receiving fairly large amount of radiation as compared to many parts of the world especially Japan, Europe and the US where development and deployment of solar technologies is maximum.Whether accompanied with this benefit or not, usually we have to concentrate the solar radiation in order to compensate for the attenuation of solar radiation in its way to earthís surface, which results in from 63,2 GW/m2 at the Sun to 1 kW/m2 at

  10. What Makes Red Giants Tick? Linking Tidal Forces, Activity, and Solar-Like Oscillations via Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Rawls, Meredith L.; Gaulme, Patrick; McKeever, Jean; Jackiewicz, Jason

    2016-01-01

    Thanks to advances in asteroseismology, red giants have become astrophysical laboratories for studying stellar evolution and probing the Milky Way. However, not all red giants show solar-like oscillations. It has been proposed that stronger tidal interactions from short-period binaries and increased magnetic activity on spotty giants are linked to absent or damped solar-like oscillations, yet each star tells a nuanced story. In this work, we characterize a subset of red giants in eclipsing binaries observed by Kepler. The binaries exhibit a range of orbital periods, solar-like oscillation behavior, and stellar activity. We use orbital solutions together with a suite of modeling tools to combine photometry and spectroscopy in a detailed analysis of tidal synchronization timescales, star spot activity, and stellar evolution histories. These red giants offer an unprecedented opportunity to test stellar physics and are important benchmarks for ensemble asteroseismology.

  11. The Shape of Solar Cycles Described by a Simplified Binary Mixture of Gaussian Functions

    NASA Astrophysics Data System (ADS)

    Li, F. Y.; Xiang, N. B.; Kong, D. F.; Xie, J. L.

    2017-01-01

    Sunspot cycles usually present a double-peak structure. This work is devoted to using a function to describe the shape of sunspot cycles, including bimodal cycles, and we find that the shape of sunspot cycles can be described by a binary mixture of Gaussian functions with six parameters, two amplitudes, two gradients of curve, and two rising times, and the parameters could be reduced to three. The fitting result of this binary mixture of Gaussian functions is compared with some other functions used previously in the literature, and this function works pretty well, especially at cycle peaks. It is worth mentioning that the function can describe well the shape of those sunspot cycles that show double peaks, and it is superior to the binary mixture of the Laplace functions that was once utilized. The Solar Influences Data Analysis Center, on behalf of the World Data Center, recently issued a new version (version 2) of sunspot number. The characteristics of sunspot cycles are investigated, based on the function description of the new version.

  12. Interstellar medium perturbations on transport-dominated debris discs in binary star systems

    NASA Astrophysics Data System (ADS)

    Marzari, F.

    2012-04-01

    I explore the dynamics of small dust particles in transport-dominated circumstellar debris discs in binary star systems. In these tenuous discs the effects of mutual collisions are negligible and their morphology is determined by Poynting-Robertson drag and, possibly, by the strong perturbations induced by the interaction with the interstellar medium (ISM) flux of neutral atoms. The force due to the ISM flux can significantly affect the dynamical behaviour of the dust grains, causing a fast inward drift and a large periodic oscillation of both eccentricity and inclination. If the disc is around a star in a binary system, the gravity of the companion star competes with the ISM force and the dynamics is complex. The balance between the two forces depends strongly on the binary semimajor axis aB and eccentricity eB. In a scenario with an ISM flux similar to that observed in the Solar system neighbourhood, the binary secular perturbations, assuming a mass ratio of 0.5, dominate over the ISM force when aB < 600 au and eB= 0.2. This occurs when the dust disc is generated by a parent body ring encompassed between 50 and 60 aufrom the primary star. For a larger binary eccentricity eB= 0.6, the limit moves to aB < 700 au. Within these values of aB, the time-scale of the binary secular perturbations is much shorter than the period of the ISM-induced orbital variations, and the disc shape and density distribution are dominated by the companion gravity. It appears slightly eccentric and, if the binary is coplanar with the disc, only a limited warping due to the ISM perturbations is observed. In this scenario, the strong ISM perturbations, which may significantly affect debris discs around single stars embedded in strong ISM winds, are almost completely silenced. For larger semimajor axes, the scenario is reversed with the ISM perturbations ruling the dynamics of the dust. The disc develops a large clump oriented at 90° with respect to the direction of the ISM flux and it

  13. Solar System Observations with JWST

    NASA Technical Reports Server (NTRS)

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; Ferruit, Pierre

    2014-01-01

    The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid- infrared, with sensitivity and spatial-spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010 (Lunine et al., 2010). It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV in 2012.

  14. Views of the solar system

    SciTech Connect

    Hamilton, C.

    1995-02-01

    Views of the Solar System has been created as an educational tour of the solar system. It contains images and information about the Sun, planets, moons, asteroids and comets found within the solar system. The image processing for many of the images was done by the author. This tour uses hypertext to allow space travel by simply clicking on a desired planet. This causes information and images about the planet to appear on screen. While on a planet page, hyperlinks travel to pages about the moons and other relevant available resources. Unusual terms are linked to and defined in the Glossary page. Statistical information of the planets and satellites can be browsed through lists sorted by name, radius and distance. History of Space Exploration contains information about rocket history, early astronauts, space missions, spacecraft and detailed chronology tables of space exploration. The Table of Contents page has links to all of the various pages within Views Of the Solar System.

  15. Evolution of the Solar System

    NASA Technical Reports Server (NTRS)

    Alfven, H.; Arrhenius, G.

    1976-01-01

    The origin and evolution of the solar system are analyzed. Physical processes are first discussed, followed by experimental studies of plasma-solid reactions and chemical and mineralogical analyses of meteorites and lunar and terrestrial samples.

  16. Exobiology in Solar System Exploration

    NASA Technical Reports Server (NTRS)

    Carle, Glenn C. (Editor); Schwartz, Deborah E. (Editor); Huntington, Judith L. (Editor)

    1992-01-01

    A symposium, 'Exobiology in Solar System Exploration,' was held on 24-26 Aug. 1988. The symposium provided an in-depth investigation of the role of Exobiology in solar system exploration. It is expected that the symposium will provide direction for future participation of the Exobiology community in solar system exploration and alert the Planetary community to the continued importance of an Exobiology Flight Program. Although the focus of the symposium was primarily on Exobiology in solar system exploration missions, several ground based and Earth-orbital projects such as the Search for Extraterrestrial Intelligence, Gas Grain Facility, and Cosmic Dust Collection Facility represent upcoming research opportunities planned to accommodate the goals and objectives of the Exobiology community as well. This report contains papers for all but one of the presentations given at the symposium.

  17. Radiation reaction in binary systems in general relativity

    NASA Astrophysics Data System (ADS)

    Kennefick, Daniel John

    1997-09-01

    This thesis is concerned with current problems in, and historical aspects of, the problem of radiation reaction in stellar binary systems in general relativity. Part I addresses current issues in the orbital evolution due to gravitational radiation damping of compact binaries. A particular focus is on the inspiral of small bodies orbiting large black holes, employing a perturbation formalism. In addition, the merger, at the end of the insprial, of comparable mass compact binaries, such as neutron star binaries is also discussed. The emphasis of Part I is on providing detailed descriptions of sources and signals with a view to optimising signal analysis in gravitational wave detectors, whether ground- or space- based interferometers, or resonant mass detectors. Part II of the thesis examines the historical controversies surrounding the problem of gravitational waves, and gravitational radiation damping in stellar binaries. In particular, it focuses on debates in the mid 20th-century on whether binary star systems would really exhibit this type of damping and emit gravitational waves, and on the 'quadrupole formula controversy' of the 1970s and 1980s, on the question whether the standard formular describing energy loss due to emission of gravitational waves was correctly derived for such systems. The study shed light on the role of analogy in science, especially where its use is controversial, on the importance of style in physics and on the problem of identity in science, as the use of history as a rhetorical device in controversial debate is examined. The concept of the Theoretician's Regress is introduced to explain the difficulty encountered by relativists in closing debate in this controversy, which persisted in one forms or another for several decades.

  18. Supernovae in Binary Systems: An Application of Classical Mechanics.

    ERIC Educational Resources Information Center

    Mitalas, R.

    1980-01-01

    Presents the supernova explosion in a binary system as an application of classical mechanics. This presentation is intended to illustrate the power of the equivalent one-body problem and provide undergraduate students with a variety of insights into elementary classical mechanics. (HM)

  19. A statistical study of close binary systems: testing evolutionary models

    NASA Astrophysics Data System (ADS)

    Leão, I. C.; de Medeiros, J. R.

    2003-08-01

    The evolution of stars in close binary systems differs from that of their single counterparts essentially in two main aspects: (i) the rotation of each component is directly affected by tidal interactions, which determine the evolution of orbital parameters and rotations of the system, and (ii) the evolutionary tracks of the stars run in considerably different ways when the mass transfer process begins, which occurs when the primary evolves sufficiently and reaches its Roche limit. The present work brings a confrontation between observational data, including orbital parameters, rotation and age, and theoretical predictions obtained from detailed models of binary systems evolution. For this study we have selected a sample of binary systems, mostly with a F-, G- or K-type primary component, with orbital parameters and rotational velocity available in the literature. For the theoretical predictions we have used stellar evolutionary models by Claret 1998 (A&AS 131, 395) and Schaller et al. 1992 (A&AS 96, 269) combined with models of binary orbital parameters evolution by Zahn 1977 (A&A 57, 383) and Zahn 1978 (A&A 67, 162). The preliminary results point for a good agreement between the observed orbital eccentricity, orbital and rotational periods and the predicted values as a function of stellar age. In addition, we present an analysis of the relationship between Vrot/Vk (where Vrot and Vk are, respectively, the rotational and keplerian velocities) and the stellar fractional radius, to rediscuss the synchronization process between rotation and orbital motions.

  20. A new open cluster binary system in the Milky Way

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Clariá, J. J.; Ahumada, A. V.

    2011-10-01

    We have obtained CCD UBVI_{KC} photometry for the open clusters (OCs) Hogg 12 and NGC 3590. Based on photometric and morphological criteria, as well as on the stellar density in the region, our evidence is sufficient to consider them a new open cluster binary system candidate.

  1. Parameters of radio pulsars in binary systems and globular clusters

    NASA Astrophysics Data System (ADS)

    Loginov, A. A.; Malov, I. F.

    2017-02-01

    The parameters of radio pulsars in binary systems and globular clusters are investigated. It is shown that such pulsars tend to have short periods (of the order of several milliseconds). Themagnetic fields of most of the pulsars considered are weak (surface fields of the order of 108-109 G). This corresponds to the generally accepted view that short-period neutron stars are spun up by angular momentum associated with the stellar wind from a companion. However, the fields at the light cylinders in these objects are two to three orders of magnitude higher than for the main population of single neutron stars. The dependence of the pulse width on the period does not differ from the corresponding dependences for single pulsars, assuming the emission is generated inside the polar cap, at moderate distances from the surface or near the light cylinder. The radio luminosities of pulsars in binary systems do not show the correlation with the rate of loss of rotational energy that is characteristic for single pulsars, probably due to the influence of accreting matter from a companion. Moreover, accretion apparently decreases the power of the emergent radiation, and can explain the observed systematic excess of the radio luminosity of single pulsars compared to pulsars in binary systems. The distributions and dependences presented in the article support generally accepted concepts concerning the processes occurring in binary systems containing neutron stars.

  2. K2 & Solar System Science

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack

    2015-01-01

    All of the fields that K2 observes are near the ecliptic plane in order to minimize the spin-up of the spacecraft in response to the effects of solar irradiation. The fields observed by K2 are thus rich in Solar System objects including planets, asteroids and trans-Neptunian objects (TNOs). K2 has already performed observations of Neptune and its large moon Triton, 68 Trojan and Hilda asteroids, 5 TNOs (including Pluto) and Comet C/2013 A1 (Siding Springs). About 10,000 main-belt asteroids that fell into the pixel masks of stars have been serendipitously observed. Observations of small bodies are especially useful for determining rotation periods. Uranus will be observed in a future campaign (C8), as will many more small Solar System bodies. The status of various K2 Solar System studies will be reviewed and placed within the context of our current knowledge of the objects being observed.

  3. The synchronous rotations of Eris/Dysnomia and Orcus/Vanth binary systems

    NASA Astrophysics Data System (ADS)

    Rabinowitz, David L.; Owainati, Yasi

    2014-11-01

    We have measured the rotation periods of the Eris/Dysnomia and Orcus/Vanth binary systems using long-term observations obtained with the SMARTS 1.3m telescope at Cerro Tololo, combined with incidental observations obtained by the La Silla - QUEST survey on the ESO 1.0-m Schmidt at La Silla, and using historical observations of Eris published by others. We find that both binary systems are synchronous, with the dominant periodicity in their light curves matching their mutual orbit periods (9.54 and 15.774 days, respectively). For Orcus/Vanth, the reflected light from both bodies contributes to the signal. The measured periodicity could be due to the rotation of Orcus or Vanth separately, but it is most likely the system is doubly synchronous. For Eris/Dysnomia, only Eris is bright enough to contribute significantly to the observations. The conclusion is therefore unambiguous that Eris is synchronously rotating with the orbit of Dysnomia. This is surprising given that Eris is 500 times brighter than Dysnomia, and likely to be 100 to 10000 times more massive (assuming an albedo > 5% for Dysnomia). If Dysnomia has migrated outward from Eris owing to long-term tidal interactions, the time for Eris to slow from an initially fast rotation (period < 1 day) to a synchronous one is longer than the age of the solar system. We discuss the constraints these observations place on the relative albedos, masses, and internal composition of the two binary systems.

  4. Binary system parameters and the hibernation model of cataclysmic variables

    SciTech Connect

    Livio, M.; Shara, M.M.

    1987-08-01

    The hibernation model, in which nova systems spend most of the time between eruptions in a state of low mass transfer rate, is examined. The binary systems more likely to undergo hibernation are determined. The predictions of the hibernation scenario are shown to be consistent with available observational data. It is shown how the hibernation scenario provides links between classical novae, dwarf novae, and novalike variables, all of which represent different stages in the cyclic evolution of the same systems. 72 references.

  5. High-energy signatures of binary systems of supermassive black holes

    NASA Astrophysics Data System (ADS)

    Romero, G. E.; Vila, G. S.; Pérez, D.

    2016-04-01

    Context. Binary systems of supermassive black holes are expected to be strong sources of long gravitational waves prior to merging. These systems are good candidates to be observed with forthcoming space-borne detectors. Only a few of these systems, however, have been firmly identified to date. Aims: We aim at providing a criterion for the identification of some supermassive black hole binaries based on the characteristics of the high-energy emission of a putative relativistic jet launched from the most massive of the two black holes. Methods: We study supermassive black hole binaries where the less massive black hole has carved an annular gap in the circumbinary disk, but nevertheless there is a steady mass flow across its orbit. Such a perturbed disk is hotter and more luminous than a standard thin disk in some regions. Assuming that the jet contains relativistic electrons, we calculate its broadband spectral energy distribution focusing on the inverse Compton up-scattering of the disk photons. We also compute the opacity to the gamma rays produced in the jet by photon annihilation with the disk radiation and take into account the effects of the anisotropy of the target photon field as seen from the jet. Results: We find that the excess of low-energy photons radiated by the perturbed disk causes an increment in the external Compton emission from the jet in the X-ray band, and a deep absorption feature at energies of tens of TeVs for some sets of parameters. According to our results, observations with Cherenkov telescopes might help in the identification of supermassive black hole binaries, especially those black hole binaries that host primaries from tens to hundreds of million of solar masses.

  6. Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H.

    2012-01-01

    Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

  7. Solar Radiation Alert System

    DTIC Science & Technology

    2009-03-01

    th an effectve cutoff rgdty of ~0 MV (2)), the FAA’s Cvl Aerospace Medcal Insttute (CAMI) ssues a Solar Radaton Alert (SRA) to the Nat...fluences of other partcles are too small to be of sgnficance n dose calculatons (4, 11). Earth was modeled as a sphere of lqud water of rad

  8. VX Her: Eclipsing Binary System or Single Variable Star

    NASA Astrophysics Data System (ADS)

    Perry, Kathleen; Castelaz, Michael; Henson, Gary; Boghozian, Andrew

    2015-01-01

    VX Her is a pulsating variable star with a period of .4556504 days. It is believed to be part of an eclipsing binary system (Fitch et al. 1966). This hypothesis originated from Fitch seeing VX Her's minimum point on its light curve reaching a 0.7 magnitude fainter than normal and remaining that way for nearly two hours. If VX Her were indeed a binary system, I would expect to see similar results with a fainter minimum and a broader, more horizontal dip. Having reduced and analyzed images from the Southeastern Association for Research in Astronomy Observatory in Chile and Kitt Peak, as well as images from a 0.15m reflector at East Tennessee State University, I found that VX Her has the standard light curve of the prototype variable star, RR Lyrae. Using photometry, I found no differing features in its light curve to suggest that it is indeed a binary system. However, more observations are needed in case VX Her is a wide binary.

  9. Solar Program Assessment: Environmental Factors - Solar Total Energy Systems.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    The purpose of this report is to present and prioritize the major environmental, safety, and social/institutional issues associated with the further development of Solar Total Energy Systems (STES). Solar total energy systems represent a specific application of the Federally-funded solar technologies. To provide a background for this analysis, the…

  10. Experiences in solar cooling systems

    NASA Astrophysics Data System (ADS)

    Ward, D. S.; Oberoi, H. S.

    Six of the nine solar cooling systems discussed in this paper had negative energy savings. In several cases the solar cooling system used substantially more energy than a conventional system could have been expected to use. Two systems, however, had significant energy savings. These systems (1 residential and 1 commercial) obtained system thermal efficiencies of 12.0 to 12.4 percent. Their system overall efficiences averaged 11.2 and 5.2 percent respectively. The residential-sized system achieved an annual energy savings of about 16.8 GJ/year, or approximately .34 GJ/year.m2 of collector. The commercial system had equivalent values of 137 GJ/year or about .22 GJ/year/sq m of collector. It should be noted that these efficiencies re much lower than those of well-designed and properly controlled cooling systems in commercial sizes. However, with realistic system modifications and subsequent improvements in performance these solar cooling systems can be expected to achieve savings in nonrenewable energy sources of approximately 1.2 GJ/year/sq m of collector. These savings can be compared to those associated with solar space and domestic hot water heating systems of 2.2 and 2.5 GJ/year/sq m of collector, respectively.

  11. Binary Minor Planets

    NASA Astrophysics Data System (ADS)

    Richardson, Derek C.; Walsh, Kevin J.

    2006-05-01

    A review of observations and theories regarding binary asteroids and binary trans-Neptunian objects [collectively, binary minor planets (BMPs)] is presented. To date, these objects have been discovered using a combination of direct imaging, lightcurve analysis, and radar. They are found throughout the Solar System, and present a challenge for theorists modeling their formation in the context of Solar System evolution. The most promising models invoke rotational disruption for the smallest, shortest-lived objects (the asteroids nearest to Earth), consistent with the observed fast rotation of these bodies; impacts for the larger, longer-lived asteroids in the main belt, consistent with the range of size ratios of their components and slower rotation rates; and mutual capture for the distant, icy, trans-Neptunian objects, consistent with their large component separations and near-equal sizes. Numerical simulations have successfully reproduced key features of the binaries in the first two categories; the third remains to be investigated in detail.

  12. Mass transfer in binary X-ray systems

    NASA Technical Reports Server (NTRS)

    Mccray, R.; Hatchett, S.

    1975-01-01

    The influence of X-ray heating on gas flows in binary X-ray systems is examined. A simple estimate is obtained for the evaporative wind flux from a stellar atmosphere due to X-ray heating which agrees with numerical calculations by Alme and Wilson (1974) but disagrees with calculations by Arons (1973) and by Basko and Sunyaev (1974) for the Her X-1/HZ Her system. The wind flux is sensitive to the soft X-ray spectrum. The self-excited wind mechanism does not work. Mass transfer in the Hercules system probably occurs by flow of the atmosphere of HZ Her through the gravitational saddle point of the system. The accretion gas stream is probably opaque with atomic density of not less than 10 to the 15th power per cu cm and is confined to a small fraction of 4(pi) steradians. Other binary X-ray systems are briefly discussed.

  13. UNDERSTANDING THE EVOLUTION OF CLOSE BINARY SYSTEMS WITH RADIO PULSARS

    SciTech Connect

    Benvenuto, O. G.; De Vito, M. A.

    2014-05-01

    We calculate the evolution of close binary systems (CBSs) formed by a neutron star (behaving as a radio pulsar) and a normal donor star, which evolve either to a helium white dwarf (HeWD) or to ultra-short orbital period systems. We consider X-ray irradiation feedback and evaporation due to radio pulsar irradiation. We show that irradiation feedback leads to cyclic mass transfer episodes, allowing CBSs to be observed in between episodes as binary radio pulsars under conditions in which standard, non-irradiated models predict the occurrence of a low-mass X-ray binary. This behavior accounts for the existence of a family of eclipsing binary systems known as redbacks. We predict that redback companions should almost fill their Roche lobe, as observed in PSR J1723-2837. This state is also possible for systems evolving with larger orbital periods. Therefore, binary radio pulsars with companion star masses usually interpreted as larger than expected to produce HeWDs may also result in such quasi-Roche lobe overflow states, rather than hosting a carbon-oxygen WD. We found that CBSs with initial orbital periods of P{sub i} < 1 day evolve into redbacks. Some of them produce low-mass HeWDs, and a subgroup with shorter P{sub i} becomes black widows (BWs). Thus, BWs descend from redbacks, although not all redbacks evolve into BWs. There is mounting observational evidence favoring BW pulsars to be very massive (≳ 2 M {sub ☉}). As they should be redback descendants, redback pulsars should also be very massive, since most of the mass is transferred before this stage.

  14. Continued Kinematic and Photometric Investigations of Hierarchical Solar-type Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Roberts, Lewis C., Jr.; Tokovinin, Andrei; Mason, Brian D.; Marinan, Anne D.

    2017-03-01

    We observed 15 of the solar-type binaries within 67 pc of the Sun previously observed by the Robo-AO system in the visible, with the PHARO near-infrared camera and the PALM-3000 adaptive optics system on the 5 m Hale telescope. The physical status of the binaries is confirmed through common proper motion and detection of orbital motion. In the process, we detected a new candidate companion to HIP 95309. We also resolved the primary of HIP 110626 into a close binary, making that system a triple. These detections increase the completeness of the multiplicity survey of the solar-type stars within 67 pc of the Sun. Combining our observations of HIP 103455 with archival astrometric measurements and RV measurements, we are able to compute the first orbit of HIP 103455, showing that the binary has a 68 year period. We place the components on a color–magnitude diagram and discuss each multiple system individually.

  15. Universal solar energy desalination system

    NASA Astrophysics Data System (ADS)

    Fusco, V. S.

    Design considerations to allow site-dependent flexibility in the choice of solar/wind powered desalinization plant configurations are discussed. A prototype design was developed for construction of 6300 cu m per day brackish water treatment in Brownsville, TX. The water is treated to reduce the amount of suspended solids and prevent scaling. A reverse osmosis unit processes the treated liquid to recover water at a ratio of 90%. The power system comprises a parabolic trough solar thermal system with an organic Rankine cycle generator, rock-oil thermal storage, and 200 kW wind turbines. Analysis of the complementarity of the solar and wind subsystems indicates that at any site one system will supplement the other. Energy storage, e.g., battery banks, would increase system costs to unacceptable levels. Climatic conditions will significantly influence the sizing of each segment of the total power system.

  16. Determination of the Period of Binary Asteroid Systems

    NASA Astrophysics Data System (ADS)

    Lust, Nathaniel B.; Britt, D. T.

    2008-09-01

    In the study of asteroids, binary pairs offer a unique window of study. By observing these systems and determining the period of the secondary, it is possible to determine system mass (e.g. Pravec and Hahn 1997; Ryan et al., 2004). With mass and volume, properties such as bulk density and porosity can be derived. At the University of Central Florida we have begun a binary asteroid hunt, in conjunction with the Prague consortium, in order to identify new binary candidates and to better constrain data on known pairs. All of the observations are collected on campus using a 0.5meter f/8.1 Ritchey-Chretien telescope with a SBIG STL-6303E detector. For our first test target we observed the known binary asteroid 107 Camila over a period of six days for approximately six to eight hours a night. The data is then processed using an open source python algorithm developed by Nate Lust. The data is read in, reduced, and compared to a standard star. Once the light curve was generated we make use of the CLEAN algorithm, originally developed by Hogbom (1974), to extract meaningful periods from the light curve.

  17. Solar tracking system

    NASA Technical Reports Server (NTRS)

    White, P. R.; Scott, D. R. (Inventor)

    1981-01-01

    A solar tracker for a solar collector is described in detail. The collector is angularly oriented by a motor wherein the outputs of two side-by-side photodetectors are discriminated as to three ranges: a first corresponding to a low light or darkness condition; a second corresponding to light intensity lying in an intermediate range; and a third corresponding to light above an intermediate range, direct sunlight. The first output drives the motor to a selected maximum easterly angular position; the second enables the motor to be driven westerly at the Earth rotational rate; and the third output, the separate outputs of the two photodetectors, differentially controls the direction of rotation of the motor to effect actual tracking of the Sun.

  18. Solar tracking system

    NASA Astrophysics Data System (ADS)

    White, P. R.; Scott, D. R.

    1981-04-01

    A solar tracker for a solar collector is described in detail. The collector is angularly oriented by a motor wherein the outputs of two side-by-side photodetectors are discriminated as to three ranges: a first corresponding to a low light or darkness condition; a second corresponding to light intensity lying in an intermediate range; and a third corresponding to light above an intermediate range, direct sunlight. The first output drives the motor to a selected maximum easterly angular position; the second enables the motor to be driven westerly at the Earth rotational rate; and the third output, the separate outputs of the two photodetectors, differentially controls the direction of rotation of the motor to effect actual tracking of the Sun.

  19. Tidal resonances in binary star systems. II - Slowly rotating stars

    NASA Astrophysics Data System (ADS)

    Alexander, M. E.

    1988-12-01

    The potential energy of tidal interactions in a binary system with rotating components is formulated as a perturbation Hamiltonian which self-consistently couples the dynamics of the rotating stars' oscillations and orbital motion. The action-angle formalism used to discuss tidal resonances in the nonrotating case (Alexander, 1987) is extended to rotating stars. The behavior of a two-mode system and the procedure for treating an arbitrary number of modes are discussed.

  20. Colliding stellar winds in O-type close binary systems

    NASA Technical Reports Server (NTRS)

    Gies, Douglas R.

    1991-01-01

    A study of the stellar wind properties of O-type close binary systems is presented. The main objective of this program was to search for colliding winds in four systems, AO Cas, iota Ori, Plaskett's star, and 29 UW CMa, through an examination of high dispersion UV spectra from IUE and optical spectra of the H alpha and He I lambda 6678 emission lines.

  1. Modular passive solar heating system

    SciTech Connect

    Hunter, B.D.

    1985-03-19

    A modular passive solar energy storage system comprises a plurality of heat tubes which are arranged to form a flat plate solar collector and are releasably connected to a water reservoir by, and are part of, double-walled heat exchangers which penetrate to the water reservoir and enhance the heat transfer characteristics between the collector and the reservoir. The flat plate collector-heat exchanger disassembly, the collector housing, and the reservoir are integrated into a relatively light weight, unitary structural system in which the reservoir is a primary structural element. In addition to light weight, the system features high efficiency and ease of assembly and maintenance.

  2. DETECTABILITY OF EARTH-LIKE PLANETS IN CIRCUMSTELLAR HABITABLE ZONES OF BINARY STAR SYSTEMS WITH SUN-LIKE COMPONENTS

    SciTech Connect

    Eggl, Siegfried; Pilat-Lohinger, Elke; Haghighipour, Nader

    2013-02-20

    Given the considerable percentage of stars that are members of binaries or stellar multiples in the solar neighborhood, it is expected that many of these binaries host planets, possibly even habitable ones. The discovery of a terrestrial planet in the {alpha} Centauri system supports this notion. Due to the potentially strong gravitational interaction that an Earth-like planet may experience in such systems, classical approaches to determining habitable zones (HZ), especially in close S-type binary systems, can be rather inaccurate. Recent progress in this field, however, allows us to identify regions around the star permitting permanent habitability. While the discovery of {alpha} Cen Bb has shown that terrestrial planets can be detected in solar-type binary stars using current observational facilities, it remains to be shown whether this is also the case for Earth analogs in HZs. We provide analytical expressions for the maximum and rms values of radial velocity and astrometric signals, as well as transit probabilities of terrestrial planets in such systems, showing that the dynamical interaction of the second star with the planet may indeed facilitate the planets' detection. As an example, we discuss the detectability of additional Earth-like planets in the averaged, extended, and permanent HZs around both stars of the {alpha} Centauri system.

  3. Integrated solar energy system optimization

    NASA Astrophysics Data System (ADS)

    Young, S. K.

    1982-11-01

    The computer program SYSOPT, intended as a tool for optimizing the subsystem sizing, performance, and economics of integrated wind and solar energy systems, is presented. The modular structure of the methodology additionally allows simulations when the solar subsystems are combined with conventional technologies, e.g., a utility grid. Hourly energy/mass flow balances are computed for interconnection points, yielding optimized sizing and time-dependent operation of various subsystems. The program requires meteorological data, such as insolation, diurnal and seasonal variations, and wind speed at the hub height of a wind turbine, all of which can be taken from simulations like the TRNSYS program. Examples are provided for optimization of a solar-powered (wind turbine and parabolic trough-Rankine generator) desalinization plant, and a design analysis for a solar powered greenhouse.

  4. Percolation of binary disk systems: Modeling and theory

    DOE PAGES

    Meeks, Kelsey; Tencer, John; Pantoya, Michelle L.

    2017-01-12

    The dispersion and connectivity of particles with a high degree of polydispersity is relevant to problems involving composite material properties and reaction decomposition prediction and has been the subject of much study in the literature. This paper utilizes Monte Carlo models to predict percolation thresholds for a two-dimensional systems containing disks of two different radii. Monte Carlo simulations and spanning probability are used to extend prior models into regions of higher polydispersity than those previously considered. A correlation to predict the percolation threshold for binary disk systems is proposed based on the extended dataset presented in this work and comparedmore » to previously published correlations. Finally, a set of boundary conditions necessary for a good fit is presented, and a condition for maximizing percolation threshold for binary disk systems is suggested.« less

  5. Percolation of binary disk systems: Modeling and theory

    NASA Astrophysics Data System (ADS)

    Meeks, Kelsey; Tencer, John; Pantoya, Michelle L.

    2017-01-01

    The dispersion and connectivity of particles with a high degree of polydispersity is relevant to problems involving composite material properties and reaction decomposition prediction and has been the subject of much study in the literature. This work utilizes Monte Carlo models to predict percolation thresholds for a two-dimensional systems containing disks of two different radii. Monte Carlo simulations and spanning probability are used to extend prior models into regions of higher polydispersity than those previously considered. A correlation to predict the percolation threshold for binary disk systems is proposed based on the extended dataset presented in this work and compared to previously published correlations. A set of boundary conditions necessary for a good fit is presented, and a condition for maximizing percolation threshold for binary disk systems is suggested.

  6. The evolution of highly compact binary stellar systems

    NASA Technical Reports Server (NTRS)

    Rappaport, S.; Joss, P. C.; Webbink, R. F.

    1982-01-01

    A new theoretical treatment of the evolution of highly compact binary systems is presented. The evolution is calculated until almost the entire mass of the secondary has been transferred to the primary or lost from the system. It is assumed that gravitational radiation from the system is the cause of mass transfer. It is found that the structure of the mass-losing star can be approximated by an n = 3/2 polytrope, and as a result a relatively large number of different cases can be explored and some general conclusions drawn. An explanation is found for the existence of a cutoff in the orbital period distribution among the cataclysmic variables and light is shed upon the possible generic relationships among cataclysmic variables, the low-mass X-ray binaries, and the spectrally soft transient X-ray sources.

  7. Segregation of Fluidized Binary Hard-Sphere Systems Under Gravity

    NASA Astrophysics Data System (ADS)

    Kim, Soon-Chul

    We have derived an analytic expression for the contact value of the local density of binary hard-sphere systems under gravity. We have obtained the crossover conditions for the Brazil-nut type segregation of binary hard-sphere mixtures and binary hard-sphere chain mixtures from the segregation criterion, where the segregation occurs when the density (or the pressure) of the small spheres at the bottom is higher than that of the large spheres, or vice versa. For the binary hard-sphere chain mixtures, the crossover condition for the segregation depends on the number of monomers composed of hard-sphere chains as well as the mass and the diameter of each species. The fundamental-measure theories (FMTs) and local density approximation (LDA) are employed to examine the crossover condition for the segregation of the gravity-induced hard-sphere mixtures. The calculated results show that the LDA does not explain the density oscillation near the bottom, whereas the modified fundamental-measure theory (MFMT) compares with molecular dynamics simulations.

  8. A Type System for Certified Binaries

    DTIC Science & Technology

    2004-01-01

    Pfenning 1999; Crary et al. 1999; Walker 2000; Crary and Weirich 2000; Trifonov et al. 2000] has produced many specialized, increasingly complex type systems...definitions subsume and generalize earlier systems for intensional type analysis [Harper and Morrisett 1995; Crary and Weirich 1999; Trifonov et al. 2000]. We...generalize the Typerec operator used in intensional type analysis [Harper and Morrisett 1995; Crary and Weirich 1999; Trifonov et al. 2000]. Figure 2 gives a

  9. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C

    2013-12-24

    A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

  10. Residential solar-heating system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Complete residential solar-heating and hot-water system, when installed in highly-insulated energy-saver home, can supply large percentage of total energy demand for space heating and domestic hot water. System which uses water-heating energy storage can be scaled to meet requirements of building in which it is installed.

  11. Solar thermophotovoltaic system using nanostructures.

    PubMed

    Ungaro, Craig; Gray, Stephen K; Gupta, Mool C

    2015-09-21

    This paper presents results on a highly efficient experimental solar thermophotovoltaic (STPV) system using simulated solar energy. An overall power conversion efficiency of 6.2% was recorded under solar simulation. This was matched with a thermodynamic model, and the losses within the system, as well as a path forward to mitigate these losses, have been investigated. The system consists of a planar, tungsten absorbing/emitting structure with an anti-reflection layer coated laser-microtextured absorbing surface and single-layer dielectric coated emitting surface. A GaSb PV cell was used to capture the emitted radiation and convert it into electrical energy. This simple structure is both easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.

  12. Origin of Outer Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.; Lindstrom, David (Technical Monitor)

    2005-01-01

    Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; ( 2 ) determining the size distributions or luminosity function of the individual populations or the Kuiper belt as a whole; (3) determining the inclinations distributions of these populations; (4) establishing the radial extent of the Kuiper belt; ( 5 ) measuring and relating the physical properties of different types of KBOs to those of other solar system bodies; and, (6) completing our systematic inventory of the satellites of the outer planets.

  13. Experiences in solar cooling systems

    NASA Astrophysics Data System (ADS)

    Ward, D. S.

    The results of performance evaluations for nine solar cooling systems are presented, and reasons fow low or high net energy balances are discussed. Six of the nine systems are noted to have performed unfavorably compared to standard cooling systems due to thermal storage losses, excessive system electrical demands, inappropriate control strategies, poor system-to-load matching, and poor chiller performance. A reduction in heat losses in one residential unit increased the total system efficiency by 2.5%, while eliminating heat losses to the building interior increased the efficiency by 3.3%. The best system incorporated a lithium bromide absorption chiller and a Rankine cycle compression unit for a commercial application. Improvements in the cooling tower and fan configurations to increase the solar cooling system efficiency are indicated. Best performances are expected to occur in climates inducing high annual cooling loads.

  14. Solar and stellar system tests of the cosmological constant

    SciTech Connect

    Sereno, Mauro; Jetzer, Philippe

    2006-03-15

    Some tests of gravity theories--periastron shift, geodetic precession, change in mean motion and gravitational redshift--are applied in solar and stellar systems to constrain the cosmological constant. We thus consider a length scale range from {approx}10{sup 8} to {approx}10{sup 15} km. Best bounds from the solar system come from perihelion advance and change in mean motion of Earth and Mars, {lambda} < or approx. 10{sup -36} km{sup -2}. Such a limit falls very short to estimates from observational cosmology analyses but a future experiment performing radio ranging observations of outer planets could improve it by 4 orders of magnitude. Beyond the solar system, together with future measurements of periastron advance in wide binary pulsars, gravitational redshift of white dwarfs can provide bounds competitive with Mars data.

  15. Periodic orbits of planets in binary systems

    NASA Astrophysics Data System (ADS)

    Voyatzis, G.

    2017-03-01

    Periodic solutions of the three body problem are very important for understanding its dynamics either in a theoretical framework or in various applications in celestial mechanics. In this paper we discuss the computation and continuation of periodic orbits for planetary systems. The study is restricted to coplanar motion. Starting from known results of two-planet systems around single stars, we perform continuation of solutions with respect to the mass and approach periodic orbits of single planets in two-star systems. Also, families of periodic solutions can be computed for fixed masses of the primaries. When they are linearly stable, we can conclude about the existence of phase space domains of long-term orbital stability.

