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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. Ultra-Wide Trans-Neptunian Binaries: Tracers of the Outer Solar System's History

    NASA Astrophysics Data System (ADS)

    Parker, Alex Harrison

    Ultra-wide Trans-Neptunian Binaries (TNBs) are extremely sensitive to perturbation, and therefore make excellent probes of the past and present dynamical environment of the outer Solar System. Using data gathered from a host of facilities we have determined the mutual orbits for a sample of seven wide TNBs whose periods exceed one year. This characterized sample provides us with new information about the probable formation scenarios of TNBs, and has significant implications for the early dynamical and collisional history of the Kuiper Belt. We show that these wide binaries have short collisional lifetimes, and use them to produce a new estimate of the number of small (˜1 km) objects in the Kuiper Belt. Additionally, these systems are susceptible to tidal disruption, and we show that it is unlikely that they were ever subjected to a period of close encounters with the giant planets. We find that the current properties of these ultra-wide Trans-Neptunian Binaries suggest that planetesimal growth in the Cold Classical Kuiper Belt did not occur through slow hierarchical accretion, but rather through rapid gravitational collapse.

  3. 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.

  4. 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.

  5. 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

  6. 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

    2015-01-01

    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

  7. RR-Lyrae-type pulsations from a 0.26-solar-mass star in a binary system.

    PubMed

    Pietrzyński, G; Thompson, I B; Gieren, W; Graczyk, D; Stępień, K; Bono, G; Moroni, P G Prada; Pilecki, B; Udalski, A; Soszyński, I; Preston, G W; Nardetto, N; McWilliam, A; Roederer, I U; Górski, M; Konorski, P; Storm, J

    2012-04-01

    RR Lyrae pulsating stars have been extensively used as tracers of old stellar populations for the purpose of determining the ages of galaxies, and as tools to measure distances to nearby galaxies. There was accordingly considerable interest when the RR Lyrae star OGLE-BLG-RRLYR-02792 (referred to here as RRLYR-02792) was found to be a member of an eclipsing binary system, because the mass of the pulsator (hitherto constrained only by models) could be unambiguously determined. Here we report that RRLYR-02792 has a mass of 0.26 solar masses M[symbol see text] and therefore cannot be a classical RR Lyrae star. Using models, we find that its properties are best explained by the evolution of a close binary system that started with M[symbol see text] and 0.8M[symbol see text]stars orbiting each other with an initial period of 2.9 days. Mass exchange over 5.4 billion years produced the observed system, which is now in a very short-lived phase where the physical properties of the pulsator happen to place it in the same instability strip of the Hertzsprung-Russell diagram as that occupied by RR Lyrae stars. We estimate that only 0.2 per cent of RR Lyrae stars may be contaminated by systems similar to this one, which implies that distances measured with RR Lyrae stars should not be significantly affected by these binary interlopers. PMID:22481359

  8. 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.

  9. The Spot Variability and Related Brightness variations of the Solar Type PreContact W UMa Binary System V1001 Cas

    NASA Astrophysics Data System (ADS)

    Samec, Ronald George; Koenke, Sam S.; Faulkner, Danny R.

    2015-08-01

    A new classification of eclipsing binary has emerged, Pre Contact WUMa Binaries (PCWB’s, Samec et al. 2012). These solar-type systems are usually detached or semidetached with one or both components under filling their critical Roche lobes. They usually have EA or EB-type light curves (unequal eclipse depths, indicating components with substantially different temperatures). The accepted scenario for these W UMa binaries is that they are undergoing steady but slow angular momentum losses due to magnetic braking as stellar winds blow radially away on stiff bipolar field lines. These binaries are believed to come into stable contact and eventually coalesce into blue straggler type, single, fast rotating A-type stars (Guinan and Bradstreet,1988). High precision 2012 and 2009 light curves are compared for the very short period (~0.43d) Precontact W UMa Binary (PCWB), V1001 Cassiopeia. This is the shortest period PCWB found so far. Its short period, similar to the majority of W UMa’s, in contrast to its distinct Algol-type light curve, make it a very rare and interesting system. Our solutions of light curves separated by some three years give approximately the same physical parameters. However the spots radically change, in temperature, area and position causing a distinctive variation in the shape of the light curves. We conclude that spots are very active on this solar type dwarf system and that it may mimic its larger cousins, the RS CVn binaries.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Binary star systems and extrasolar planets

    NASA Astrophysics Data System (ADS)

    Muterspaugh, Matthew Ward

    For ten years, planets around stars similar to the Sun have been discovered, confirmed, and their properties studied. Planets have been found in a variety of environments previously thought impossible. The results have revolutionized the way in which scientists understand planet and star formation and evolution, and provide context for the roles of the Earth and our own solar system. Over half of star systems contain more than one stellar component. Despite this, binary stars have often been avoided by programs searching for planets. Discovery of giant planets in compact binary systems would indirectly probe the timescales of planet formation, an important quantity in determining by which processes planets form. A new observing method has been developed to perform very high precision differential astrometry on bright binary stars with separations in the range of [approximate] 0.1--1.0 arcseconds. Typical measurement precisions over an hour of integration are on the order of 10 micro-arcseconds (mas), enabling one to look for perturbations to the Keplerian orbit that would indicate the presence of additional components to the system. This method 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 method of differential astrometry is applied to three star systems. d Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics. PHASES data are

  17. Planets in Evolved Binary Systems

    NASA Astrophysics Data System (ADS)

    Perets, Hagai B.

    2011-03-01

    Exo-planets are typically thought to form in protoplanetary disks left over from protostellar disk of their newly formed host star. However, additional planetary formation and evolution routes may exist in old evolved binary systems. Here we discuss the implications of binary stellar evolution on planetary systems in such environments. In these binary systems stellar evolution could lead to the formation of symbiotic stars, where mass is lost from one star and could be transferred to its binary companion, and may form an accretion disk around it. This raises the possibility that such a disk could provide the necessary environment for the formation of a new, second generation of planets in both circumstellar or circumbinary configurations. Pre-existing first generation planets surviving the post-MS evolution of such systems would be dynamically effected by the mass loss in the systems and may also interact with the newly formed disk. Such planets and/or planetesimals may also serve as seeds for the formation of the second generation planets, and/or interact with them, possibly forming atypical planetary systems. Second generation planetary systems should be typically found in white dwarf binary systems, and may show various observational signatures. Most notably, second generation planets could form in environment which are inaccessible, or less favorable, for first generation planets. The orbital phase space available for the second generation planets could be forbidden (in terms of the system stability) to first generation planets in the pre-evolved progenitor binaries. In addition planets could form in metal poor environments such as globular clusters and/or in double compact object binaries. Observations of exo-planets in such forbidden or unfavorable regions could possibly serve to uniquely identify their second generation character. Finally, we point out a few observed candidate second generation planetary systems, including Gl 86, HD 27442 and all of the

  18. 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.