  16. A Microprocessor-Based, Solar Cell Parameter Measurement System

    DTIC Science & Technology

    1988-06-01

    solar cell I - V curves ........................... 31 Figure 8. Sample 2, silicon solar cell I - V curves...32 Figure 9. Sample gallium-arsenide solar cell I - V curves ..................... 33 Figure 10. Practical versus ideal binary fractional...Sherif Michael and Robert Callaway developed a simple circuit for the meas- urement of a solar cell I - V curve at the Naval Postgraduate School

  17. Decentalized solar photovoltaic energy systems

    SciTech Connect

    Krupka, M. C.

    1980-09-01

    Environmental data for decentralized solar photovoltaic systems have been generated in support of the Technology Assessment of Solar Energy Systems program (TASE). Emphasis has been placed upon the selection and use of a model residential photovoltaic system to develop and quantify the necessary data. The model consists of a reference home located in Phoenix, AZ, utilizing a unique solar cell array-roof shingle combination. Silicon solar cells, rated at 13.5% efficiency at 28/sup 0/C and 100 mW/cm/sup 2/ (AMI) insolation are used to generate approx. 10 kW (peak). An all-electric home is considered with lead-acid battery storage, dc-ac inversion and utility backup. The reference home is compared to others in regions of different insolation. Major material requirements, scaled to quad levels of end-use energy include significant quantities of silicon, copper, lead, antimony, sulfuric acid and plastics. Operating residuals generated are negligible with the exception of those from the storage battery due to a short (10-year) lifetime. A brief general discussion of other environmental, health, and safety and resource availability impacts is presented. It is suggested that solar cell materials production and fabrication may have the major environmental impact when comparing all facets of photovoltaic system usage. Fabrication of the various types of solar cell systems involves the need, handling, and transportation of many toxic and hazardous chemicals with attendant health and safety impacts. Increases in production of such materials as lead, antimony, sulfuric acid, copper, plastics, cadmium and gallium will be required should large scale usage of photovoltaic systems be implemented.

  18. Orbital Parameters for a Pre-Main Sequence Binary System

    NASA Astrophysics Data System (ADS)

    Karnath, Nicole; Prato, L.; Wasserman, L.

    2011-01-01

    The young system VSB 111 was originally classified as a single-lined spectroscopic binary in the star forming region of NGC 2264. Using the Keck II telescope we measured radial velocities for both the primary and secondary components in the infrared. By combining these data with previous visible light observations of the primary star, we derived the period, eccentricity, and other orbital parameters, as well as the mass ratio of the system. With additional information gained from further observations, for example the inclination derived from the angularly resolved orbit, we will eventually obtain the individual stellar masses, necessary to help to calibrate models of young star evolution. Furthermore, by compiling dozens or even hundreds of mass ratios for young binaries we can use mass ratio distributions to improve our understanding of binary star formation. No infrared excess or any other indication of a circumstellar disk is in evidence for VSB 111, indicating that either the accretion rate has dropped to an undetectable value or that this system has aged enough that its disk has dissipated, if originally present. Given the approximately 900 day period of this system, and its relatively high eccentricity, 0.8, the action of the companion could have been responsible for early dissipation of any disk material.

  19. Tenoxicam-kollicoat IR binary systems: physicochemical and biological evaluation.

    PubMed

    Ibrahim, Mohamed Abbas

    2014-01-01

    Tenoxicam (TNX) binary systems in Kollicoat IR (KL) matrix were prepared in different drug: polymer ratios using kneading and spray-drying method. The prepared binary systems were characterized for drug dissolution rate, differential scanning calorimetry (DSC), IR spectroscopy and x-ray diffractometry. The results showed that the drug dissolution rate was remarkably enhanced by incorporating it in the KL matrix either by kneading or spray-drying, and the dissolution rate was increased by decreasing the drug weight ratio. The DSc and x-ray studies revealed the presence of TNX in less crystalline or amorphous state in its-KL binary systems. Moreover, the spray-dried TNX-KL system in 1:4 ratio, that exhibited the faster dissolution rate, was formulated in oral disintegrating tablets (ODTs). The data indicated that a fast disintegration and higher drug dissolution rate was achieved in case of the ODTs containing the spray-dried form compared to the ODTS containing untreated drug or the commercial tablet (Epicotil). Also, the drug exhibited significantly (p < 0.01) faster onset of the anti-inflammatory analgesic activities in case of the ODTs containing the spray-dried form, that was superior to that observed with both the commercial tablet product and the ODTS containing untreated drug.

  20. Advances in Solar Heating and Cooling Systems

    ERIC Educational Resources Information Center

    Ward, Dan S.

    1976-01-01

    Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)

  1. Applicability of Dynamic Facilitation Theory to Binary Hard Disk Systems

    NASA Astrophysics Data System (ADS)

    Isobe, Masaharu; Keys, Aaron S.; Chandler, David; Garrahan, Juan P.

    2016-09-01

    We numerically investigate the applicability of dynamic facilitation (DF) theory for glass-forming binary hard disk systems where supercompression is controlled by pressure. By using novel efficient algorithms for hard disks, we are able to generate equilibrium supercompressed states in an additive nonequimolar binary mixture, where microcrystallization and size segregation do not emerge at high average packing fractions. Above an onset pressure where collective heterogeneous relaxation sets in, we find that relaxation times are well described by a "parabolic law" with pressure. We identify excitations, or soft spots, that give rise to structural relaxation and find that they are spatially localized, their average concentration decays exponentially with pressure, and their associated energy scale is logarithmic in the excitation size. These observations are consistent with the predictions of DF generalized to systems controlled by pressure rather than temperature.

  2. Near Infrared Excess Energy in Binary System V367 Cygni

    NASA Astrophysics Data System (ADS)

    Gunasekera, Saraj

    Spectral energy distribution of the Serpentid type binary V367 Cyg was obtained using several previous photometric measurements made on this system in different spectral bands. We found Near IR excess starting from 3μm and this excess flux is attributed to the free-free emission from the mass accretion disk of the binary system. We adopted the temperature of primary component as 8,000°K. We added the free-free emission flux of the circumstellar disk to the black body energy of the primary component to find a best fit for the observed near infrared excess flux. In this fitting we left the electron density of the circumstellar disk ne of the free-free emission as a free parameter. We found that volume emission measure of the circumstellar disk is ˜ 9 × 1059 cm-3.

  3. Applicability of Dynamic Facilitation Theory to Binary Hard Disk Systems.

    PubMed

    Isobe, Masaharu; Keys, Aaron S; Chandler, David; Garrahan, Juan P

    2016-09-30

    We numerically investigate the applicability of dynamic facilitation (DF) theory for glass-forming binary hard disk systems where supercompression is controlled by pressure. By using novel efficient algorithms for hard disks, we are able to generate equilibrium supercompressed states in an additive nonequimolar binary mixture, where microcrystallization and size segregation do not emerge at high average packing fractions. Above an onset pressure where collective heterogeneous relaxation sets in, we find that relaxation times are well described by a "parabolic law" with pressure. We identify excitations, or soft spots, that give rise to structural relaxation and find that they are spatially localized, their average concentration decays exponentially with pressure, and their associated energy scale is logarithmic in the excitation size. These observations are consistent with the predictions of DF generalized to systems controlled by pressure rather than temperature.

  4. Our Solar System. Our Solar System Topic Set

    ERIC Educational Resources Information Center

    Phelan, Glen

    2006-01-01

    This book examines the planets and other objects in space that make up the solar system. It also shows how technology helps students learn about our neighbors in space. The suggested age range for this book is 3-8 with a guided reading level of Q-R. The Fry level is 3.2.

  5. HEARTBEAT STARS: SPECTROSCOPIC ORBITAL SOLUTIONS FOR SIX ECCENTRIC BINARY SYSTEMS

    SciTech Connect

    Smullen, Rachel A.; Kobulnicky, Henry A.

    2015-08-01

    We present multi-epoch spectroscopy of “heartbeat stars,” eccentric binaries with dynamic tidal distortions and tidally induced pulsations originally discovered with the Kepler satellite. Optical spectra of six known heartbeat stars using the Wyoming Infrared Observatory 2.3 m telescope allow measurement of stellar effective temperatures and radial velocities from which we determine orbital parameters including the periods, eccentricities, approximate mass ratios, and component masses. These spectroscopic solutions confirm that the stars are members of eccentric binary systems with eccentricities e > 0.34 and periods P = 7–20 days, strengthening conclusions from prior works that utilized purely photometric methods. Heartbeat stars in this sample have A- or F-type primary components. Constraints on orbital inclinations indicate that four of the six systems have minimum mass ratios q = 0.3–0.5, implying that most secondaries are probable M dwarfs or earlier. One system is an eclipsing, double-lined spectroscopic binary with roughly equal-mass mid-A components (q = 0.95), while another shows double-lined behavior only near periastron, indicating that the F0V primary has a G1V secondary (q = 0.65). This work constitutes the first measurements of the masses of secondaries in a statistical sample of heartbeat stars. The good agreement between our spectroscopic orbital elements and those derived using a photometric model support the idea that photometric data are sufficient to derive reliable orbital parameters for heartbeat stars.

  6. MID-INFRARED VARIABILITY OF THE BINARY SYSTEM CS Cha

    SciTech Connect

    Nagel, Erick; Espaillat, Catherine; D'Alessio, Paola; Calvet, Nuria

    2012-03-10

    CS Cha is a binary system surrounded by a circumbinary disk. We construct a model for the inner disk regions and compare the resulting synthetic spectral energy distribution (SED) with Infrared Spectrograph spectra of CS Cha taken at two different epochs. For our model, we adopt a non-axisymmetric mass distribution from results of published numerical simulations of the interaction between a circumbinary disk and a binary system, where each star is surrounded by a disk. In particular, we approximate the streams of mass from which the inner circumstellar disks accrete from the circumbinary disk. This structure is due to the gravitational interaction of the stars with the disk, in which an array of disks and streams is formed in an inner hole. We calculate the temperature distribution of the optically thin dust in these inner regions considering the variable impinging radiation from both stars and use the observations to estimate the mass variations in the streams. We find that the SEDs for both epochs can be explained with emission from an optically thick inner edge of the circumbinary disk and from the optically thin streams that connect the circumbinary disk with the two smaller circumstellar disks. To the best of our knowledge, this is the first time that the emission from the optically thin material in the hole, suggested by the theory, is tested against observations of a binary system.

  7. Eclipse timing variations to detect exoplanets in binary star systems

    NASA Astrophysics Data System (ADS)

    Schwarz, Richard; Funk, Barbara; Bazso, Akos; Zechner, Renate

    2016-02-01

    This work is devoted to study the circumstances favorable to detect planets in S- or P-Type orbits in close binary star systems by the help of eclipse timing variations (ETVs). A planet in S-Type motion orbits one of the two stars while a planet in P-Type Motion orbits both stars. One can detect ETV signals with the help of former (CoRoT and Kepler) and future space missions Plato, Tess and Cheops). To determine the probability of the detection of such ETV signals with ground based and space telescopes we investigated the dynamics of close binary star systems (stars separated by 0.5 to 3 AU). Therefore we did numerical simulations by using the full three-body problem as dynamical model. The stability and the ETVs are investigated by computing ETV maps for different masses of the secondary star and the exoplanet (Earth, Neptune and Jupiter mass). In addition we changed the planets eccentricity. We can conclude that many ETV amplitudes are large enough to detect planets in S- or P-Type orbits in binary star systems.

  8. Solar rocket system concept analysis

    NASA Technical Reports Server (NTRS)

    Boddy, J. A.

    1980-01-01

    The use of solar energy to heat propellant for application to Earth orbital/planetary propulsion systems is of interest because of its performance capabilities. The achievable specific impulse values are approximately double those delivered by a chemical rocket system, and the thrust is at least an order of magnitude greater than that produced by a mercury bombardment ion propulsion thruster. The primary advantage the solar heater thruster has over a mercury ion bombardment system is that its significantly higher thrust permits a marked reduction in mission trip time. The development of the space transportation system, offers the opportunity to utilize the full performance potential of the solar rocket. The requirements for transfer from low Earth orbit (LEO) to geosynchronous equatorial orbit (GEO) was examined as the return trip, GEO to LEO, both with and without payload. Payload weights considered ranged from 2000 to 100,000 pounds. The performance of the solar rocket was compared with that provided by LO2-LH2, N2O4-MMH, and mercury ion bombardment systems.

  9. High-Throughput Screening and Optimization of Binary Quantum Dots Cosensitized Solar Cell.

    PubMed

    Yuan, Ding; Xiao, Lina; Luo, Jianheng; Luo, Yanhong; Meng, Qingbo; Mao, Bing-Wei; Zhan, Dongping

    2016-07-20

    Quantum dots (QDs) are considered as the alternative of dye sensitizers for solar cells. However, interfacial construction and evaluation of photocatalytic nanomaterials still remains challenge through the conventional methodology involving demo devices. We propose here a high-throughput screening and optimizing method based on combinatorial chemistry and scanning electrochemical microscopy (SECM). A homogeneous TiO2 catalyst layer is coated on a FTO substrate, which is then covered by a dark mask to expose the photocatalyst array. On each photocatalyst spot, different successive ionic layer adsorption and reaction (SILAR) processes are performed by a programmed solution dispenser to load the binary PbxCd1-xS QDs sensitizers. An optical fiber is employed as the scanning tip of SECM, and the photocatalytic current is recorded during the imaging experiment, through which the optimized technical parameters are figured out. To verify the validity of the combinatorial SECM imaging results, the controlled trials are performed with the corresponding photovoltaic demo devices. The harmonious accordance proved that the methodology based on combinatorial chemistry and SECM is valuable for the interfacial construction, high-throughput screening, and optimization of QDSSCs. Furthermore, the PbxCd1-xS/CdS QDs cosensitized solar cell optimized by SECM achieves a short circuit current density of 24.47 mA/cm(2), an open circuit potential of 421 mV, a fill factor of 0.52, and a photovoltaic conversion efficiency of 5.33%.

  10. Perfluoro anion based binary and ternary ionic liquids as electrolytes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Hsi-Hsin; Peng, Jia-De; Suryanarayanan, V.; Velayutham, D.; Ho, Kuo-Chuan

    2016-04-01

    In this work, eight new ionic liquids (ILs) based on triethylammonium (TEA) or n-methylpiperidinium (NMP) cations and perfluoro carboxylate (PFC) anions having different carbon chain lengths are synthesized and their physico-chemical properties such as density, decomposition temperature, viscosity and conductivity are determined. Photovoltaic characteristics of dye-sensitized solar cells (DSSCs) with binary ionic liquids electrolytes, containing the mixture of the synthesized ILs and 1-methyl-3-propyl imidazolium iodide (PMII) (v/v = 35/65), are evaluated. Among the different ILs, solar cells containing NMP based ILs show higher VOC than that of TEA, whereas, higher JSC is noted for the DSSCs incorporated with the latter when compared to the former. Further, the photo-current of the DSSCs decreases with the increase of the carbon chain length of perfluoro carboxylate anionic group of ILs. The cell performance of the DSSC containing ternary ionic liquids-based electrolytes compose of NMP-2C/TEA-2C/PMII (v/v/v = 28/7/65) exhibits a JSC of 12.99 mA cm-2, a VOC of 639.0 mV, a FF of 0.72, and a cell efficiency of 6.01%. The extraordinary durability of the DSSC containing the above combination of electrolytes stored in dark at 50 °C is proved to be unfailing up to 1200 h.

  11. Life beyond the solar system.

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1972-01-01

    Review of some of the highlights and more recent developments in the search for extraterrestrial intelligence. The first major problem is one of the generality of the formation of planetary systems. Observations of the nearest stars which are not members of binary or multiple stars indicates that fully half have companions of planetary mass. The presence of organic compounds in meteorites, probably in Jovian planets, in comets, in the interstellar medium, and in cool stars implies that the production of organic compounds essential for the origin of life should be pervasive throughout the universe. Possibilities of interstellar communication are discussed.

  12. Maximum collectible solar energy by different solar tracking systems

    SciTech Connect

    Helwa, N.H.; Bahgat, A.B.G.; El Shafee, A.M.R.; El Shenawy, E.T.

    2000-01-01

    The output energy from any solar energy system depends on the solar energy input to that system. Using different ways to track the solar energy system to follow the sun can increase solar energy input according to the type of the tracker. A practical study was carried out on difference solar tract systems. The layout of these systems are a fixed system facing south and tilted 40{degree}, a vertical-axis tracker, a 6{degree} tilted-axis tracker, and a two-axis tracker. All the trackers are microprocessor controlled systems, and all systems have photovoltaic arrays for electric energy production. The evaluation of the different systems is based on a complete year of measurements for solar radiation input to the systems and the electric power output from them. The study also includes the effect of some operating parameters on the tracker operation. These studies showed that the collected solar energy as well as the electrical output energy of the tracking solar system are more than that of the stationary system. These gains are higher in the case of the two-axis tracker and decrease gradually from the vertical-axis tracker to the tilted-axis tracker.

  13. Surveying of the solar system

    NASA Technical Reports Server (NTRS)

    Gehrels, Tom

    1991-01-01

    Some populations of objects in the solar system are poorly known, and the long range goal of this program is to improve that situation. For instance, the statistics of Trojan asteroids is being studied. A new technique is being developed for sky surveillance by scanning with CCD, particularly for the discovery of near Earth asteroids.

  14. Precipitation in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  15. Sizing up the Solar System

    ERIC Educational Resources Information Center

    Wiebke, Heidi; Rogers, Meredith Park; Nargund-Joshi, Vanashri

    2011-01-01

    The American Association for the Advancement of Science (AAAS 1993) states that by the end of fifth grade, students should understand that a model, such as those depicting the solar system, is a smaller version of the real product, making it easier to physically work with and therefore learn from. However, for students and even adults,…

  16. Magnetospheres in the solar system

    SciTech Connect

    Mcnutt, R.L.

    1984-11-01

    Intrinsic and induced magnetospheres of planets, moons, and comets in the solar system are described. Magnetospheric electric fields, the plasmasphere, rotational effects, and corotation and convection dominated intrinsic magnetospheres are considered. Supersonic and subsonic interactions in induced magnetospheres are discussed. (ESA)

  17. Exploration of the Solar System.

    ERIC Educational Resources Information Center

    Henderson, Arthur, Jr., Ed.; Grey, Jerry, Ed.

    This review is one of a series of assessments and reviews prepared in the public interest by the American Institute of Aeronautics and Astronautics (AIAA). The purpose of this review is to outline the potential achievements of solar system exploration and suggest a course of action which will maximize the rewards to mankind. A secondary purpose is…

  18. Simulating binary inspirals in a corotating spherical coordinate system

    NASA Astrophysics Data System (ADS)

    Garrett, Travis Marshall

    The gravitational waves produced by the inspiral and merger of two black holes are expected to be the first detected by the newly constructed gravitational wave observatories. Accurate theoretical models that describe the generation and shape of these gravitational waves need to be constructed. These theoretical waveforms will aid in the detection of astrophysical wave sources, and will allow us to test general relativity in the strong field regime. Numerical relativity is the leading candidate for constructing accurate waveforms, and in this thesis we develop methods to help advance the field. In particular we use a corotating spherical coordinate system to simulate the evolution of a compact binary system as it produces gravitational radiation. We combine this method with both the Weak Radiation Reaction and Hydro-without- Hydro approximations to produce stable dynamical evolutions. We also utilize Nordström's conformally flat theory of gravitation as a relativistic laboratory during the development process. Additionally we perform semi-analytic calculations to determine the approximate way in which binaries decay in Nordström's theory. We find an excellent agreement between our semi-analytic calculations and the orbital evolutions produced by the code, and thus conclude that these methods form a solid basis for simulating binary inspirals and the gravitational waves they produce in general relativity.

  19. Numerical Simulations of Binary Systems with Matter Companions

    NASA Astrophysics Data System (ADS)

    Etienne, Zachariah

    2011-04-01

    With the advent of gravitational wave interferometers such as LIGO, VIRGO, and LISA, a revolution in astronomy and relativistic astrophysics is about to begin. Compact objects---black holes (BHs), neutron stars (NSs), and white dwarfs (WDs)---in binary systems are among the most promising sources of gravitational radiation detectable by these interferometers. In addition, merging compact object binaries with matter companions may also emit a detectable electromagnetic counterpart, leading to an exciting possibility: a simultaneous detection of both gravitational and electromagnetic radiation. Such a detection could lead to breakthroughs in our understanding of matter under extreme conditions, as there are currently many competing ideas about how this matter should behave. Determining the correct one will require careful modeling of the gravitational and electromagnetic waves these systems emit through the late- inspiral, merger, and post-merger stages. During these stages, the effects of high-velocity, strong-field gravitation become paramount, and accurate modeling requires large-scale, fully general relativistic simulations. I will review some of the latest results from fully general relativistic simulations of compact object binaries with matter companions, including NSNSs, BHNSs, and WDNSs. These simulations examine the effects of mass ratio, BH spin, equations of state, and magnetic fields on the gravitational waveforms and possible electromagnetic counterparts. Future work will focus on producing longer gravitational waveforms, incorporating more physics, and inventing new algorithms to efficiently handle the disparate length and timescales.

  20. WOBBLING AND PRECESSING JETS FROM WARPED DISKS IN BINARY SYSTEMS

    SciTech Connect

    Sheikhnezami, Somayeh; Fendt, Christian E-mail: fendt@mpia.de

    2015-12-01

    We present results of the first ever three-dimensional (3D) magnetohydrodynamic (MHD) simulations of the accretion–ejection structure. We investigate the 3D evolution of jets launched symmetrically from single stars but also jets from warped disks in binary systems. We have applied various model setups and tested them by simulating a stable and bipolar symmetric 3D structure from a single star–disk–jet system. Our reference simulation maintains a good axial symmetry and also a bipolar symmetry for more than 500 rotations of the inner disk, confirming the quality of our model setup. We have then implemented a 3D gravitational potential (Roche potential) due by a companion star and run a variety of simulations with different binary separations and mass ratios. These simulations show typical 3D deviations from axial symmetry, such as jet bending outside the Roche lobe or spiral arms forming in the accretion disk. In order to find indications of precession effects, we have also run an exemplary parameter setup, essentially governed by a small binary separation of only ≃200 inner disk radii. This simulation shows a strong indication that we observe the onset of a jet precession caused by the wobbling of the jet-launching disk. We estimate the opening angle of the precession cone defined by the lateral motion of the jet axis to be about 4° after about 5000 dynamical time steps.

  1. CLOSE STELLAR BINARY SYSTEMS BY GRAZING ENVELOPE EVOLUTION

    SciTech Connect

    Soker, Noam

    2015-02-20

    I suggest a spiral-in process in which a stellar companion grazes the envelope of a giant star while both the orbital separation and the giant radius shrink simultaneously, forming a close binary system. The binary system might be viewed as evolving in a constant state of 'just entering a common envelope (CE) phase.' In cases where this process takes place, it can be an alternative to CE evolution where the secondary star is immersed in the giant's envelope. Grazing envelope evolution (GEE) is made possible only if the companion manages to accrete mass at a high rate and launches jets that remove the outskirts of the giant envelope, hence preventing the formation of a CE. The high accretion rate is made possible by the accretion disk launching jets which efficiently carry the excess angular momentum and energy from the accreted mass. The orbital decay itself is caused by the gravitational interaction of the secondary star with the envelope inward of its orbit, i.e., dynamical friction (gravitational tide). Mass loss through the second Lagrangian point can carry additional angular momentum and envelope mass. The GEE lasts for tens to hundreds of years. The high accretion rate, with peaks lasting from months to years, might lead to a bright object referred to as the intermediate luminosity optical transient (Red Novae; Red Transients). A bipolar nebula and/or equatorial ring are formed around the binary remnant.

  2. Solafern solar system design brochure

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A complete residential solar space heating and hot water system is described. Low maintenance, durable, and efficient air heating collectors are used. The collectors have a selective absorber and a tempered glass cover nearly one-quarter of an inch thick with an aluminum frame. The solar energy can be delivered directly to the living area when there is a demand; otherwise, it is stored in the form of hot water. Hot water storage is accomplished through the use of an air-to-water exchanger. The hot water storage is used simultaneously to preheat the domestic hot water, as well as to store energy for space heating.

  3. Solar active region display system

    NASA Astrophysics Data System (ADS)

    Golightly, M.; Raben, V.; Weyland, M.

    2003-04-01

    The Solar Active Region Display System (SARDS) is a client-server application that automatically collects a wide range of solar data and displays it in a format easy for users to assimilate and interpret. Users can rapidly identify active regions of interest or concern from color-coded indicators that visually summarize each region's size, magnetic configuration, recent growth history, and recent flare and CME production. The active region information can be overlaid onto solar maps, multiple solar images, and solar difference images in orthographic, Mercator or cylindrical equidistant projections. Near real-time graphs display the GOES soft and hard x-ray flux, flare events, and daily F10.7 value as a function of time; color-coded indicators show current trends in soft x-ray flux, flare temperature, daily F10.7 flux, and x-ray flare occurrence. Through a separate window up to 4 real-time or static graphs can simultaneously display values of KP, AP, daily F10.7 flux, GOES soft and hard x-ray flux, GOES >10 and >100 MeV proton flux, and Thule neutron monitor count rate. Climatologic displays use color-valued cells to show F10.7 and AP values as a function of Carrington/Bartel's rotation sequences - this format allows users to detect recurrent patterns in solar and geomagnetic activity as well as variations in activity levels over multiple solar cycles. Users can customize many of the display and graph features; all displays can be printed or copied to the system's clipboard for "pasting" into other applications. The system obtains and stores space weather data and images from sources such as the NOAA Space Environment Center, NOAA National Geophysical Data Center, the joint ESA/NASA SOHO spacecraft, and the Kitt Peak National Solar Observatory, and can be extended to include other data series and image sources. Data and images retrieved from the system's database are converted to XML and transported from a central server using HTTP and SOAP protocols, allowing

  4. Resonance Overlap Is Responsible for Ejecting Planets in Binary Systems

    NASA Astrophysics Data System (ADS)

    Mudryk, Lawrence R.; Wu, Yanqin

    2006-03-01

    A planet orbiting around a star in a binary system experiences both secular and resonant perturbations from the companion star. It may be dislodged from its host star if it is simultaneously affected by two or more resonances. We find that overlap between subresonances lying within mean-motion resonances (mostly of the j:1 type) can account for the boundary of orbital stability within binary systems first observed in numerical studies (e.g., Holman & Wiegert). Strong secular forcing from the companion displaces the centroids of different subresonances, producing large regions of resonance overlap. Planets lying within these overlapping regions experience chaotic diffusion, which in most cases leads to their eventual ejection. The overlap region extends to shorter period orbits as either the companion's mass or its eccentricity increase, with boundaries largely agreeing with those obtained by Holman & Wiegert. Furthermore, we find the following two results: First, at a given binary mass ratio, the instability boundary as a function of eccentricity appears jagged, with jutting peninsulas and deep inlets corresponding to islands of instability and stability, respectively; as a result, the largest stable orbit could be reduced from the Holman & Wiegert values by as much as 20%. Second, very high-order resonances (e.g., 50:3) do not significantly modify the instability boundary; these weak resonances, while producing slow chaotic diffusion that may be missed by finite-duration numerical integrations, do not contribute markedly to planet instability. We present some numerical evidence for the first result. More extensive experiments are called for to confirm these conclusions. For the special case of circular binaries, we are intrigued to find that the Hill criterion (based on the critical Jacobi integral) yields an instability boundary that is very similar to that obtained by resonance overlap arguments, making the former both a necessary and a sufficient condition for

  5. Challenges in Solar System Ionospheres

    NASA Astrophysics Data System (ADS)

    Mendillo, M.

    2001-12-01

    The solar system contains a robust set of ionospheres among its nine planets, many moons and comets. If one sets aside the transient atmospheres/ionospheres of comets, and those of larger bodies with tenuous surface-boundary-exospheres (e.g., Mercury, Moon, Europa, etc.), plus the under-sampled Pluto, then 10 case studies exist for detailed study and comparison (Venus, Earth, Mars, Jupiter & Io, Saturn & Titan, Uranus, and Neptune & Triton). The ionospheres of these bodies define the full range of natural processes that govern plasma environments in our solar system, and indeed for extra-solar-system planets: (a) photo-chemical mechanisms, (b) energetic (auroral) ionization sources, (c) mesospheric/thermospheric tides, winds and waves, (d) electrodynamics, and (e) solar wind impact and/or shielding by a magnetosphere. This brief review will summarize and compare the dominant production, loss and transport mechanisms thought to occur at each site. Major uncertainties are, surprisingly, not due entirely to remoteness of the bodies being studied.

  6. OBSERVATIONS OF HIERARCHICAL SOLAR-TYPE MULTIPLE STAR SYSTEMS

    SciTech Connect

    Roberts, Lewis C. Jr.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Riddle, Reed L.

    2015-10-15

    Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible Robo-AO system with new near-infrared observations with PALM-3000. The physical status of most, but not all, of the new pairs is confirmed by photometry in the Ks band and new positional measurements. In addition, we resolved for the first time five close sub-systems: the known astrometric binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP 118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We place the components on a color–magnitude diagram and discuss each multiple system individually.

  7. Observations of Hierarchical Solar-type Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Roberts, Lewis C., Jr.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Riddle, Reed L.

    2015-10-01

    Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible Robo-AO system with new near-infrared observations with PALM-3000. The physical status of most, but not all, of the new pairs is confirmed by photometry in the Ks band and new positional measurements. In addition, we resolved for the first time five close sub-systems: the known astrometric binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP 118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We place the components on a color-magnitude diagram and discuss each multiple system individually.

  8. Change in the orbital period of a binary system due to dynamical tides for main-sequence stars

    NASA Astrophysics Data System (ADS)

    Chernov, S. V.

    2017-03-01

    We investigate the change in the orbital period of a binary system due to dynamical tides by taking into account the evolution of a main-sequence star. Three stars with masses of one, one and a half, and two solar masses are considered. A star of one solar mass at lifetimes t = 4.57 × 109 yr closely corresponds to our Sun. We show that a planet of one Jupiter mass revolving around a star of one solar mass will fall onto the star in the main-sequence lifetime of the star due to dynamical tides if the initial orbital period of the planet is less than P orb ≈ 2.8 days. Planets of one Jupiter mass with an orbital period P orb ≈ 2 days or shorter will fall onto a star of one and a half and two solar masses in the mainsequence lifetime of the star.

  9. From Binaries to Triples

    NASA Astrophysics Data System (ADS)

    Freismuth, T.; Tokovinin, A.

    2002-12-01

    About 10% of all binary systems are close binaries (P<1000 days). Among those with P<10d, over 40% are known to belong to higher-multiplicity systems (triples, quadruples, etc.). Do ALL close systems have tertiary companions? For a selection of 12 nearby, and apparently "single" close binaries with solar-mass dwarf primary components from the 8-th catalogue of spectroscopic binary orbits, images in the B and R filters were taken at the CTIO 0.9m telescope and suitable tertiary candidates were be identified on color-magnitude diagrams (CMDs). Of the 12 SBs, four were found to have tertiary candidates: HD 67084, HD 120734, HD 93486, and VV Mon. However, none of these candidates were found to be common proper motion companions. Follow up observations using adaptive optics reveal a companion to HD 148704. Future observations are planned.

  10. Solar system: Interplanetary kidnap

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro

    2006-05-01

    Triton, Neptune's largest moon, was probably part of a two-body object similar to the Pluto-Charon system. This tandem might have been ripped apart when it strayed too close to the planet that Triton is now orbiting.

  11. Adaptive, full-spectrum solar energy system

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.

    2003-08-05

    An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

  12. SELF-REGULATED SHOCKS IN MASSIVE STAR BINARY SYSTEMS

    SciTech Connect

    Parkin, E. R.; Sim, S. A. E-mail: s.sim@qub.ac.uk

    2013-04-20

    In an early-type, massive star binary system, X-ray bright shocks result from the powerful collision of stellar winds driven by radiation pressure on spectral line transitions. We examine the influence of the X-rays from the wind-wind collision shocks on the radiative driving of the stellar winds using steady-state models that include a parameterized line force with X-ray ionization dependence. Our primary result is that X-ray radiation from the shocks inhibits wind acceleration and can lead to a lower pre-shock velocity, and a correspondingly lower shocked plasma temperature, yet the intrinsic X-ray luminosity of the shocks, L{sub X}, remains largely unaltered, with the exception of a modest increase at small binary separations. Due to the feedback loop between the ionizing X-rays from the shocks and the wind driving, we term this scenario as self-regulated shocks. This effect is found to greatly increase the range of binary separations at which a wind-photosphere collision is likely to occur in systems where the momenta of the two winds are significantly different. Furthermore, the excessive levels of X-ray ionization close to the shocks completely suppress the line force, and we suggest that this may render radiative braking less effective. Comparisons of model results against observations reveal reasonable agreement in terms of log (L{sub X}/L{sub bol}). The inclusion of self-regulated shocks improves the match for kT values in roughly equal wind momenta systems, but there is a systematic offset for systems with unequal wind momenta (if considered to be a wind-photosphere collision).

  13. Analytic orbit propagation of planets in binary star systems

    NASA Astrophysics Data System (ADS)

    Eggl, Siegfried; Georgakarakos, Nikolaos

    2015-08-01

    We present an analytical framework that accurately describes the motion of co-planar planets in binary star systems on orbital as well as secular timescales. The method builds upon analytic solutions of the differential equations governing the behavior of the system's perturbed Laplace-Runge-Lenz vectors. Multiple time-scale analysis is used to derive the short period evolutions of the system, while octupole secular theory is applied to describe its long term behavior. A post Newtonian correction on the stellar orbit is included for circumbinary planets. Our model is tested against results from numerical integrations of the full equations of motion. An application to circumbinary planetary systems discovered by NASA's Kepler satellite reveals that the formation history of the systems Kepler-34 and Kepler-413 has most likely been different from the one of Kepler-16, Kepler-35, Kepler-38 and Kepler-64, as the former systems are not compatible with the assumption of almost circular initial planetary orbits.

  14. Dynamical evolution of small bodies in the Solar System

    NASA Astrophysics Data System (ADS)

    Jacobson, Seth A.

    2012-05-01

    This thesis explores the dynamical evolution of small bodies in the Solar System. It focuses on the asteroid population but parts of the theory can be applied to other systems such as comets or Kuiper Belt objects. Small is a relative term that refers to bodies whose dynamics can be significantly perturbed by non-gravitational forces and tidal torques on timescales less than their lifetimes (for instance the collisional timescale in the Main Belt asteroid population or the sun impact timescale for the near-Earth asteroid population). Non-gravitational torques such as the YORP effect can result in the active endogenous evolution of asteroid systems; something that was not considered more than twenty years ago. This thesis is divided into three independent studies. The first explores the dynamics of a binary systems immediately after formation from rotational fission. The rotational fission hypothesis states that a rotationally torqued asteroid will fission when the centrifugal accelerations across the body exceed gravitational attraction. Asteroids must have very little or no tensile strength for this to occur, and are often referred to as "rubble piles.'' A more complete description of the hypothesis and the ensuing dynamics is provided there. From that study a framework of asteroid evolution is assembled. It is determined that mass ratio is the most important factor for determining the outcome of a rotational fission event. Each observed binary morphology is tied to this evolutionary schema and the relevant timescales are assessed. In the second study, the role of non-gravitational and tidal torques in binary asteroid systems is explored. Understanding the competition between tides and the YORP effect provides insight into the relative abundances of the different binary morphologies and the effect of planetary flybys. The interplay between tides and the BYORP effect creates dramatic evolutionary pathways that lead to interesting end states including stranded

  15. Steamy Solar System

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Annotated Version

    This diagram illustrates the earliest journeys of water in a young, forming star system. Stars are born out of icy cocoons of gas and dust. As the cocoon collapses under its own weight in an inside-out fashion, a stellar embryo forms at the center surrounded by a dense, dusty disk. The stellar embryo 'feeds' from the disk for a few million years, while material in the disk begins to clump together to form planets.

    NASA's Spitzer Space Telescope was able to probe a crucial phase of this stellar evolution - a time when the cocoon is vigorously falling onto the pre-planetary disk. The infrared telescope detected water vapor as it smacks down on a disk circling a forming star called NGC 1333-IRAS 4B. This vapor started out as ice in the outer envelope, but vaporized upon its arrival at the disk.

    By analyzing the water in the system, astronomers were also able learn about other characteristics of the disk, such as its size, density and temperature.

    How did Spitzer see the water vapor deep in the NGC 1333-IRAS 4B system? This is most likely because the system is oriented in just the right way, such that its thicker disk is seen face-on from our Earthly perspective. In this 'face-on' orientation, Spitzer can peer through a window carved by an outflow of material from the embryonic star. This system in this drawing is shown in the opposite 'edge-on' configuration.

  16. New systemic radial velocities of suspected RR Lyrae binary stars

    NASA Astrophysics Data System (ADS)

    Guggenberger, E.; Barnes, T. G.; Kolenberg, K.