  19. Discs in misaligned binary systems

    NASA Astrophysics Data System (ADS)

    Rawiraswattana, Krisada; Hubber, David A.; Goodwin, Simon P.

    2016-08-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-alignment processes, which tend to misalign the components. The alignment process dominates in systems with misalignment angle near 90°, while the anti-alignment process dominates in systems with the misalignment angle near 0° or 180°. This means that highly misaligned systems will become more aligned but slightly misaligned systems will become more misaligned.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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.…

  5. Absolute dimensions of solar-type eclipsing binaries. III. EW Orionis: stellar evolutionary models tested by a G0 V system

    NASA Astrophysics Data System (ADS)

    Clausen, J. V.; Bruntt, H.; Olsen, E. H.; Helt, B. E.; Claret, A.

    2010-02-01

    Context. Recent studies of inactive and active solar-type binaries suggest that chromospheric activity, and its effect on envelope convection, is likely to cause significant radius and temperature discrepancies. Accurate mass, radius, and abundance determinations from additional 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 G0 V detached eclipsing binary EW Ori, and to perform a detailed comparison with results from recent stellar evolutionary models. Methods: uvby light curves and {uvby}β standard photometry were obtained with the Strömgren Automatic Telescope, published radial velocity observations from the CORAVEL spectrometer were reanalysed, and high-resolution spectra were observed at the FEROS spectrograph; all are/were ESO, La Silla facilities. State-of-the-art methods were applied for the photometric and spectroscopic analyses. Results: Masses and radii that are precise to 0.9% and 0.5%, respectively, have been established for both components of EW Ori. The 1.12 M⊙ secondary component reveals weak Ca ii H and K emission and is probably mildly active; no signs of activity are seen for the 1.17 M⊙ primary. We derive an [Fe/H] abundance of +0.05 ± 0.09 and similar abundances for Si, Ca, Sc, Ti, Cr, and Ni. Yonsai-Yale and Granada solar-scaled evolutionary models for the observed metal abundance reproduce the components fairly well at an age of ≈2 Gyr. Perfect agreement is, however, obtained at an age of 2.3 Gyr for a combination of a) a slight downwards adjustment of the envelope mixing length parameter for the secondary, as seen for other active solar-type stars; and b) a slightly lower helium content than prescribed by the Y-Z relations adopted for the standard model grids. The orbit is eccentric (e = 0.0758 ± 0.0020), and apsidal motion with a 62% relativistic contribution has been

  6. 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.

  7. 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

  8. Binary Systems Within Star Clusters

    NASA Astrophysics Data System (ADS)

    Paunzen, Ernst; Stütz, Christian; Baumann, Bernhard

    2012-04-01

    WEBDA (http://www.univie.ac.at/webda) is a site devoted to observational data of stellar clusters in the Milky Way and the Small Magellanic Cloud. It is intended to provide a reliable presentation of the available data and knowledge about these objects. The success of WEBDA is documented by its worldwide usage and the related acknowledgements in the literature: more than 650 refereed publications within the last twelve years acknowledged its use. It collects all published data for stars in open clusters that may be useful either to determine membership, or to study the stellar content and properties of the clusters. The database content includes astrometric data in the form of coordinates, rectangular positions, and proper motions, photometric data in the major systems in which star clusters have been observed, but also spectroscopic data like spectral classification, radial velocities, and rotational velocities. It also contains miscellaneous types of supplementary data like membership probabilities, orbital elements of spectroscopic binaries, and periods for different kinds of variable stars as well as an extensive bibliography. Several powerful tools help to plot, query and extract the data, which can be directly retrieved via http. At the time of writing, about four million individual measurements have been included in the database. The Star Clusters Young & Old Newsletter (SCYON), a bi-monthly newsletter devoted to star cluster research with about 600 subscribers, is hosted in parallel with the database. We present the current and upcoming new interface and tools, which are needed to visualize and analyze the increasing amount of data from all-sky surveys, and deeper investigations of binary systems, low mass dwarfs, as well as planet-hosting stars.

  9. 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.

  10. 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.

  11. 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.

  12. KIC 7177553: A Quadruple System of Two Close Binaries

    NASA Astrophysics Data System (ADS)

    Lehmann, H.; Borkovits, T.; Rappaport, S. A.; Ngo, H.; Mawet, D.; Csizmadia, Sz.; Forgács-Dajka, E.

    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.

  13. Late type close binary system CM Dra

    NASA Astrophysics Data System (ADS)

    Kalomeni, Belinda

    2015-08-01

    In this study, we present new observations of the close binary system CM Dra. We analyzed all the available data of the system and estimated the physical parameters of the system stars highly accurately. Using the newly obtained parameters the distance of the system is determined to be 11.6 pc. A possible giant planet orbiting the close binary system has been detected. This orbital period would likely make it one of the longest known orbital period planet.

  14. 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.

  15. Misaligned protoplanetary disks in a young binary star system.

    PubMed

    Jensen, Eric L N; Akeson, Rachel

    2014-07-31

    Many extrasolar planets follow orbits that differ from the nearly coplanar and circular orbits found in our Solar System; their orbits may be eccentric or inclined with respect to the host star's equator, and the population of giant planets orbiting close to their host stars suggests appreciable orbital migration. There is at present no consensus on what produces such orbits. Theoretical explanations often invoke interactions with a binary companion star in an orbit that is inclined relative to the planet's orbital plane. Such mechanisms require significant mutual inclinations between the planetary and binary star orbital planes. The protoplanetary disks in a few young binaries are misaligned, but often the measurements of these misalignments are sensitive only to a small portion of the inner disk, and the three-dimensional misalignment of the bulk of the planet-forming disk mass has hitherto not been determined. Here we report that the protoplanetary disks in the young binary system HK Tauri are misaligned by 60 to 68 degrees, such that one or both of the disks are significantly inclined to the binary orbital plane. Our results demonstrate that the necessary conditions exist for misalignment-driven mechanisms to modify planetary orbits, and that these conditions are present at the time of planet formation, apparently because of the binary formation process. PMID:25079553

  16. Misaligned protoplanetary disks in a young binary star system.

    PubMed

    Jensen, Eric L N; Akeson, Rachel

    2014-07-31

    Many extrasolar planets follow orbits that differ from the nearly coplanar and circular orbits found in our Solar System; their orbits may be eccentric or inclined with respect to the host star's equator, and the population of giant planets orbiting close to their host stars suggests appreciable orbital migration. There is at present no consensus on what produces such orbits. Theoretical explanations often invoke interactions with a binary companion star in an orbit that is inclined relative to the planet's orbital plane. Such mechanisms require significant mutual inclinations between the planetary and binary star orbital planes. The protoplanetary disks in a few young binaries are misaligned, but often the measurements of these misalignments are sensitive only to a small portion of the inner disk, and the three-dimensional misalignment of the bulk of the planet-forming disk mass has hitherto not been determined. Here we report that the protoplanetary disks in the young binary system HK Tauri are misaligned by 60 to 68 degrees, such that one or both of the disks are significantly inclined to the binary orbital plane. Our results demonstrate that the necessary conditions exist for misalignment-driven mechanisms to modify planetary orbits, and that these conditions are present at the time of planet formation, apparently because of the binary formation process.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Solar array drive system

    NASA Technical Reports Server (NTRS)

    Berkopec, F. D.; Sturman, J. C.; Stanhouse, R. W.