    2016-05-01

    Among the tens of thousands of known RR Lyrae stars there are only a handful that show indications of possible binarity. The question why this is the case is still unsolved, and has recently sparked several studies dedicated to the search for additional RR Lyraes in binary systems. Such systems are particularly valuable because they might allow to constrain the stellar mass. Most of the recent studies, however, are based on photometry by finding a light time effect in the timings of maximum light. This approach is a very promising and successful one, but it has a major drawback: by itself, it cannot serve as a definite proof of binarity, because other phenomena such as the Blazhko effect or intrinsic period changes could lead to similar results. Spectroscopic radial velocity measurements, on the other hand, can serve as definite proof of binarity. We have therefore started a project to study spectroscopically RR Lyrae stars that are suspected to be binaries. We have obtained radial velocity (RV) curves with the 2.1m telescope at McDonald observatory. From these we derive systemic RVs which we will compare to previous measurements in order to find changes induced by orbital motions. We also construct templates of the RV curves that can facilitate future studies. We also observed the most promising RR Lyrae binary candidate, TU UMa, as no recent spectroscopic measurements were available. We present a densely covered pulsational RV curve, which will be used to test the predictions of the orbit models that are based on the O - C variations.

  17. Study of the sailboat stable region for binaries systems

    NASA Astrophysics Data System (ADS)

    Sfair, Rafael; Vieira Neto, Ernesto; Villa Espinoza, Omar Jose; Francisco Lins Leal Pinheiro, Tiago

    2016-10-01

    Before the visit of the New Horizons mission, Giuliatti Winter et al. (2013) through numerical simulations analysed the Pluto-Charon system looking for possible stable regions. Among their results it was found a peculiar stable region located at a = (0.5d, 0.7d) and e = (0.2, 0.9), being a, d and e the values of semimajor axis, Pluto-Charon's distance and the eccentricity, respectively. In this work we explore in details the variation of the size and shape of this region for different binaries systems, considering several parameters for the massive bodies and initial conditions of the test particles. We first created hypothetical systems with different mass ratio (μ) and then we numerically integrated the orbit of test particles for a time span of 104 orbital periods of the binary. Our results show that the existence of the sailboat is limited to μ=(0.05, 0.27) and small changes in the eccentricity of the secondary body are enough to decrease substantially the extend of the stable region. However, the sailboat is robust to changes in the inclination of the particles and the region exists even for retrograde orbits. We also found a larger extend of the sailboat for intervals of pericentre ω around 0° and 180°, but the size of the interval varies with the mass ratio of system.

  18. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  19. Inhabiting the solar system

    NASA Astrophysics Data System (ADS)

    Sherwood, Brent

    2011-03-01

    The new field of space architecture is introduced. Defined as the "theory and practice of designing and building inhabited environments in outer space," the field synthesizes human space flight systems engineering subjects with the long tradition of making environments that support human living, work, and aspiration. The scope of the field is outlined, and its three principal domains differentiated. The current state of the art is described in terms of executed projects. Foreseeable options for 21st century developments in human space flight provide a framework to tease out potential space architecture opportunities for the next century.

  20. George gamov and the origin of the solar system

    NASA Astrophysics Data System (ADS)

    Drobyshevski, E. M.

    G. Gamov's point of view on the origin of the Solar System is presented. He was skeptical concerning the modern wide-spread nebular approach to the formation of planets. At the same time, he stopped quite close to the close-binary hypothesis considering the Sun-Jupiter system as the limiting case of a close binary. The latter approach is developed in detail here. The observed close binary systems appear after 4-5 fragmentations of a cloud with excessive angular momentum as a result of rotational-exchange fission of the last fragment-a fast-spinning cloud with density 10-13 - 10-11 g/cm3. Due to high density, the cloud rapidly collapses according to classical Hayashi scenario, with the appearance of a protostar with an outer convective zone. For M < 1 - 1.5M this zone spans the whole protostar, while for M < 1.5M⊙ it occupies only a part of its mass. In a protostar whose dense inner part rotates faster than its periphery, large angular momentum is stored. When the convection arises, momentum is carried outwards and the outer layers form a massive ring breaking up into self-gravitating fragments. The convective matter of the protostar flows through the inner Lagrangian point to the heaviest fragment. Thus, rotational-exchange fission of a star with M < 1.5M⊙ produces a close binary with components of comparable mass. In the M < 1.5M⊙ case, the matter of the whole star flows onto a newly formed component, so that only a remnant with M˜ 0.001M⊙ is left behind. So the limiting case of a close binary star is the Sun-Jupiter type system (E. M. Drobyshevski, Nature 250, 35, 1974). The other planets were formed within the originally massive and fast-rotating component, a very dense analog of a classical protoplanetary disk, and were lost, except for the last Galilean satellites, because of rapid mass decrease of this component-future Jupiter. This model explains all properties of the Solar System, including slow rotation of the Sun and fast rotation of the planets

  1. Ultra-Short-Period Binary Systems in the OGLE Fields Toward the Galactic Bulge

    NASA Astrophysics Data System (ADS)

    Soszyński, I.; Stępień, K.; Pilecki, B.; Mróz, P.; Udalski, A.; Szymański, M. K.; Pietrzyński, G.; Wyrzykowski, Ł.; Ulaczyk, K.; Poleski, R.; Kozłowski, S.; Pietrukowicz, P.; Skowron, J.; Pawlak, M.

    2015-03-01

    We present a sample of 242 ultra-short-period (Porb<0.22 d) eclipsing and ellipsoidal binary stars identified in the OGLE fields toward the Galactic bulge. Based on the light curve morphology, we divide the sample into candidates for contact binaries and non-contact binaries. In the latter group we distinguish binary systems consisting of a cool main-sequence star and a B-type subdwarf (HW Vir stars) and candidates for cataclysmic variables, including five eclipsing dwarf novae. One of the detected eclipsing binary systems - OGLE-BLG-ECL-000066 - with the orbital period below 0.1 d, likely consists of M dwarfs in a nearly contact configuration. If confirmed, this would be the shortest-period M-dwarf binary system currently known. We discuss possible evolutionary mechanisms that could lead to the orbital period below 0.1 d in an M-dwarf binary.

  2. THE QUASI-ROCHE LOBE OVERFLOW STATE IN THE EVOLUTION OF CLOSE BINARY SYSTEMS CONTAINING A RADIO PULSAR

    SciTech Connect

    Benvenuto, O. G.; De Vito, M. A.

    2015-01-01

    We study the evolution of close binary systems formed by a normal (solar composition), intermediate-mass-donor star together with a neutron star. We consider models including irradiation feedback and evaporation. These nonstandard ingredients deeply modify the mass-transfer stages of these binaries. While models that neglect irradiation feedback undergo continuous, long-standing mass-transfer episodes, models including these effects suffer a number of cycles of mass transfer and detachment. During mass transfer, the systems should reveal themselves as low-mass X-ray binaries (LMXBs), whereas when they are detached they behave as binary radio pulsars. We show that at these stages irradiated models are in a Roche lobe overflow (RLOF) state or in a quasi-RLOF state. Quasi-RLOF stars have radii slightly smaller than their Roche lobes. Remarkably, these conditions are attained for an orbital period as well as donor mass values in the range corresponding to a family of binary radio pulsars known as ''redbacks''. Thus, redback companions should be quasi-RLOF stars. We show that the characteristics of the redback system PSR J1723-2837 are accounted for by these models. In each mass-transfer cycle these systems should switch from LMXB to binary radio pulsar states with a timescale of approximately one million years. However, there is recent and fast growing evidence of systems switching on far shorter, human timescales. This should be related to instabilities in the accretion disk surrounding the neutron star and/or radio ejection, still to be included in the model having the quasi-RLOF state as a general condition.

  3. Small grains of truth. [solar system evolution

    NASA Technical Reports Server (NTRS)

    Nuth, Joe

    1991-01-01

    The evidence concerning the formation of the solar nebula from preexisting clouds found in the chemical composition of solar system grains is discussed. Evidence for sequential star formation in the grains is examined. It is argued that there is no model for the origin of the solar system which can account for the increasing complexity of the evidence.

  4. Solar-powered hot-water system

    NASA Technical Reports Server (NTRS)

    Collins, E. R.

    1979-01-01

    Hot-water system requires no external power except solar energy. System is completely self-controlling. It includes solar-powered pump, solar-thermally and hydrothermally operated valves, and storage tank filled with open-celled foam, to maintain thermal stratification in stored water.

  5. Hybrid solar lighting systems and components

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2007-06-12

    A hybrid solar lighting system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates each component.

  6. Hybrid solar lighting distribution systems and components

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2011-07-05

    A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

  7. Basics of Solar Heating & Hot Water Systems.

    ERIC Educational Resources Information Center

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  8. A spectrophotometric study of the Algol binary system RX Geminorum

    NASA Technical Reports Server (NTRS)

    Dobias, Jan J.; Plavec, Mirek J.

    1987-01-01

    IUE low-dispersion spectra and optical ITS scans of the semidetached Algol-type binary system RX Gem have been obtained. The spectral type of the primary component was determined to be A0, with good accuracy. Since the primary eclipse is only partial, the spectral type of the cooler component has been determined with less accuracy as K2 (+ or - 2). The system is only slightly reddened: its color excess is E(B-V) = 0.04 + or - 0.01 mag. Two models of the system are considered, depending on the luminosity class of the hotter star. Optically, the system is a Be star, since it displays Balmer line emission, visible most clearly during the primary eclipse. The ultraviolet spectrum observed near mideclipse does not display the expected 'W Serpentis-type' emission lines. Probably the main reason is that the primary eclipse is only partial.

  9. Jupiter: Giant of the solar system. [its solar orbits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Jupiter, its relationship to the other planets in the solar system, its twelve natural satellites, solar orbit and the appearance of Jupiter in the sky, and the sightings and motions of Jupiter in 1973 are discussed. Educational study projects for students are also included.

  10. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    A major constraint to the evolution of solar thermal power systems is the need to provide continuous operation during periods of solar outage. A number of high temperature thermal energy storage technologies which have the potential to meet this need are currently under development. The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  11. Solar-Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2001-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure. and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  12. Solar-Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  13. Solar-Powered Refrigeration System

    NASA Astrophysics Data System (ADS)

    Ewert, Michael K.; Bergeron, David J., III

    2002-10-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  14. Solar system employing ground level heliostats and solar collectors

    SciTech Connect

    Blake, F.A.; Northrup, L.L.

    1981-07-07

    This specification discloses an improvement in a solar system having one or more collectors for receiving and using radiant energy from the sun and at least one and preferably a plurality of respective reflector means for reflecting the radiant energy onto the collectors. The improvement is characterized by having towerless collectors and towerless reflectors that are disposed at ground level or substantially the same level, to eliminate the major expense of a collector tower, which is inefficient and nonfunctional in a solar system. Also disclosed is a complete system, or combination, for generating power employing solar energy and the improvement delineated above; as well as structural details of preferred arrangements and equipment.

  15. Thermodynamic modeling of the Ge-La binary system

    NASA Astrophysics Data System (ADS)

    Liu, Miao; Li, Chang-rong; Du, Zhen-min; Guo, Cui-ping; Niu, Chun-ju

    2012-08-01

    The Ge-La binary system was critically assessed by means of the calculation of phase diagram (CALPHAD) technique. The associate model was used for the liquid phase containing the constituent species Ge, La, Ge3La5, and Ge1.7La. The terminal solid solution diamond-(Ge) with a small solubility of La was described using the substitutional model, in which the excess Gibbs energy was formulated with the Redlich-Kister equation. The compounds with homogeneity ranges, α(Ge1.7La), β(Ge1.7La), and (GeLa), were modeled using two sublattices as α(Ge,La)1.7La, β(Ge,La)1.7La, and (Ge,La)(Ge,La), respectively. The intermediate phases with no solubility ranges, Ge4La5, Ge3La4, Ge3La5, and GeLa3, were treated as stoichiometric compounds. The three allotropic modifications of La, dhcp-La, fcc-La, and bcc-La, were kept as pure element phases since no solubility of Ge in La was reported. A set of self-consistent thermodynamic parameters of the Ge-La binary system was obtained. The calculation results agree well with the available experimental data from literatures.

  16. Early Solar System Leftovers: Testing Solar System Formation Models

    NASA Astrophysics Data System (ADS)

    Meech, Karen Jean; Yang, Bin; Kleyna, Jan; Hainaut, Olivier R.; Keane, Jacqueline V.; Micheli, Marco; Berdyugina, Svetlana; Bhatt, Bhuwan; Sahu, Devendra; Hsieh, Henry; Veres, Peter; Wainscoat, Richard J.; Riesen, Timm-Emanuel; Kaluna, Heather

    2015-11-01

    One of the most intriguing predictions of the Grand Tack model is the presence of volatile poor objects in the Oort cloud that were swept from the region where the terrestrial planets formed. This volatile-poor material is represented today by ordinary chondrites, enstatite chondrites and differentiated planetesimals. These are the main constituents of the S-type asteroids that reside in the inner Solar system. According to the Grand Tack model, the fraction of S-type material in cometary orbits should be around 0.1-0.2%. Recent Pan-STARRS 1 discoveries of objects on long-period comet orbits that are minimally active while at small perihelia have suggested the intriguing possibility that these could potentially represent inner solar system material that was ejected into the outer solar system during planet migration, that is now making its way back in. The first object discovered, C/2013 P2 has a spectrum redder than D-type objects, but exhibits low-level activity throughout its perihelion passage. The second one, C/2014 S3, appears to have an S-type asteroid spectrum, and likewise exhibits low-level activity.Nearly 100 of these objects have now been identified, approximately half of which are still observable, and more are being discovered. We will report on observations made for a selection of these objects with several facilities including Gemini N 8 m, VLT 8 m, Canada-France-Hawaii 3.6 m, PS1 2 m, UH2.2 m, HCT 2 m, and the Lowell 1.8 m telescopes. We will discuss the implications of seeing volatile activity in these objects.

  17. PHASES: A Search for Planets in Binary Systems

    NASA Astrophysics Data System (ADS)

    Lane, Benjamin; Muterpspaugh, M.; Konacki, M.; Kulkarni, S.; Shao, M.; Colavita, M.; Burke, B.

    2006-12-01

    For the past three years we have used the Palomar Testbed Interferometer to undertake an astrometric search for planets in binary stellar systems. By using phase referencing and long-baseline near-IR interferometry we are able to obtain an astrometric precision of approximately 20 micro-arcseconds between pairs of stars with separations in the range 0.1-1 arcsecond. We have followed 40 systems intensively and to date have over 800 astrometric measurements. We will present results from the first comprehensive analysis of this data set, including strong limits on the occurrence of planets in our target systems. The PHASES program serves as an excellent precursor to the type of program we expect to undertake with the Space Interferometry Mission PlanetQuest.

  18. The Habitable Zone of the Binary System Kepler-16

    NASA Astrophysics Data System (ADS)

    Moorman, Sarah; Cuntz, Manfred

    2017-01-01

    We report on the current results and envisioned future work from our study of the binary star system Kepler-16, which consists of a K-type main-sequence star and an M dwarf as well as a circumbinary Saturnian planet, Kepler-16b. We focus on the calculation of the location and extent of the habitable zone while considering several criteria for both the inner and outer boundaries previously given in the literature. In particular, we investigate the impact of the two stellar components (especially Kepler-16A) as well as of the system’s binarity regarding the provision of circumbinary habitability. Another aspect of our work consists in a careful assessment of how the extent of the system’s habitable zone is impacted by the relative uncertainties of the stellar and system parameters. Finally, we comment on the likelihood of habitable objects in the system by taking into account both radiative criteria and the need of orbital stability.

  19. HIGH FILL-OUT, EXTREME MASS RATIO OVERCONTACT BINARY SYSTEMS. X. THE NEWLY DISCOVERED BINARY XY LEONIS MINORIS

    SciTech Connect

    Qian, S.-B.; Liu, L.; Zhu, L.-Y.; He, J.-J.; Bernasconi, L. E-mail: yygcn@163.com

    2011-05-15

    The newly discovered short-period close binary star, XY LMi, has been monitored photometrically since 2006. Its light curves are typical EW-type light curves and show complete eclipses with durations of about 80 minutes. Photometric solutions were determined through an analysis of the complete B, V, R, and I light curves using the 2003 version of the Wilson-Devinney code. XY LMi is a high fill-out, extreme mass ratio overcontact binary system with a mass ratio of q = 0.148 and a fill-out factor of f = 74.1%, suggesting that it is in the late evolutionary stage of late-type tidal-locked binary stars. As observed in other overcontact binary stars, evidence for the presence of two dark spots on both components is given. Based on our 19 epochs of eclipse times, we found that the orbital period of the overcontact binary is decreasing continuously at a rate of dP/dt = -1.67 x 10{sup -7} days yr{sup -1}, which may be caused by mass transfer from the primary to the secondary and/or angular momentum loss via magnetic stellar wind. The decrease of the orbital period may result in the increase of the fill-out, and finally, it will evolve into a single rapid-rotation star when the fluid surface reaches the outer critical Roche lobe.

  20. S-type and P-type Habitability in Stellar Binary Systems: A Comprehensive Approach. I. Method and Applications

    NASA Astrophysics Data System (ADS)

    Cuntz, M.

    2014-01-01

    A comprehensive approach is provided for the study of both S-type and P-type habitability in stellar binary systems, which in principle can also be expanded to systems of higher order. P-type orbits occur when the planet orbits both binary components, whereas in the case of S-type orbits, the planet orbits only one of the binary components with the second component considered a perturbator. The selected approach encapsulates a variety of different aspects, which include: (1) the consideration of a joint constraint, including orbital stability and a habitable region for a putative system planet through the stellar radiative energy fluxes ("radiative habitable zone"; RHZ), needs to be met; (2) the treatment of conservative, general, and extended zones of habitability for the various systems as defined for the solar system and beyond; (3) the provision of a combined formalism for the assessment of both S-type and P-type habitability; in particular, mathematical criteria are presented for the kind of system in which S-type and P-type habitability is realized; (4) applications of the attained theoretical approach to standard (theoretical) main-sequence stars. In principle, five different cases of habitability are identified, which are S-type and P-type habitability provided by the full extent of the RHZs; habitability, where the RHZs are truncated by the additional constraint of planetary orbital stability (referred to as ST- and PT-type, respectively); and cases of no habitability at all. Regarding the treatment of planetary orbital stability, we utilize the formulae of Holman & Wiegert as also used in previous studies. In this work, we focus on binary systems in circular orbits. Future applications will also consider binary systems in elliptical orbits and provide thorough comparisons to other methods and results given in the literature.

  1. S-type and P-type habitability in stellar binary systems: A comprehensive approach. I. Method and applications

    SciTech Connect

    Cuntz, M.

    2014-01-01

    A comprehensive approach is provided for the study of both S-type and P-type habitability in stellar binary systems, which in principle can also be expanded to systems of higher order. P-type orbits occur when the planet orbits both binary components, whereas in the case of S-type orbits, the planet orbits only one of the binary components with the second component considered a perturbator. The selected approach encapsulates a variety of different aspects, which include: (1) the consideration of a joint constraint, including orbital stability and a habitable region for a putative system planet through the stellar radiative energy fluxes ({sup r}adiative habitable zone{sup ;} RHZ), needs to be met; (2) the treatment of conservative, general, and extended zones of habitability for the various systems as defined for the solar system and beyond; (3) the provision of a combined formalism for the assessment of both S-type and P-type habitability; in particular, mathematical criteria are presented for the kind of system in which S-type and P-type habitability is realized; (4) applications of the attained theoretical approach to standard (theoretical) main-sequence stars. In principle, five different cases of habitability are identified, which are S-type and P-type habitability provided by the full extent of the RHZs; habitability, where the RHZs are truncated by the additional constraint of planetary orbital stability (referred to as ST- and PT-type, respectively); and cases of no habitability at all. Regarding the treatment of planetary orbital stability, we utilize the formulae of Holman and Wiegert as also used in previous studies. In this work, we focus on binary systems in circular orbits. Future applications will also consider binary systems in elliptical orbits and provide thorough comparisons to other methods and results given in the literature.

  2. Planetary Nebulae that Cannot Be Explained by Binary Systems

    NASA Astrophysics Data System (ADS)

    Bear, Ealeal; Soker, Noam

    2017-03-01

    We examine the images of hundreds of planetary nebulae (PNe) and find that for about one in six PNe the morphology is too “messy” to be accounted for by models of stellar binary interaction. We speculate that interacting triple stellar systems shaped these PNe. In this preliminary study, we qualitatively classify PNe by one of four categories. (1) PNe that show no need for a tertiary star to account for their morphology. (2) PNe whose structure possesses a pronounced departure from axial-symmetry and/or mirror-symmetry. We classify these, according to our speculation, as “having a triple stellar progenitor.” (3) PNe whose morphology possesses departure from axial-symmetry and/or mirror-symmetry, but not as pronounced as in the previous class, and are classified as “likely shaped by triple stellar system.” (4) PNe with minor departure from axial-symmetry and/or mirror-symmetry that could have been also caused by an eccentric binary system or the interstellar medium. These are classified as “maybe shaped by a triple stellar system.” Given a weight η t = 1, η l = 0.67, and η m = 0.33 to classes 2, 3, and 4, respectively, we find that according to our assumption about 13%–21% of PNe have been shaped by triple stellar systems. Although in some evolutionary scenarios not all three stars survive the evolution, we encourage the search for a triple stellar systems at the center of some PNe.

  3. The solar wind-magnetosphere-ionosphere system

    PubMed

    Lyon

    2000-06-16

    The solar wind, magnetosphere, and ionosphere form a single system driven by the transfer of energy and momentum from the solar wind to the magnetosphere and ionosphere. Variations in the solar wind can lead to disruptions of space- and ground-based systems caused by enhanced currents flowing into the ionosphere and increased radiation in the near-Earth environment. The coupling between the solar wind and the magnetosphere is mediated and controlled by the magnetic field in the solar wind through the process of magnetic reconnection. Understanding of the global behavior of this system has improved markedly in the recent past from coordinated observations with a constellation of satellite and ground instruments.

  4. Spin-Spin Coupling in the Solar System

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Morbidelli, Alessandro

    2015-09-01

    The richness of dynamical behavior exhibited by the rotational states of various solar system objects has driven significant advances in the theoretical understanding of their evolutionary histories. An important factor that determines whether a given object is prone to exhibiting non-trivial rotational evolution is the extent to which such an object can maintain a permanent aspheroidal shape, meaning that exotic behavior is far more common among the small body populations of the solar system. Gravitationally bound binary objects constitute a substantial fraction of asteroidal and TNO populations, comprising systems of triaxial satellites that orbit permanently deformed central bodies. In this work, we explore the rotational evolution of such systems with specific emphasis on quadrupole-quadrupole interactions, and show that for closely orbiting, highly deformed objects, both prograde and retrograde spin-spin resonances naturally arise. Subsequently, we derive capture probabilities for leading order commensurabilities and apply our results to the illustrative examples of (87) Sylvia and (216) Kleopatra asteroid systems. Cumulatively, our results suggest that spin-spin coupling may be consequential for highly elongated, tightly orbiting binary objects.

  5. SPIN–SPIN COUPLING IN THE SOLAR SYSTEM

    SciTech Connect

    Batygin, Konstantin; Morbidelli, Alessandro

    2015-09-10

    The richness of dynamical behavior exhibited by the rotational states of various solar system objects has driven significant advances in the theoretical understanding of their evolutionary histories. An important factor that determines whether a given object is prone to exhibiting non-trivial rotational evolution is the extent to which such an object can maintain a permanent aspheroidal shape, meaning that exotic behavior is far more common among the small body populations of the solar system. Gravitationally bound binary objects constitute a substantial fraction of asteroidal and TNO populations, comprising systems of triaxial satellites that orbit permanently deformed central bodies. In this work, we explore the rotational evolution of such systems with specific emphasis on quadrupole–quadrupole interactions, and show that for closely orbiting, highly deformed objects, both prograde and retrograde spin–spin resonances naturally arise. Subsequently, we derive capture probabilities for leading order commensurabilities and apply our results to the illustrative examples of (87) Sylvia and (216) Kleopatra asteroid systems. Cumulatively, our results suggest that spin–spin coupling may be consequential for highly elongated, tightly orbiting binary objects.

  6. Photometric Study of the Solar Type Pre-Contact Binary, V2421 Cygni

    NASA Astrophysics Data System (ADS)

    Hill, Robert L.; Shebs, T.; Samec, R. G.; Kring, J.; Van Hamme, W. V.; Faulkner, D. R.

    2013-06-01

    We present the first precision BVRI light curves, and synthetic light curve solutions and a period study for the 14th magnitude (V) pre-contact W UMa Binary, V2421 Cygni. Observations were taken with the NURO 0.81-m Lowell reflector on 30 September, 1 and 2 October. Our light curves were premodeled with Binary Maker 3.0, and solved with the Wilson-Devinney program. The observations included 140 B, 149 V, 139 R and 135 I individual and calibrated observations. These were taken with the Lowell CRYOTIGER cooled (-100k) 2KX2K NASACAM. Three mean times of minimum light were determined, including HJDMin I = 2455469.82375±0.00037, and 2455471.72232±0.0012 and HJDMin II = 2455470.77149±0.0012. Eight eclipse timings were taken from the the literature for our calculation of its first precision ephemeris: JD Tmin I = 2455469.8238± 0.0047 + 0.6331290 ± 0.0000015 d*E The light curve has the appearance of an Algol (EA) type, however it is made up of dwarf solar type components in a detached mode with a period of only 0.6331 days. The light curve solution gives a mass ratio of ~0.5, an inclination of 86° and amplitudes of 1.3, 1.1, 0.98, and 0.87 in B,V,R and I, respectively. Flare-like disruptions occur in the light curves following the primary and secondary eclipses. The fill-outs are 83% and 98% for star one (hotter more massive component) and star two, respectively. The model includes two hot spots, possibly, stream spots (one a direct hit and the second, a splash spot). Further observations are needed to determine its orbital evolution. We thank USC, Lancaster for their support of our membership in NURO for the past 8 years, the American Astronomical Society for its support through its small research program and Arizona Space grant for the partial support for our student’s travel.

  7. The formation of a helium white dwarf in a close binary system with diffusion

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; De Vito, M. A.

    2004-07-01

    We study the evolution of a system composed of a 1.4-Msolar neutron star and a normal, solar composition star of 2 Msolar in orbit with a period of 1 d. Calculations were performed employing the binary HYDRO code presented by Benvenuto & De Vito that handle the mass transfer rate in a fully implicit way. We then included the main standard physical ingredients together with the diffusion processes and a proper outer boundary condition. We have assumed fully non-conservative mass transfer episodes. In order to study the interplay of mass loss episodes and diffusion we considered evolutionary sequences with and without diffusion in which all Roche lobe overflows (RLOFs) produce mass transfer. Another two sequences in which thermonuclearly driven RLOFs were not allowed to drive mass transfer have been computed with and without diffusion. As far as we are aware, this study represents the first binary evolution calculations in which diffusion is considered. The system produces a helium white dwarf of ~0.21 Msolar in an orbit with a period of ~4.3 d for the four cases. We find that mass transfer episodes induced by hydrogen thermonuclear flashes drive a tiny amount of mass transfer. As diffusion produces stronger flashes, the amount of hydrogen-rich matter transferred is slightly higher than in the models without diffusion. We find that diffusion is the main agent in determining the evolutionary time-scale of low-mass white dwarfs even in the presence of mass transfer episodes.

  8. Hogg 12 and NGC 3590: A New Open Cluster Binary System Candidate

    NASA Astrophysics Data System (ADS)

    Piatti, Andrés E.; Clariá, Juan J.; Ahumada, Andrea V.

    2010-05-01

    We have obtained CCD UBVIKC photometry down to V ∼ 22.0 for the open clusters Hogg 12 and NGC 3590 and the fields surrounding them. Based on photometric and morphological criteria, as well as on the stellar density in the region, our evidence is sufficient to confirm that Hogg 12 is a genuine open cluster. NGC 3590 was used as a control cluster. The color-magnitude diagrams of Hogg 12, cleaned from field star contamination, reveal that this is a solar metal content cluster, affected by E(B - V) = 0.40 ± 0.05, located at a heliocentric distance d = 2.0 ± 0.5 kpc, and of an age similar to that of NGC 3590 (t = 30 Myr). Both clusters are surprisingly small objects whose radii are barely ∼1 pc, andthey are separated in the sky by scarcely 3.6 pc. These facts, added to their similar ages, reddenings, and metallicities, allow us to consider them a new open cluster binary system candidate. Of the ∼180 open cluster binary systems estimated to exist in the Galaxy, of which 27 are actually well known, Hogg 12 and NGC 3590 appear to be one of the two closest pairs.

  9. Thermal expansion of solid solutions in apatite binary systems

    SciTech Connect

    Knyazev, Alexander V.; Bulanov, Evgeny N. Korokin, Vitaly Zh.

    2015-01-15

    Graphical abstract: Thermal dependencies of volume thermal expansion parameter for with thermal expansion diagrams for Pb{sub 5}(PO{sub 4}){sub 3}F{sub x}Cl{sub 1−x}. - Highlights: • Solid solutions in three apatitic binary systems were investigated via HT-XRD. • Thermal expansion coefficients of solid solutions in the systems were calculated. • Features of the thermal deformation of the apatites were described. • Termoroentgenography is a sensitive method for the investigation of isomorphism. - Abstract: High-temperature insitu X-ray diffraction was used to investigate isomorphism and the thermal expansion of apatite-structured compounds in three binary systems in the entire temperature range of the existence of its hexagonal modifications. Most of the studied compounds are highly expandable (α{sub l} > 8 × 10{sup 6} (K{sup −1})). In Pb{sub 5}(PO{sub 4}){sub 3}F–Pb{sub 5}(PO{sub 4}){sub 3}Cl system, volume thermal expansion coefficient is independence from the composition at 573 K. In Pb{sub 5}(PO{sub 4}){sub 3}Cl–Pb{sub 5}(VO{sub 4}){sub 3}Cl, the compound with equimolar ratio of substituted atoms has constant volume thermal expansion coefficient in temperature range 298–973 K. Ca{sub 5}(PO{sub 4}){sub 3}Cl–Pb{sub 5}(PO{sub 4}){sub 3}Cl system is characterized by the most thermal sensitive composition, in which there is an equal ratio of isomorphic substituted atoms.

  10. Be discs in binary systems - I. Coplanar orbits

    NASA Astrophysics Data System (ADS)

    Panoglou, Despina; Carciofi, Alex C.; Vieira, Rodrigo G.; Cyr, Isabelle H.; Jones, Carol E.; Okazaki, Atsuo T.; Rivinius, Thomas

    2016-09-01

    Be stars are surrounded by outflowing circumstellar matter structured in the form of decretion discs. They are often members of binary systems, where it is expected that the decretion disc interacts both radiatively and gravitationally with the companion. In this work we study how various orbital (period, mass ratio and eccentricity) and disc (viscosity) parameters affect the disc structure in coplanar binaries. The main effects of the secondary on the disc are its truncation and the accumulation of material inwards of truncation. We find two limiting cases with respect to the effects of eccentricity: in circular or nearly circular prograde orbits, the disc maintains a rotating, constant in shape, configuration, which is locked to the orbital phase. The disc structure appears smaller in size, more elongated and more massive for small viscosity parameter, small orbital separation and/or high mass ratio. In highly eccentric orbits, the effects are more complex, with the disc structure strongly dependent on the orbital phase. We also studied the effects of binarity in the disc continuum emission. Since the infrared and radio SED are sensitive to the disc size and density slope, the truncation and matter accumulation result in considerable modifications in the emergent spectrum. We conclude that binarity can serve as an explanation for the variability exhibited in observations of Be stars, and that our model can be used to detect invisible companions.

  11. Evolution of an accretion disc in binary black hole systems

    NASA Astrophysics Data System (ADS)

    Kimura, Shigeo S.; Takahashi, Sanemichi Z.; Toma, Kenji

    2017-03-01

    We investigate evolution of an accretion disc in binary black hole (BBH) systems and possible electromagnetic counterparts of the gravitational waves from mergers of BBHs. Perna et al. proposed a novel evolutionary scenario of an accretion disc in BBHs in which a disc eventually becomes 'dead', i.e. the magnetorotational instability (MRI) becomes inactive. In their scenario, the dead disc survives until a few seconds before the merger event. We improve the dead disc model and propose another scenario, taking account of effects of the tidal torque from the companion and the critical ionization degree for MRI activation more carefully. We find that the mass of the dead disc is much lower than that in the Perna's scenario. When the binary separation sufficiently becomes small, the mass inflow induced by the tidal torque reactivates MRI, restarting mass accretion on to the black hole. We also find that this disc 'revival' happens more than thousands of years before the merger. The mass accretion induced by the tidal torque increases as the separation decreases, and a relativistic jet could be launched before the merger. The emissions from these jets are too faint compared to gamma-ray bursts, but detectable if the merger events happen within ≲10 Mpc or if the masses of the black holes are as massive as ∼105 M⊙.

  12. Non-tracking solar energy collector system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1978-01-01

    A solar energy collector system is described characterized by an improved concentrator for directing incident rays of solar energy on parallel strip-like segments of a flatplate receiver. Individually mounted reflector modules of a common asymmetrical triangular cross-sectional configuration supported for independent orientation are asymmetric included with vee-trough concentrators for deflecting incident solar energy toward the receiver.

  13. Is the Hogg 12-NGC 3590 pair a new open cluster binary system?

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Clariá, J. J.; Ahumada, A. V.

    Based on CCD UBVI_(KC) images obtained at Cerro Tololo Inter-American Observatory (CTIO, Chile) and on morphological criteria, as well as on the stellar density in the region, we confirm that Hogg 12 is a genuine open cluster (OC) separated in the sky from NGC 3590 by scarcely 3.6 pc. The colour-magnitude diagrams of Hogg 12, cleaned from field star contamina- tion, reveal that this is a solar metal content cluster, affected by E(B-V) = 0.40 ± 0.05, located at a heliocentric distance d = 2.0 ± 0.5 kpc, and of an age similar to that of NGC 3590. Evidence that these two objects form an OC binary system is presented. A detailed version of this work can be seen in PASP, 122, 516 (2010).

  14. HIP 13962 - The Possible Former Member of Binary System with Supernova

    NASA Astrophysics Data System (ADS)

    Yushchenko, V.; Yushchenko, A.; Gopka, V.; Shavrina, A.; Kovtyukh, V.; Hong, K. S.; Mkrtichian, D.; Thano, N. A.

    2016-12-01

    The runaway supergiant star HIP 13962 (spectral type G0Ia) was recently pointed as a possible former binary companion of young pulsar PSR J0826+2637. The spectra of HIP 13962 were obtained in Haute-Provence observatory (France), in Bohuynsan observatory (Korea), and also in NARIT (Thailand) with 1.9, 1.8, and 2.4 meter telescopes respectively. The spectra were obtained in 1995, 2003, 2005, 2014, and 2015. Significant variations of the spectrum are detected. The cores of strong lines show complicated structure, the brightness of the star is variable. The cycles of photometric variations have been changed. We analyzed the spectral observations and present the preliminary chemical composition for elements from iron to lead. The abundance pattern can not be fitted by solar system r- & s-process abundance distribution.

  15. Solar-gas systems impact analysis study

    NASA Astrophysics Data System (ADS)

    Neill, C. P.; Hahn, E. F.; Loose, J. C.; Poe, T. E.; Hirshberg, A. S.; Haas, S.; Preble, B.; Halpin, J.

    1984-07-01

    The impacts of solar/gas technologies on gas consumers and on gas utilities were measured separately and compared against the impacts of competing gas and electric systems in four climatic regions of the U.S. A methodology was developed for measuring the benefits or penalties of solar/gas systems on a combined basis for consumers sand distribution companies. It is shown that the combined benefits associated with solar/gas systems are generally greatest when the systems are purchased by customers who would have otherwise chosen high-efficiency electric systems (were solar/gas systems not available in the market place). The role of gas utilities in encouraging consumer acceptance of solar/gas systems was also examined ion a qualitative fashion. A decision framework for analyzing the type and level of utility involvement in solar/gas technologies was developed.

  16. Near-Infrared Observations of Compact Binary Systems

    NASA Astrophysics Data System (ADS)

    Khargharia, Juthika

    Low mass X-ray binaries (LMXBs) are a subset of compact binary systems in which a main-sequence or slightly evolved star fills its Roche lobe and donates mass to a neutron star or a black hole (BH) via an accretion disk. Robust estimates of compact object masses in these systems are required to enhance our current understanding of the physics of compact object formation, accretion disks and jets. Compact object masses are typically determined at near-infrared (NIR) wavelengths when the system is in quiescence and the donor star is the dominant source of flux. Previous studies have assumed that any non-stellar contribution at these wavelengths is minimal. However, this assumption is rarely true. By performing NIR spectroscopy, we determined the fractional donor star contribution to the NIR flux and the compact object masses in two LMXBs: V404 Cyg and Cen X-4. In our analysis, it was assumed that the light curve morphology remains consistent throughout quiescence. It has now been shown in several systems that veiling measurements from non-stellar sources are meaningful only if acquired contemporaneously with light curve measurements. We accounted for this in the measurement of the BH mass in the LMXB, XTE J1118+480. LMXBs are also considered to be the most likely candidates responsible for the formation of milli-second pulsars (MSP). Here, I present the unique case of PSR J1903+0327 that challenges this currently accepted theory of MSP formation and is a potential candidate for testing General Relativity. Observations in the NIR come with their own set of challenges. NIR detector arrays used in these observations generally have high dark current and readout noise. In an effort to lower the read noise in NICFPS at APO, we present a study done on the Hawaii-1RG engineering grade chip that served as a test bed for reducing the read noise in NICFPS.