    1976-01-01

    A solar array drive system consisting of a solar array drive mechanism and the corresponding solar array drive electronics is being developed. The principal feature of the solar array drive mechanism is its bidirectional capability which enables its use in mechanical redundancy. The solar array drive system is of a widely applicable design. This configuration will be tested to determine its acceptability for generic mission sets. Foremost of the testing to be performed is the testing for extended duration.

  4. 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.

  5. Solar electric systems

    NASA Astrophysics Data System (ADS)

    Warfield, G.

    Subjects discussed in connection with solar electricity are related to solar radiation fundamentals, wind electric conversion and utilization, the basic theory of solar cells, photovoltaic materials, photovoltaic technology, components of solar thermal electric systems, solar thermal power plants, and integrated solar thermal electric complexes. The solar technology development in the Arab world is also examined, taking into account the horizon of solar energy in the Arab countries, solar energy activities at the Scientific Research Council in Iraq, solar energy activities at the Royal Scientific Society in Jordan, the solar energy program at Kuwait Institute for Scientific Research, application of solar energy in Libya, prospects of solar energy for Egypt, solar energy programs in Qatar, performance characteristics of a 350 kW photovoltaic power system for Saudi Arabian villages, nonconventional energy in Syria, wind and solar energies in Sudan, solar electric research and development program in Tunisia, and solar energy research and utilization in Yemen Arab Republic. No individual items are abstracted in this volume

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. White dwarfs in Be star binary systems

    NASA Technical Reports Server (NTRS)

    Apparao, K. M. V.

    1991-01-01

    An evaluation is made of possible reasons for the persistent inability to identify white dwarf stars in the Be binary systems. It is noted that many Be stars exhibiting large optical enhancements may be Be + WD and Be + He systems, and that observations of pulsations in the H-alpha emission, as well as observation of time delays between enhancements of optical line and continuum, can identify such systems.

  14. Gravitational wave astrophysics with compact binary systems

    NASA Astrophysics Data System (ADS)

    Addison, Eric

    2014-10-01

    Gravitational waves are ripples in the fabric of spacetime that convey information about changing gravitational fields. Large-scale detection projects are currently in operation, and more advanced detectors are being designed and built. Though we have yet to make a direct detection of a gravitational wave signal, upgrades to current detectors are expected to bring the first detections within the next year or two. Gravitational waves will bring us information about astrophysical phenomena that is complementary to the information gained from photon-based observations (e.g., telescopes and radio receivers). One of the primary sources of gravitational waves are binary systems: two massive objects that orbit around each other due to their mutual gravitational attraction. These systems can have very predictable gravitational wave signatures due to their repetitive motions, making them ideal gravitational wave sources. In this dissertation, I present two research projects pertaining to gravitational wave astrophysics and compact binary systems. In the first, I explore interactions between compact binary systems near the center of our galaxy with the supermassive black hole that resides there. I am interested in the final state of the binary as a result of the interaction, ranging from small perturbations to the orbit up to total disruption. In the case of disruption, I characterize the new orbits formed between the binary components and the central black hole, known as extreme mass ratio inspirals. For binaries that survive the encounter, I examine the changes they experience, and find on average, they will merge together as a result of gravitational wave emission faster than before the encounter. In the second project, I propose a new method of measuring the radius of the swirling disc of gas and dust that encircles some stars in compact binary systems, known as the accretion disc. This method relies on the use of coupled electromagnetic and gravitational wave

  15. THE COEVALITY OF YOUNG BINARY SYSTEMS

    SciTech Connect

    Kraus, Adam L.; Hillenbrand, Lynne A.

    2009-10-10

    Multiple star systems are commonly assumed to form coevally; they thus provide the anchor for most calibrations of stellar evolutionary models. In this paper, we study the binary population of the Taurus-Auriga association, using the component positions in an HR diagram in order to quantify the frequency and degree of coevality in young binary systems. After identifying and rejecting the systems that are known to be affected by systematic errors (due to further multiplicity or obscuration by circumstellar material), we find that the relative binary ages, |DELTAlog tau|, have an overall dispersion sigma{sub |D}ELTA{sub logt}au{sub |}approx 0.40 dex. Random pairs of Taurus members are coeval only to within sigma{sub |D}ELTA{sub logt}au{sub |}approx 0.58 dex, indicating that Taurus binaries are indeed more coeval than the association as a whole. However, the distribution of |DELTAlog tau| suggests two populations, with approx2/3 of the sample appearing coeval to within the errors (sigma{sub |D}ELTA{sub logt}au{sub |}approx 0.16 dex) and the other approx1/3 distributed in an extended tail reaching |DELTAlog tau|approx 0.4-0.9 dex. To explain the finding of a multipeaked distribution, we suggest that the tail of the differential age distribution includes unrecognized hierarchical multiples, stars seen in scattered light, or stars with disk contamination; additional follow-up is required to rule out or correct for these explanations. The relative coevality of binary systems does not depend significantly on the system mass, mass ratio, or separation. Indeed, any pair of Taurus members wider than approx10' (approx0.7 pc) shows the full age spread of the association.

  16. Acceleration by pulsar winds in binary systems

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.; Gaisser, T. K.

    1990-01-01

    In the absence of accretion torques, a pulsar in a binary system will spin down due to electromagnetic dipole radiation and the spin-down power will drive a wind of relativistic electron-positron pairs. Winds from pulsars with short periods will prevent any subsequent accretion but may be confined by the companion star atmosphere, wind, or magnetosphere to form a standing shock. The authors investigate the possibility of particle acceleration at such a pulsar wind shock and the production of very high energy (VHE) and ultra high energy (UHE) gamma rays from interactions of accelerated protons in the companion star's wind or atmosphere. They find that in close binaries containing active pulsars, protons will be shock accelerated to a maximum energy dependent on the pulsar spin-down luminosity. If a significant fraction of the spin-down power goes into particle acceleration, these systems should be sources of VHE and possibly UHE gamma rays. The authors discuss the application of the pulsar wind model to binary sources such as Cygnus X-3, as well as the possibility of observing VHE gamma-rays from known binary radio pulsar systems.