  17. Isobaric vapor-liquid equilibria for methanol + ethanol + water and the three constituent binary systems

    SciTech Connect

    Kurihara, Kiyofumi; Nakamichi, Mikiyoshi; Kojima, Kazuo . Dept. of Industrial Chemistry)

    1993-07-01

    Vapor-liquid equilibrium data for methanol + ethanol + water and its three constituent binary systems methanol + ethanol, ethanol + water, and methanol + water were measured at 101.3 kPa using a liquid-vapor ebullition-type equilibrium still. The experimental binary data were correlated by the NRTL equation. The ternary system methanol + ethanol + water was predicted by means of the binary NRTL parameters with good accuracy.

  18. Tracing Rays In A Solar Power System

    NASA Technical Reports Server (NTRS)

    Jefferies, Kent; Gallo, Chris

    1989-01-01

    OFFSET is ray-tracing computer code for analysis of optics of solar collector. Code models distributions of solar flux within receiver cavity, produced by reflections from collector. Developed to model mathematically offset solar collector of solar dynamic electric power system being developed for Space Station Freedom. Used to develop revised collector-facet concept of four groups of toroidally contoured facets. Also used to develop methods for tailoring distribution of flux incident on receiver. Written in FORTRAN 77 (100 percent).

  19. The solar system beyond Neptune

    NASA Technical Reports Server (NTRS)

    Jewitt, David C.; Luu, Jane X.

    1995-01-01

    We present the results of a deep optical survey for distant solar system objects. An area of 1.2 sq deg of the ecliptic has been imaged to apparent red magnitude 25, resulting in the detection of seven trans-Neptunian objects. These are the first detected members of a trans-Neptunian disk that compries about 35 000 objects larger than 100 km in the 30-50 AU heliocentric distance range. We interpret the new measurements using a set of Monte Carlo models in which the effects of observational bias in the data are taken into account.

  20. Tracking system for solar collectors

    DOEpatents

    Butler, B.

    1980-10-01

    A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

  1. Tracking system for solar collectors

    DOEpatents

    Butler, Barry L.

    1984-01-01

    A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

  2. 2007 Mutual events within the binary system of (22) Kalliope

    NASA Astrophysics Data System (ADS)

    Descamps, P.; Marchis, F.; Pollock, J.; Berthier, J.; Birlan, M.; Vachier, F.; Colas, F.

    2008-11-01

    In 2007, the asteroid Kalliope will reach one of its annual equinoxes. As a consequence, its small satellite Linus orbiting in the equatorial plane will undergo a season of mutual eclipses and occultations very similar to the one that the Galilean satellites undergo every 6 years. This paper is aimed at preparing a campaign of observations of these mutual events occurring from February to May 2007. This opportunity occurs only under favorable geometric conditions when the Sun and/or the Earth are close to the orbital plane of the system. This is the first international campaign devoted to the observation of photometric events within an asynchronous asteroidal binary system. We took advantage of a reliable orbit solution of Linus to predict a series of 24 mutual eclipses and 12 mutual occultations observable in the spring of 2007. Thanks to the brightness of Kalliope ( mv≃11), these observations are easy to perform even with a small telescope. Anomalous attenuation events could be observed lasting for about 1-3 h with amplitude up to 0.09 mag. The attenuations are of two distinct types that can clearly be identified as primary and secondary eclipses similar to those that have been previously observed in other minor planet binary systems [Pravec, P., Scheirich, P., Kusnirák, P., Sarounová, L., Mottola, S., Hahn, G., Brown, P., Esquerdo, G., Kaiser, N., Krzeminski, Z., Pray, D.P., Warner, B.D., Harris, A.W., Nolan, M.C., Howell, E.S., Benner, L.A.M., Margot, J.-L., Galád, A., Holliday, W., Hicks, M.D., Krugly, Yu.N., Tholen, D., Whiteley, R., Marchis, F., Degraff, D.R., Grauer, A., Larson, S., Velichko, F.P., Cooney, W.R., Stephens, R., Zhu, J., Kirsch, K., Dyvig, R., Snyder, L., Reddy, V., Moore, S., Gajdos, S., Világi, J., Masi, G., Higgins, D., Funkhouser, G., Knight, B., Slivan, S., Behrend, R., Grenon, M., Burki, G., Roy, R., Demeautis, C., Matter, D., Waelchli, N., Revaz, Y., Klotz, A., Rieugné, M., Thierry, P., Cotrez, V., Brunetto, L., Kober, G., 2006

  3. Single-Junction Binary-Blend Nonfullerene Polymer Solar Cells with 12.1% Efficiency.

    PubMed

    Zhao, Fuwen; Dai, Shuixing; Wu, Yang; Zhang, Qianqian; Wang, Jiayu; Jiang, Li; Ling, Qidan; Wei, Zhixiang; Ma, Wei; You, Wei; Wang, Chunru; Zhan, Xiaowei

    2017-03-10

    A new fluorinated nonfullerene acceptor, ITIC-Th1, has been designed and synthesized by introducing fluorine (F) atoms onto the end-capping group 1,1-dicyanomethylene-3-indanone (IC). On the one hand, incorporation of F would improve intramolecular interaction, enhance the push-pull effect between the donor unit indacenodithieno[3,2-b]thiophene and the acceptor unit IC due to electron-withdrawing effect of F, and finally adjust energy levels and reduce bandgap, which is beneficial to light harvesting and enhancing short-circuit current density (JSC ). On the other hand, incorporation of F would improve intermolecular interactions through CF···S, CF···H, and CF···π noncovalent interactions and enhance electron mobility, which is beneficial to enhancing JSC and fill factor. Indeed, the results show that fluorinated ITIC-Th1 exhibits redshifted absorption, smaller optical bandgap, and higher electron mobility than the nonfluorinated ITIC-Th. Furthermore, nonfullerene organic solar cells (OSCs) based on fluorinated ITIC-Th1 electron acceptor and a wide-bandgap polymer donor FTAZ based on benzodithiophene and benzotriazole exhibit power conversion efficiency (PCE) as high as 12.1%, significantly higher than that of nonfluorinated ITIC-Th (8.88%). The PCE of 12.1% is the highest in fullerene and nonfullerene-based single-junction binary-blend OSCs. Moreover, the OSCs based on FTAZ:ITIC-Th1 show much better efficiency and better stability than the control devices based on FTAZ:PC71 BM (PCE = 5.22%).

  4. Solar thermal power systems. Summary report

    SciTech Connect

    Not Available

    1980-06-01

    The work accomplished by the Aerospace Corporation from April 1973 through November 1979 in the mission analysis of solar thermal power systems is summarized. Sponsorship of this effort was initiated by the National Science Foundation, continued by the Energy Research and Development Administration, and most recently directed by the United States Department of Energy, Division of Solar Thermal Systems. Major findings and conclusions are sumarized for large power systems, small power systems, solar total energy systems, and solar irrigation systems, as well as special studies in the areas of energy storage, industrial process heat, and solar fuels and chemicals. The various data bases and computer programs utilized in these studies are described, and tables are provided listing financial and solar cost assumptions for each study. An extensive bibliography is included to facilitate review of specific study results and methodology.

  5. The binary system containing the classical Cepheid T Mon

    NASA Technical Reports Server (NTRS)

    Evans, Nancy Remage; Lyons, Ronald W.

    1994-01-01

    Several new results are presented for the binary system containing the 27(sup d) classical Cepheid T Mon. New radial velocities for the Cepheid have been obtained, which confirm the decreasing orbital motion at the current epoch. The spectral type of the companion (B9.8 V) has been determined from an International Ultraviolet Explorer (IUE) low resolution spectrum. An IUE high resolution spectrum has been measured to search for the velocity of the companion. A velocity signal at +36 km/s on JD 2,446,105.21 has been tentatively identified as the velocity of the companion, but confirmation of this velocity would be very valuable. Results based on this tentative identification of the velocity are that the companion does not have a high projected rotation velocity, that the companion is unlikely to be a short period binary, and that the gamma velocity of the system is between 20 and 36 km/s. The luminosity and temperature of both the Cepheid and the companion are well determined from the satellite and ground-based observations and the Cepheid PLC relation. However, the companion is above the ZAMS in the H-R diagram, which is inconsistent with the large luminosity difference between the two stars. High rotation for the companion (viewed pole-on) is a possible explanation. The lower limit to the mass function (from the lower limits to the orbital period and amplitude) requires a very high eccentricity for the system for reasonable estimates for the masses of the two stars.

  6. MULTIFUNCTIONAL SOLAR ENERGY SYSTEMS RESEARCH PROJECT

    SciTech Connect

    Byard Wood, Lance Seefeldt, Ronald Sims, Bradley Wahlen, and Dan Dye

    2012-06-29

    The solar energy available within the visible portion of the solar spectrum is about 300 W/m2 (43%) and that available in the UV and IR portion is about 400 W/m2 (57%). This provides opportunities for developing integrated energy systems that capture and use specific wavelengths of the solar spectrum for different purposes. For example: biofuels from photosynthetic microbes use only the visible light; solar cells use a narrow band of the solar spectrum that could be either mostly in the visible or in the IR regions of the solar spectrum, depending on the photovoltaic materials, e.g., gallium antimonide (GaSb) cells utilize predominately IR radiation; and finally, solar panels that heat water utilize a broad range of wavelengths (visible plus IR). The basic idea of this research is that sunlight has many possible end-use applications including both direct use and energy conversion schemes; it is technically feasible to develop multifunctional solar energy systems capable of addressing several end-use needs while increasing the overall solar energy utilization efficiency when compared to single-purpose solar technologies. Such a combination of technologies could lead to more cost-competitive ?multifunctional? systems that add value and broaden opportunities for integrated energy systems. The goal of this research is to increase the overall energy efficacy and cost competitiveness of solar systems. The specific objectives of this research were: 1) Evaluate the efficacy of a combined photobioreactor and electric power system; 2) Improve the reliability and cost effectiveness of hybrid solar lighting systems ? a technology in which sunlight is collected and distributed via optical fibers into the interior of a building; 3) Evaluate the efficacy of using filtered light to increase the production of biomass in photobioreactors and provide more solar energy for other uses; 4) Evaluates several concepts for wavelength shifting such that a greater percentage of the solar

  7. Small Solar Power Systems /SSPS/

    NASA Astrophysics Data System (ADS)

    Grasse, W.

    1981-05-01

    A detailed description is given of the project organization, hardware, and projected performance of the distributed collector and central receiver solar thermal research facilities comprising the Small Power Systems (SSPS) plants in Almeria, Spain. The Distributed Collector System (DCS) is rated at 500 kWe and employs two fields of line-focusing parabolic trough collectors. The Central Receiver System (CRS) has the same rating and uses liquid sodium as a heat-transfer medium to circulate the 530 C heat yielded by a concentration factor of 450 from 4000 sq m of reflective surface. The purpose of the plant's dual configuration is the comparison of the two concentration methods under identical environmental conditions and the responsibility of a single operator/evaluator.

  8. Compact Objects In Binary Systems: Formation and Evolution of X-ray Binaries and Tides in Double White Dwarfs

    NASA Astrophysics Data System (ADS)

    Valsecchi, Francesca

    Binary star systems hosting black holes, neutron stars, and white dwarfs are unique laboratories for investigating both extreme physical conditions, and stellar and binary evolution. Black holes and neutron stars are observed in X-ray binaries, where mass accretion from a stellar companion renders them X-ray bright. Although instruments like Chandra have revolutionized the field of X-ray binaries, our theoretical understanding of their origin and formation lags behind. Progress can be made by unravelling the evolutionary history of observed systems. As part of my thesis work, I have developed an analysis method that uses detailed stellar models and all the observational constraints of a system to reconstruct its evolutionary path. This analysis models the orbital evolution from compact-object formation to the present time, the binary orbital dynamics due to explosive mass loss and a possible kick at core collapse, and the evolution from the progenitor's Zero Age Main Sequence to compact-object formation. This method led to a theoretical model for M33 X-7, one of the most massive X-ray binaries known and originally marked as an evolutionary challenge. Compact objects are also expected gravitational wave (GW) sources. In particular, double white dwarfs are both guaranteed GW sources and observed electromagnetically. Although known systems show evidence of tidal deformation and a successful GW astronomy requires realistic models of the sources, detached double white dwarfs are generally approximated to point masses. For the first time, I used realistic models to study tidally-driven periastron precession in eccentric binaries. I demonstrated that its imprint on the GW signal yields constrains on the components' masses and that the source would be misclassified if tides are neglected. Beyond this adiabatic precession, tidal dissipation creates a sink of orbital angular momentum. Its efficiency is strongest when tides are dynamic and excite the components' free

  9. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  10. Viscosity mixing rules for binary systems containing one ionic liquid.

    PubMed

    Tariq, Mohammed; Altamash, Tausif; Salavera, Daniel; Coronas, Alberto; Rebelo, Luis P N; Canongia Lopes, Jose N

    2013-06-24

    In this work the applicability of four of the most commonly used viscosity mixing rules to [ionic liquid (IL)+molecular solvent (MS)] systems is assessed. More than one hundred (IL+MS) binary mixtures were selected from the literature to test the viscosity mixing rules proposed by 1) Hind (Hi), 2) Grunberg and Nissan (G-N), 3) Herric (He) and 4) Katti and Chaudhri (K-C). The analyses were performed by estimating the average (absolute or relative) deviations, AADs and ARDs, between the available experimental data and the predicted ideal mixture viscosity values obtained by means of each rule. The interaction terms corresponding to the adjustable parameters inherent to each rule were also calculated and their trends discussed.

  11. Binary system of unequal counterrotating Kerr-Newman sources

    NASA Astrophysics Data System (ADS)

    Cabrera-Munguia, I.

    2015-02-01

    Stationary axisymmetric binary systems of unequal counterrotating Kerr-Newman sources with a massless strut in between are studied. By means of the choice of a suitable parametrization, the axis conditions and the absence of individual magnetic charges are fulfilled; thus, the entire metric reduces to a six-parametric asymptotically flat exact solution. Later on, with the purpose to describe interacting black holes, the analytic functional form of the horizon half-length parameter σk is obtained explicitly in terms of physical Komar parameters: mass Mk, electric charge Qk, angular momentum Jk, and coordinate distance R , where the seven physical parameters satisfy a simple algebraic relation. Finally, in the limit of extreme black holes, the full metric is derived in a closed analytical form, and a study on the absence or appearance of naked singularities off the axis is presented.

  12. Five New Low-Mass Eclipsing Binary Systems

    NASA Astrophysics Data System (ADS)

    Coughlin, Jeffrey L.; López-Morales, M.; Shaw, J. S.

    2006-12-01

    We present the discovery of five new low-mass eclipsing binaries with masses between 0.54 and 0.95 M⊙, their photometric light curves, and preliminary models. This is part of a continuing campaign to increase the available data on these interesting systems. Once radial-velocity curves are completed, physical parameters will be determined with an error of less than 2-3%, thus allowing for a rigorous examination of stellar models in the lower-main sequence. Our initial analysis seems to support the current findings that low-mass stars have greater radii than models predict, most likely due to the presence of strong magnetic fields. This work is funded by a partnership between the National Science Foundation (NSF AST-0552798) Research Experiences for Undergraduates (REU) and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs.

  13. Second derivative in the model of classical binary system

    NASA Astrophysics Data System (ADS)

    Abubekerov, M. K.; Gostev, N. Yu.

    2016-06-01

    We have obtained an analytical expression for the second derivatives of the light curve with respect to geometric parameters in the model of eclipsing classical binary systems. These expressions are essentially efficient algorithm to calculate the numerical values of these second derivatives for all physical values of geometric parameters. Knowledge of the values of second derivatives of the light curve at some point provides additional information about asymptotical behaviour of the function near this point and can significantly improve the search for the best-fitting light curve through the use of second-order optimization method. We write the expression for the second derivatives in a form which is most compact and uniform for all values of the geometric parameters and so make it easy to write a computer program to calculate the values of these derivatives.

  14. Hybridizing Gravitationl Waveforms of Inspiralling Binary Neutron Star Systems

    NASA Astrophysics Data System (ADS)

    Cullen, Torrey; LIGO Collaboration

    2016-03-01

    Gravitational waves are ripples in space and time and were predicted to be produced by astrophysical systems such as binary neutron stars by Albert Einstein. These are key targets for Laser Interferometer and Gravitational Wave Observatory (LIGO), which uses template waveforms to find weak signals. The simplified template models are known to break down at high frequency, so I wrote code that constructs hybrid waveforms from numerical simulations to accurately cover a large range of frequencies. These hybrid waveforms use Post Newtonian template models at low frequencies and numerical data from simulations at high frequencies. They are constructed by reading in existing Post Newtonian models with the same masses as simulated stars, reading in the numerical data from simulations, and finding the ideal frequency and alignment to ``stitch'' these waveforms together.

  15. Analytical estimates of secular frequencies for binary star systems

    NASA Astrophysics Data System (ADS)

    Bazsó, Á.; Pilat-Lohinger, E.

    2017-03-01

    Binary and multiple star systems are extreme environments for the formation and long-term presence of extrasolar planets. Circumstellar planets are subject to gravitational perturbations from the distant companion star, and this interaction leads to a long-period precession of their orbits. We investigate analytical models that allow to quantify these perturbations and calculate the secular precession frequency in the dynamical model of the restricted three-body problem. These models are applied to test cases and we discuss some of their shortcomings. In addition, we introduce a modified Laplace-Lagrange model which allows to obtain better frequency estimates than the traditional model for large eccentricities of the perturber. We then generalize this model to any number of perturbers, and present an application to the four-body problem.

  16. Solar System Exploration with LUVOIR

    NASA Astrophysics Data System (ADS)

    Harris, Walter M.; Villanueva, Geronimo Luis; Schmidt, Britney E.

    2016-10-01

    The Large UV/Optical/IR (LUVOIR) Surveyor is one of four mission concepts under study as a next-generation space observatory in the post Webb Telescope era. LUVOIR is envisioned as a large, 10 m class, remotely serviceable observatory with a suite of advanced-technology instruments designed to leap beyond the current generation of space-based telescopes to explore fundamental astrophysical phenomena on all scales. A 24-member science and technology definition team (STDT) represents all sectors of the astronomy and technologist communities, and it is charged with identifying the observational challenges best addressed with LUVOIR and the instrumental innovations that are required to achieve them.This presentation describes the developing science case for LUVOIR as a Solar System observatory for the study of Sun-planet interactions, thick and sublimation based atmospheres, the small body populations in the inner and outer solar system, surface volatility, and planet/satellite surfaces. We will provide an overview of several key science and technical drivers for each scientific target and how they can be addressed with a LUVOIR facility. We also solicit community input to refine these individual programs and to identify additional areas of emphasis in the development of a final report to NASA.

  17. A millisecond pulsar in an extremely wide binary system

    NASA Astrophysics Data System (ADS)

    Bassa, C. G.; Janssen, G. H.; Stappers, B. W.; Tauris, T. M.; Wevers, T.; Jonker, P. G.; Lentati, L.; Verbiest, J. P. W.; Desvignes, G.; Graikou, E.; Guillemot, L.; Freire, P. C. C.; Lazarus, P.; Caballero, R. N.; Champion, D. J.; Cognard, I.; Jessner, A.; Jordan, C.; Karuppusamy, R.; Kramer, M.; Lazaridis, K.; Lee, K. J.; Liu, K.; Lyne, A. G.; McKee, J.; Osłowski, S.; Perrodin, D.; Sanidas, S.; Shaifullah, G.; Smits, R.; Theureau, G.; Tiburzi, C.; Zhu, W. W.

    2016-08-01

    We report on 22 yr of radio timing observations of the millisecond pulsar J1024-0719 by the telescopes participating in the European Pulsar Timing Array (EPTA). These observations reveal a significant second derivative of the pulsar spin frequency and confirm the discrepancy between the parallax and Shklovskii distances that has been reported earlier. We also present optical astrometry, photometry and spectroscopy of 2MASS J10243869-0719190. We find that it is a low-metallicity main-sequence star (K7V spectral type, [M/H] = -1.0, Teff = 4050 ± 50 K) and that its position, proper motion and distance are consistent with those of PSR J1024-0719. We conclude that PSR J1024-0719 and 2MASS J10243869-0719190 form a common proper motion pair and are gravitationally bound. The gravitational interaction between the main-sequence star and the pulsar accounts for the spin frequency derivatives, which in turn resolves the distance discrepancy. Our observations suggest that the pulsar and main-sequence star are in an extremely wide (Pb > 200 yr) orbit. Combining the radial velocity of the companion and proper motion of the pulsar, we find that the binary system has a high spatial velocity of 384 ± 45 km s-1 with respect to the local standard of rest and has a Galactic orbit consistent with halo objects. Since the observed main-sequence companion star cannot have recycled the pulsar to millisecond spin periods, an exotic formation scenario is required. We demonstrate that this extremely wide-orbit binary could have evolved from a triple system that underwent an asymmetric supernova explosion, though find that significant fine-tuning during the explosion is required. Finally, we discuss the implications of the long period orbit on the timing stability of PSR J1024-0719 in light of its inclusion in pulsar timing arrays.

  18. Complicated Structure of Interacting Young Binary System: Outflows and Gas-Streams

    NASA Astrophysics Data System (ADS)

    Pyo, Tae-Soo; Hayashi, M.; Beck, T. L.; Chris, C. J.; Takami, M.

    2014-07-01

    It is important to understand the formation and evolution of the young binary system because many young stars are born in binary or multiple systems. We report recent discovery of binary jet and wind from UY Aur system with high-angular resolution observation by using NIFS (NIR Integral Field Spectrograph) /GEMINI combined with adaptive optics system, Altair. The primary, UY Aur A, reveals widely opened wind while the secondary, UY Aur B, shows small jets in NIR [Fe II] emission. Outflows from low-mass young binary or multiple systems have been observed from a few tens of samples. Outflows are closely related mass accretion. Many simulations show an accretion flow toward the individual circumstellar disks from the outer circumbinary disk as well as a stream bridge between the circumstellar disks. We will discuss how to use TMT and ALMA for anatomy of young binary systems.

  19. Economic Evaluation of Townhouse Solar Energy System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar-energy site in Columbia, South Carolina, is comprised of four townhouse apartments. Report summarizes economic evaluation of solar--energy system and projected performance of similar systems in four other selected cities. System is designed to supply 65 percent of heating and 75 percent of hot water.

  20. Evaluating Performances of Solar-Energy Systems

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.

    1987-01-01

    CONC11 computer program calculates performances of dish-type solar thermal collectors and power systems. Solar thermal power system consists of one or more collectors, power-conversion subsystems, and powerprocessing subsystems. CONC11 intended to aid system designer in comparing performance of various design alternatives. Written in Athena FORTRAN and Assembler.

  1. Biospheres and solar system exploration

    NASA Technical Reports Server (NTRS)

    Paine, Thomas O.

    1990-01-01

    The implications of biosphere technology is briefly examined. The exploration status and prospects of each world in the solar system is briefly reviewed, including the asteroid belt, the moon, and comets. Five program elements are listed as particularly critical for future interplanetary operations during the coming extraterrestrial century. They include the following: (1) a highway to Space (earth orbits); (2) Orbital Spaceports to support spacecraft assembly, storage, repair, maintenance, refueling, launch, and recovery; (3) a Bridge Between Worlds to transport cargo and crews to the moon and beyond to Mars; (4) Prospecting and Resource Utilization Systems to map and characterize the resources of planets, moons, and asteroids; and (5) Closed Ecology Biospheres. The progress in these five field is reviewed.

  2. Modeling mergers of known galactic systems of binary neutron stars

    NASA Astrophysics Data System (ADS)

    Feo, Alessandra; De Pietri, Roberto; Maione, Francesco; Löffler, Frank

    2017-02-01

    We present a study of the merger of six different known galactic systems of binary neutron stars (BNS) of unequal mass with a mass ratio between 0.75 and 0.99. Specifically, these systems are J1756-2251, J0737-3039A, J1906  +  0746, B1534  +  12, J0453  +  1559 and B1913  +  16. We follow the dynamics of the merger from the late stage of the inspiral process up to  ∼20ms after the system has merged, either to form a hyper-massive neutron star (NS) or a rotating black hole (BH), using a semi-realistic equation of state (EOS), namely the seven-segment piece-wise polytropic SLy with a thermal component. For the most extreme of these systems (q  =  0.75, J0453  +  1559), we also investigate the effects of different EOSs: APR4, H4, and MS1. Our numerical simulations are performed using only publicly available open source code such as, the Einstein toolkit code deployed for the dynamical evolution and the LORENE code for the generation of the initial models. We show results on the gravitational wave signals, spectrogram and frequencies of the BNS after the merger and the BH properties in the two cases in which the system collapses within the simulated time.

  3. Dynamical Study of the Exoplanet Host Binary System HD 106515

    NASA Astrophysics Data System (ADS)

    Rica, F. M.; Barrena, R.; Henríquez, J. A.; Pérez, F. M.; Vargas, P.

    2017-01-01

    HD 106515 AB (STF1619 AB) is a high common proper motion and common radial velocity binary star system composed of two G-type bright stars located at 35 pc and separated by about 7 arcsec. This system was observed by the Hipparcos satellite with a precision in distance and proper motion of 3 and 2%, respectively. The system includes a circumprimary planet of nearly 10 Jupiter masses and a semimajor axis of 4.59 AU, discovered using the radial velocity method. The observational arc of 21° shows a small curvature that evidences HD 106515 AB is a gravitationally bound system. This work determines the dynamical parameters for this system which reinforce the bound status of both stellar components. We determine orbital solutions from instantaneous position and velocity vectors. In addition, we provide a very preliminary orbital solution and a distribution of the orbital parameters, obtained from the line of sight (z). Our results show that HD 106515 AB presents an orbital period of about 4 800 years, a semimajor axis of 345 AU and an eccentricity of about 0.42. Finally, we use an N-body numerical code to perform simulations and reproduce the longer term octupole perturbations on the inner orbit.

  4. Solar thermal system engineering guidebook

    NASA Astrophysics Data System (ADS)

    Selcuk, M. K.; Bluhm, S. A.

    1983-05-01

    This report presents a graphical methodology for the preliminary evaluation of solar thermal energy plants by Air Force base civil engineers. The report is organized as a Guidebook with worksheets and nomograms provided for rapid estimation of solar collector area, land area, energy output, and thermal power output of a solar thermal plant. Flat plate, evacuated tube, parabolic trough, and parabolic dish solar thermal technologies are considered.

  5. Self-organization in a system of binary strings with spatial interactions

    NASA Astrophysics Data System (ADS)

    Banzhaf, W.; Dittrich, P.; Eller, B.

    1999-01-01

    We consider an artificial reaction system whose components are binary strings. Upon encounter, two binary strings produce a third string which competes for storage space with the originators. String types or species can only survive when produced in sufficient numbers. Spatial interactions through introduction of a topology and rules for distance-dependent reactions are discussed. We observe various kinds of survival strategies of binary strings.

  6. Short review on solar energy systems

    NASA Astrophysics Data System (ADS)

    Herez, Amal; Ramadan, Mohamad; Abdulhay, Bakri; Khaled, Mahmoud

    2016-07-01

    Solar energy can be utilized mainly in heat generation and electricity production. International energy agency (IEA) shows, in a comparative study on the world energy consumption that in 2050 solar arrays installation will provide about 45% of world energy demand. Solar energy is one of the most important renewable energy source which plays a great role in providing energy solutions. As known there is wide variety of types of collectors and applications of solar energy. This paper aimed to make a short review on solar energy systems, according to types of collectors and applications used.

  7. Design of a Traditional Solar Tracking System

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader; Vasant, Pandian

    2010-06-01

    Solar energy is rapidly advancing as an important means of renewable energy resource. More energy is produced by tracking the solar panel to remain aligned to the sun at a right angle to the rays of light. This paper describes in detail the design and construction of a prototype for solar tracking system with two degrees of freedom, which detects the sunlight using photocells. The control circuit for the solar tracker is based on a PIC16F84A microcontroller (MCU). This is programmed to detect the sunlight through the photocells and then actuate the motor to position the solar panel where it can receive maximum sunlight.

  8. Implementing slab solar water heating system

    NASA Astrophysics Data System (ADS)

    Raveendran, S. K.; Shen, C. Q.

    2015-08-01

    Water heating contributes a significant part of energy consumption in typical household. One of the most employed technologies today that helps in reducing the energy consumption of water heating would be conventional solar water heating system. However, this system is expensive and less affordable by most family. The main objective of this project is to design and implement an alternative type of solar water heating system that utilize only passive solar energy which is known as slab solar water heating system. Slab solar water heating system is a system that heat up cold water using the solar radiance from the sun. The unique part of this system is that it does not require any form of electricity in order to operate. Solar radiance is converted into heat energy through convection method and cold water will be heated up by using conduction method [1]. The design of this system is governed by the criteria of low implementation cost and energy saving. Selection of material in the construction of a slab solar water heating system is important as it will directly affect the efficiency and performance of the system. A prototype has been built to realize the idea and it had been proven that this system was able to provide sufficient hot water supply for typical household usage at any given time.

  9. Satellite capture mechanism in a sun-planet-binary four-body system

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Li, Miao

    2017-02-01

    This paper studies the binary disruption problem and asteroid capture mechanism in a sun-planet-binary four-body system. Firstly, the binary disruption condition is studied and the result shows that the binary is always disrupted at the perigee of their orbit instantaneously. Secondly, an analytic expression to describe the energy exchange between the binary is derived based on the `instantaneous disruption' hypothesis. The analytic result is validated through numerical integration. We obtain the energy exchange in encounters simultaneously by the analytic expression and numerical integration. The maximum deviation of these two results is always less than 25 % and the mean deviation is about 8.69 %. The analytic expression can give us an intuitive description of the energy exchange between the binary. It indicates that the energy change depends on the hyperbolic shape of the binary orbit with respect to the planet, the masses of planet and the primary member of the binary, the binary phase at perigee. We can illustrate the capture/escape processes and give the capture/escape region of the binary clearly by numerical simulation. We analyze the influence of some critical factors to the capture region finally.

  10. Modelling of Be Disks in Binary Systems Using the Hydrodynamic Code PLUTO

    NASA Astrophysics Data System (ADS)

    Cyr, I. H.; Panoglou, D.; Jones, C. E.; Carciofi, A. C.

    2016-11-01

    The study of the gas structure and dynamics of Be star disks is critical to our understanding of the Be star phenomenon. The central star is the major force driving the evolution of these disks, however other external forces may also affect the formation of the disk, for example, the gravitational torque produced in a close binary system. We are interested in understanding the gravitational effects of a low-mass binary companion on the formation and growth of a disk in a close binary system. To study these effects, we used the grid-based hydrodynamic code PLUTO. Because this code has not been used to study such systems before, we compared our simulations against codes used in previous work on binary systems. We were able to simulate the formation of a disk in both an isolated and binary system. Our current results suggest that PLUTO is in fact a well suited tool to study the dynamics of Be disks.

  11. Installation package for a solar heating system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Installation information is given for a solar heating system installed in Concho Indian School at El Reno, Oklahoma. This package includes a system Operation and Maintenance Manual, hardware brochures, schematics, system operating modes and drawings.

  12. Influence of rotation on BN separation in binary particle system

    NASA Astrophysics Data System (ADS)

    Wu, Ping; Wang, Shuang; Xie, Ziang; Huang, Yuming; Tong, Lige; Zhang, Peikun; Yin, Shaowu; Liu, Chuanping; Wang, Li

    2013-06-01

    Granular particles systems under vertical vibration exhibit Brazilian Nut separation (BN), Reversed BN (RBN) separation or transitional phases at different vibrating conditions. In the present work, we investigate the influence of rotation on the BN separation of a binary granular particle system by changing rotational speed. 13X molecular sieve particles with diameter 6.00 mm and 0.60 mm are used. Vibration frequency f is 30 Hz and dimensionless acceleration Γ is 1.52 or 1.75, in which the particle system mainly exhibits BN separation tendency. Rotational speed ω varies from 0 to 150rpm, while the upper surface of the particle system maintains flat. We took the pictures of the particles distribution and measured the particles mass layer by layer to obtain the 3-D distribution of the particles. The results show that rotation enhances the BN separation tendency at slow rotational speed. The BN separation becomes strongest when ω is approximately 50rpm, then the BN separation tendency reduces as ω continues to increase. A butterfly pattern appears in the middle particles layer under the simultaneous stimulations of vibration and rotation.

  13. Optical Studies of model binary miscibility gap system

    NASA Technical Reports Server (NTRS)

    Lacy, L. L.; Witherow, W. K.; Facemire, B. R.; Nishioka, G. M.

    1982-01-01

    In order to develop a better understanding of separation processes in binary miscibility gap metal alloys, model transparent fluid systems were studied. The system selected was diethylene glycol-ethyl salicylate which has convenient working temperatures (288 to 350 K), low toxicity, and is relatively easy to purify. The system is well characterized with respect to its phase diagram, density, surface and interfacial tensions, viscosity and other pertinent physical properties. Studies of migration of the dispersed phase in a thermal gradient were performed using conventional photomicroscopy. Velocities of the droplets of the dispersed phase were measured and compared to calculated rates which included both Stokes and thermal components. A holographic microscopy system was used to study growth, coalescence, and particle motions. Sequential holograms allowed determination of particle size distribution changes with respect to time and temperature. Holographic microscopy is capable of recording particle densities up to 10 to the 7th power particles/cu cm and is able to resolve particles of the order of 2 to 3 microns in diameter throughout the entire volume of the test cell. The reconstructed hologram produces a wavefront that is identical to the original wavefront as it existed when the hologram was made. The reconstructed wavefront is analyzed using a variety of conventional optical methods.

  14. Orbital Parameters for Two Young Spectroscopic Binary Systems

    NASA Astrophysics Data System (ADS)

    Karnath, Nicole; Prato, L. A.; Wasserman, L. H.; Torres, G.; Mathieu, R. D.

    2013-01-01

    Orbital parameters for two young, low-mass, pre-main sequence binary systems are described. Originally, VSB 111 and VSB 126 had parameters reported based on single-lined spectroscopic solutions. High-resolution, infrared spectra were obtained with the Keck II telescope on Mauna Kea and used to identify the lines of the secondary stars, yielding double-lined orbital solutions that include the systems' mass ratios. VSB 126 has a period of 12.9247±0.0001 days, an eccentricity of 0.184±0.015, and a mass ratio of 0.27±0.01. VSB 111 has a period of 901.3062±1.1792 days, an eccentricity of 0.791±0.008, and a mass ratio of 0.60±0.06. The two systems are located in the ~3 Myr old star forming region NGC 2264, at a distance of ~800 pc. We compare the cluster age and dynamical properties of the stars in these systems with the masses and ages predicted by models of pre-main sequence evolution. Partial support for this work was provided by NSF grant AST-1009136 (to LP).

  15. Methanogens in the Solar System

    NASA Astrophysics Data System (ADS)

    Taubner, Ruth-Sophie; Schleper, Christa; Firneis, Maria G.; Rittmann, Simon

    2015-04-01

    The last decade of space science revealed that potential habitats in the Solar System may not be limited to the classical habitable zone supporting life as we know it. These microorganisms were shown to thrive under extremophilic growth conditions. Here, we outline the main eco-physiological characteristics of methanogens like their response on temperature, pressure, or pH changes or their resistance against radiation or desiccation. They can withstand extreme environmental conditions which makes them intriguing organisms for astrobiological studies. On Earth, they are found for example in wetlands, in arctic and antarctic subglacial environments, in ruminants, and even in the environment surrounding the Mars Desert Research Station in Utah. These obligate anaerobic chemolithoautotrophs or chemolithoheterotrophs are able to use e.g. hydrogen and C1 compounds like CO2, formate, or methanol as energy source and carbon source, respectively. We point out their capability to be able to habitat potential extraterrestrial biospheres all over the planetary system. We will give an overview about these possible environments on Mars, icy moons like Europa or Enceladus, and minor planets. We present an overview about studies of methanogens with an astrobiological relevance and we show our conclusions about the role of methanogens for the search for extraterrestrial life in the Solar System. We will present first results of our study about the possibility to cultivate methanogens under Enceladus-like conditions. For that, based on the observations obtained by the Cassini spacecraft concerning the plume compounds, we produce a medium with a composition similar to the ocean composition of this icy moon which is far more Enceladus-like than in any (published) experiment before. Eventually, we give an outlook on the feasibility and the necessity of future astrobiological studies with these microbes. We point out the importance of future in-situ or even sample and return missions to

  16. The Binary Fission Model for the Formation of the Pluto system

    NASA Astrophysics Data System (ADS)

    Prentice, Andrew

    2016-10-01

    The ratio F of the mass of Pluto (P) to Charon (C), viz. F ≈ 8:1, is the largest ratio of any planet-satellite pair in the solar system. Another measure of the PC binary is its normalized angular momentum density J (see McKinnon 1989). Analysis of astrometric data (Brozovic et al 2015) acquired before the New Horizons (NH) arrival at Pluto and new measurements made by NH (Stern et al 2015) show that J = 0.39. Yet these F & J values are ones expected if the PC binary had formed by the rotational fission of a single liquid mass (Darwin 1902; Lyttleton 1953). At first glance, therefore, the fission model seems to be a viable model for the formation of the Pluto system. In fact, Prentice (1993 Aust J Astron 5 111) had used this model to successfully predict the existence of several moons orbiting beyond Charon, before their discovery in 2005-2012. The main problem with the fission model is that the observed mean density of Charon, namely 1.70 g/cm3, greatly exceeds that of water ice. Charon thus could not have once been a globe of pure water. Here I review the fission model within the framework of the modern Laplacian theory of solar system origin (Prentice 1978 Moon Planets 19 341; 2006 PASA 23 1) and the NH results. I assume that Pluto and Charon were initially a single object (proto-Pluto [p-P]) which had condensed within the same gas ring shed by the proto-solar cloud at orbital distance ~43 AU, where the Kuiper belt was born. The temperature of this gas ring is 26 K and the mean orbit pressure is 1.3 × 10-9 bar. After the gas ring is shed, chemical condensation takes place. The bulk chemical composition of the condensate is anhydrous rock (mass fraction 0.5255), graphite (0.0163), water ice (0.1858), CO2 ice (0.2211) and methane ice (0.0513). Next I assume that melting of the ices in p-P takes place through the decay of short-lived radioactive nuclides, thus causing internal segregation of the rock & graphite. Settling of heavy grains to the centre lowers the

  17. Third post-Newtonian gravitational waveforms for compact binary systems in general orbits: Instantaneous terms

    NASA Astrophysics Data System (ADS)

    Mishra, Chandra Kant; Arun, K. G.; Iyer, Bala R.

    2015-04-01

    We compute the instantaneous contributions to the spherical harmonic modes of gravitational waveforms from compact binary systems in general orbits up to the third post-Newtonian (PN) order. We further extend these results for compact binaries in quasielliptical orbits using the 3PN quasi-Keplerian representation of the conserved dynamics of compact binaries in eccentric orbits. Using the multipolar post-Minkowskian formalism, starting from the different mass and current-type multipole moments, we compute the spin-weighted spherical harmonic decomposition of the instantaneous part of the gravitational waveform. These are terms which are functions of the retarded time and do not depend on the history of the binary evolution. Together with the hereditary part, which depends on the binary's dynamical history, these waveforms form the basis for construction of accurate templates for the detection of gravitational wave signals from binaries moving in quasielliptical orbits.

  18. The Solar System Beyond Neptune

    NASA Technical Reports Server (NTRS)

    Jewitt, David; Nava, David (Technical Monitor)

    2002-01-01

    This proposal supported deep and wide-field optical imaging of the trans-Neptunian Solar System capitalizing on our broad access to state-of-the-art facilities on Mauna Kea. Key quantities determined include the size distribution of Kuiper Belt objects (a differential power law with an index -4), and the inclination and radial distance distributions. We identified an outer edge to the classical Kuiper Belt that has since been confirmed by independent workers. We also obtained an assessment of the population densities in the mean-motion resonances with Neptune and discovered the Scattered Kuiper Belt Object dynamical class. Scientific issues on which these measurements have direct bearing include the collisional environment of the Kuiper Belt, the origin of the short-period comets, and the origin by capture into resonance of Pluto and other Kuiper Belt objects.

  19. Solar System Visualization (SSV) Project

    NASA Technical Reports Server (NTRS)

    Todd, Jessida L.

    2005-01-01

    The Solar System Visualization (SSV) project aims at enhancing scientific and public understanding through visual representations and modeling procedures. The SSV project's objectives are to (1) create new visualization technologies, (2) organize science observations and models, and (3) visualize science results and mission Plans. The SSV project currently supports the Mars Exploration Rovers (MER) mission, the Mars Reconnaissance Orbiter (MRO), and Cassini. In support of the these missions, the SSV team has produced pan and zoom animations of large mosaics to reveal details of surface features and topography, created 3D animations of science instruments and procedures, formed 3-D anaglyphs from left and right stereo pairs, and animated registered multi-resolution mosaics to provide context for microscopic images.

  20. Phase equilibria in the neodymium–cadmium binary system

    PubMed Central

    Skołyszewska-Kühberger, Barbara; Reichmann, Thomas L.; Ipser, Herbert

    2014-01-01

    The equilibrium phase diagram of the neodymium–cadmium system has been established by thermal, metallographic and X-ray analysis based on a study of 70 alloys. The system contains three congruently melting intermetallic compounds, i.e. NdCd (1040 °C), NdCd2 (995 °C), Nd11Cd45 (855 °C), and four incongruently melting compounds NdCd3 (860 °C), Nd13Cd58 (740 °C), NdCd6 (655 °C) and NdCd11 (520 °C). Four eutectic reactions are found in this binary system, i.e. at ∼25 at.% Cd and 770 °C, at 58 at.% Cd and 955 °C, at 79 at.% Cd and 850 °C, and very close to pure Cd at 318 °C, as well as one eutectoid reaction at ∼15 at.% Cd and 500 °C. The solid solubility of Nd in Cd is negligible. Dilatometric curves were recorded for three Nd–Cd compositions up to 4 at.% Cd, to accurately determine phase transitions between the solid solutions of Cd in the low- and high-temperature modification of Nd. PMID:25197164

  1. Phase equilibria in the neodymium-cadmium binary system.

    PubMed

    Skołyszewska-Kühberger, Barbara; Reichmann, Thomas L; Ipser, Herbert

    2014-09-05

    The equilibrium phase diagram of the neodymium-cadmium system has been established by thermal, metallographic and X-ray analysis based on a study of 70 alloys. The system contains three congruently melting intermetallic compounds, i.e. NdCd (1040 °C), NdCd2 (995 °C), Nd11Cd45 (855 °C), and four incongruently melting compounds NdCd3 (860 °C), Nd13Cd58 (740 °C), NdCd6 (655 °C) and NdCd11 (520 °C). Four eutectic reactions are found in this binary system, i.e. at ∼25 at.% Cd and 770 °C, at 58 at.% Cd and 955 °C, at 79 at.% Cd and 850 °C, and very close to pure Cd at 318 °C, as well as one eutectoid reaction at ∼15 at.% Cd and 500 °C. The solid solubility of Nd in Cd is negligible. Dilatometric curves were recorded for three Nd-Cd compositions up to 4 at.% Cd, to accurately determine phase transitions between the solid solutions of Cd in the low- and high-temperature modification of Nd.

  2. Performance evaluation of solar water sterilization system

    SciTech Connect

    Saitoh, Takeo; El-Ghetany, H.H.

    1998-07-01

    In most countries, the contaminated water is the major cause of most of the water-born diseases. Solar energy can be used in this field because the inactivation of micro-organisms is done by the ultraviolet solar radiation. A pilot solar system for sterilizing the contaminated water is designed, constructed and tested. The experimental data showed good viability for using solar energy in the sterilization process. A mathematical model of the solar sterilizer is also presented. The governing equations are solved numerically using fourth-order Runge-Kutta method. The effects of environmental conditions (ambient temperature, wind speed and solar radiation) on the solar sterilizer performance are examined. It is found that the system is affected by the ambient temperature, wind speed, ultraviolet solar radiation intensity, level of contamination of water, quantity of water being exposed, contact area between the transparent water container in the solar sterilizer and absorber plate and system geometrical parameters. It is pointed that, for a partial cloud condition, low ambient temperature and high wind speed the thermal efficiency of the solar sterilizer was minimum.

  3. Dormitory Solar-Energy-System Economics

    NASA Technical Reports Server (NTRS)

    1982-01-01

    102-page report analyzes long-term economic performance of a prepackaged solar energy assembly system at a dormitory installation and extrapolates to four additional sites about the U.S. Method of evaluation is f-chart procedure for solar-heating and domestic hotwater systems.

  4. Gamma ray observations of the solar system

    SciTech Connect

    Not Available

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  5. Gamma ray observations of the solar system

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach; and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  6. The Solar System: An Introductory Bibliography.

    ERIC Educational Resources Information Center

    Fraknoi, Andrew

    1987-01-01

    Surveys resources of astronomical information. Includes bibliographies of books and articles on the solar system in general as well as all of the bodies that occur in the solar system. Lists slide sets available from the Astronomical Society of the Pacific. (CW)

  7. Distant Comets in the Early Solar System

    DTIC Science & Technology

    2000-05-23

    the small outer solar system bodies in comparison with comets in the inner solar system and in the Kuiper Belt will give us infor- mation about the...Small Satellites This is the focus of the thesis work of G. Bauer. It is thought that the origin of the Centaurs is the L(Igeworth- Kuiper Belt , the

  8. Distant Comets in the Early Solar System

    NASA Technical Reports Server (NTRS)

    Meech, Karen J.

    2000-01-01

    The main goal of this project is to physically characterize the small outer solar system bodies. An understanding of the dynamics and physical properties of the outer solar system small bodies is currently one of planetary science's highest priorities. The measurement of the size distributions of these bodies will help constrain the early mass of the outer solar system as well as lead to an understanding of the collisional and accretional processes. A study of the physical properties of the small outer solar system bodies in comparison with comets in the inner solar system and in the Kuiper Belt will give us information about the nebular volatile distribution and small body surface processing. We will increase the database of comet nucleus sizes making it statistically meaningful (for both Short-Period and Centaur comets) to compare with those of the Trans-Neptunian Objects. In addition, we are proposing to do active ground-based observations in preparation for several upcoming space missions.

  9. Grid-connected distributed solar power systems

    NASA Astrophysics Data System (ADS)

    Moyle, R.; Chernoff, H.; Schweizer, T.

    This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

  10. An image stabilization system for solar observations

    NASA Astrophysics Data System (ADS)

    Sridharan, R.; Raja Bayanna, A.; Louis, Rohan Eugene; Kumar, Brajesh; Mathew, Shibu K.; Venkatakrishnan, P.

    2007-09-01

    An image stabilization system has been developed and demonstrated for solar observations in the visible wave-length at Udaipur Solar Observatory (USO) with a 15 cm Coudé-refractor. The softwa4re and hardware components of the system are similar to that of the low cost solar adaptive optics system developed for the 1.5 m McMath-Pierce solar telescope at Kitt Peak observatory for solar observations in the infrared. The first results presented. The system has a closed loop correction bandwidth in the range of 70 to 100 Hz. The root mean by a factor of 10 to 20. The software developes and key issues concerning optimum system performance have been addressed.

  11. Creation of an anti-imaging system using binary optics

    PubMed Central

    Wang, Haifeng; Lin, Jian; Zhang, Dawei; Wang, Yang; Gu, Min; Urbach, H. P.; Gan, Fuxi; Zhuang, Songlin

    2016-01-01

    We present a concealing method in which an anti-point spread function (APSF) is generated using binary optics, which produces a large-scale dark area in the focal region that can hide any object located within it. This result is achieved by generating two identical PSFs of opposite signs, one consisting of positive electromagnetic waves from the zero-phase region of the binary optical element and the other consisting of negative electromagnetic waves from the pi-phase region of the binary optical element. PMID:27620068

  12. Simulation of DKIST solar adaptive optics system

    NASA Astrophysics Data System (ADS)

    Marino, Jose; Carlisle, Elizabeth; Schmidt, Dirk

    2016-07-01

    Solar adaptive optics (AO) simulations are a valuable tool to guide the design and optimization process of current and future solar AO and multi-conjugate AO (MCAO) systems. Solar AO and MCAO systems rely on extended object cross-correlating Shack-Hartmann wavefront sensors to measure the wavefront. Accurate solar AO simulations require computationally intensive operations, which have until recently presented a prohibitive computational cost. We present an update on the status of a solar AO and MCAO simulation tool being developed at the National Solar Observatory. The simulation tool is a multi-threaded application written in the C++ language that takes advantage of current large multi-core CPU computer systems and fast ethernet connections to provide accurate full simulation of solar AO and MCAO systems. It interfaces with KAOS, a state of the art solar AO control software developed by the Kiepenheuer-Institut fuer Sonnenphysik, that provides reliable AO control. We report on the latest results produced by the solar AO simulation tool.

  13. DPI: Symplectic mapping for binary star systems for the Mercury software package

    NASA Astrophysics Data System (ADS)

    Turrini, D.

    2015-04-01

    DPI is a FORTRAN77 library that supplies the symplectic mapping method for binary star systems for the Mercury N-Body software package (ascl:1201.008). The binary symplectic mapping is implemented as a hybrid symplectic method that allows close encounters and collisions between massive bodies and is therefore suitable for planetary accretion simulations.

  14. Solar heated fluidized bed gasification system

    NASA Technical Reports Server (NTRS)

    Qader, S. A. (Inventor)

    1981-01-01

    A solar-powered fluidized bed gasification system for gasifying carbonaceous material is presented. The system includes a solar gasifier which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb which surrounds the fluid bed reactor zone. The high heat capacity refractory honeycomb is heated by solar energy focused on the honeycomb by solar concentrator through solar window. The fluid bed reaction zone is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb with the walls of the fluidized bed reactor. Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace is provided for start-up procedures and for supplying heat to the fluid bed reaction zone when adequate supplies of solar energy are not available.

  15. Binary random systematic erasure code for RAID system

    NASA Astrophysics Data System (ADS)

    Teng, Pengguo; Wang, Xiaojing; Chen, Liang; Yuan, Dezhai

    2017-03-01

    As the increasing expansion of data scale, storage systems grow in size and complexity, the requirements for systems scalability and methodologies to recover simultaneous disk and sector failures are inevitable. To ensure high reliability and flexible scalability, erasure codes with high fault tolerance and flexibility are required. In this pa per, we present a class of erasure codes satisfied the previous requirements, which referred as Binary Random Systematic erasure code, called BRS code for short. BRS code constructs its generator matrix based on random matrix, whose elements are in Galois Field GF (2), and takes the advantage of exclusive-or (XOR) operations to make it work much fast. It is designed as a systematic code to facilitate the store and recovery. Moreover, δ random redundancies make the probability of successfully decoding controllable. Our evaluations and experiments show that BRS code is flexible on parameters and fault tolerance setting, and has high computing efficiency on encoding and decoding speeds, what is more, when the code length is long enough, BRS code is approximately MDS, thus make it have nearly optimal storage efficiency.

  16. Temperature condensation trend in the debris-disk binary system ζ2 Reticuli

    NASA Astrophysics Data System (ADS)

    Saffe, C.; Flores, M.; Jaque Arancibia, M.; Buccino, A.; Jofré, E.

    2016-04-01

    Context. Detailed abundance studies have reported different trends between samples of stars with and without planets, possibly related to the planet formation process. Whether these differences are still present between samples of stars with and without debris disk is still unclear. Aims: We explore condensation temperature Tc trends in the unique binary system ζ1 Ret -ζ2 Ret to determine whether there is a depletion of refractories that could be related to the planet formation process. The star ζ2 Ret hosts a debris disk which was detected by an IR excess and confirmed by direct imaging and numerical simulations, while ζ1 Ret does not present IR excess or planets. These characteristics convert ζ2 Ret in a remarkable system where their binary nature together with the strong similarity of both components allow us, for the first time, to achieve the highest possible abundance precision in this system. Methods: We carried out a high-precision abundance determination in both components of the binary system via a line-by-line, strictly differential approach. First we used the Sun as a reference and then we used ζ2 Ret. The stellar parameters Teff, log g, [Fe/H], and vturb were determined by imposing differential ionization and excitation equilibrium of Fe I and Fe II lines, with an updated version of the program FUNDPAR, together with plane-parallel local thermodynamic equilibrium ATLAS9 model atmospheres and the MOOG code. We then derived detailed abundances of 24 different species with equivalent widths and spectral synthesis with the MOOG program. The chemical patterns were compared with a recently calculated solar-twins Tc trend, and then mutually between both stars of the binary system. The rocky mass of depleted refractory material was estimated according to recent data. Results: The star ζ1 Ret is found to be slightly more metal rich than ζ2 Ret by ~0.02 dex. In the differential calculation of ζ1 Ret using ζ2 Ret as reference, the abundances of the

  17. The age-metallicity relation in the solar neighbourhood from a pilot sample of white dwarf-main sequence binaries

    NASA Astrophysics Data System (ADS)

    Rebassa-Mansergas, A.; Anguiano, B.; García-Berro, E.; Freeman, K. C.; Cojocaru, R.; Manser, C. J.; Pala, A. F.; Gänsicke, B. T.; Liu, X.-W.

    2016-12-01

    The age-metallicity relation (AMR) is a fundamental observational constraint for understanding how the Galactic disc formed and evolved chemically in time. However, there is not yet an agreement on the observational properties of the AMR for the solar neighbourhood, primarily due to the difficulty in obtaining accurate stellar ages for individual field stars. We have started an observational campaign for providing the much needed observational input by using wide white-dwarf-main-sequence (WDMS) binaries. White dwarfs are `natural' clocks and can be used to derive accurate ages. Metallicities can be obtained from the main-sequence companions. Since the progenitors of white dwarfs and the main-sequence stars were born at the same time, WDMS binaries provide a unique opportunity to observationally constrain in a robust way the properties of the AMR. In this work we present the AMR derived from analysing a pilot sample of 23 WDMS binaries and provide clear observational evidence for the lack of correlation between age and metallicity at young and intermediate ages (0-7 Gyr).

  18. Solar powered desalination system using Fresnel lens

    NASA Astrophysics Data System (ADS)

    Sales, M. T. B. F.

    2016-11-01

    The Philippines is surrounded by coastal areas and these areas can be a potential source for potable water. This study aims to design and construct a solar powered desalination system using Fresnel lens. The experimental study was conducted using polluted salt water for the sample and desalination was carried out using the designed system. The desalination system was composed of the solar concentrator, solar still and the condenser system. The Fresnel lens was made of acrylic plastic and was an effective solar concentrator. Solar stills made of dark colored glass bottles were effective in absorbing the solar energy. The condenser system made of polybutylene and polystyrene were effective in condensing the vapor at ambient temperature. The shortest time of vaporization of the salt water was at 293 sec and the optimum angle of position of the lens was 36.42°. The amount of condensate collected was directly proportional to the amount of salt water in the solar still. The highest mean efficiency of the designed set-up was 34.82%. The water produced by the solar powered desalination system using Fresnel lens passed the standards set by WHO (World Health Organization) for drinking water.

  19. Life and light: exotic photosynthesis in binary and multiple-star systems.

    PubMed

    O'Malley-James, J T; Raven, J A; Cockell, C S; Greaves, J S

    2012-02-01

    The potential for Earth-like planets within binary/multiple-star systems to host photosynthetic life was evaluated by modeling the levels of photosynthetically active radiation (PAR) such planets receive. Combinations of M and G stars in (i) close-binary systems; (ii) wide-binary systems, and (iii) three-star systems were investigated, and a range of stable radiation environments were found to be possible. These environmental conditions allow for the possibility of familiar, but also more exotic, forms of photosynthetic life, such as IR photosynthesizers and organisms that are specialized for specific spectral niches.

  20. MILLIONS OF MULTIPLES: DETECTING AND CHARACTERIZING CLOSE-SEPARATION BINARY SYSTEMS IN SYNOPTIC SKY SURVEYS

    SciTech Connect

    Terziev, Emil; Law, Nicholas M.; Arcavi, Iair; Baranec, Christoph; Bui, Khanh; Dekany, Richard G.; Kulkarni, S. R.; Riddle, Reed; Tendulkar, Shriharsh P.; Bloom, Joshua S.; Burse, Mahesh P.; Chorida, Pravin; Das, H. K.; Punnadi, Sujit; Ramaprakash, A. N.; Kraus, Adam L.; Nugent, Peter; Ofek, Eran O.; Sullivan, Mark

    2013-06-01

    The direct detection of binary systems in wide-field surveys is limited by the size of the stars' point-spread functions (PSFs). A search for elongated objects can find closer companions, but is limited by the precision to which the PSF shape can be calibrated for individual stars. Based on a technique from weak-lensing analysis, we have developed the BinaryFinder algorithm to search for close binaries by using precision measurements of PSF ellipticity across wide-field survey images. We show that the algorithm is capable of reliably detecting binary systems down to Almost-Equal-To 1/5 of the seeing limit, and can directly measure the systems' position angles, separations, and contrast ratios. To verify the algorithm's performance we evaluated 100,000 objects in Palomar Transient Factory (PTF) wide-field-survey data for signs of binarity, and then used the Robo-AO robotic laser adaptive optics system to verify the parameters of 44 high-confidence targets. We show that BinaryFinder correctly predicts the presence of close companions with a <11% false-positive rate, measures the detected binaries' position angles within 1 Degree-Sign to 4 Degree-Sign (depending on signal-to-noise ratio and separation), and separations within 25%, and weakly constrains their contrast ratios. When applied to the full PTF data set, we estimate that BinaryFinder will discover and characterize {approx}450,000 physically associated binary systems with separations <2 arcsec and magnitudes brighter than m{sub R} = 18. New wide-field synoptic surveys with high sensitivity and sub-arcsecond angular resolution, such as LSST, will allow BinaryFinder to reliably detect millions of very faint binary systems with separations as small as 0.1 arcsec.

  1. Millions of Multiples: Detecting and Characterizing Close-separation Binary Systems in Synoptic Sky Surveys

    NASA Astrophysics Data System (ADS)

    Terziev, Emil; Law, Nicholas M.; Arcavi, Iair; Baranec, Christoph; Bloom, Joshua S.; Bui, Khanh; Burse, Mahesh P.; Chorida, Pravin; Das, H. K.; Dekany, Richard G.; Kraus, Adam L.; Kulkarni, S. R.; Nugent, Peter; Ofek, Eran O.; Punnadi, Sujit; Ramaprakash, A. N.; Riddle, Reed; Sullivan, Mark; Tendulkar, Shriharsh P.

    2013-06-01

    The direct detection of binary systems in wide-field surveys is limited by the size of the stars' point-spread functions (PSFs). A search for elongated objects can find closer companions, but is limited by the precision to which the PSF shape can be calibrated for individual stars. Based on a technique from weak-lensing analysis, we have developed the BinaryFinder algorithm to search for close binaries by using precision measurements of PSF ellipticity across wide-field survey images. We show that the algorithm is capable of reliably detecting binary systems down to ≈1/5 of the seeing limit, and can directly measure the systems' position angles, separations, and contrast ratios. To verify the algorithm's performance we evaluated 100,000 objects in Palomar Transient Factory (PTF) wide-field-survey data for signs of binarity, and then used the Robo-AO robotic laser adaptive optics system to verify the parameters of 44 high-confidence targets. We show that BinaryFinder correctly predicts the presence of close companions with a <11% false-positive rate, measures the detected binaries' position angles within 1° to 4° (depending on signal-to-noise ratio and separation), and separations within 25%, and weakly constrains their contrast ratios. When applied to the full PTF data set, we estimate that BinaryFinder will discover and characterize ~450,000 physically associated binary systems with separations <2 arcsec and magnitudes brighter than mR = 18. New wide-field synoptic surveys with high sensitivity and sub-arcsecond angular resolution, such as LSST, will allow BinaryFinder to reliably detect millions of very faint binary systems with separations as small as 0.1 arcsec.

  2. Indoor Astronomy: A Model Eclipsing Binary Star System.

    ERIC Educational Resources Information Center

    Bloomer, Raymond H., Jr.

    1979-01-01

    Describes a two-hour physics laboratory experiment modeling the phenomena of eclipsing binary stars developed by the Air Force Academy as part of a week-long laboratory-oriented experience for visiting high school students. (BT)

  3. The Solar System and Its Origin

    ERIC Educational Resources Information Center

    Dormand, J. R.

    1973-01-01

    Presents a brief explanation of the solar system, including planets, asteroids, satellites, comets, planetary orbits, as well as, old and recent cosmogonic theories. Indicates that man is nearer a solution to the origin of the planetary system than ever before.

  4. Solar residential heating and cooling system

    NASA Technical Reports Server (NTRS)

    Melton, D. E.; Humphries, W. R.

    1975-01-01

    System has been placed in operation to verify technical feasibility of using solar energy to provide residential heating and cooling. Complete system analysis was performed to provide design information.

  5. Despinning and Tidally Driven Tectonics in the Pluto-Charon Binary System

    NASA Astrophysics Data System (ADS)

    Barr, A. C.; Collins, G. C.

    2013-12-01

    When the New Horizons spacecraft reaches Pluto, we will have a fresh opportunity to study the effects of the tidal evolution of a binary planetary system. The Pluto-Charon system is thought to have formed from an impact between two like-sized precursor objects (Canup 2005; Canup 2011). Although each member is small, it is truly a binary system: Charon is about 1/10th the mass of Pluto and orbits at 16 Pluto radii (our moon is 1/100th the mass of the Earth and orbits at ~60 Earth radii.) The system is unique among major bodies in the solar system because it has reached the natural endpoint of its dynamical evolution: the 'dual synchronous' state in which Charon's orbital period, spin period, and Pluto's rotation period are equal. After the Charon-forming impact, tidal torques acting on each body cause the secondary to evolve rapidly to a synchronous rotation state, in which its spin and orbital period are equal. The system then evolves to the dual synchronous state over a longer time scale, lasting perhaps millions of years (Dobrovolskis et al., 1997). We use a simple model of orbital and interior evolution to show that evolution of the system into the dual-synchronous state likely created and/or maintained an ocean within Pluto, leaving behind a pattern of tectonic features on its surface consistent with de-spinning stresses. At the same time, high stresses leading to possible tectonic activity would have been created on Charon due to the collapse of its tidal and rotational bulges. Unlike prior studies of the system evolution that assume a nominal, constant Love number, we calculate frequency- and structure-dependent tidal Love numbers to estimate the magnitude of stress on Pluto and Charon, and the amount of tidal heat dissipated within Pluto. We show that the time scale for the overall evolution of the system is strongly dependent on the interior state of the primary after the satellite-forming impact. For Charon to evolve to its present-day location on a time

  6. The dynamical importance of binary systems in young massive star clusters

    NASA Astrophysics Data System (ADS)

    de Grijs, Richard; Li, Chengyuan; Geller, Aaron M.

    2017-03-01

    Characterization of the binary fractions in star clusters is of fundamental importance for many fields in astrophysics. Observations indicate that the majority of stars are found in binary systems, while most stars with masses greater than 0.5M ⊙ are formed in star clusters. In addition, since binaries are on average more massive than single stars, in resolved star clusters these systems are thought to be good tracers of (dynamical) mass segregation. Over time, dynamical evolution through two-body relaxation will cause the most massive objects to migrate to the cluster center, while the relatively lower-mass objects remain in or migrate to orbits at greater radii. This process will globally dominate a cluster's stellar distribution. However, close encounters involving binary systems may disrupt `soft' binaries. This process will occur more frequently in a cluster's central, dense region than in its periphery, which may mask the effects of mass segregation. Using high resolution Hubble Space Telescope observations, combined with sophisticated N-body simulations, we investigate the radial distributions of the main-sequence binary fractions in massive young Large Magellanic Cloud star clusters. We show that binary disruption may play an important role on very short timescales, depending on the environmental conditions in the cluster cores. This may lead to radial binary fractions that initially decline in the cluster centers, which is contrary to the effects expected from dynamical mass segregation.

  7. Solar heating system installed at Stamford, Connecticut

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The solar heating system installed at the Lutz-Sotire Partnership Executive East Office Building, Stamford, Connecticut is described. The Executive East Office Building is of moderate size with 25,000 sq ft of heated space in 2 1/2 stories. The solar system was designed to provide approximately 50 percent of the heating requirements. The system components are described. Appended data includes: the system design acceptance test, the operation and maintenance manual, and as-built drawings and photographs.

  8. High voltage solar cell power generating system

    NASA Technical Reports Server (NTRS)

    Levy, E., Jr.; Opjorden, R. W.; Hoffman, A. C.

    1974-01-01

    A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kW), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2,560 series-connected cells. Each light source consists of twenty 500-watt tungsten iodide lamps providing plus or minus 5 percent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water-cooled plate, a vacuum hold-down system, and air flushing.

  9. DISCOVERY OF A BINARY SYSTEM IN IRAM 04191+1522

    SciTech Connect

    Chen Xuepeng; Arce, Hector G.; Dunham, Michael M.; Zhang Qizhou

    2012-03-10

    We present high angular resolution observations of the Class 0 protostar IRAM 04191+1522 using the Submillimeter Array (SMA). The SMA 1.3 mm continuum images reveal within IRAM 04191+1522 two distinct sources with an angular separation of 7.''8 {+-} 0.''2. The two continuum sources are located in the southeast-northwest direction, with total gas masses of {approx}0.011 M{sub Sun} and {approx}0.005 M{sub Sun }, respectively. The southeastern source, associated with an infrared source seen in the Spitzer images, is the well-known Class 0 protostar with a bolometric luminosity of {approx}0.08 L{sub Sun }. The newly discovered northwestern continuum source is not visible in the Spitzer images at wavelengths from 3.6 to 70 {mu}m and has an extremely low bolometric luminosity (<0.03 L{sub Sun }). Complementary IRAM N{sub 2}H{sup +} (1-0) data that probe the dense gas in the common envelope suggest that the two sources were formed through the rotational fragmentation of an elongated dense core. Furthermore, comparisons between IRAM 04191+1522 and other protostars suggest that most cores with binary systems formed therein have ratios of rotational energy to gravitational energy {beta}{sub rot} > 1%. This is consistent with theoretical simulations and indicates that the level of rotational energy in a dense core plays an important role in the fragmentation process.

  10. Poster: Water transport into circumprimary habitable zones in binary star systems

    NASA Astrophysics Data System (ADS)

    Bancelin, D.; Pilat-Lohinger, E.; Maindl, T. I.; Eggl, S.; Dvorak, R.

    2015-07-01

    So far, multiple stellar systems harbor more than 100 extra solar planets. Dynamical simulations show that the outcome of planetary formation process can lead to various planetary architectures (i.e. location, size, mass and water content) when the star system is single or double. In the late phase of planetary formation, when embryos-sized objects dominate the inner region of the system, asteroids are also present and can provide additional material for objects inside the habitable zone (HZ). In this study, we make a comparison of several binary star systems and their efficiency to move icy asteroids from beyond the snow-line into orbits crossing the HZ. We modeled a belt of 10000 asteroids (remnants from the late phase of planetary formation process) beyond the snow-line. The planetesimals are placed randomly around the primary star and move under the gravitational influence of the two stars and a gas giant. In our results, we highlight the key role of secular and mean motion resonances, causing an efficient flux of asteroids to the HZ on a short timescale. This in turn leads to asteroids bearing a non negligeable amount of water to the HZ and for any planets or embryos moving in this area. We also discuss how mass loss mechanisms can alter the water content on asteroids' surface.

  11. Solar System and stellar tests of noncommutative spectral geometry

    NASA Astrophysics Data System (ADS)

    Deng, Xue-Mei

    2017-02-01

    By using purely geometric forces on a noncommutative spacetime, noncommutative spectral geometry (NCSG) was proposed as a possible way to unify gravitation with the other known fundamental forces. The correction of the NCSG solution to Einstein's general relativity (GR) in the four-dimensional spacetime can be characterized by a parameter β∼1/f0-√β∼1/f0, where f0f0 denotes the coupling constants at the unification. The parameter ββ contributes a Yukawa-type correction exp(-βr)/rexp(-βr)/r to the Newtonian gravitational potential at the leading order, which can be interpreted as either the massive component of the gravitational field or the typical range of interactions carried by that component of the field. As an extension of previous works, we mainly focus on the Solar System and stellar tests of the theory, and the constraints on ββ obtained by the present work is independent of the previous ones. In the Solar System, we investigate the effects of the NCSG on the perihelion shift of a planet, deflection of light, time delay at superior conjunction (SC) and inferior conjunction (IC), and the Cassini experiment by modeling new observational results and adopting new datasets. In the binary pulsars system, based on the observational data sets of four systems of binary pulsars, PSR B1913+16, PSR B1534+12, PSR J0737-3039, and PSR B2127+11C, the secular periastron precessions are used to constrain this theory. These effects in the scale of the Solar System and binary pulsars were not considered in previous works. We find that the lower bounds given by these experiments are β≃10-9∼10-10β≃10-9∼10-10 m-1, considerably smaller than those obtained in laboratory experiments. This confirms that experiments and observations at smaller scales are more favorable for testing the NCSG theory.

  12. The shortest period detached binary white dwarf system

    NASA Astrophysics Data System (ADS)

    Kilic, Mukremin; Brown, Warren R.; Kenyon, S. J.; Allende Prieto, Carlos; Andrews, J.; Kleinman, S. J.; Winget, K. I.; Winget, D. E.; Hermes, J. J.

    2011-05-01

    We identify SDSS J010657.39-100003.3 (hereafter J0106-1000) as the shortest period detached binary white dwarf (WD) system currently known. We targeted J0106-1000 as part of our radial velocity programme to search for companions around known extremely low-mass (ELM; ˜0.2 M⊙) WDs using the 6.5-m Multiple Mirror Telescope. We detect peak-to-peak radial velocity variations of 740 km s-1 with an orbital period of 39.1 min. The mass function and optical photometry rule out a main-sequence star companion. Follow-up high-speed photometric observations obtained at the McDonald 2.1-m telescope reveal ellipsoidal variations from the distorted primary but no eclipses. This is the first example of a tidally distorted WD. Modelling the light curve, we constrain the inclination angle of the system to be 67°± 13°. J0106-1000 contains a pair of WDs (0.17 M⊙ primary + 0.43 M⊙ invisible secondary) at a separation of 0.32 R⊙. The two WDs will merge in 37 Myr and most likely form a core He-burning single subdwarf star. J0106-1000 is the shortest time-scale merger system currently known. The gravitational wave strain from J0106-1000 is at the detection limit of the Laser Interferometer Space Antenna (LISA). However, accurate ephemeris and orbital period measurements may enable LISA to detect J0106-1000 above the Galactic background noise. Based on observations obtained at the Multiple Mirror Telescope (MMT) Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.

  13. Doubled-lined eclipsing binary system KIC~2306740 with pulsating component discovered from Kepler space photometry

    NASA Astrophysics Data System (ADS)

    Yakut, Kadri

    2015-08-01

    We present a detailed study of KIC 2306740, an eccentric double-lined eclipsing binary system with a pulsating component.Archive Kepler satellite data were combined with newly obtained spectroscopic data with 4.2\\,m William Herschel Telescope(WHT). This allowed us to determine rather precise orbital and physical parameters of this long period, slightly eccentric, pulsating binary system. Duplicity effects are extracted from the light curve in order to estimate pulsation frequencies from the residuals.We modelled the detached binary system assuming non-conservative evolution models with the Cambridge STARS(TWIN) code.

  14. HST/COS FUV Spectrophotometry of the Key Binary Solar Twins 16 Cyg A&B: Astrophysical Laboratories for the Future Sun and Older Solar Analogs

    NASA Astrophysics Data System (ADS)

    Guinan, Edward

    2014-10-01

    The fortuitous location of the wide G1.5V/G2.5V binary 16 Cyg A&B as the brightest stars in the Kepler Field is a "game changer," permitting the determination of the stars' fundamental properties from asteroseismolgy analyses. Recent studies returned precise determinations of the stars' basic properties including masses and age (6.8+/-0.4 Gyr), along with the rotation periods. Thus, 16 Cyg A&B are now the oldest solar-mass analogs with reliable ages and physical properties. Only the Sun has better determined physical properties. 16 Cyg A&B now serve as old-age anchors for Rotation-Age-Activity-Irradiance relations (and Gyrochronology studies) for solar-type stars. Extensive Ca II HK spectrophotometry reveals low levels of chromospheric emission are below the lowest values for our Sun. These stars serve as critical test beds for studying solar/stellar dynamos for stars less active than the Sun. These advances have catapulted 16 Cyg A&B into a prominent place in solar/stellar astrophysics for studying the evolution, internal structure, magnetic dynamos, angular momentum loss, and FUV irradiances of old solar-mass stars. Although 16 Cyg has been observed from X-ray - IR, there are no observations in the FUV region where most of the crucial diagnostic chromospheric & transition region emissions occur. We request COS FUV medium resolution (G130M, G160M) spectra (six orbits/star). This permits the important FUV (1150-1750A) line emission strengths, profiles and Doppler shifts to be analyzed and compared with the Sun and other solar-analogs. This program is complemented by Ca II HK, high precision uvby observations, and by proposed Chandra X-ray coronal observations.