  17. 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.

  18. Dynamics and Habitability in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Eggl, Siegfried; Georgakarakos, Nikolaos; Pilat-Lohinger, Elke

    2014-07-01

    Determining planetary habitability is a complex matter, as the interplay between a planet's physical and atmospheric properties with stellar insolation has to be studied in a self consistent manner. Standardized atmospheric models for Earth-like planets exist and are commonly accepted as a reference for estimates of Habitable Zones. In order to define Habitable Zone boundaries, circular orbital configurations around main sequence stars are generally assumed. In gravitationally interacting multibody systems, such as double stars, however, planetary orbits are forcibly becoming non circular with time. Especially in binary star systems even relatively small changes in a planet's orbit can have a large impact on habitability. Hence, we argue that a minimum model for calculating Habitable Zones in binary star systems has to include dynamical interactions.

  19. 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.

  20. Coalescence of Magnetized Binary Neutron Star Systems

    NASA Astrophysics Data System (ADS)

    Motl, Patrick M.; Anderson, Matthew; Lehner, Luis; Liebling, Steven L.; Neilsen, David; Palenzuela, Carlos; Ponce, Marcelo

    2015-01-01

    We present simulations of the merger of binary neutron star systems calculated with full general relativity and incorporating the global magnetic field structure for the stars evolved with resistive magnetohydrodynamics. Our simulation tools have recently been improved to incorporate the effects of neutrino cooling and have been generalized to allow for tabular equations of state to describe the degenerate matter. Of particular interest are possible electromagnetic counterparts to the gravitational radiation that emerges from these systems. We focus on magnetospheric interactions that ultimately tap into the gravitational potential energy of the binary to power a Poynting flux and deposition of energy through Joule heating and magnetic reconnection. We gratefully acknowledge the support of NASA through the Astrophysics Theory Program grant NNX13AH01G.

  1. 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.

  2. 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. PMID:15105492

  3. The Solar-Type Contact Binary BX Pegasi Revisited

    NASA Astrophysics Data System (ADS)

    Lee, Jae Woo; Kim, Seung-Lee; Lee, Chung-Uk; Youn, Jae-Hyuck

    2009-12-01

    We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on 2008 September. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-term brightness disturbance. For these variations, model spots are applied separately to the two data sets, Group I (Sep.-Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel time (LTT) effect due to the orbit of a low-mass third companion, and a previously unknown short-term oscillation. This last period modulation could be produced either by a second LTT orbit with a period of about 16 yr due to the existence of a fourth body, or by the effect of magnetic activity with a cycle length of about 12 yr.

  4. 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.

  5. Accretion Disks in Massive Binary Systems

    NASA Astrophysics Data System (ADS)

    Djurašević, G. R.; Vince, I.; Atanacković, O.

    2010-12-01

    The results of our investigations of some massive close binaries (CB) (RY Sct, V448 Cyg, UU Cas and V455 Cyg), based on the photometric and spectroscopic observations indicate the existance of the accretion disk around the more massive component, located deep inside the Roche lobe. The light curve shapes of some of this systems are similar to the ones of the overcontact systems like W UMa, but the nature of these massive CBs is completely different. Here we present the models of these systems and their basic elements.

  6. Coordinate System Issues in Binary Star Computations

    NASA Astrophysics Data System (ADS)

    Kaplan, George H.

    2015-08-01

    It has been estimated that half of all stars are components of binary or multiple systems. Yet the number of known orbits for astrometric and spectroscopic binary systems together is less than 7,000 (including redundancies), almost all of them for bright stars. A new generation of deep all-sky surveys such as Pan-STARRS, Gaia, and LSST are expected to lead to the discovery of millions of new systems. Although for many of these systems, the orbits may be undersampled initially, it is to be expected that combinations of new and old data sources will eventually lead to many more orbits being known. As a result, a revolution in the scientific understanding of these systems may be upon us.The current database of visual (astrometric) binary orbits represents them relative to the “plane of the sky”, that is, the plane orthogonal to the line of sight. Although the line of sight to stars constantly changes due to proper motion, aberration, and other effects, there is no agreed upon standard for what line of sight defines the orbital reference plane. Furthermore, the computation of differential coordinates (component B relative to A) for a given date must be based on the binary system’s direction at that date. Thus, a different “plane of the sky” is appropriate for each such date, i.e., each observation. However, projection effects between the reference planes, differential aberration, and the curvature of the sky are generally neglected in such computations. Usually the only correction applied is for the change in the north direction (position angle zero) due to precession (and sometimes also proper motion). This paper will present an algorithm for a more complete model of the geometry involved, and will show that such a model is necessary to avoid errors in the computed observables that are significant at modern astrometric accuracy. The paper will also suggest where conventions need to be established to avoid ambiguities in how quantities related to binary star

  7. 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.

  8. OO Aquilae: a solar-type contact binary with intrinsic light curve changes

    NASA Astrophysics Data System (ADS)

    Li, Hua-Li; Wei, Jian-Yan; Yang, Yuan-Gui; Dai, Hai-Feng

    2016-01-01

    New multi-color photometry of the solar-type contact binary OO Aql was obtained in 2012 and 2013, using the 60 cm telescope at Xinglong Station of the National Astronomical Observatories, Chinese Academy of Sciences. From two sets of light curves LC1 and LC2, photometric models were performed by using the 2003 version of the Wilson-Devinney code. The overcontact factor of the binary system was determined to be f = 37.0(±0.5)%. The intrinsic variability of this binary occurs in light maxima and minima, which could result from a possible third component and magnetic activity of the late type components. Based on all available light minimum times, the orbital period may change in a complicated mode, i.e., sudden period jumps or continuous period variations. The period of OO Aql may possibly undergo a secular period decrease with a rate of dP/dt = -3.63(±0.30) × 10-8 d yr-1, superimposed by two possible cyclic variations in the O - C curve. The long-term period decrease may be interpreted as conserved mass transfer from the more massive component to the less massive one. The 21.5-yr oscillation may be attributed to cyclic magnetic activity, and the 69.3-yr one may result from the light-time effect of an unseen tertiary body.

  9. 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).

  10. Solar Electric System

    NASA Astrophysics Data System (ADS)

    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.