  15. Cancer-specific binary expression system activated in mice by bacteriophage HK022 Integrase

    PubMed Central

    Elias, Amer; Spector, Itay; Sogolovsky-Bard, Ilana; Gritsenko, Natalia; Rask, Lene; Mainbakh, Yuli; Zilberstein, Yael; Yagil, Ezra; Kolot, Mikhail

    2016-01-01

    Binary systems based on site-specific recombination have been used for tumor specific transcription targeting of suicide genes in animal models. In these binary systems a site specific recombinase or integrase that is expressed from a tumor specific promoter drives tumor specific expression of a cytotoxic gene. In the present study we developed a new cancer specific binary expression system activated by the Integrase (Int) of the lambdoid phage HK022. We demonstrate the validity of this system by the specific expression of a luciferase (luc) reporter in human embryonic kidney 293T (HEK293T) cells and in a lung cancer mouse model. Due to the absence viral vectors and of cytotoxicity the Int based binary system offers advantages over previously described counterparts and may therefore be developed into a safer cancer cell killing system. PMID:27117628

  16. Investigating Exoplanet Orbital Evolution Around Binary Star Systems with Mass Loss

    NASA Astrophysics Data System (ADS)

    Rahoma, Walid A.

    2016-12-01

    A planet revolving around binary star system is a familiar system. Studies of these systems are important because they provide precise knowledge of planet formation and orbit evolution. In this study, a method to determine the evolution of an exoplanet revolving around a binary star system using different rates of stellar mass loss will be introduced. Using a hierarchical triple body system, in which the outer body can be moved with the center of mass of the inner binary star as a two-body problem, the long period evolution of the exoplanet orbit is determined depending on a Hamiltonian formulation. The model is simulated by numerical integrations of the Hamiltonian equations for the system over a long time. As a conclusion, the behavior of the planet orbital elements is quite affected by the rate of the mass loss from the accompanying binary star.

  17. Non-tracking solar energy collector system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1978-01-01

    A solar energy collector system characterized by an improved concentrator for directing incident rays of solar energy on parallel vacuum-jacketed receivers or absorbers is described. Numerous individually mounted reflector modules of a common asymmetrical triangular cross-sectional configuration are supported for independent reorientation. Asymmetric vee-trough concentrators are defined.

  18. Combined solar collector and energy storage system

    NASA Technical Reports Server (NTRS)

    Jensen, R. N. (Inventor)

    1980-01-01

    A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

  19. Prototype solar heating and hot water system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Progress is reported in the development of a solar heating and hot water system which uses a pyramidal optics solar concentrator for heating, and consists of the following subsystems: collector, control, transport, and site data acquisition. Improvements made in the components and subsystems are discussed.

  20. The Solar System primordial lead

    NASA Astrophysics Data System (ADS)

    Blichert-Toft, Janne; Zanda, Brigitte; Ebel, Denton S.; Albarède, Francis

    2010-11-01

    Knowledge of the primordial isotope composition of Pb in the Solar System is critical to the understanding of the early evolution of Earth and other planetary bodies. Here we present new Pb isotopic data on troilite (FeS) nodules from a number of different iron meteorites: Canyon Diablo, Mundrabilla, Nantan, Seeläsgen, Toluca (IAB-IIICD), Cape York (IIIA), Mt Edith (IIIB), and Seymchan (pallasite). Lead abundances and isotopic compositions typically vary from one troilite inclusion to another, even within the same meteorite. The most primitive Pb was found in three leach fractions of two exceptionally Pb-rich Nantan troilite nodules. Its 204Pb/ 206Pb is identical to that of Canyon Diablo troilite as measured by Tatsumoto et al. [M. Tatsumoto, R.J. Knight, C.J. Allègre, Time differences in the formation of meteorites as determined from the ratio of lead-207 to lead-206, Science 180(1973) 1279-1283]. However, our measurements of 207Pb/ 206Pb and 208Pb/ 206Pb are significantly higher than theirs, as well as other older literature data obtained by TIMS, while consistent with the recent data of Connelly et al. [J.N. Connelly, M. Bizzarro, K. Thrane, J.A. Baker, The Pb-Pb age of Angrite SAH99555 revisited, Geochim. Cosmochim. Acta 72(2008) 4813-4824], a result we ascribe to instrumental mass fractionation having biased the older data. Our current best estimate of the Solar System primordial Pb is that of Nantan troilite, which has the following isotopic composition: 204Pb/ 206Pb = 0.107459(16), 207Pb/ 206Pb = 1.10759(10), and 208Pb/ 206Pb = 3.17347(28). This is slightly less radiogenic than the intercept of the bundle of isotopic arrays formed in 207Pb/ 206Pb- 204Pb/ 206Pb space by our measurements of Canyon Diablo, Nantan, Seeläsgen, Cape York, and Mundrabilla, as well as literature data, which, in spite of rather large uncertainties, suggests a common primordial Pb component for all of these meteorites. The radiogenic Pb present in most of these irons is dominantly

  1. SIM Lite Detection of Habitable Planets in P-Type Binary-Planetary Systems

    NASA Technical Reports Server (NTRS)

    Pan, Xiaopei; Shao, Michael; Shaklan, Stuart; Goullioud, Renaud

    2010-01-01

    Close binary stars like spectroscopic binaries create a completely different environment than single stars for the evolution of a protoplanetary disk. Dynamical interactions between one star and protoplanets in such systems provide more challenges for theorists to model giant planet migration and formation of multiple planets. For habitable planets the majority of host stars are in binary star systems. So far only a small amount of Jupiter-size planets have been discovered in binary stars, whose minimum separations are 20 AU and the median value is about 1000 AU (because of difficulties in radial velocity measurements). The SIM Lite mission, a space-based astrometric observatory, has a unique capability to detect habitable planets in binary star systems. This work analyzed responses of the optical system to the field stop for companion stars and demonstrated that SIM Lite can observe exoplanets in visual binaries with small angular separations. In particular we investigated the issues for the search for terrestrial planets in P-type binary-planetary systems, where the planets move around both stars in a relatively distant orbit.

  2. Communicating across the solar system

    NASA Technical Reports Server (NTRS)

    Reid, M. S.; Lyman, P. T.; Force, C. T.

    1984-01-01

    The exploration of the solar system by means of spacecraft would not be possible in its present form without the art and science of communications. Particularly exacting requirements arise in connection with the study of the planets and the interplanetary medium beyond the orbit of Jupiter. Developments in technology providing the required communication capability are partly based on the principle of the phase-locked loop as a narrow-band tracking filter. Mission objectives and performance are discussed for Pioneers 10 and 11 and Voyagers 1 and 2 which at present are the only spacecraft beyond the orbit of Jupiter. A description is given of challenges related to communication in the case of the passage of Voyager 2 near Uranus in 1986 and near Neptune in 1989, taking into account the approaches employed to meet these challenges. Attention is given to requirements concerning international cooperation regarding the ground network, the development of interagency and intra-agency arraying, and the improvement of antenna efficiency.

  3. Binary Plutinos

    NASA Astrophysics Data System (ADS)

    Noll, Keith S.

    2015-08-01

    The Pluto-Charon binary was the first trans-neptunian binary to be identified in 1978. Pluto-Charon is a true binary with both components orbiting a barycenter located between them. The Pluto system is also the first, and to date only, known binary with a satellite system consisting of four small satellites in near-resonant orbits around the common center of mass. Seven other Plutinos, objects in 3:2 mean motion resonance with Neptune, have orbital companions including 2004 KB19 reported here for the first time. Compared to the Cold Classical population, the Plutinos differ in the frequency of binaries, the relative sizes of the components, and their inclination distribution. These differences point to distinct dynamical histories and binary formation processes encountered by Plutinos.

  4. Optimal control studies of solar heating systems

    SciTech Connect

    Winn, C B

    1980-01-01

    In the past few years fuel prices have seen steady increases. Also, the supply of fuel has been on the decline. Because of these two problems there has been an increase in the number of solar heated buildings. Since conventional fuel prices are increasing and as a solar heating system represents a high capital cost it is desirable to obtain the maximum performance from a solar heating system. The control scheme that is used in a solar heated building has an effect on the performance of the solar system. The best control scheme possible would, of course, be desired. This report deals with the control problems of a solar heated building. The first of these problems is to control the inside temperature of the building and to minimize the fuel consumption. This problem applies to both solar and conventionally heated buildings. The second problem considered is to control the collector fluid flow to maximize the difference between the useful energy collected and the energy required to pump the fluid. The third problem is to control the enclosure temperature of a building which has two sources of heat, one solar and the other conventional.

  5. Detection of a white dwarf in a visual binary system

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1980-01-01

    The F6 giant HD 160365 was detected to have a white dwarf companion about 8 arcsec south of the star. The UV energy distribution observed with International Ultraviolet Explorer (IUE) shows that the white dwarf has an effective temperature of 23,000 +/- 2,000 K. If log g = 8 the Ly(alpha) profile indicates an effective temperature around 24,500 K. Using the theoretical models, one finds a visual magnitude of m(sub v) is approximately 16.5. For T(sub eff) = 24,500 K one expects for a white dwarf a luminosity of log L/solar luminosity is approximately -1.3 and M(sub V) is approximately 10.67. This gives a distance modulus for the system of m(sub v) - M(sub V) = 5.83 and an absolute magnitude M(sub v) = 0.3 for the giant.

  6. Detection of a white dwarf in a visual binary system

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1992-01-01

    The F6 giant HD 160365 was detected to have a white dwarf companion about 8 arcsec south of the star. The UV energy distribution observed with IUE shows that the white dwarf has an effective temperature of 23,000 +/- 2000 K. If log g = 8 the Lya profile indicates an effective temperature around 24,500 K. Using the theoretical models by Wesemael et al. (1980) one finds a visual magnitude of m(V) about 16.5. For T(eff) = 24,500 K one expects for a white dwarf a luminosity of log L/L(solar) about 1.3 and M(V) about 10.67. This gives a distance modulus for the system of m(V) - M(V) = 5.83 and an absolute magnitude M(V)= 0.3 for the giant.

  7. Development of Solar Powered Irrigation System

    NASA Astrophysics Data System (ADS)

    Abdelkerim, A. I.; Sami Eusuf, M. M. R.; Salami, M. J. E.; Aibinu, A.; Eusuf, M. A.

    2013-12-01

    Development of a solar powered irrigation system has been discussed in this paper. This system would be SCADA-based and quite useful in areas where there is plenty of sunshine but insufficient water to carry out farming activities, such as rubber plantation, strawberry plantation, or any plantation, that requires frequent watering. The system is powered by solar system as a renewable energy which uses solar panel module to convert Sunlight into electricity. The development and implementation of an automated SCADA controlled system that uses PLC as a controller is significant to agricultural, oil and gas monitoring and control purpose purposes. In addition, the system is powered by an intelligent solar system in which solar panel targets the radiation from the Sun. Other than that, the solar system has reduced energy cost as well as pollution. The system is equipped with four input sensors; two soil moisture sensors, two level detection sensors. Soil moisture sensor measures the humidity of the soil, whereas the level detection sensors detect the level of water in the tank. The output sides consist of two solenoid valves, which are controlled respectively by two moistures sensors.

  8. Terrestrial Planet Formation Around Close Binary Stars

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Quintana, Elisa V.

    2003-01-01

    Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets around close binary stars, using a new, ultrafast, symplectic integrator that we have developed for this purpose. The sum of the masses of the two stars is one solar mass, and the initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and in the Alpha Centauri wide binary star system. Giant planets &are included in the simulations, as they are in most simulations of the late stages of terrestrial planet accumulation in our Solar System. When the stars travel on a circular orbit with semimajor axis of up to 0.1 AU about their mutual center of mass, the planetary embryos grow into a system of terrestrial planets that is statistically identical to those formed about single stars, but a larger semimajor axis and/or a significantly eccentric binary orbit can lead to significantly more dynamically hot terrestrial planet systems.

  9. TYPE Ib/c SUPERNOVAE IN BINARY SYSTEMS. I. EVOLUTION AND PROPERTIES OF THE PROGENITOR STARS

    SciTech Connect

    Yoon, S.-C.; Woosley, S. E.

    2010-12-10

    We investigate the evolution of Type Ib/c supernova (SN Ib/c) progenitors in close binary systems, using new evolutionary models that include the effects of rotation, with initial masses of 12-25 M{sub sun} for the primary components, and of single helium stars with initial masses of 2.8-20 M{sub sun}. We find that, despite the impact of tidal interaction on the rotation of primary stars, the amount of angular momentum retained in the core at the presupernova stage in different binary model sequences converges to a value similar to those found in previous single star models. This amount is large enough to produce millisecond pulsars, but too small to produce magnetars or long gamma-ray bursts. We employ the most up-to-date estimate for the Wolf-Rayet mass-loss rate, and its implications for SN Ib/c progenitors are discussed in detail. In terms of stellar structure, SN Ib/c progenitors in binary systems at solar metallicity are predicted to have a wide range of final masses up to about 7 M{sub sun}, with helium envelopes of M{sub He} {approx_equal} 0.16-1.5 M{sub sun}. Our results indicate that, if the lack of helium lines in the spectra of SNe Ic were due to small amounts of helium (e.g., M{sub He} {approx}< 0.5), the distribution of both initial and final masses of SN Ic progenitors should be bimodal. Furthermore, we find that a thin hydrogen layer (0.001 M{sub sun} {approx}< M{sub H} {approx}< 0.01 M{sub sun}) is expected to be present in many SN Ib progenitors at the presupernova stage. We show that the presence of hydrogen, together with a rather thick helium envelope, can lead to a significant expansion of some SN Ib/c progenitors by the time of supernova explosion. This may have important consequences for the shock break-out and supernova light curve. We also argue that some SN progenitors with thin hydrogen layers produced via Case AB/B transfer might be related to Type IIb supernova progenitors with relatively small radii of about 10 R{sub sun}.

  10. Demonstration of portable solar adaptive optics system

    NASA Astrophysics Data System (ADS)

    Ren, Deqing; Dong, Bing

    2012-10-01

    Solar-adaptive optics (AO) are more challenging than night-time AO, in some aspects. A portable solar adaptive optics (PSAO) system featuring compact physical size, low cost, and good performance has been proposed and developed. PSAO can serve as a visiting instrument for any existing ground-based solar telescope to improve solar image quality by replacing just a few optical components. High-level programming language, LabVIEW, is used to develop the wavefront sensing and control software, and general purpose computers are used to drive the whole system. During October 2011, the feasibility and good performance of PSAO was demonstrated with the 61-cm solar telescope at San Fernando Observatory. The image contrast and resolution are noticeably improved after AO correction.

  11. Solar passive systems for buildings

    NASA Astrophysics Data System (ADS)

    1980-03-01

    A survey is provided of what is known about the design of solar passive buildings. A systematic presentation is given of proven concepts with suitable illustrations. It is intended as a general guide for architects, designers and other building practitioners. Topics include the various concepts of solar passive heating and cooling, design factors such as location, climate, microclimate, form; building metabolism, thermal and visual comfort; location and form of illumination; and natural cooling via wind towers and cisterns.

  12. Evolution of Intermediate and Low Mass Binary Systems

    SciTech Connect

    Eggleton, P P

    2005-10-25

    There are a number of binaries, fairly wide and with one or even two evolved giant components, that do not agree very well with conventional stellar evolution: the secondaries are substantially larger (oversized) than they should be because their masses are quite low compared with the primaries. I discuss the possibility that these binaries are former triples, in which a merger has occurred fairly recently in a short-period binary sub-component. Some mergers are expected, and may follow a phase of contact evolution. I suggest that in contact there is substantial transfer of luminosity between the components due to differential rotation, of the character observed by helioseismology in the Sun's surface convection zone.

  13. Hi Observations of the Supermassive Binary Black Hole System in 0402+379

    DTIC Science & Technology

    2009-05-20

    Printed in the U.S.A. H i OBSERVATIONS OF THE SUPERMASSIVE BINARY BLACK HOLE SYSTEM IN 0402+379 C. Rodriguez1, G. B. Taylor1,5, R. T. Zavala2, Y. M...April 30 ABSTRACT We have recently discovered a supermassive binary black hole system with a projected separation between the two black holes of 7.3 pc in...the radio galaxy 0402+379 (Rodriguez et al. 2006). This is the most compact supermassive binary black hole pair yet imaged by more than two orders of

  14. An interacting binary system powers precessing outflows of an evolved star.

    PubMed

    Boffin, Henri M J; Miszalski, Brent; Rauch, Thomas; Jones, David; Corradi, Romano L M; Napiwotzki, Ralf; Day-Jones, Avril C; Köppen, Joachim

    2012-11-09

    Stars are generally spherical, yet their gaseous envelopes often appear nonspherical when ejected near the end of their lives. This quirk is most notable during the planetary nebula phase, when these envelopes become ionized. Interactions among stars in a binary system are suspected to cause the asymmetry. In particular, a precessing accretion disk around a companion is believed to launch point-symmetric jets, as seen in the prototype Fleming 1. Our finding of a post-common-envelope binary nucleus in Fleming 1 confirms that this scenario is highly favorable. Similar binary interactions are therefore likely to explain these kinds of outflows in a large variety of systems.

  15. BVRI Photometric 2015 WD Analysis of the Southern Totally Eclipsing, Solar-type, Shallow-contact W UMa Binary, DD Indus

    NASA Astrophysics Data System (ADS)

    Samec, Ronald G.; Norris, Cody L.; Van Hamme, Walter; Faulkner, Danny R.; Hill, Robert L.

    2016-12-01

    Observations and a 2015 Wilson-Devinney Program analysis are undertaken for the first precision observations of DD Indi. DD Indi is of solar-type (T 1 ˜ 5750 K) and was determined to be a shallow-contact eclipsing binary. It was observed from 2013 June through September at Cerro Tololo InterAmerican Observatory in remote mode. The 24 inch Boller and Chivens reflector, now under management by The Southeastern Association for Resarch in Astronomomy (SARA) was used. Five new eclipse timings were obtained, for three primary and two secondary eclipses. Seven more eclipse timings were calculated from All Sky Automated Survey data. A possibly increasing period was found from all available eclipse timings with a 5 ± 2 × 10-11 × E 2 quadratic term. A BVR c I c simultaneous synthetic light-curve analysis reveals that the system has a mass ratio of ˜0.46, a ˜ 140 K component temperature difference, and two weak cool spots. The Roche Lobe fill-out of this W-type binary is only ˜11%, and an inclination of ˜86° was determined. A time of constant light of ˜16 minutes is measured around phase zero. More detail is included in this report.

  16. A SURVEY OF THE HIGH ORDER MULTIPLICITY OF NEARBY SOLAR-TYPE BINARY STARS WITH Robo-AO

    SciTech Connect

    Riddle, Reed L.; Bui, Khanh; Dekany, Richard G.; Kulkarni, Shrinivas; Tendulkar, Shriharsh P.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Roberts, Lewis C. Jr.; Baranec, Christoph; Law, Nicholas M.; Burse, Mahesh P.; Das, H. K.; Punnadi, Sujit; Ramaprakash, A. N.

    2015-01-20

    We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the Sloan Digital Sky Survey i' band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over 10'' to quantify the still poorly constrained frequency of their subsystems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary subsystems with periods from 10{sup 3.5} to 10{sup 5} days is 0.12 ± 0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of subsystems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100 yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a subsample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from 10{sup 6} to 10{sup 7.5} days (separations on the order of 500 AU), the frequency of tertiary components is 0.16 ± 0.03, exceeding the frequency of similar systems among all targets (0.09) by almost a factor of two. Measurements of binary stars with Robo-AO allowed us to compute first orbits for 9 pairs and to improve orbits of another 11 pairs.

  17. A Survey of the High Order Multiplicity of Nearby Solar-type Binary Stars with Robo-AO

    NASA Astrophysics Data System (ADS)

    Riddle, Reed L.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Roberts, Lewis C., Jr.; Baranec, Christoph; Law, Nicholas M.; Bui, Khanh; Burse, Mahesh P.; Das, H. K.; Dekany, Richard G.; Kulkarni, Shrinivas; Punnadi, Sujit; Ramaprakash, A. N.; Tendulkar, Shriharsh P.

    2015-01-01

    We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the Sloan Digital Sky Survey i' band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over 10'' to quantify the still poorly constrained frequency of their subsystems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary subsystems with periods from 103.5 to 105 days is 0.12 ± 0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of subsystems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100 yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a subsample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from 106 to 107.5 days (separations on the order of 500 AU), the frequency of tertiary components is 0.16 ± 0.03, exceeding the frequency of similar systems among all targets (0.09) by almost a factor of two. Measurements of binary stars with Robo-AO allowed us to compute first orbits for 9 pairs and to improve orbits of another 11 pairs.

  18. Follow-up Observations and Analysis of V530 Andromedae: A Totally Eclipsing Shallow Contact Solar Type Binary

    NASA Astrophysics Data System (ADS)

    Chamberlain, Heather; Samec, Ronald G.; Caton, Daniel B.; Faulkner, Danny R.; Clark, Jeremy; Shebs, Travis

    2015-01-01

    We follow up on early, single coverage, UBVRcIc light curves (2013) and analyses. These early curves were taken in September 27 and 29 2011. Our present, BVRcIc, but full coverage light curves were taken on 6 nights: October 1,2,9, November 4,5, 2013 and January 4, 2014 by RGS, DBC, JDC, TS with the Dark Sky Observatory 0.81-m reflector of Appalachian State University and a (-40ºC) 2KX2K Apogee Alta CCD. Our present curves reveal V530 Andromedae as a totally eclipsing, shallow contact solar type binary rather than semidetached, near contact one. The newly determined times of minima include:HJD MinI = 2456566.84275 ±0.00007HJD MinII = 2456598.881995±0.0004, 24556600.6111±0.0002, 2456601.76665±0.00046.Using a new method of obtaining minima from earlier patrol light curves, in this case, NSVS, nine low weight timings of minimum light were added to the period study. Including these additional timings, we uncovered a period change. In our now, extended, period study over 9000 epochs, a 14.25 year interval, we find that the period is decreasing. This fits the scenario of magnetic breaking for solar type binaries. The temperatures of the primary and secondary components are estimated at 7000 and 6300 K, respectively, a large temperature difference for a contact binary. The fill-out, however, is a mere 4%. (Our earlier scant light curves modeled very nearly in contact.) The mass ratio, M2/M1, was found to be 0.385, almost identical with our first curves solution. The two star spots, probably magnetic in origin, were determined. A hot spot was modeled by the iterative process on the polar region of the smaller star. A cool spot is on the larger star facing the smaller star. The spot parameters have changed appreciably over the course of the two intervening years. We believe the binary has recently come into contact and thermal contact has not yet been achieved.

  19. The near-infrared properties of compact binary systems

    NASA Astrophysics Data System (ADS)

    Froning, Cynthia Suzanne

    , the light curve has a hump outside of primary eclipse which was modeled as flux from the secondary star when irradiated by a 0.2-0.3 Lsolar source. The light curve has a dip at φ = 0.5 which is consistent with an eclipse of the irradiated face of the secondary star by an opaque accretion disk. The accretion disk has a brightness temperature profile much flatter than the theoretical profile of a steady- state disk. The disk is asymmetric, with the front of the disk (the side facing the secondary star at mid-eclipse) hotter than the back. The bright spot, which appears in visible disk maps of SW Sex, is not seen in the NIR light curve. I also present H-band light curves of the X-ray binary system, A0620-00, and NIR spectra of two X-ray binaries, CI Cam, and the relativistic jet source, SS 433. (Abstract shortened by UMI.)

  20. Flaring Black Hole Accretion Disk in the Binary System V404 Cygni

    NASA Video Gallery

    On June 15, NASA's Swift caught the onset of a rare X-ray outburst from a stellar-mass black hole in the binary system V404 Cygni. Astronomers around the world are watching the event. In this syste...

  1. Titration of selected bases in benzene-acetonitrile binary solvent system.

    PubMed

    Amirjahed, K; al-Khamis, K I

    1980-10-01

    The benzene-acetonitrile binary solvent system was used in the determination of the half-neutralization potentials (hnp) of selected bases varying widely in basicity (pKb). The solvent mixtures had specific dielectric constants (Dm). The hnp values of the bases determined in a solvent of a specific Dm value were related to the corresponding pKb values. The slopes of these linear relationships were related to Dm values. A certain mixture of the binary solvent system was selected, and successful differentiating titration of various base mixtures was demonstrated in this medium. The delta hnp/delta pK versus Dm data for acids were compared with those of bases in the benzene-acetonitrile binary solvent system. The resulting data on bases were compared with previously published data on acids, and the present report describes the behavior of acids and bases in the entire composition spectrum of the benzene-acetonitrile binary solvent system.

  2. Calculation of Liquid-Solid Interfacial Free Energy in Pb-Cu Binary Immiscible System

    NASA Astrophysics Data System (ADS)

    Li, Hong-shan; Zhou, Sheng-gang; Cao, Yong

    2016-11-01

    Based on the solid-liquid interfacial free energy theory of the complex Warren binary & pseudo-binary system and through the simplification of it by taking Pb-Cu binary system as an example, the physical model for it in binary immiscible system can be obtained. Next, its thermodynamic formula is derived to obtain a theoretical formula that only contains two parameters, and comparisons are made with regard to γSL calculated values and experimental values of MPE (multiphase equilibrium method) under several kinds of temperatures. As manifested in the outcomes, the improved physical model and theoretical formula will become not only easy to understand but also simple for calculation (the calculated value of γSL depends on two parameters, i.e. temperature and percentage composition of Cu atom). It can be treated as the foundation of application for the γSL calculation of liquid-solid interfacial free energy in other immiscible systems.

  3. Black holes in binary stellar systems and galactic nuclei

    NASA Astrophysics Data System (ADS)

    Cherepashchuk, A. M.

    2014-04-01

    In the last 40 years, following pioneering papers by Ya B Zeldovich and E E Salpeter, in which a powerful energy release from nonspherical accretion of matter onto a black hole (BH) was predicted, many observational studies of black holes in the Universe have been carried out. To date, the masses of several dozen stellar-mass black holes (M_BH = (4{-}20) M_\\odot) in X-ray binary systems and of several hundred supermassive black holes (M_BH = (10^{6}{-}10^{10}) M_\\odot) in galactic nuclei have been measured. The estimated radii of these massive and compact objects do not exceed several gravitational radii. For about ten stellar-mass black holes and several dozen supermassive black holes, the values of the dimensionless angular momentum a_* have been estimated, which, in agreement with theoretical predictions, do not exceed the limiting value a_* = 0.998. A new field of astrophysics, so-called black hole demography, which studies the birth and growth of black holes and their evolutionary connection to other objects in the Universe, namely stars, galaxies, etc., is rapidly developing. In addition to supermassive black holes, massive stellar clusters are observed in galactic nuclei, and their evolution is distinct from that of supermassive black holes. The evolutionary relations between supermassive black holes in galactic centers and spheroidal stellar components (bulges) of galaxies, as well as dark-matter galactic haloes are brought out. The launch into Earth's orbit of the space radio interferometer RadioAstron opened up the real possibility of finally proving that numerous discovered massive and highly compact objects with properties very similar to those of black holes make up real black holes in the sense of Albert Einstein's General Relativity. Similar proofs of the existence of black holes in the Universe can be obtained by intercontinental radio interferometry at short wavelengths \\lambda \\lesssim 1 mm (the international program, Event Horizon Telescope).

  4. Chandra resolves the T Tauri binary system RW Aur

    SciTech Connect

    Skinner, Stephen L.; Güdel, Manuel E-mail: manuel.guedel@univie.ac.at

    2014-06-20

    RW Aur is a multiple T Tauri system consisting of an early-K type primary (A) and a K5 companion (B) at a separation of 1.''4. RW Aur A drives a bipolar optical jet that is well characterized optically. We present results of a sensitive Chandra observation whose primary objective was to search for evidence of soft extended X-ray emission along the jet, as has been seen for a few other nearby T Tauri stars. The binary is clearly resolved by Chandra and both stars are detected as X-ray sources. The X-ray spectra of both stars reveal evidence for cool and hot plasma. Surprisingly, the X-ray luminosity of the less-massive secondary is at least twice that of the primary and is variable. The disparity is attributed to the primary whose X-ray luminosity is at the low end of the range for classical T Tauri stars of similar mass based on established correlations. Deconvolved soft-band images show evidence for slight outward elongation of the source structure of RW Aur A along the blueshifted jet axis inside the central arcsecond. In addition, a faint X-ray emission peak is present on the redshifted axis at an offset of 1.''2 ± 0.''2 from the star. Deprojected jet speeds determined from previous optical studies are too low to explain this faint emission peak as shock-heated jet plasma. Thus, unless flow speeds in the redshifted jet have been underestimated, other mechanisms such as magnetic jet heating may be involved.

  5. Solar Energy Systems for Ohioan Residential Homeowners

    NASA Astrophysics Data System (ADS)

    Luckett, Rickey D.

    Dwindling nonrenewable energy resources and rising energy costs have forced the United States to develop alternative renewable energy sources. The United States' solar energy industry has seen an upsurge in recent years, and photovoltaic holds considerable promise as a renewable energy technology. The purpose of this case study was to explore homeowner's awareness of the benefits of solar energy. Disruptive-innovation theory was used to explore marketing strategies for conveying information to homeowners about access to new solar energy products and services. Twenty residential homeowners were interviewed face-to-face to explore (a) perceived benefits of solar energy in their county in Ohio, and (b) perceptions on the rationale behind the marketing strategy of solar energy systems sold for residential use. The study findings used inductive analyses and coding interpretation to explore the participants' responses that revealed 3 themes: the existence of environmental benefits for using solar energy systems, the expensive cost of equipment associated with government incentives, and the lack of marketing information that is available for consumer use. The implications for positive social change include the potential to enable corporate leaders, small business owners, and entrepreneurs to develop marketing strategies for renewable energy systems. These strategies may promote use of solar energy systems as a clean, renewable, and affordable alternative electricity energy source for the 21st century.

  6. Solar System Exploration -- What Comes Next?

    NASA Video Gallery

    Do you think we already know everything about our solar system? Think again. We've barely scratched the surface of what there is to learn. Join NASA as it sends missions to the far ends of the sola...

  7. Prototype solar heating and hot water systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress made in the development of a solar hot water and space heating system is described in four quarterly reports. The program schedules, technical status and other program activities from 6 October 1976 through 30 September 1977 are provided.

  8. Chasing shadows in the outer solar system

    NASA Astrophysics Data System (ADS)

    Bianco, Federica

    The characteristics of the populations of objects that inhabit the outer solar system carry the fingerprint of the processes that governed the formation and evolution of the solar system. Occultation surveys push the limit of observation into the very small and distant outer solar system objects, allowing us to set constraints on the structure of the Kuiper belt, Scattered disk and Sedna populations. I collected, reduced, and analyzed vast datasets looking for occultations of stars by outer solar system objects, both working with the Taiwanese American Occultation Survey (TAOS) collaboration and leading the MMT/Megacam occultation effort. Having found no such events in my data, I was able to place upper limits on the Kuiper belt, scattered disk and Sedna population. These limits and their derivation are described here.

  9. The Birth Environment of the Solar System

    NASA Astrophysics Data System (ADS)

    Brown, Michael; Allen, Lori; Trilling, Davif

    2014-02-01

    In his comprehensive review on the birth environment of the solar system, Adams (2010) uses four primary dynamical, chemical, and radiation constraints to conclude that the solar system formed in a cluster with between 1000 and 10,000 members. The existence of the planetoid Sedna, on a highly elliptical orbit disconnected from the giant planets, is perhaps the weakest of these primary constraints. We propose a small Gemini imaging program to followup serendipitous discoveries of distant objets in the outer solar system from a 30 night Dark Energy Camera near earth asteroid survey. The Gemini observations will allow us to determine orbits of these distant objects which will allow us to (1) determine if Sedna was indeed emplaced by a birth cluster and (2) use full orbital population statistics to constrain the birth environment of the sun using this unique fossil record of the earliest history of our solar system.

  10. Cosmic ray hazards in the solar system.

    NASA Technical Reports Server (NTRS)

    Milford, S. N.

    1965-01-01

    Cosmic ray hazards in solar system considered from measurements of cosmic ray energy and charge spectra near Earth and in interplanetary space near Earth, together with interaction of cosmic rays with Moon surface

  11. Design data brochure: Solar hot water system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A design calculation is detailed for a single-family residence housing a family of four in a nonspecific geographical area. The solar water heater system is designed to provide 80 gallons of 140 F hot water per day.

  12. The NASA atlas of the solar system

    USGS Publications Warehouse

    Greeley, Ronald; Batson, Raymond M.

    1997-01-01

    Describes every planet, moon, and body that has been the subject of a NASA mission, including images of 30 solar system objects and maps of 26 objects. The presentation includes geologic history, geologic and reference maps, and shaded relief maps.

  13. Formation of the widest binary stars from dynamical unfolding of triple systems.

    PubMed

    Reipurth, Bo; Mikkola, Seppo

    2012-12-13

    The formation of very wide binary systems, such as the α Centauri system with Proxima (also known as α Centauri C) separated from α Centauri (which itself is a close binary A/B) by 15,000 astronomical units (1 AU is the distance from Earth to the Sun), challenges current theories of star formation, because their separation can exceed the typical size of a collapsing cloud core. Various hypotheses have been proposed to overcome this problem, including the suggestion that ultrawide binaries result from the dissolution of a star cluster--when a cluster star gravitationally captures another, distant, cluster star. Recent observations have shown that very wide binaries are frequently members of triple systems and that close binaries often have a distant third companion. Here we report N-body simulations of the dynamical evolution of newborn triple systems still embedded in their nascent cloud cores that match observations of very wide systems. We find that although the triple systems are born very compact--and therefore initially are more protected against disruption by passing stars--they can develop extreme hierarchical architectures on timescales of millions of years as one component is dynamically scattered into a very distant orbit. The energy of ejection comes from shrinking the orbits of the other two stars, often making them look from a distance like a single star. Such loosely bound triple systems will therefore appear to be very wide binaries.

  14. Tehachapi solar thermal system first annual report

    SciTech Connect

    Rosenthal, A.

    1993-05-01

    The staff of the Southwest Technology Development Institute (SWTDI), in conjunction with the staff of Industrial Solar Technology (IST), have analyzed the performance, operation, and maintenance of a large solar process heat system in use at the 5,000 inmate California Correctional Institution (CCI) in Tehachapi, CA. This report summarizes the key design features of the solar plant, its construction and maintenance histories through the end of 1991, and the performance data collected at the plant by a dedicated on-site data acquisition system (DAS).

  15. Solar energy system with composite concentrating lenses

    SciTech Connect

    Genequand, P.; Stark, V.

    1980-12-09

    In order to improve the efficiency of a solar energy system utilizing a Fresnel lens for concentrating solar rays on a conduit system or the like, only the central portion of a Fresnel lens, otherwise of large width, is utilized and slide assemblies, each containing a plurality of slats with a reflective coating and disposed at an angle such as to reflect solar energy to the same focal point as the Fresnel lens, are disposed on each side of the lens thereby effectively increasing the aperture of the lens and increasing efficiency of concentration.

  16. Solar energy control system. [temperature measurement

    NASA Technical Reports Server (NTRS)

    Currie, J. R. (Inventor)

    1981-01-01

    A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit is disclosed. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal.

  17. Basics of a Solar Electric System: Better Buildings Series Solar Electric Fact Sheet

    SciTech Connect

    Not Available

    2002-07-01

    Today's solar technologies are more efficient and versatile than ever before, adding to the appeal of an already desirable energy source. This fact sheet provides information on the basics of a solar electric system, including components of a system, how to choose solar modules, and how to choose a solar system.

  18. The Solar System: Recent Exploration Results

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.

    2006-01-01

    The solar system has been visited by space probes, ranging from the Mariner Mercury-Venus mission exploring inward toward the sun, and continuing through the Voyager probes out into interstellar space and (on its way now) the New Horizons probe to Pluto and the Kuiper belt. This talk examines what we know of the planets of the solar system from probes, and talks about where we will go from here.

  19. Meteoroids: The Smallest Solar System Bodies

    NASA Technical Reports Server (NTRS)

    Moser, Danielle E. (Compiler); Hardin, B. F. (Compiler); Janches, Diego (Compiler)

    2011-01-01

    This volume is a compilation of articles reflecting the current state of knowledge on the physics, chemistry, astronomy, and aeronomy of small bodies in the solar system. The articles included here represent the most recent results in meteor, meteoroid, and related research fields and were presented May 24-28, 2010, in Breckenridge, Colorado, USA at Meteoroids 2010: An International Conference on Minor Bodies in the Solar System.

  20. Origin of Outer Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.; Boyce, J. (Technical Monitor)

    2003-01-01

    We feel that at the present moment the available theoretical models of the Kuiper belt are still in advance of the data, and thus our main task has been to conduct observational work guided by theoretical motivations. Our efforts over the past year can be divided into four categories: A) Wide-field Searches for Kuiper Belt Objects; B) Pencil-beam Searches for Kuiper Belt Objects; C) Wide-field Searches for Moons of the Outer Planets; D) Pencil-beam Searches for Faint Uranian and Neptunian Moons; E) Recovery Observations. As of April 2002, we have conducted several searches for Kuiper belt objects using large-format mosaic CCD camera on 4-meter class telescopes. In May 1999, we used the Kitt Peak 4-meter with the NOAO Mosaic camera we attempted a search for KBOs at a range of ecliptic latitudes. In addition to our wide-field searches, we have conducted three 'pencil-beam' searches in the past year. In a pencil-beam search we take repeated integrations of the same field throughout a night. After preprocessing the resulting images we shift and recombine them along a range of rates and directions consistent with the motion of KBOs. Stationary objects then smear out, while objects moving at near the shift rate appear as point sources. In addition to our searches for Kuiper belt objects, we are completing the inventory of the outer solar system by search for faint satellites of the outer planets. In August 2001 we conducted pencil beam searches for faint Uranian and Neptunian satellites at CFHT and CTIO. These searches resulted in the discover of two Neptunian and four Uranian satellite candidates. The discovery of Kuiper belt objects and outer planet satellites is of little use if the discoveries are not followed by systematic, repeated astrometric observations that permit reliable estimates of their orbits.

  1. Astrometric Solar-System Anomalies

    NASA Astrophysics Data System (ADS)

    Anderson, John D.

    2009-05-01

    There are four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it experiences a gain in total orbital energy per unit mass (Anderson et al., Phys. Rev. Lett. 100, 091102). This amounts to a net velocity increase of 13.5 mm/s for the NEAR spacecraft at a closest approach of 539 km, 3.9 mm/s for the Galileo spacecraft at 960 km, and 1.8 mm/s for the Rosetta spacecraft at 1956 km. Next, I suggest the change in the astronomical unit AU is definitely a concern. It is increasing by about 15 cm/yr (Krasinsky and Brumberg, Celes. Mech. & Dynam. Astron. 90, 267). The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions (Anderson et al., Phys. Rev. D 65, 082004). Some, including me, are convinced this effect is of concern, but many are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon's orbit. Here again, an increase is expected from tidal friction in both the Earth and Moon. However, there is a reported increase that is about three times larger than expected (J. G. Williams, DDA/AAS Brouwer Award Lecture, Halifax, Nova Scotia 2006). We suspect that all four anomalies have mundane explanations. However, the possibility that they will be explained by a new theory of gravitation is not ruled out, perhaps analogous to Einstein's 1916 explanation of the excess precession of Mercury's perihelion.

  2. Parachute suspended solar pointing control system

    NASA Astrophysics Data System (ADS)

    Sakoda, G. T.; Fujimoto, R. J.; Shigemoto, J. M.; Windsor, R. M.

    A high altitude parachute suspended solar pointing control system has been developed and flight tested for use in the altitude range of 30 to 70 kilometers. This development provides an opportunity for extended solar observations at altitudes higher than that attainable by helium balloons. The new system utilizes the NASA high altitude cross parachute to slow the descent of a rocket launched payload allowing observations in the region of interest. Solar pointing is established by using solar sensors in conjunction with a servo controlled platform and cold gas thrusters for payload roll control. The inherent spin of the cross parachute is decoupled by a swivel joint attached to the parachute suspension lines. This paper describes the design, test and flight performance of the new system.

  3. Parachute-suspended solar pointing control system

    NASA Astrophysics Data System (ADS)

    Sakoda, G. T.; Fujimoto, R. J.; Shigemoto, J. M.; Windsor, R. M.

    1984-04-01

    A high altitude parachute suspended solar pointing control system has been developed and flight tested for use in the altitude range of 30 to 70 kilometers. This development provides an opportunity for extended solar observations at altitudes higher than that attainable by helium balloons. The new system utilizes the NASA high altitude cross parachute to slow the descent of a rocket launched payload allowing observations in the region of interest. Solar pointing is established by using solar sensors in conjunction with a servo controlled platform and cold gas thrusters for payload roll control. The inherent spin of the cross parachute is decoupled by a swivel joint attached to the parachute suspension lines. This paper describes the design, test and flight performance of the new system.

  4. Concentrators Enhance Solar Power Systems

    NASA Technical Reports Server (NTRS)

    2013-01-01

    "Right now, solar electric propulsion is being looked at very seriously," says Michael Piszczor, chief of the photovoltaic and power technologies branch at Glen Research Center. The reason, he explains, originates with a unique NASA mission from the late 1990s. In 1998, the Deep Space 1 spacecraft launched from Kennedy Space Center to test a dozen different space technologies, including SCARLET, or the Solar Concentrator Array with Refractive Linear Element Technology. As a solar array that focused sunlight on a smaller solar cell to generate electric power, SCARLET not only powered Deep Space 1 s instruments but also powered its ion engine, which propelled the spacecraft throughout its journey. Deep Space 1 was the first spacecraft powered by a refractive concentrator design like SCARLET, and also utilized multi-junction solar cells, or cells made of multiple layers of different materials. For the duration of its 38-month mission, SCARLET performed flawlessly, even as Deep Space 1 flew by Comet Borrelly and Asteroid Braille. "Everyone remembers the ion engine on Deep Space 1, but they tend to forget that the SCARLET array powered it," says Piszczor. "Not only did both technologies work as designed, but the synergy between the two, solar power and propulsion together, is really the important aspect of this technology demonstration mission. It was the first successful use of solar electric propulsion for primary propulsion." More than a decade later, NASA is keenly interested in using solar electric propulsion (SEP) for future space missions. A key issue is cost, and SEP has the potential to substantially reduce cost compared to conventional chemical propulsion technology. "SEP allows you to use spacecraft that are smaller, lighter, and less costly," says Piszczor. "Even though it might take longer to get somewhere using SEP, if you are willing to trade time for cost and smaller vehicles, it s a good trade." Potentially, SEP could be used on future science missions

  5. Perovskite Solar Cells: High Efficiency Pb-In Binary Metal Perovskite Solar Cells (Adv. Mater. 31/2016).

    PubMed

    Wang, Zhao-Kui; Li, Meng; Yang, Ying-Guo; Hu, Yun; Ma, Heng; Gao, Xing-Yu; Liao, Liang-Sheng

    2016-08-01

    On page 6695, X. Y. Gao, L.-S. Liao, and co-workers describe the fabrication of mixed Pb-In perovskite solar cells, using indium (III) chloride and lead (II) chloride with methylammonium iodide. A maximum power conversion efficiency as high as 17.55% is achieved owing to the high quality of the perovskites with multiple ordered crystal orientations. This work demonstrates the possibility of substituting the Pb (II) by using In (III), which opens a broad route to fabricating alloy perovskite solar cells with mitigated ecological impact.

  6. Solvent-molecule-mediated manipulation of crystalline grains for efficient planar binary lead and tin triiodide perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Zhu, Leize; Yuh, Brian; Schoen, Stefan; Li, Xinpei; Aldighaithir, Mohammed; Richardson, Beau J.; Alamer, Ahmed; Yu, Qiuming

    2016-03-01

    Binary lead and tin perovskites offer the benefits of narrower band gaps for broader adsorption of solar spectrum and better charge transport for higher photocurrent density. Here, we report the growth of large, smooth crystalline grains of bianry lead and tin triiodide perovskite films via a two-step solution process with thermal plus solvent vapor-assisted thermal annealing. The crystalline SnxPb1-xI2 films formed in the first step served as the templates for the formation of crystalline CH3NH3SnxPb1-xI3 films during the second step interdiffusion of methylammonium iodide (MAI). Followed by dimethylsulfoxide (DMSO) vapor-assisted thermal annealing, small, faceted perovskite grains grew into large, smooth grains via the possible mechanism involving bond breaking and reforming mediated by DMSO solvent molecules. The absorption onset was extended to 950 and 1010 nm for the CH3NH3SnxPb1-xI3 perovskites with x = 0.1 and 0.25, respectively. The highest PCE of 10.25% was achieved from the planar perovskite solar cell with the CH3NH3Sn0.1Pb0.9I3 layer prepared via the thermal plus DMSO vapor-assisted thermal annealing. This research provides a way to control and manipulate film morphology, grain size, and especially the distribution of metal cations in binary metal perovskite layers, which opens an avenue to grow perovskite materials with desired properties to enhance device performance.Binary lead and tin perovskites offer the benefits of narrower band gaps for broader adsorption of solar spectrum and better charge transport for higher photocurrent density. Here, we report the growth of large, smooth crystalline grains of bianry lead and tin triiodide perovskite films via a two-step solution process with thermal plus solvent vapor-assisted thermal annealing. The crystalline SnxPb1-xI2 films formed in the first step served as the templates for the formation of crystalline CH3NH3SnxPb1-xI3 films during the second step interdiffusion of methylammonium iodide (MAI

  7. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  8. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  9. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  10. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  11. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  12. Goldstone Solar System Radar Waveform Generator

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Patawaran, Ferze D.; Nguyen, Danh H.; Nguyen, Huy

    2012-01-01

    Due to distances and relative motions among the transmitter, target object, and receiver, the time-base between any transmitted and received signal will undergo distortion. Pre-distortion of the transmitted signal to compensate for this time-base distortion allows reception of an undistorted signal. In most radar applications, an arbitrary waveform generator (AWG) would be used to store the pre-calculated waveform and then play back this waveform during transmission. The Goldstone Solar System Radar (GSSR), however, has transmission durations that exceed the available memory storage of such a device. A waveform generator capable of real-time pre-distortion of a radar waveform to a given time-base distortion function is needed. To pre-distort the transmitted signal, both the baseband radar waveform and the RF carrier must be modified. In the GSSR, this occurs at the up-conversion mixing stage to an intermediate frequency (IF). A programmable oscillator (PO) is used to generate the IF along with a time-varying phase component that matches the time-base distortion of the RF carrier. This serves as the IF input to the waveform generator where it is mixed with a baseband radar waveform whose time-base has been distorted to match the given time-base distortion function producing the modulated IF output. An error control feedback loop is used to precisely control the time-base distortion of the baseband waveform, allowing its real-time generation. The waveform generator produces IF modulated radar waveforms whose time-base has been pre-distorted to match a given arbitrary function. The following waveforms are supported: continuous wave (CW), frequency hopped (FH), binary phase code (BPC), and linear frequency modulation (LFM). The waveform generator takes as input an IF with a time varying phase component that matches the time-base distortion of the carrier. The waveform generator supports interconnection with deep-space network (DSN) timing and frequency standards, and

  13. Photovoltaics: Solar electric power systems

    NASA Astrophysics Data System (ADS)

    1980-02-01

    The operation and uses of solar cells and the National Photovoltaic Program are briefly described. Eleven DOE photovoltaic application projects are described including forest lookout towers; Wilcox Memorial Hospital in Hawaii; WBNO daytime AM radio station; Schuchuli Indian Village; Meade, Nebraska, agricultural experiment; Mt. Laguna Air Force Station; public schools and colleges; residential applications; and Sea World of Florida.

  14. Photovoltaics: solar electric power systems

    SciTech Connect

    1980-02-01

    The operation and uses of solar cells and the National Photovoltaic Program are briefly described. Eleven DOE photovoltaic application projects are described including forest lookout towers; Wilcox Memorial Hospital in Hawaii; WBNO daytime AM radio station; Schuchuli Indian Village; Meade, Nebraska, agricultural experiment; Mt. Laguna Air Force Station; public schools and colleges; residential applications; and Sea World of Florida. (WHK)

  15. A 15.65-solar-mass black hole in an eclipsing binary in the nearby spiral galaxy M 33.

    PubMed

    Orosz, Jerome A; McClintock, Jeffrey E; Narayan, Ramesh; Bailyn, Charles D; Hartman, Joel D; Macri, Lucas; Liu, Jiefeng; Pietsch, Wolfgang; Remillard, Ronald A; Shporer, Avi; Mazeh, Tsevi

    2007-10-18

    Stellar-mass black holes are found in X-ray-emitting binary systems, where their mass can be determined from the dynamics of their companion stars. Models of stellar evolution have difficulty producing black holes in close binaries with masses more than ten times that of the Sun (>10; ref. 4), which is consistent with the fact that the most massive stellar black holes known so far all have masses within one standard deviation of 10. Here we report a mass of (15.65 +/- 1.45) for the black hole in the recently discovered system M 33 X-7, which is located in the nearby galaxy Messier 33 (M 33) and is the only known black hole that is in an eclipsing binary. To produce such a massive black hole, the progenitor star must have retained much of its outer envelope until after helium fusion in the core was completed. On the other hand, in order for the black hole to be in its present 3.45-day orbit about its (70.0 +/- 6.9) companion, there must have been a 'common envelope' phase of evolution in which a significant amount of mass was lost from the system. We find that the common envelope phase could not have occurred in M 33 X-7 unless the amount of mass lost from the progenitor during its evolution was an order of magnitude less than what is usually assumed in evolutionary models of massive stars.

  16. ELEMENTAL ABUNDANCE DIFFERENCES IN THE 16 CYGNI BINARY SYSTEM: A SIGNATURE OF GAS GIANT PLANET FORMATION?

    SciTech Connect

    RamIrez, I.; Roederer, I. U.; Fish, J. R.; Melendez, J.

    2011-10-20

    The atmospheric parameters of the components of the 16 Cygni binary system, in which the secondary has a gas giant planet detected, are measured accurately using high-quality observational data. Abundances relative to solar are obtained for 25 elements with a mean error of {sigma}([X/H]) = 0.023 dex. The fact that 16 Cyg A has about four times more lithium than 16 Cyg B is normal considering the slightly different masses of the stars. The abundance patterns of 16 Cyg A and B, relative to iron, are typical of that observed in most of the so-called solar twin stars, with the exception of the heavy elements (Z > 30), which can, however, be explained by Galactic chemical evolution. Differential (A-B) abundances are measured with even higher precision ({sigma}({Delta}[X/H]) = 0.018 dex, on average). We find that 16 Cyg A is more metal-rich than 16 Cyg B by {Delta}[M/H] = +0.041 {+-} 0.007 dex. On an element-to-element basis, no correlation between the A-B abundance differences and dust condensation temperature (T{sub C}) is detected. Based on these results, we conclude that if the process of planet formation around 16 Cyg B is responsible for the observed abundance pattern, the formation of gas giants produces a constant downward shift in the photospheric abundance of metals, without a T{sub C} correlation. The latter would be produced by the formation of terrestrial planets instead, as suggested by other recent works on precise elemental abundances. Nevertheless, a scenario consistent with these observations requires the convective envelopes of {approx_equal} 1 M{sub sun} stars to reach their present-day sizes about three times quicker than predicted by standard stellar evolution models.

  17. Planets in Wide Binaries from Kepler: Ages, Stability and Evolution of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Weisenburger, Kolby L.; West, Andrew A.; Janes, Kenneth; Dhital, Saurav

    2014-06-01

    Using the Kepler Input Catalog and the fourth U.S. Naval Observatory CCD Astrograph Catalog, we have identified 1509 common proper motion (CPM) binaries in the Kepler field of view, of which a small subset host planet candidates, or Kepler Objects of Interest (KOIs). We have verified the fidelity of the CPM pairs using a Galactic model and follow-up astrometric observations. We present 73 KOIs distributed over 58 CPM pairs and highlight the first wide binary system (separation > 1000 AU) where both stellar components host at least one KOI. Because our binary sample was initially targeted for a gyrochronology analysis, we also present measurements of stellar rotation periods and preliminary estimates of stellar (and planetary) ages. We use these extrapolated planetary ages to investigate longterm planet stability in wide binaries and test potential formation and evolution scenarios of these dynamically complex systems.

  18. UBVR{sub c} I{sub c} ANALYSIS OF THE RECENTLY DISCOVERED TOTALLY ECLIPSING EXTREME MASS RATIO BINARY V1853 ORIONIS, AND A STATISTICAL LOOK AT 25 OTHER EXTREME MASS RATIO SOLAR-TYPE CONTACT BINARIES

    SciTech Connect

    Samec, R. G.; Labadorf, C. M.; Hawkins, N. C.; Faulkner, D. R.; Van Hamme, W.

    2011-10-15

    We present precision CCD light curves, a period study, photometrically derived standard magnitudes, and a five-color simultaneous Wilson code solution of the totally eclipsing, yet shallow amplitude (A{sub v} {approx} 0.4 mag) eclipsing, binary V1853 Orionis. It is determined to be an extreme mass ratio, q = 0.20, W-type W UMa overcontact binary. From our standard star observations, we find that the variable is a late-type F spectral-type dwarf, with a secondary component of about 0.24 solar masses (stellar type M5V). Its long eclipse duration (41 minutes) as compared to its period, 0.383 days, attests to the small relative size of the secondary. Furthermore, it has reached a Roche lobe fill-out of {approx}50% of its outer critical lobe as it approaches its final stages of binary star evolution, that of a fast spinning single star. Finally, a summary of about 25 extreme mass ratio solar-type binaries is given.

  19. Mineralogy of the Solar System

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.

    1999-01-01

    The coming decade will witnesses the first sample return missions from solar system bodies in 30 years. These samples will all be very small, some missions return only a few milligrams of total mass. Fortunately, the capability of modem methods to characterize ultra-small samples is well established from analysis of interplanetary dust particles (IDPs), interstellar grains recovered from meteorites, and other materials requiring ultra-sensitive analytical capabilities. Powerful analytical techniques are available that require, under favorable circumstances, single particles of only a few nanograms for entire suites of fairly comprehensive characterizations. A returned sample of greater than 1,000 particles with total mass of just one microgram permits comprehensive quantitative geochemical measurements that are impractical to can-y out in situ by flight instruments. With the Galileo flybys of Gaspra and Ida, it is now recognized that even very small airless bodies have indeed developed a particulate regolith. Acquiring a sample of the bulk regolith, a simple sampling strategy, provides two critical pieces of information about the body. Regolith samples are excellent bulk samples since they normally contain all the key components of the local environment, albeit in particulate form. Furthermore, since this fine fraction dominates remote measurements, regolith samples also provide information about surface alteration processes and are a key link to remote sensing of other bodies. Studies indicate that a statistically significant number of nanogram-sized particles should be able to characterize the regolith of a primitive asteroid, although the presence of larger components within even primitive meteorites (e.g.. Murchison), e.g. chondrules, CAI, large crystal fragments, etc., points out the limitations of using data obtained from nanogram-sized samples to characterize entire primitive asteroids. However, most important asteroidal geological processes have left their

  20. New Magnetically Uniaxial Phases in the Samarium, Iron Binary System.

    NASA Astrophysics Data System (ADS)

    Rani, Raj

    1995-01-01

    For the first time, films magnets of binary rm Sm_5Fe_{17}, and SmFe_{12}, magnetically uniaxial phases have been sputter synthesized without any addition of a phase stabilizing third element. Perpendicular to the film plane, the room temperature saturation magnetization for highly (002) aligned film samples of SmFe_ {12} phase were measured to be 14.3 +/- 0.5 kG and the estimated anisotropy field was 130 +/- 10 kOe. X-ray diffraction studies, hysterisis loop measurements, composition measurements, and projection of moment calculations allowed to identify the SmFe_{12} phase as ThMn_{12} type tetragonal structure with a = 8.438 +/- 0.006 A, and c = 4.805 +/- 0.006 A. Film samples of this phase were synthesized by depositing the material on preheated substrates. For rm Sm_5Fe_{17} phase, the material was first deposited in amorphous form and subsequently crystallized. rm Sm_5Fe_{17 } film samples were synthesized with record high room temperature coercivity of 14.1 kOe for the two element Sm, Fe system. On nitriding rm Sm _2Fe_{17}, profound changes in magnetic properties have occurred, room temperature inplane coercivity rose from 0.75 kOe to 23 kOe. The rm Sm_2Fe_{17}N_ {x} compound retained its parent structure with the cell volume increase of ~7%. The room temperature coercivity as a function of the Sm concentration reached a maximum value of ~23 kOe at a slightly richer than stoichiometric Sm composition. High anisotropy (002) textured film samples of rm Pr(Fe_{12-y-z},Co_{y},Mo _{z})N_{x}, where y = 0-2.5, and z = 0.4-1.0 compounds were synthesized with so far the highest coercivity of 9.4 kOe. X-ray diffraction data showed that the ThMn_{12} type tetragonal structure was retained with a saturation increase in the cell volume over the first 15 minutes of nitriding time at 750 K. The coercivity reached a maximum for nitriding time of 25 minutes of nitriding time. For rm Pr_{1.04}Fe_{10.36 }Co_{1.16}Mo_{0.44}N _{x} sample measured at 293 K, perpendicular to the

  1. Theory and Simulations of Solar System Plasmas

    NASA Technical Reports Server (NTRS)

    Goldstein, Melvyn L.

    2011-01-01

    "Theory and simulations of solar system plasmas" aims to highlight results from microscopic to global scales, achieved by theoretical investigations and numerical simulations of the plasma dynamics in the solar system. The theoretical approach must allow evidencing the universality of the phenomena being considered, whatever the region is where their role is studied; at the Sun, in the solar corona, in the interplanetary space or in planetary magnetospheres. All possible theoretical issues concerning plasma dynamics are welcome, especially those using numerical models and simulations, since these tools are mandatory whenever analytical treatments fail, in particular when complex nonlinear phenomena are at work. Comparative studies for ongoing missions like Cassini, Cluster, Demeter, Stereo, Wind, SDO, Hinode, as well as those preparing future missions and proposals, like, e.g., MMS and Solar Orbiter, are especially encouraged.

  2. Discovery of two young brown dwarfs in an eclipsing binary system.

    PubMed

    Stassun, Keivan G; Mathieu, Robert D; Valenti, Jeff A

    2006-03-16

    Brown dwarfs are considered to be 'failed stars' in the sense that they are born with masses between the least massive stars (0.072 solar masses, M(o)) and the most massive planets (approximately 0.013M(o)); they therefore serve as a critical link in our understanding of the formation of both stars and planets. Even the most fundamental physical properties of brown dwarfs remain, however, largely unconstrained by direct measurement. Here we report the discovery of a brown-dwarf eclipsing binary system, in the Orion Nebula star-forming region, from which we obtain direct measurements of mass and radius for these newly formed brown dwarfs. Our mass measurements establish both objects as brown dwarfs, with masses of 0.054 +/- 0.005M(o) and 0.034 +/- 0.003M(o). At the same time, with radii relative to the Sun's of 0.669 +/- 0.034R(o) and 0.511 +/- 0.026R(o), these brown dwarfs are more akin to low-mass stars in size. Such large radii are generally consistent with theoretical predictions for young brown dwarfs in the earliest stages of gravitational contraction. Surprisingly, however, we find that the less-massive brown dwarf is the hotter of the pair; this result is contrary to the predictions of all current theoretical models of coeval brown dwarfs.

  3. Solar Thermal Power Systems parabolic dish project

    NASA Technical Reports Server (NTRS)

    Truscello, V. C.

    1981-01-01

    The status of the Solar Thermal Power Systems Project for FY 1980 is summarized. Included is: a discussion of the project's goals, program structure, and progress in parabolic dish technology. Analyses and test results of concentrators, receivers, and power converters are discussed. Progress toward the objectives of technology feasibility, technology readiness, system feasibility, and system readiness are covered.

  4. Prototype solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A collection of monthly status reports on the development of eight prototype solar heating and cooling systems is presented. The effort calls for the development, manufacture, test, system installation, maintenance, problem resolution, and performance evaluation. The systems are 3, 25, and 75 ton size units.

  5. Residential solar-heating system - design brochure

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Design brochure for commercially-available solar-heating system is valuable to architects, engineers, and designers. It contains information on system configuration, system sizing, and mechanical layout. Drawings and specifications of all components and typical installation details are included in appendix.

  6. Prototype residential solar-energy system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Complete solar-energy domestic-hot-water system for single-family residences is described in brochure. It contains data on procurement, installation, operation, and maintainance of system in residential or light commercial buildings. Appendix includes vendor brochures for major system components. Drawings, tables, and graphs complement text.

  7. An orientable solar panel system for nanospacecraft

    NASA Astrophysics Data System (ADS)

    Santoni, Fabio; Piergentili, Fabrizio; Candini, Gian Paolo; Perelli, Massimo; Negri, Andrea; Marino, Michele

    2014-08-01

    An orientable deployed solar array system for 1-5 kg weight nanospacecraft is described, enhancing the achievable performance of these typically power-limited systems. The system is based on a deployable solar panel system, previously developed with cooperation between Laboratorio di Sistemi Aerospaziali of University of Roma “la Sapienza” and the company IMT (Ingegneria Marketing Tecnologia). The system proposed is a modular one, and suitable in principle for the 1U, 2U and 3U standard Cubesat bus, even if the need for three axis attitude stabilization makes it typically preferred for 3U Cubesats. The size of each solar panel is the size of a lateral Cubesat surface. A single degree of freedom maneuvering capability is given to the deployed solar array, in order to follow the apparent motion of the sun as close as possible, given the mission requirements on the spacecraft attitude. Considerable effort has been devoted to design the system compatible with the Cubesat standard, being mounted outside on the external spacecraft structure, without requiring modifications on the standard prescriptions. The small available volume is the major constraint, which forces to use miniaturized electric motor technology. The system design trade-off is discussed, leading to the selection of an architecture based on two independently steerable solar array wings.

  8. Solid/liquid interfacial free energies in binary systems

    NASA Technical Reports Server (NTRS)

    Nason, D.; Tiller, W. A.

    1973-01-01

    Description of a semiquantitative technique for predicting the segregation characteristics of smooth interfaces between binary solid and liquid solutions in terms of readily available thermodynamic parameters of the bulk solutions. A lattice-liquid interfacial model and a pair-bonded regular solution model are employed in the treatment with an accommodation for liquid interfacial entropy. The method is used to calculate the interfacial segregation and the free energy of segregation for solid-liquid interfaces between binary solutions for the (111) boundary of fcc crystals. The zone of compositional transition across the interface is shown to be on the order of a few atomic layers in width, being moderately narrower for ideal solutions. The free energy of the segregated interface depends primarily upon the solid composition and the heats of fusion of the component atoms, the composition difference of the solutions, and the difference of the heats of mixing of the solutions.

  9. Multi-kilowatt solar power system concept

    SciTech Connect

    Kirpich, A.; Chung, A.

    1984-08-01

    As part of a feasibility study for large satellite communications, the conceptual design of a multi-kilowatt solar power system has been completed. The concept is based on using two flat-pack SEP solar arrays having a beginning-of-life output of 25 KW. The bulk of this power is supplied to the communication payload at 200 VDC. Further processing to various user voltage levels is performed within the communications subsystem. A limited amount of energy storage is used to maintain the payload during eclipse periods. The system has been designed for a geosynchronous orbit. Key technical issues of this concept are the use of a high distribution voltage (200 VDC) and the effects of electro-static discharge (ESD) associated with the large solar array area. Assessments of these issues are presented together with approaches for reducing deleterious effects to acceptable levels. Housekeeping loads, estimated at 1 KW, are supported by a small segment of the solar array along with a complement of batteries for operation through eclipse periods. This power is provided at 28 VDC. A unique feature of the design is the manner in which the solar array is mounted to the spacecraft. Instead of articulating the solar array with respect to the main spacecraft body, as implemented in many geosynchronous spacecraft, the solar array is fixed to the main body. Both the solar array and main body are then sun oriented. Key advantages of this approach are: elimination of high power slip rings; simple thermal control because sun-pointing results in constant thermal conditions; straightforward structural and mechanical integration resulting largely from elimination of view factor considerations associated with articulated solar arrays.

  10. An Automated Solar Synoptic Analysis Software System

    NASA Astrophysics Data System (ADS)

    Hong, S.; Lee, S.; Oh, S.; Kim, J.; Lee, J.; Kim, Y.; Lee, J.; Moon, Y.; Lee, D.

    2012-12-01

    We have developed an automated software system of identifying solar active regions, filament channels, and coronal holes, those are three major solar sources causing the space weather. Space weather forecasters of NOAA Space Weather Prediction Center produce the solar synoptic drawings as a daily basis to predict solar activities, i.e., solar flares, filament eruptions, high speed solar wind streams, and co-rotating interaction regions as well as their possible effects to the Earth. As an attempt to emulate this process with a fully automated and consistent way, we developed a software system named ASSA(Automated Solar Synoptic Analysis). When identifying solar active regions, ASSA uses high-resolution SDO HMI intensitygram and magnetogram as inputs and providing McIntosh classification and Mt. Wilson magnetic classification of each active region by applying appropriate image processing techniques such as thresholding, morphology extraction, and region growing. At the same time, it also extracts morphological and physical properties of active regions in a quantitative way for the short-term prediction of flares and CMEs. When identifying filament channels and coronal holes, images of global H-alpha network and SDO AIA 193 are used for morphological identification and also SDO HMI magnetograms for quantitative verification. The output results of ASSA are routinely checked and validated against NOAA's daily SRS(Solar Region Summary) and UCOHO(URSIgram code for coronal hole information). A couple of preliminary scientific results are to be presented using available output results. ASSA will be deployed at the Korean Space Weather Center and serve its customers in an operational status by the end of 2012.

  11. Planetary magnetism in the outer solar system.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.

    1973-01-01

    A brief review of the salient considerations which apply to the existence of magnetic fields in connection with planetary and subplanetary objects in the outer solar system is given. Consideration is given to internal dynamo fields, fields which might originate from interaction with the solar wind or magnetospheres (externally driven dynamos) and lastly fossil magnetic fields such as have been discovered on the moon. Where possible, connection is made between magnetism, means of detection, and internal body properties.

  12. Solar energy system with wind vane

    DOEpatents

    Grip, Robert E

    2015-11-03

    A solar energy system including a pedestal defining a longitudinal axis, a frame that is supported by the pedestal and that is rotateable relative to the pedestal about the longitudinal axis, the frame including at least one solar device, and a wind vane operatively connected to the frame to urge the frame relative to the pedestal about the longitudinal axis in response to wind acting on the wind vane.

  13. Habitability in Binary Systems: The Role of UV Reduction and Magnetic Protection

    NASA Astrophysics Data System (ADS)

    Clark, Joni; Mason, P. A.; Zuluaga, J. I.; Cuartas, P. A.; Bustamonte, S.

    2013-06-01

    The number of planets found in binary systems is growing rapidly and the discovery of many more planets in binary systems appears inevitable. We use the newly refined and more restrictive, single star habitable zone (HZ) models of Kopparapu et al. (2013) and include planetary magnetic protection calculations in order to investigate binary star habitability. Here we present results on circumstellar or S-type planets, which are planets orbiting a single star member of a binary. P-type planets, on the other hand, orbit the center of mass of the binary. Stable planetary orbits exist in HZs for both types of binaries as long as the semi-major axis of the planet is either greater than (P-type) or less than (S-type) a few times the semi-major axis of the binary. We define two types of S-type binaries for this investigation. The SA-type is a circumstellar planet orbiting the binary’s primary star. In this case, the limits of habitability are dominated by the primary being only slightly affected by the presence of the lower mass companion. Thus, the SA-type planets have habitability characteristics, including magnetic protection, similar to single stars of the same type. The SB-type is a circumstellar planet orbiting the secondary star in a wide binary. An SB-type planet needs to orbit slightly outside the secondary’s single star HZ and remain within the primary’s single star HZ at all times. We explore the parameter space for which this is possible. We have found that planets lying in the combined HZ of SB binaries can be magnetically protected against the effects of stellar winds from both primary and secondary stars in a limited number of cases. We conclude that habitable conditions exist for a subset of SA-type, and a smaller subset of SB-type binaries. However, circumbinary planets (P-types) provide the most intriguing possibilities for the existence of complex life due to the effect of synchronization of binaries with periods in the 20-30 day range which allows

  14. Solar-Electric Dish Stirling System Development

    SciTech Connect

    Mancini, T.R.

    1997-12-31

    Electrical power generated with the heat from the sun, called solar thermal power, is produced with three types of concentrating solar systems - trough or line-focus systems; power towers in which a centrally-located thermal receiver is illuminated with a large field of sun-tracking heliostats; and dish/engine systems. A special case of the third type of system, a dish/Stirling system, is the subject of this paper. A dish/Stirling system comprises a parabolic dish concentrator, a thermal receiver, and a Stirling engine/generator located at the focus of the dish. Several different dish/Stirling systems have been built and operated during the past 15 years. One system claims the world record for net conversion of solar energy to electric power of 29.4%; and two different company`s systems have accumulated thousands of hours of on-sun operation. Due to de-regulation and intense competition in global energy markets as well as the immaturity of the technology, dish/Stirling systems have not yet found their way into the marketplace. This situation is changing as solar technologies become more mature and manufacturers identify high-value niche markets for their products. In this paper, I review the history of dish/Stirling system development with an emphasis on technical and other issues that directly impact the Stirling engine. I also try to provide some insight to the opportunities and barriers confronting the application of dish/Stirling in power generation markets.

  15. High Resolution Imaging of Very Low Mass Spectral Binaries: Three Resolved Systems and Detection of Orbital Motion in an L/T Transition Binary

    NASA Astrophysics Data System (ADS)

    Bardalez Gagliuffi, Daniella C.; Gelino, Christopher R.; Burgasser, Adam J.

    2015-11-01

    We present high resolution Laser Guide Star Adaptive Optics imaging of 43 late-M, L and T dwarf systems with Keck/NIRC2. These include 17 spectral binary candidates, systems whose spectra suggest the presence of a T dwarf secondary. We resolve three systems: 2MASS J1341-3052, SDSS J1511+0607 and SDSS J2052-1609 the first two are resolved for the first time. All three have projected separations <8 AU and estimated periods of 14-80 years. We also report a preliminary orbit determination for SDSS J2052-1609 based on six epochs of resolved astrometry between 2005 and 2010. Among the 14 unresolved spectral binaries, 5 systems were confirmed binaries but remained unresolved, implying a minimum binary fraction of {47}-11+12% for this sample. Our inability to resolve most of the spectral binaries, including the confirmed binaries, supports the hypothesis that a large fraction of very low mass systems have relatively small separations and are missed with direct imaging. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  16. Solar thermionic power systems for terrestrial applications

    NASA Technical Reports Server (NTRS)

    Shimada, K.; Swerdling, M.

    1977-01-01

    The results of a feasibility study which showed that a low-temperature, high-efficient thermionic power system can efficiently convert solar energy to electrical energy without heat transport, as required by most solar thermal systems are described. A 3-dimensional (2-axis tracking) 93 sq m parabolic solar concentrator, consisting of mirrors on a foam glass substrate and designed to a concentration ratio (mirror area/aperture area) of 2000 is considered for producing a design temperature of 1100 C at an efficiency of 74%. A tracking subsystem must track the sun at an accuracy of a nominal plus or minus 1.0 degree for maximum use of the sun's energy. Each complete solar thermionic power system unit rated at about 20 kWe peak can generate approximately 48,000 kWh/yr. In addition, a thermal energy conversion system can be cascaded within the thermionic power system so that the high quality waste heat can be further utilized to increase the net electrical output. Potential applications of a solar thermionic power generation system are remote sites, apartment house complexes, heating and cooling, hydrogen production and large power stations.

  17. Design and installation of solar heating and hot water systems

    SciTech Connect

    Williams, J.R.

    1983-01-01

    A no-nonsense explanation of information on the use of solar energy for heating, cooling, and producing hot water. The work is both scholarly and practical. Background of high school algebra is the only mathematics expected. Worked examples but no exercises. Contents: Solar radiation. Heating loads. Design and analysis of flat-place liquid-heating collectors. Flat-plate air-heating collectors. Evacuated solar collectors. Solar hot water systems. Solar ponds. Active solar heating and cooling systems.

  18. Development of a Conceptual Structure for Architectural Solar Energy Systems.

    ERIC Educational Resources Information Center

    Ringel, Robert F.

    Solar subsystems and components were identified and conceptual structure was developed for architectural solar energy heating and cooling systems. Recent literature related to solar energy systems was reviewed and analyzed. Solar heating and cooling system, subsystem, and component data were compared for agreement and completeness. Significant…

  19. Formation and Evolution of Planets in and Around Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Haghighipour, N.

    2015-07-01

    The discovery of planets in and around binary stars (also known as circumprimary and circumbinary planets) has opened a new chapter in the studies of the formation and dynamical evolution of planetary systems. Computational simulations indicate that in binaries with separations smaller than ˜50 au, the perturbation of the secondary star can have profound effects on the dynamics of solid bodies around the primary, prohibiting their collisions to result in coalescence and growth to larger objects. However, several circumprimary planets are known to exist in binaries with separations of ˜20 au raising questions about how these planets formed and acquired their final orbital architecture. Also, a survey of the currently known circumbinary planets (CBPs) points to several interesting characteristics of these bodies. The detection of multiple transits in these systems points to the (almost) co-planarity of the planet-binary orbits, giving strong support to the idea that these planets formed in circumbinary protoplanetary disks. The proximity of some of these planets to the boundary of orbital instability around the binary suggests an evolutionary scenario in which planets form at large distances and either migrate to their present orbits, or are scattered to their current locations. Surprisingly, all currently known CBPs are Neptune-sized or smaller, and no CBP seems to exist around very short-period binaries. These specific characteristics of binary-planetary systems have raised many questions regarding the formation, dynamical evolution, and orbital architecture of these objects. I will review the current state of research on the formation of planets in and around binary stars, and discuss the new developments on the understanding of their dynamical evolution.

  20. Geophysics and cosmogony of solar system

    NASA Astrophysics Data System (ADS)

    Kuzjmenko, G. I.; Smirnov, V. A.