  11. Synchronization of magnetic stars in binary systems

    NASA Technical Reports Server (NTRS)

    Lamb, F. K.; Aly, J.-J.; Cook, M. C.; Lamb, D. Q.

    1983-01-01

    Asynchronous rotation of magnetic stars in close binary systems drives substantial field-aligned electrical currents between the magnetic star and its companion. The resulting magnetohydrodynamic torque is able to account for the heretofore unexplained synchronous rotation of the strongly magnetic degenerate dwarf component in systems like AM Her, VV Pup, AN UMa, and EF Eri as well as the magnetic A type component in systems like HD 98088 and 41 Tauri. The electric fields produced by even a small asynchronism are large and may accelerate some electrons to high energies, producing radio emission. The total energy dissipation rate in systems with degenerate dwarf spin periods as short as 1 minute may reach 10 to the 33rd ergs/s. Total luminosities of this order may be a characteristic feature of such systems.

  12. RS CV sub n binary systems

    NASA Technical Reports Server (NTRS)

    Linsky, J. L.

    1984-01-01

    An attempt is made to place in context the vast amount of data obtained as a result of X-ray, ultraviolet, optical, and microwave observations of RS CVn and similar spectroscopic binary systems. Emphasis is on the RS CVn systems and their long period analogs. The following questions are considered: (1) are the original defining characteristics still valid and still adequate? (2) what is the evidence for discrete active regions? (3) have any meaningful physical properties for the atmospheres of RS CVn systems been derived? (4) what do the flare observations tell about magnetic fields in RS CVn systems? (5) is there evidence for systematic trends in RS CVn systems with spectral type?

  13. Long-Term Stability of Planets in Binary Systems

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.; Wiegert, Paul A.

    1999-01-01

    A simple question of celestial mechanics is investigated: in what regions of phase space near a binary system can planets persist for long times? The planets are taken to be test particles moving in the field of an eccentric binary system. A range of values of the binary eccentricity and mass ratio is studied, and both the case of planets orbiting close to one of the stars, and that of planets outside the binary orbiting the systems center of mass, are examined. From the results, empirical expressions are developed for both (1) the largest orbit around each of the stars and (2) the smallest orbit around the binary system as a whole, in which test particles survive the length of the integration (10A4 binary periods). The empirical expressions developed, which are roughly linear in both the mass ratio mu and the binary eccentricity e, are determined for the range 0.0=e=0.7-0.8 and 0.1=mu=0.9 in both regions and can be used to guide searches for planets in binary systems. After considering the case of a single low-mass planet in binary systems, the stability of a mutually interacting system of planets orbiting one star of a binary system is examined, though in less detail.

  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. 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.

  16. 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.

  17. 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.

  18. 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. PMID:27456294

  19. 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.

  20. 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…

  1. Solar system fault detection

    NASA Astrophysics Data System (ADS)

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

    1984-05-01

    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 combing 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. 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.

  3. 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.

  4. 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.

  5. The new solar system

    SciTech Connect

    Beatty, J.K.; Oleary, B.; Chaikin, A.

    1981-01-01

    Current knowledge about the solar system is reviewed, with particular emphasis on the results of recent space exploration. Among the many topics discussed are the sun, magnetospheres and the interplanetary medium, the surfaces of the terrestrial bodies, the moon, Mars, asteroids, Jupiter and Saturn, planetary rings, the Galilean satellites, Titan, the outer solar system, comets, and meteorites. Particular attention is given to the Voyager 1 and 2 flybys of Jupiter and Saturn. The work includes many illustrative photographs of the celestial bodies discussed.

  6. 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.

  7. Orbit of an Astrometric Binary System

    NASA Astrophysics Data System (ADS)

    Descamps, Pascal

    2005-08-01

    We present a new method to solve the problem of initial orbit determination of any binary system. This method is mainly based on the material available for an observer, for example relative positions at a given time of the couple in the “plane of sky”, namely the tangent plane to the celestial sphere at the position of the primary component. The problem of orbit determination is solved by splitting in successive stages in order to decorrelate the parameters of each other as much as possible. On one hand, the geometric problem is solved using the first Kepler’s law from a single observing run and, on the other hand, dynamical parameters are then inferred from the fit of the Kepler’s equation. At last, the final stage consists in determining the main physical parameters involved in the secular evolution of the system, that is the spin axis and the J2 parameter of the primary if we assume that it is a quasi-spherical body. As a matter of fact there is no need to make too restrictive initial assumptions (such as circular orbit or zero eccentricity) and initial guesses of parameters required by a non-linear least-squares Levenberg Marquardt algorithm are finally obtained after each stage. Such a protocol is very useful to study systems like binary asteroids for which all of the parameters should be considered a priori as unknowns. As an example of application, we used our method to estimate the set of the Pluto Charon system parameters from observations collected in the literature since 1980.

  8. 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.

  9. 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. PMID:17749544

  10. 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.

  11. 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

  12. 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. PMID:23292514

  13. 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.

  14. Production of gamma-ray bursts in massive binary systems

    NASA Astrophysics Data System (ADS)

    Joss, Paul C.

    Long γ-ray bursts may be produced by hypernova events in the rapidly rotating cores of massive stars. A serious problem that must be confronted in this scenario is how the core of the hypernova progenitor retains or acquires sufficient angular momentum to produce the requisite axisymmetric collapse. Physical processes during the evolution of an isolated massive star will tend to extract any initial angular momentum from the stellar core, rendering it difficult for such a star to become a hypernova. However, a substantial fraction of massive stars are members of binary systems. Tidal locking, mass transfer, and/or stellar merger in an evolved massive binary may transfer orbital angular momentum to the core of one of the stars (or the merged star), sufficient to produce the progenitor of a hypernova. To investigate this issue, we have substantially refined a binary stellar evolution code that we had previously developed. The code includes the effects of mass and angular momentum transfer between the component stars and the subsequent transport of angular momentum through one of the stars. This transport is effected by dynamical and secular shear instabilities, convective motions, the critical layer instability, and gravity waves. Our code treats in a self-consistent way the dynamical distortion of the star resulting from the induced rapid differential rotation. The results of numerical computations with our refined code indicate that late main-sequence or early post-main-sequence accretion from a binary companion onto a star with an initial mass greater than ˜ 20 solar masses produces a rapidly rotating core within the accretor. The rotation will often be sufficiently rapid to provide the initial conditions necessary for a hypernova event, and the concomitant emission of a γ-ray burst, when the core collapses. We also find that the merger of a late post-main-sequence star with its binary companion may lead to a hypernova event in the stellar core, but is unlikely

  15. Analytical modeling and experimental investigation on optical properties of new class of nanofluids (Al2O3-CuO binary nanofluids) for direct absorption solar thermal energy

    NASA Astrophysics Data System (ADS)

    Menbari, Amir; Alemrajabi, Ali Akbar

    2016-02-01

    Nanofluids play a major role in many modern engineering processes. Binary nanofluids are a new class of nanofluids that are prepared by dispersing simultaneously two dissimilar nanoparticles in a base fluid. They offer a good potential for use in direct absorption solar systems. The present study investigates both experimentally and analytically the optical properties of binary nanofluids for direct absorption in solar applications. For this purpose, two dissimilar nanoparticles, i.e. CuO and γ-Al2O3, are dispersed in water, ethylene glycol, and the ethylene glycol-water mixture to form binary nanofluids. In addition, a new method is developed for calculating the extinction coefficient of the binary nanofluids based on the classical electromagnetic theory. It will be shown that the extinction coefficients obtained from both analytical and experimental studies are in good agreement. Moreover, the extinction coefficient of the binary nanofluids is found to be approximately equal to the sum of the extinction coefficients of the constituent components, determined both analytically and experimentally. By increasing the nanoparticle volume fraction, improvements are observed in the extinction coefficient of the binary nanofluids prepared. Also, the analytical and experimental results of the study show that the extinction coefficient of the binary nanoparticles dispersed in water as the "base fluid" is greater than those of the binary nanoparticles dispersed in ethylene glycol or the mixture of ethylene glycol-water.

  16. 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.

  17. 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

  18. GLAST Solar System Science

    SciTech Connect

    Share, Gerald H.; Murphy, Ronald J.

    2007-07-12

    We briefly discuss GLAST's capabilities for observing high-energy radiation from various energetic phenomena in our solar system. These emissions include: bremsstrahlung, nuclear-line and pion-decay gamma-radiation, and neutrons from solar flares; bremsstrahlung and pion-decay gamma radiation from cosmic-ray interactions with the Sun, the Moon, and the Earth's atmosphere; and inverse Compton radiation from cosmic-ray electron interactions with sunlight.

  19. 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.

  20. Solar System Educators Program

    NASA Astrophysics Data System (ADS)

    Knudsen, R.

    2004-11-01

    The Solar System Educators Program is a nationwide network of highly motivated teachers who lead workshops that show other teachers in their local communities how to successfully incorporate NASA materials and research into their classes. Currently there are 57 Solar System Educators in 37 states whose workshops are designed to assist their fellow teachers in understanding and including standards-based NASA materials into their classroom activities. Solar System Educators attend a training institute during their first year in the program and have the option of attending subsequent annual institutes. The volunteers in this program receive additional web-based mission-specific telecon trainings in conjunction with the Solar System Ambassadors. Resource and handout materials in the form of DVDs, posters, pamphlets, fact sheets, postcards and bookmarks are also provided. Scientists can get involved with this program by partnering with the Solar System Educators in their regions, presenting at their workshops and mentoring these outstanding volunteers. This formal education program helps optimize project funding set aside for education through the efforts of these volunteer master teachers. At the same time, teachers become familiar with NASA's educational materials with which to inspire students into pursuing careers in science, technology, engineering and math.

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

    Atmospheric Science Data Center

    2016-06-14

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

  2. 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.

  3. 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.

  4. 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.

  5. Dynamics of Satellites in Binary Near-Earth Asteroid Systems: A Study Based on Radar Observations

    NASA Astrophysics Data System (ADS)

    Naidu, Shantanu

    In the past 15 years, three previously unrecognized sub-populations of near-Earth asteroids (NEAs) have been discovered. About 15% of NEAs are binaries, at least 10% of NEAs are contact binaries, and dozens of asteroid pairs have been identified. Numerous science questions have arisen about the formation and evolution processes of these systems and about the inter-relationships between these groups. Addressing these questions informs us about a wide range of important solar system processes that shape small bodies and planetesimals. Here I have chosen to focus on providing one of the most complete characterizations of a binary system among all known asteroid binaries, and on studying the spin-orbit interactions in this and 8 additional binary systems. One hypothesis that has not been fully explored is the possibility of chaotic rotation of asteroid satellites and the impact that such a state has on the evolution of the binary systems. I examine this problem as well as the possibility of detecting librational motions in synchronous satellites. Because the Arecibo and Goldstone radar systems enable superb characterizations of binaries and NEAs in general, this dissertation makes abundant use of radar data. Radar observations provide images of asteroids at decameter resolution, and these images can be inverted to determine the 3D shapes of the components, which are essential to properly model the system dynamics. Radar data also enable precise determination of the mutual orbit, which is another crucial ingredient. In the first two chapters of the dissertation, I describe the observations and physical characterizations of asteroid 2000~ET70 and binary asteroid 2000 DP107. The characterization of 2000 DP107 includes size, shape, spin, mass, and density of each component, making this binary one of the best-characterized asteroid binary to date. In the last chapter of the dissertation, I describe a computationally efficient fourth-order numerical integrator that I used to

  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. 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.

  8. Solar system exploration

    NASA Astrophysics Data System (ADS)

    Briggs, Geoffrey A.; Quaide, William L.

    Two fundamental goals lie at the heart of U.S. solar system exploration efforts: first, to characterize the evolution of the solar system; second, to understand the processes which produced life. Progress in planetary science is traced from Newton's definition of the principles of gravitation through a variety of NASA planetary probes in orbit, on other planets and traveling beyond the solar system. It is noted that most of the planetary data collected by space probes are always eventually applied to improving the understanding of the earth, moon, Venus and Mars, the planets of greatest interest to humans. Significant data gathered by the Mariner, Viking, Apollo, Pioneer, and Voyager spacecraft are summarized, along with the required mission support capabilities and mission profiles. Proposed and planned future missions to Jupiter, Saturn, Titan, the asteroids and for a comet rendzvous are described.

  9. 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.

  10. Milankovitch Cycles of Terrestrial Planets in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan

    2016-08-01

    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 timescales. We investigate the Kepler-47 and Alpha Centauri systems as archetypes of P and S type binary systems respectively. In the first case, Earthlike planets would experience rapid Milankovitch cycles (of order 1000 years) 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 timescale of the binary period. In the Alpha Centauri system, the influence of the secondary produces eccentricity variations on 15,000 year timescales. This produces climate oscillations of similar strength to the variation on the orbital timescale of the binary. Phase drifts between eccentricity and obliquity oscillations creates further cycles that are of order 100,000 years in duration, which are further modulated by neighbouring planets.

  11. 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

  12. A high temperature Rankine binary cycle for ground and space solar engine applications

    NASA Technical Reports Server (NTRS)

    Hertzberg, A.; Lau, C.-V.