    2003-04-01

    The attention to primary importance of geophysics in formation of modern representations about planets of Solar system is inverted. [ Kuzjmenko G.I. Deep Processes in the Earth's Interior. Geophys. J. 2001. Vol. 20, pp 813 -831; Kuzjmenko G.I., Smirnov V.A. Minor Bodys and Cosmogony of a Solar System. CAMMAC 2002. Intern. Conf. September 23 - 29, Vinnitsia, 2002, pp 35 -36]. The analysis rocket given about electromagnetic properties of Solar system has helped utilization Generalized Statistical-Wavemechanical Equations (GSWE), which special case is the quantum equation of Schrödinger. From GSWE the decision not only old problems of Solar system, but also prediction of presence of a belt of small bodies of Kuiper's and features of absent-minded substance in Solar system follows. The modern geophysical data on properties of the Earth with use GSWE result not only in the description of the electromagnetic characteristics of planets, but open existence dark mattery, which properties now are actively studied [Kuzjmenko G.I., Zelinsky I.P. Generalized Statistical-Wavemechanical Equations (GSWE) and its Applications. Proc. of 16-th IMACS World Congress 2000. Lausanne, Switzerland, August 21-25, 2000. CD File 416 -1].

  1. Predicting Solar Disturbance Effects on Navigation Systems

    NASA Astrophysics Data System (ADS)

    Lockwood, M.; Wild, M. N.; Stamper, R.; Davis, C. J.; Grande, M.

    A variety of operational systems are vulnerable to disruption by solar disturbances brought to the Earth by the solar wind. Of particular importance to navigation systems are energetic charged particles which can generate temporary malfunctions and permanent damage in satellites. Modern spacecraft technology may prove to be particularly at risk during the next maximum of the solar cycle. In addition, the associated ionospheric disturbances cause phase shifts of transionospheric and ionosphere-reflected signals, giving positioning errors and loss of signal for GPS and Loran-C positioning systems and for over-the-horizon radars. We now have sufficient understanding of the solar wind, and how it interacts with the Earth's magnetic field, to predict statistically the likely effects on operational systems over the next solar cycle. We also have a number of advanced ways of detecting and tracking these disturbances through space but we cannot, as yet, provide accurate forecasts of individual disturbances that could be used to protect satellites and to correct errors. In addition, we have recently discovered long-term changes in the Sun, which mean that the number and severity of the disturbances to operational systems are increasing.

  2. Solar dynamic space power system heat rejection

    NASA Technical Reports Server (NTRS)

    Carlson, A. W.; Gustafson, E.; Mclallin, K. L.

    1986-01-01

    A radiator system concept is described that meets the heat rejection requirements of the NASA Space Station solar dynamic power modules. The heat pipe radiator is a high-reliability, high-performance approach that is capable of erection in space and is maintainable on orbit. Results are present of trade studies that compare the radiator system area and weight estimates for candidate advanced high performance heat pipes. The results indicate the advantages of the dual-slot heat pipe radiator for high temperature applications as well as its weight-reduction potential over the range of temperatures to be encountered in the solar dynamic heat rejection systems.

  3. 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.

  4. Absolute dimensions of solar-type eclipsing binaries. EF Aquarii: a G0 test for stellar evolution models

    NASA Astrophysics Data System (ADS)

    Vos, J.; Clausen, J. V.; Jørgensen, U. G.; Østensen, R. H.; Claret, A.; Hillen, M.; Exter, K.

    2012-04-01

    Context. Recent studies have shown that stellar chromospheric activity, and its effect on convective energy transport in the envelope, is most likely the cause of significant radius and temperature discrepancies between theoretical evolution models and observations. Accurate mass, radius, and abundance determinations from solar-type binaries exhibiting various levels of activity are needed for a better insight into the structure and evolution of these stars. Aims: We aim to determine absolute dimensions and abundances for the solar-type detached eclipsing binary EF Aqr, and to perform a detailed comparison with results from recent stellar evolutionary models. Methods.uvby light curves and uvbyβ standard photometry were obtained with the Strömgren Automatic Telescope. The broadening function formalism was applied on spectra observed with HERMES at the Mercator telescope in La Palma, to obtain radial velocity curves. State-of-the-art methods were applied for the photometric and spectroscopic analyses. Results: Masses and radii with a precision of 0.6% and 1.0% respectively have been established for both components of EF Aqr. The active 0.956 M⊙ secondary shows star spots and strong Ca II H and K emission lines. The 1.224 M⊙ primary shows signs of activity as well, but at a lower level. An [Fe/H] abundance of 0.00 ± 0.10 is derived with similar abundances for Si, Ca, Sc, Ti, V, Cr, Co, and Ni. Solar calibrated evolutionary models such as Yonsei-Yale, Victoria-Regina and BaSTI isochrones and evolutionary tracks are unable to reproduce EF Aqr, especially for the secondary, which is 9% larger and 400 K cooler than predicted. Models adopting significantly lower mixing length parameters l/Hp remove these discrepancies, as seen in other solar type binaries. For the observed metallicity, Granada models with a mixing length of l/Hp = 1.30 (primary) and 1.05 (secondary) reproduce both components at a common age of 1.5 ± 0.6 Gyr. Conclusions: Observations of EF Aqr

  5. Application and design of solar photovoltaic system

    NASA Astrophysics Data System (ADS)

    Tianze, Li; Hengwei, Lu; Chuan, Jiang; Luan, Hou; Xia, Zhang

    2011-02-01

    Solar modules, power electronic equipments which include the charge-discharge controller, the inverter, the test instrumentation and the computer monitoring, and the storage battery or the other energy storage and auxiliary generating plant make up of the photovoltaic system which is shown in the thesis. PV system design should follow to meet the load supply requirements, make system low cost, seriously consider the design of software and hardware, and make general software design prior to hardware design in the paper. To take the design of PV system for an example, the paper gives the analysis of the design of system software and system hardware, economic benefit, and basic ideas and steps of the installation and the connection of the system. It elaborates on the information acquisition, the software and hardware design of the system, the evaluation and optimization of the system. Finally, it shows the analysis and prospect of the application of photovoltaic technology in outer space, solar lamps, freeways and communications.

  6. THE OCCURRENCE OF WIDE-ORBIT PLANETS IN BINARY STAR SYSTEMS

    SciTech Connect

    Zuckerman, B.

    2014-08-20

    The occurrence of planets in binary star systems has been investigated via a variety of techniques that sample a wide range of semi-major axes, but with a preponderance of such results applicable to planets with semi-major axes less than a few astronomical units. We utilize a new method—the presence or absence of heavy elements in the atmospheres of white dwarf stars—to elucidate the frequency in main sequence binary star systems of planets with semi-major axes greater than a few astronomical units. We consider only binaries where a putative planetary system orbits one member (no circumbinary planets). For main sequence binaries where the primary star is of spectral type A or F, data in the published literature suggests that the existence of a secondary star with a semi-major axis less than about 1000 AU suppresses the formation and/or long-term stability of an extended planetary system around the primary. For these spectral types and initial semi-major axis ≥1000 AU, extended planetary systems appear to be as common around stars in binary systems as they are around single stars.

  7. THE PHASES DIFFERENTIAL ASTROMETRY DATA ARCHIVE. V. CANDIDATE SUBSTELLAR COMPANIONS TO BINARY SYSTEMS

    SciTech Connect

    Muterspaugh, Matthew W.; Lane, Benjamin F.; Kulkarni, S. R.; Konacki, Maciej; Burke, Bernard F.; Colavita, M. M.; Shao, M.; Hartkopf, William I.; Boss, Alan P.; Williamson, M. E-mail: blane@draper.co

    2010-12-15

    The Palomar High-precision Astrometric Search for Exoplanet Systems monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small as Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Six binaries are presented that show evidence of substellar companions orbiting either the primary or secondary star. Of these six systems, the likelihoods of two of the detected perturbations to represent real objects are considered to be 'high confidence', while the remaining four systems are less certain and will require continued observations for confirmation.

  8. Optimal reliability design method for remote solar systems

    NASA Astrophysics Data System (ADS)

    Suwapaet, Nuchida

    A unique optimal reliability design algorithm is developed for remote communication systems. The algorithm deals with either minimizing an unavailability of the system within a fixed cost or minimizing the cost of the system with an unavailability constraint. The unavailability of the system is a function of three possible failure occurrences: individual component breakdown, solar energy deficiency (loss of load probability), and satellite/radio transmission loss. The three mathematical models of component failure, solar power failure, transmission failure are combined and formulated as a nonlinear programming optimization problem with binary decision variables, such as number and type (or size) of photovoltaic modules, batteries, radios, antennas, and controllers. Three possible failures are identified and integrated in computer algorithm to generate the parameters for the optimization algorithm. The optimization algorithm is implemented with a branch-and-bound technique solution in MS Excel Solver. The algorithm is applied to a case study design for an actual system that will be set up in remote mountainous areas of Peru. The automated algorithm is verified with independent calculations. The optimal results from minimizing the unavailability of the system with the cost constraint case and minimizing the total cost of the system with the unavailability constraint case are consistent with each other. The tradeoff feature in the algorithm allows designers to observe results of 'what-if' scenarios of relaxing constraint bounds, thus obtaining the most benefit from the optimization process. An example of this approach applied to an existing communication system in the Andes shows dramatic improvement in reliability for little increase in cost. The algorithm is a real design tool, unlike other existing simulation design tools. The algorithm should be useful for other stochastic systems where component reliability, random supply and demand, and communication are

  9. Pump efficiency in solar-energy systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Study investigates characteristics of typical off-the-shelf pumping systems that might be used in solar systems. Report includes discussion of difficulties in predicting pump efficiency from manufacturers' data. Sample calculations are given. Peak efficiencies, flow-rate control, and noise levels are investigated. Review or theory of pumps types and operating characteristics is presented.

  10. Solar Hot-Air System --Memphis, Tennessee

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar collectors using air as collection medium provide space heating for four-building office complex in Memphis. 98 page report furnishes details on installation, including: description of system; system startup and acceptance-test results; technical data on collector; installation manuals for collectors, air handler and heat-storage unit.

  11. The Angular Momentum of the Solar System

    NASA Astrophysics Data System (ADS)

    Cang, Rongquin; Guo, Jianpo; Hu, Juanxiu; He, Chaoquiong

    2016-05-01

    The angular momentum of the Solar System is a very important physical quantity to the formation and evolution of the Solar System. Previously, the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets were only taken into consideration, when researchers calculated the angular momentum of the Solar System. Nowadays, it seems narrow and conservative. Using Eggleton's code, we calculate the rotational inertia of the Sun. Furthermore, we obtain that the spin angular momentum of the Sun is 1.8838 x 10^41 kg m^2 s^-1. Besides the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets, we also account for the orbital angular momentum of the Asteroid Belt, the Kuiper Belt, the Oort Cloud, the Ninth Giant Planet and the Solar Companion. We obtain that the angular momentum of the whole Solar System is 3.3212 x 10^45 kg m^2 s^-1.

  12. Origin of the Outer Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J. (Principal Investigator); Boyce, Joseph (Technical Monitor)

    2003-01-01

    Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; (2) determining the size distributions or luminosity function of the individual populations or the Kuiper belt as a whole; (3) determining the inclinations distributions of these populations; (4) establishing the radial extent of the Kuiper belt; (5) measuring and relating the physical properties of different types of KBOs to those of other solar system bodies; and, (6) completing our systematic inventory of the satellites of the outer planets.

  13. Volcanic processes in the Solar System

    USGS Publications Warehouse

    Carr, M.H.

    1987-01-01

    This article stresses that terrestrial volcanism represents only part of the range of volcanism in the solar system. Earth processes of volcanicity are dominated by plate tectonics, which does not seem to operate on other planets, except possibly on Venus. Lunar volcanicity is dominated by lava effusion at enormous rates. Mars is similar, with the addition to huge shield volcanoes developed over fixed hotspots. Io, the moon closest to Jupiter, is the most active body in the Solar System and, for example, much sulphur and silicates are emitted. The eruptions of Io are generated by heating caused by tides induced by Jupiter. Europa nearby seems to emit water from fractures and Ganymede is similar. The satellites of Saturn and Uranus are also marked by volcanic craters, but they are of very low temperature melts, possibly of ammonia and water. The volcanism of the solar system is generally more exotic, the greater the distance from Earth. -A.Scarth

  14. Cryovolcanism in the outer solar system

    USGS Publications Warehouse

    Geissler, Paul E.

    2015-01-01

    Cryovolcanism is defined as the extrusion of liquids and vapors of materials that would be frozen solid at the planetary surface temperatures of the icy bodies of the outer solar system. Active cryovolcanism is now known to occur on Saturn's moon Enceladus and on Neptune's moon Triton and is suspected on Jupiter's moon Europa, while evidence for past cryovolcanic activity is widespread throughout the outer solar system. This chapter examines the mechanisms and manifestations of cryovolcanism, beginning with a review of the materials that make up these unusual ‘‘magmas’’ and the means by which they might erupt and concluding with a volcanologist's tour of the farthest reaches of the solar system.

  15. Star Formation and the Solar System

    NASA Technical Reports Server (NTRS)

    Bally, John; Boss, Alan; Papanastassiou, Dimitri; Sandford, Scott; Sargent, Anneila

    1988-01-01

    We have seen that studies of nearby star-forming regions are beginning to reveal the first signs of protoplanetary disks. Studies of interstellar and interplanetary grains are starting to provide clues about the processing and incorporation of matter into the Solar System. Studies of meteorites have yielded isotopic anomalies which indicate that some of the grains and inclusions in these bodies are very primitive. Although we have not yet detected a true interstellar grain, some of these materials have not been extensively modified since their removal from the ISM. We are indeed close to seeing our interstellar heritage. The overlap between astronomical and Solar System studies is in its infancy. What future experiments, observations, and missions can be performed in the near future that will greatly enhance our understanding of star formation and the formation of the Solar System?

  16. NSVS4484038, A contact binary system at the short-period cutoff

    SciTech Connect

    Zhang, X. B.; Deng, L. C.; Wang, K.; Yan, Z. Z.; Tian, J. F.; Peng, Y. J.; Pan, Y.; Luo, Z. Q.; Sun, J. J.; Liu, Q. L.; Xin, H. Q.; Zhou, Q.

    2014-09-01

    We present a photometric study of the short-period eclipsing binary NSVS4484038. Time-series CCD photometry of the star in the B and V band was carried out. An orbital period of 0.218551 days was determined for the eclipsing binary and a revised linear ephemeris was given. The first photometric solution of the binary system was detected through light-curve synthesis using the Wilson-Devinney method. It reveals an overcontact configuration for the system with a filling-out factor of about 10%. The mass ratio was determined to be 2.74 with an inclination of 72.°1. The less massive secondary component is found to have a higher surface temperature than the primary by about 90 K, indicating that NSVS4484038 could be a contact system of W subtype. The star is then identified to be a new member of W UMa systems at the short-period cutoff. Comparisons with known contact binaries at the short-period cutoff, the properties, and the evolutionary status of the binary system are discussed.

  17. Fluorescence resonance energy transfer in a binary organic nanoparticle system and its application.

    PubMed

    Wu, Meng; Xu, Xinjun; Wang, Jinshan; Li, Lidong

    2015-04-22

    Fluorescent organic nanoparticles have a much better photostability than molecule-based probes. Here, we report a simple strategy to detect chemicals and biomolecules by a binary nanoparticle system based on fluorescence resonance energy transfer (FRET). Poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO, energy donor) and poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV, energy acceptor) are utilized to prepare the binary nanoparticle system through a reprecipitation method. Since the FRET process is strongly distance-dependent, a change in the interparticle distance between the two kinds of nanoparticles after introduction of analytes will alter the FRET efficiency. The response of the binary nanoparticle system to cationic polyelectrolytes was investigated by monitoring the FRET efficiency from PFO to MEH-PPV nanoparticles and the fluorescence color of the nanoparticle solutions. Furthermore, the cationic polyelectrolyte pretreated binary nanoparticle system can be used to detect DNA by desorption of nanoparticles from the polyelectrolyte's chains and the detection concentration can go down to 10(-14) M. Thus, the binary nanoparticle system shows great promise for applications in chemical sensing or biosensing.

  18. Dynamics of Binary Near-Earth Asteroid System (35107) 1991 VH

    NASA Astrophysics Data System (ADS)

    Naidu, Shantanu P.; Margot, J. L.; Busch, M. W.; Taylor, P. A.; Nolan, M. C.; Howell, E. S.; Giorgini, J. D.; Benner, L. A. M.; Brozovic, M.; Magri, C.

    2012-05-01

    Near-Earth Asteroid (35107) 1991 VH was discovered to be a binary in March 1997, based on its light-curve (IAUC 6607). It made a very close approach to the Earth in August 2008 at a distance of 0.045 AU. We used this opportunity to secure an extensive radar data set with the Arecibo S-band (2380 MHz, 13 cm wavelength) planetary radar system, including range-Doppler images with spatial resolution as fine as 15 m. The images (spanning 14 days) reveal that the primary is roughly spheroidal with a radius of 650 m. The range extent of the secondary in these images varies from less than 100 m to more than 200 m indicating that it is highly elongated. The radar data provide an excellent determination of the mutual orbit: The orbital period is 32 hours, the eccentricity is 0.05, and the total system mass is 1.5e12 kg. Numerical simulations of the spin of the elongated secondary in this eccentric mutual orbit reveal a large region of chaos in the phase space, similar to that observed in Saturn’s moon Hyperion (Wisdom, Peale, Mignard 1984). The chaotic region surrounds the 1:2, 1:1, 3:2 and 2:1 spin-orbit resonances, but allows for islands of stability around the 1:2 and 1:1 spin-orbit states. The secondary’s echo bandwidths indicate that its spin rate indeed lies within or very close to this chaotic region. To date no acceptable fit to the sequence of secondary images has been found under the assumption of synchronous spin. Saturn’s moon Hyperion is the only solar system object known so far to have a chaotic spin state (Wisdom, Peale, Mignard 1984).

  19. 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].

  20. Communication: radial distribution functions in a two-dimensional binary colloidal hard sphere system.

    PubMed

    Thorneywork, Alice L; Roth, Roland; Aarts, Dirk G A L; Dullens, Roel P A

    2014-04-28

    Two-dimensional hard disks are a fundamentally important many-body model system in classical statistical mechanics. Despite their significance, a comprehensive experimental data set for two-dimensional single component and binary hard disks is lacking. Here, we present a direct comparison between the full set of radial distribution functions and the contact values of a two-dimensional binary colloidal hard sphere model system and those calculated using fundamental measure theory. We find excellent quantitative agreement between our experimental data and theoretical predictions for both single component and binary hard disk systems. Our results provide a unique and fully quantitative mapping between experiments and theory, which is crucial in establishing the fundamental link between structure and dynamics in simple liquids and glass forming systems.

  1. Observational Investigations on Contact Binaries in Multiple-star Systems and Star Clusters

    NASA Astrophysics Data System (ADS)

    Liu, L.

    2013-01-01

    The W UMa-type contact binaries are strongly interacting systems whose components both fill their critical Roche lobes and share a convective common envelope. The models of contact binaries are bottlenecked due to too many uncertain parameters. In the 1960s and 1970s, the common convective envelope model was accepted after several fierce controversies. And then, the thermal relaxation oscillation (TRO) model, the discontinuity model, and the angular momentum loss (AML) model appeared. However, in the past forty years, there lacked remarkable advance. The coexistence of many unknown parameters blocks the theoretical development of contact binaries. A study on the contact binaries in multiple star systems and star clusters, which could provide lots of information for their formation and evolution, may be a potential growing point for understanding these objects. More and more evidence shows that many of contact binaries are located in multiple star systems and star clusters. In this thesis, we observed and analyzed contact binaries in the forementioned systems. The observational and theoretical studies for contact binary are also summarized briefly. The results obtained are as follows: (1) Three contact binaries V1128 Tau, GZ And, VW Boo which possess visual companions show periodic oscillations. The period ranges from 16.7 years to 46.5 years. These oscillations probably come from the orbital movement of a close third body. (2) Four contact binaries GSC 02393-00680, V396 Mon, FU Dra, SS Ari which do not have visual companions also present periodic oscillations. Whether they are real members of multiple star systems needs further investigations. These oscillations probably result from the orbital movement of a close M-type companion. (3) The periods of three contact binaries EQ Cep, ER Cep and V371 Cep in the old open cluster NGC 188 show a long-term increase. There is a cyclic period oscillation in ER Cep, with a period of 5.4 years. We find that the total mass of

  2. Solar system planets observed with Suzaku

    NASA Astrophysics Data System (ADS)

    Ezoe, Yuichiro; Ishikawa, Kumi; Ohashi, Takaya; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa; Fujimoto, Ryuichi; Miyoshi, Yoshizumi; Terada, Naoki; Uchiyama, Yasunobu; Futaana, Yoshifumi

    2011-02-01

    Recent results of solar system planets observed with the Japanese X-ray astronomy satellite Suzaku are reviewed. Thanks to the low instrumental background and good energy resolution, X-ray CCDs onboard Suzaku are one of the best probes to study diffuse X-ray emission. An overview of the Suzaku data of Jupiter and Earth is presented, along with preliminary results of Mars. Firstly, diffuse hard X-ray emission is discovered in 1-5 keV at Jovian radiation belts. Its spectrum is represented by a power-law continuum with a photon index of ˜1.4. This emission could originate from inverse-Compton scattering of solar photons by tens MeV electrons. Secondly, variable diffuse soft X-rays are serendipitously found during observations in the directions of the north ecliptic pole and galactic ridge. Good time correlations with the solar wind and emission lines found in the X-ray spectra are firm evidences of a solar wind charge exchange emission with Earth’s exosphere. Thirdly, diffuse X-ray emission from Martian exosphere via the solar wind charge exchange is investigated for the first time at solar minimum. A stringent upper limit on the density of the Martian exosphere is placed from the Suzaku data.

  3. Solar-System Tests of Gravitational Theories

    NASA Technical Reports Server (NTRS)

    Shapiro, Irwin I.

    2005-01-01

    We are engaged in testing gravitational theory, mainly using observations of objects in the solar system and mainly on the interplanetary scale. Our goal is either to detect departures from the standard model (general relativity) - if any exist within the level of sensitivity of our data - or to support this model by placing tighter bounds on any departure from it. For this project, we have analyzed a combination of observational data with our model of the solar system, including planetary radar ranging, lunar laser ranging, and spacecraft tracking, as well as pulsar timing and pulsar VLBI measurements. In the past year, we have added to our data, primarily lunar laser ranging measurements, but also supplementary data concerning the physical properties of solar-system objects, such as the solar quadrupole moment, planetary masses, and asteroid radii. Because the solar quadrupole moment contributes to the classical precession of planetary perihelia, but with a dependence on distance from the Sun that differs from that of the relativistic precession, it is possible to estimate effects simultaneously. However, our interest is mainly in the relativistic effect, and we find that imposing a constraint on the quadrupole moment from helioseismology studies, gives us a dramatic (about ten-fold) decrease in the standard error of our estimate of the relativistic component of the perihelion advance.

  4. Solar-System Tests of Gravitational Theories

    NASA Technical Reports Server (NTRS)

    Shapiro, Irwin I.

    2005-01-01

    This research is aimed at testing gravitational theory, primarily on an interplanetary scale and using mainly observations of objects in the solar system. Our goal is either to detect departures from the standard model (general relativity) - if any exist within the level of sensitivity of our data - or to support this model by placing tighter bounds on any departure from it. For this project, we have analyzed a combination of observational data with our model of the solar system, including planetary radar ranging, lunar laser ranging, and spacecraft tracking, as well as pulsar timing and pulsar VLBI measurements.

  5. High throughput solar cell ablation system

    SciTech Connect

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2014-10-14

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  6. Testing relativity with solar system dynamics

    NASA Technical Reports Server (NTRS)

    Hellings, R. W.

    1984-01-01

    A major breakthrough is described in the accuracy of Solar System dynamical tests of relativistic gravity. The breakthrough was achieved by factoring in ranging data from Viking Landers 1 and 2 from the surface of Mars. Other key data sources included optical transit circle observations, lunar laser ranging, planetary radar, and spacecraft (Mariner 9 to Mars and Mariner 10 to Mercury). The Solar System model which is used to fit the data and the process by which such fits are performed are explained and results are discussed. The results are fully consistent with the predictions of General Relativity.

  7. High throughput solar cell ablation system

    DOEpatents

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2012-09-11

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  8. A Multi-wavelength Study of the Close M-dwarf Eclipsing Binary System BX Tri

    NASA Astrophysics Data System (ADS)

    Perdelwitz, V.; Czesla, S.; Robrade, J.; Schmitt, J. H. M. M.

    2015-01-01

    We present the first detailed X-ray study of the close dMe binary system BX Tri, whose optical variation has been continously monitored in the frame of the DWARF project (Pribulla et al.(2012)). We observed BX Tri with XMM-Newton for two full orbital periods and confirm that the system is an ultra-active M-dwarf binary showing frequent flares and an X-ray luminosity close to the saturation limit. The strong magnetic activity could have influenced the angular momentum evolution of the system via magnetic braking.

  9. Black holes in stellar-mass binary systems: expiating original spin?

    NASA Astrophysics Data System (ADS)

    King, Andrew; Nixon, Chris

    2016-10-01

    We investigate systematically whether accreting black hole systems are likely to reach global alignment of the black hole spin and its accretion disc with the binary plane. In low-mass X-ray binaries (LMXBs), there is only a modest tendency to reach such global alignment, and it is difficult to achieve fully: except for special initial conditions, we expect misalignment of the spin and orbital planes by ˜1 rad for most of the LMXB lifetime. The same is expected in high-mass X-ray binaries. A fairly close approach to global alignment is likely in most stellar-mass ultraluminous X-ray binary systems (ULXs) where the companion star fills its Roche lobe and transfers mass on a thermal or nuclear time-scale to a black hole of lower mass. These systems are unlikely to show orbital eclipses, as their emission cones are close to the hole's spin axis. This offers a potential observational test, as models for ULXs invoking intermediate-mass black holes do predict eclipses for ensembles of ≳ 10 systems. Recent observational work shows that eclipses are either absent or extremely rare in ULXs, supporting the picture that most ULXs are stellar-mass binaries with companion stars more massive than the accretor.

  10. Solar dynamic power system definition study

    NASA Technical Reports Server (NTRS)

    Wallin, Wayne E.; Friefeld, Jerry M.

    1988-01-01

    The solar dynamic power system design and analysis study compared Brayton, alkali-metal Rankine, and free-piston Stirling cycles with silicon planar and GaAs concentrator photovoltaic power systems for application to missions beyond the Phase 2 Space Station level of technology for all power systems. Conceptual designs for Brayton and Stirling power systems were developed for 35 kWe and 7 kWe power levels. All power systems were designed for 7-year end-of-life conditions in low Earth orbit. LiF was selected for thermal energy storage for the solar dynamic systems. Results indicate that the Stirling cycle systems have the highest performance (lowest weight and area) followed by the Brayton cycle, with photovoltaic systems considerably lower in performance. For example, based on the performance assumptions used, the planar silicon power system weight was 55 to 75 percent higher than for the Stirling system. A technology program was developed to address areas wherein significant performance improvements could be realized relative to the current state-of-the-art as represented by Space Station. In addition, a preliminary evaluation of hardenability potential found that solar dynamic systems can be hardened beyond the hardness inherent in the conceptual designs of this study.

  11. Solar-system abundances of the elements

    NASA Technical Reports Server (NTRS)

    Anders, E.; Ebihara, M.

    1982-01-01

    Elemental analyses of the Ogueil Cl meteorite and all previous Cl chondrite analyses were employed to develop a new solar system abundance table, including the standard deviation and number of analyses for each element. The table also comprises the abundances of radioactive and radiogenic nuclides at the present and 4.55 AE ago, as well as abundances by weight in a typical Cl chondrite. The new abundances were within 20% of those determined by Cameron (1982), except for 14 cases in the range 20-50%, and 5 over 50%. The solar abundances were compared with the Cl abundances, showing a total of only 7 disagreements. No significant discrepancies were detected in the major cosmochemical groups, and a smooth trend was found in the abundances of odd-A nuclides. The new set is interpreted as accurate to 10%, with the Cl chondrites matching the primordial solar system abundances to at most 10% deviation.

  12. Exploring the Trans-Neptunian Solar System

    NASA Astrophysics Data System (ADS)

    1998-01-01

    A profound question for scientists, philosophers and, indeed, all humans concerns how the solar system originated and subsequently evolved. To understand the solar system's formation, it is necessary to document fully the chemical and physical makeup of its components today, particularly those parts thought to retain clues about primordial conditions and processes.] In the past decade, our knowledge of the outermost, or trans-neptunian, region of the solar system has been transformed as a result of Earth-based observations of the Pluto-Charon system, Voyager 2's encounter with Neptune and its satellite Triton, and recent discoveries of dozens of bodies near to or beyond the orbit of Neptune. As a class, these newly detected objects, along with Pluto, Charon, and Triton, occupy the inner region of a hitherto unexplored component of the solar system, the Kuiper Belt. The Kuiper Belt is believed to be a reservoir of primordial objects of the type that formed in the solar nebula and eventually accreted to form the major planets. The Kuiper Belt is also thought to be the source of short-period comets and a population of icy bodies, the Centaurs, with orbits among the giant planets. Additional components of the distant outer solar system, such as dust and the Oort comet cloud, as well as the planet Neptune itself, are not discussed in this report. Our increasing knowledge of the trans-neptunian solar system has been matched by a corresponding increase in our capabilities for remote and in situ observation of these distant regions. Over the next 10 to 15 years, a new generation of ground- and space-based instruments, including the Keck and Gemini telescopes and the Space Infrared Telescope Facility, will greatly expand our ability to search for and conduct physical and chemical studies on these distant bodies. Over the same time span, a new generation of lightweight spacecraft should become available and enable the first missions designed specifically to explore the icy

  13. Modeling microstructure evolution of binary systems subjected to irradiation and mechanical loading

    NASA Astrophysics Data System (ADS)

    Kharchenko, Dmitrii O.; Shchokotova, Olga M.; Lysenko, Irina O.; Kharchenko, Vasyl O.

    2015-07-01

    We study a change in mechanical properties of binary systems subjected to irradiation influence described by ballistic flux of atomic mixing having regular and stochastic contributions. By using numerical modeling based on the phase field approach we study dynamics of deformation fields in a previously irradiated system and in the binary system deformed during irradiation. An influence of both deterministic and stochastic components of ballistic flux onto both yield strength and ultimate strength is studied. We have found that degradation of mechanical properties relates to the formation of percolating clusters of shear bands. Considering a hardening coefficient we analyze stages of plastic deformation of both initially irradiated alloy and alloy subjected to sustained irradiation. Stability of binary alloy under mechanical loading in the form of shear strain with a constant rate and cyclic deformation is discussed.

  14. Realization of a Binary-Outcome Projection Measurement of a Three-Level Superconducting Quantum System

    NASA Astrophysics Data System (ADS)

    Jerger, Markus; Macha, Pascal; Hamann, Andrés Rosario; Reshitnyk, Yarema; Juliusson, Kristinn; Fedorov, Arkady

    2016-07-01

    Binary-outcome measurements allow one to determine whether a multilevel quantum system is in a certain state while preserving quantum coherence between all orthogonal states. In this paper, we explore different regimes of the dispersive readout of a three-level superconducting quantum system coupled to a microwave cavity in order to implement binary-outcome measurements. By designing identical cavity-frequency shifts for the first and second excited states of the system, we realize strong projective binary-outcome measurements onto its ground state with a fidelity of 94.3%. Complemented with standard microwave control and low-noise parametric amplification, this scheme enables the quantum nondemolition detection of leakage errors and can be used to create sets of compatible measurements to reveal the contextual nature of superconducting circuits.

  15. Solar heating system final design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The system is composed of a warm air collector, a logic control unit and a universal switching and transport unit. The collector was originally conceived and designed as an integrated roof/wall system and therefore provides a dual function in the structure. The collector serves both as a solar energy conversion system and as a structural weather resistant skin. The control unit provides totally automatic control over the operation of the system. It receives input data from sensor probes in collectors, storage and living space. The logic was designed so as to make maximum use of solar energy and minimize use of conventional energy. The transport and switching unit is a high-efficiency air-handling system equipped with gear motor valves that respond to outputs from the control system. The fan unit was designed for maximum durability and efficiency in operation, and has permanently lubricated ball bearings and excellent air-handling efficiency.

  16. Solar heating system installed at Troy, Ohio

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The completed system was composed of three basic subsystems: the collector system consisting of 3,264 square feet of Owens Illinois evacuated glass tube collectors; the storage system which included a 5,000 gallon insulated steel tank; and the distribution and control system which included piping, pumping and heat transfer components as well as the solemoid activated valves and control logic for the efficient and safe operation of the entire system. This solar heating system was installed in an existing facility and was, therefore, a retrofit system. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are included.

  17. Solar dynamic power systems for space station

    NASA Technical Reports Server (NTRS)

    Irvine, Thomas B.; Nall, Marsha M.; Seidel, Robert C.

    1986-01-01

    The Parabolic Offset Linearly Actuated Reflector (POLAR) solar dynamic module was selected as the baseline design for a solar dynamic power system aboard the space station. The POLAR concept was chosen over other candidate designs after extensive trade studies. The primary advantages of the POLAR concept are the low mass moment of inertia of the module about the transverse boom and the compactness of the stowed module which enables packaging of two complete modules in the Shuttle orbiter payload bay. The fine pointing control system required for the solar dynamic module has been studied and initial results indicate that if disturbances from the station are allowed to back drive the rotary alpha joint, pointing errors caused by transient loads on the space station can be minimized. This would allow pointing controls to operate in bandwidths near system structural frequencies. The incorporation of the fine pointing control system into the solar dynamic module is fairly straightforward for the three strut concentrator support structure. However, results of structural analyses indicate that this three strut support is not optimum. Incorporation of a vernier pointing system into the proposed six strut support structure is being studied.

  18. DC CIRCUIT POWERED BY ORBITAL MOTION: MAGNETIC INTERACTIONS IN COMPACT OBJECT BINARIES AND EXOPLANETARY SYSTEMS

    SciTech Connect

    Lai Dong

    2012-09-20

    The unipolar induction DC circuit model, originally developed by Goldreich and Lynden-Bell for the Jupiter-Io system, has been applied to different types of binary systems in recent years. We show that there exists an upper limit to the magnetic interaction torque and energy dissipation rate in such a model. This arises because when the resistance of the circuit is too small, the large current flow severely twists the magnetic flux tube connecting the two binary components, leading to the breakdown of the circuit. Applying this limit, we find that in coalescing neutron star binaries, magnetic interactions produce negligible correction to the phase evolution of the gravitational waveform, even for magnetar-like field strengths. However, energy dissipation in the binary magnetosphere may still give rise to electromagnetic radiation prior to the final merger. For ultracompact white dwarf binaries, we find that unipolar induction does not provide adequate energy dissipation to explain the observed X-ray luminosities of several sources. For exoplanetary systems containing close-in Jupiters or super-Earths, the magnetic torque and energy dissipation induced by the orbital motion are negligible, except possibly during the early T Tauri phase, when the stellar magnetic field is stronger than 10{sup 3} G.

  19. Outflows Driven by a Potential Proto-Brown Dwarf Binary System IRAS 16253-2429

    NASA Astrophysics Data System (ADS)

    Hsieh, Tien-Hao; Lai, Shih-Ping; Belloche, Arnaud; Wyrowski, Friedrich

    2015-08-01

    We have studied the molecular outflows driven by a potential proto-brown dwarf candidate IRAS 16253-2429 (hereafter IRAS 16253) with CO (2—1) using SMA and IRAM 30m telescope and CO (6—5) using APEX. Our SMA observations suggest that IRAS 16253 is hosting a binary system. The low mass of its envelope suggests that the central objects may eventually accrete only ~0.14 Msun of material (assuming the star formation efficiency is at most 0.3), which makes IRAS 16253 a potential proto brown dwarf binary system since the maximum mass of a brown dwarf is 0.08 Msun; one or two brown dwarfs may form depending on the current mass of the protostars and the future accretion process. The Position-Velocity diagrams of the outflows show sinusoidal structures which may be related to the outflow wiggling from the binary rotation. This allowed us to estimate the orbital period of the binary system. On the basis of Kepler's third law, we suggest that IRAS 16253 is very likely to contain at least one proto brown dwarf if the binary separation is less than ~0.5 arcsec. The large-scale outflows are further mapped with IRAM 30m telescope and APEX Champ+. We found that CO (6—5) traces high-excited gas around the precessing H2 jets and CO (2—1) likely probes the cold swept-up gas or entrained gas with cone-like structure.

  20. System integration issues of residential solar photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Yamayee, Z. A.; Peschon, J.

    1980-03-01

    The economic effects of residential solar PV systems on the utility's revenue, capacity, and energy requirements from the electric utility's perspective are evaluated. The price that it might pay for surplus energy and what it would charge for deficits are compared. The power and energy generated by the solar PV systems reduce the capital and operating costs that would otherwise be incurred by the utility. These avoided costs suggest what the utility might pay for surplus solar PV energy. The avoided costs are evaluated under three integration hypotheses, namely: (1) the utility has no system storage; (2) the utility has system storage; and (3) the solar PV systems are supported by dedicated storage devices, the purpose of which is to minimize sales to and purchases from the utility.