    1978-01-01

    A Rankine cycle covering the range of plasma temperatures possible from a solar radiation boiler is studied. The working fluid is potassium. A binary cycle with potassium as the topping cycle fluid and a conventional steam cycle as the bottoming cycle for earth-based applications is analyzed. Operation in conjunction with a wave energy exchanger is considered.

  13. 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.

  14. Primitive Solar System Objects

    NASA Astrophysics Data System (ADS)

    Jewitt, David

    1999-10-01

    Some of the most fundamental and topical questions in astronomy concern the origin and evolution of planetary systems. In the solar system, these questions are most directly addressed through observations of chemically and physically primitive bodies in which a record of the initial conditions may be preserved. The most primitive materials in the solar system reside near its outer edge, in a trans-Neptunian ring known as the Kuiper Belt and in a surrounding spherical cloud first postulated by Oort. These regions supply comets to the inner solar system and, in the case of the Kuiper Belt, preserve evidence of dynamical processes operative in the first 100 million years after formation. The Kuiper Belt is also a source of collisionally produced dust and may be analogous to the dusty rings observed encircling a number of nearby main-sequence stars. I will review the currently known properties of these primitive objects, and discuss how ALMA can contribute to our understanding of the early solar system.

  15. Solar heating system

    SciTech Connect

    Larkin, W.J.

    1984-01-31

    A solar heating system is provided incorporating the flat plate collector and storage tanks substantially in the same unit and avoiding the usual reverse-siphon problems that are inherent in the nature of a passive integral system of this type by a piping system wherein heating and elevation of certain vertical components of connecting piping reverses, or almost reverses, the usual net pressure head which is responsible for creating the reverse siphon.

  16. 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.

  17. 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…

  18. 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.

  19. 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…

  20. 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

  1. 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

  2. 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.

  3. UBVRI Observations And Analysis Of The Solar Type, Total Eclipsing Binary, TYC 3034-299-1

    NASA Astrophysics Data System (ADS)

    Faulkner, Danny R.; Blum, N.; Samec, R. G.; Jaso, A.; Smith, P. M.; White, J.; Van Hamme, W.

    2012-01-01

    TYC 3034-299-1 (CVn) is a magnetically active, solar type contact binary and a ROTSE variable. This system was observed as a part of our continuing student/professional collaborative study of interacting binaries. The current UBVRI light curves were taken with the Lowell 0.81-m reflector in Flagstaff on May 10 and May 11, 2010. Four times of minimum light were determined from our observations. They include (with standard errors): HJD I = 2455326.72754±0.00024, 2455327.713303±0.00025, HJD II = 2455326.92427±0.00068, 2455327.91256±0.00060. We also obtained the following timings of minimum light from parabolic fits to the data of Blattler (IBVS number 5699, 2006): HJD I = 2453382.6915, 2453445.4980, 2453502.3800, 2453515.4154, 2453517.3907, HJD II = 2453463.4719, 2453515.607. From these and Nelson's (IBVS numbers 5875 and 5929, 2009) observations, an improved ephemeris was calculated from all the available eclipse timings: J.D. Hel Min I = 2455326.9244±0.0005 + 0.39500870 ± 0.00000016 d*E. Our light curve amplitudes are deep for a contact binary, ranging from 0.85 magnitude in U to 0.66 in I. Time of totality of 7 minutes was detected in the secondary eclipse indicating that this system is a W-type W UMa system (less massive star is hotter). The O'Connell effect ranges from 67 mmag to 36 mmag in U to I, respectively, revealing substantial magnetic activity. A 5-color simultaneous light curve solution was calculated using the Wilson Code. Our model reveals a dark spot region at longitude 58°. The 18% fill-out and the virtually identical temperatures of the two stars show that the system has nearly reached thermal contact. We performed a q-search over the interval from q = 0.3 to 0.8. The mass ratio is 0.46. We wish to thank Lowell Observatory for their allocation of observing time and the American Astronomical Society and the Arizona Space Grant for travel support for this observing run.

  4. 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.

  5. Absolute parameters of stars in semidetached eclipsing binary systems

    NASA Astrophysics Data System (ADS)

    Budding, E.

    1985-06-01

    A number of questions concerning the absolute parameters of stars in semidetached binary systems are addressed. Consideration is given to: similarities between Algol-type binaries and unevolved detached binaries with respect to the mass-luminosity law; and the single-line classical Algol candidates with known mass functions and photometric solutions for mass ratio. It is shown that the validity of the mass luminosity-law cannot be verified for individual Algol-type binaries though it does hold well on average; and (2), the existence of a definite class of sd-binaries not containing a proportion of significantly undersize types is apparent. The conclusions are found to be in general agreement with the observations of Hall and Neff (1979).

  6. 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. PMID:24744369

  7. 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.

  8. KOI-3278: A Self-Lensing Binary Star System

    NASA Astrophysics Data System (ADS)

    Kruse, Ethan; Agol, Eric

    2014-04-01

    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.

  9. 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).

  10. BVRI Photometric Study of the Totally Eclipsing Short Period Solar Type, Near-Contact W UMA Binary, NSVS 5066754

    NASA Astrophysics Data System (ADS)

    Caton, Daniel B.; Samec, Ronald G.; Nyaude, Ropafadzo; Faulkner, Danny R.

    2016-06-01

    High precision BVRcIc light curves of NSVS 5066754 were observed on May 17-20, 2014 at Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University. It is a solar type eclipsing binary (T1~5750 K) with a period of only 0.375132 (1) d. In fact, it appeared as one of the shortest period in Shaw’s list of near contact binaries. Therefore, we initially believed this to be a pre-contact WUMa Binary (PCWB’s). However, the Binary Maker fits and our Wilson-Devinney solutions show that the binary could have either a semi-detached or a contact binary configuration.Five times of minimum light were calculated, for 3 primary and 2 secondary eclipses from our present observations: In addition, observations at minima were introduced from archived All Sky Automated Survey Data along with the discovery ephemeris. The following decreasing quadratic ephemeris was determined from all available times of minimum light:JDHelMinI=2456797.63848±0.00047d + 0.3747796± 0. 0000068 X E --0.0000000241± 0.0000000005X E2Our contact solution, with a sum of square residuals = 0.49, gave a mass ratio of 0.50, and a component temperature difference of ~360 K, somewhat large for a contact binary. Two substantial cool spots were determined in this solution of 37 deg and 28 deg radius with a t-factor or 0.92 and 0.78 respectively. The fill-out is very shallow, ~6%.The semi-detached solution (mode 4: V1010 Oph configuration, meaning the system is approaching first contact) is of poorer quality with a sum of square residuals = 0.87. It has a mass ratio of 0.63, and a component temperature of ~460 K. The fill-outs are 100% and 97% for the primary and secondary components, respectively. Two spots were determined, one hot (t-factor of 1.16, 14 deg radius, colatitude 101 deg) and one cool spot (t-factor of 0.94, 48 deg radius, colatitude 90 deg). The models in both cases are total eclipsing with high inclinations in the 86-89 deg range, and a time of constant light is

  11. The influence of binary processing additives on the performance of polymer solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Hu, Xiaowen; Zhong, Chengmei; Huang, Mingjun; Wang, Kai; Zhang, Zhan; Gong, Xiong; Cao, Yong; Heeger, Alan J.

    2014-11-01

    In this study, we report the investigation of the influence of binary processing additives, 1,8-octanedithiol (ODT) and 1-chloronaphthalene (CN) on the performance of polymer solar cells (PSCs). It was found that the power conversion efficiency (PCE) can be enhanced to 8.55% from the PSCs processed with binary processing additives as compared with ~6.50% from the PSCs processed with either ODT or CN processing additives. With binary processing additives, the crystallinity of the electron donor polymer, poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2 ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  12. Digital solar system geology

    NASA Technical Reports Server (NTRS)

    Batson, R. M.; Kozak, R. C.; Isbell, Nancy K.

    1991-01-01

    All available synoptic maps of the solid-surface bodies of the Solar System were digitized for presentation in the planned Atlas of the Solar System by Greeley and Batson. Since the last report (Batson et al., 1990), preliminary Uranian satellite maps were replaced with improved versions, Galilean satellite geology was simplified and digitized, structure was added to many maps, and the maps were converted to a standard format, with corresponding standing colors for the mapped units. Following these changes, the maps were re-reviewed by their authors and are now undergoing final editing before preparation for publication. In some cases (for Mercury, Venus, and Mars), more detailed maps were digitized and then simplified for the Atlas. Other detailed maps are planned to be digitized in the coming year for the Moon and the Galilean satellites. For most of the remaining bodies such as the Uranian satellites, the current digitized versions contain virtually all the detail that can be mapped given the available data; those versions will be unchanged for the Atlas. These digital geologic maps are archived at the digital scale of 1/16 degree/ pixel, in sinusoidal format. The availability of geology of the Solar System in a digital database will facilitate comparisons and integration with other data: digitized lunar geologic maps have already been used in a comparison with Galileo SSI observations of the Moon.

  13. 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.

  14. Deep, Low Mass Ratio Overcontact Binary Systems. V. The Lowest Mass Ratio Binary V857 Herculis

    NASA Astrophysics Data System (ADS)

    Qian, S.-B.; Zhu, L.-Y.; Soonthornthum, B.; Yuan, J.-Z.; Yang, Y.-G.; He, J.-J.

    2005-09-01

    Charge-coupled device (CCD) photometric light curves in the B, V, and R bands of the complete eclipsing binary star V857 Her are presented. It is shown that the light curves of the W UMa-type binary are symmetric and of A type according to Binnendijk's classification. Our four epochs of light minimum along with others compiled from the literature were used to revise the period and study the period change. Weak evidence indicates that the orbital period of V857 Her may show a continuous increase at a rate of dP/dt=+2.90×10-7 days yr-1. The photometric parameters of the system were determined with the 2003 version of the Wilson-Devinney code. It is shown that V857 Her is a deep overcontact binary system with f=83.8%+/-5.1%. The derived mass ratio of q=0.06532+/-0.0002 suggests that it has the lowest mass ratio among overcontact binary systems. As the orbital period increases, the decrease of the mass ratio will cause it to evolve into a single rapidly rotating star when it meets the more familiar criterion that the orbital angular momentum be less than 3 times the total spin angular momentum. To understand the evolutionary state of the system, long-term photometric monitoring and spectroscopic observations will be required.

  15. 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.

  16. Solar actuated drain system

    SciTech Connect

    Sarver, G. E.; Worstell, B. W.

    1985-04-30

    A temperature actuated drain system is provided that comprises a siphon that has an inlet end for immersing in a pool of water to be drained from a roof surface and a discharge end communicating with a pressure-responsive one-way valve. A solar actuated enclosed chamber that contains a solar heat energy collector is located on the roof surface and is in open communication with the siphon by means of a tubular member that has its inlet end positioned closely adjacent the bottom of the interior of the chamber. The arrangement causes any appreciable amounts of water that accumulate within the chamber to be discharged from the chamber during the pumping action created by the heating and cooling of air within the chamber.

  17. 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.

  18. 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.

  19. 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.

  20. Simulations of Solar AO Systems

    NASA Astrophysics Data System (ADS)

    Sridharan, R.; Bayanna, A. Raja; Venkatakrishnan, P.

    In this paper, first we compare the two kinds of algorithms that are being used in solar AO systems to sense a distorted wave-front through simulations. Then, we comment on the various issues related to solar AO systems and describe solar features that can be studied using AO as a tool. Then we briefly describe the laboratory model of AO that is being built at the Udaipur Solar Observatory (USO), India.

  1. 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

  2. Mergers of Binary Neutron Star Systems

    NASA Astrophysics Data System (ADS)

    Motl, Patrick M.; Anderson, Matthew; Lehner, Luis; Liebling, Steven; Neilsen, David; Palenzuela, Carlos

    2016-04-01

    We present results from fully relativistic simulations of binary neutron star mergers varying the tabular equation of state used to approximate the degenerate material and the mass ratio. The simulations incorporate both magnetic fields and the effects of neutrino cooling. In particular, we examine the amount and properties of material ejected from the merger. We gratefully acknowledge the support of NASA through the Astrophysics Theory Program grant NNX13AH01G.

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Near-Contact Binaries (NCB): Close Binary Systems in a Key Evolutionary Stage

    NASA Astrophysics Data System (ADS)

    Zhu, L. Y.; Qian, S. B.

    2007-08-01

    Short-period eclipsing binary systems with EB-type light variations are interesting objects for understanding the evolutionary changes undergone by close binaries. As investigated by many authors (Kalużny, J., Yamasaki, A., Zhai, D. S, Zhang, X. B Hilditch, R. W., McFarlane, T. M, King, D. J, Shaw, J. S., Samec, R. G., Niarchos, P. G., Oh, Kyu-Dong. etc ), a majority of them belong to an important subclass of close binaries called near-contact binaries (NCBs). According to the geometric definition of this subclass, NCBs actually comprise semi-detached, marginal-contact, and marginal-detached systems. They can be in the intermediate stage between detached or semi-detached state and contact state. Therefore, NCBs are the important observational targets which may be lying in key evolutionary states. In this paper, we observed and investigated several NCBs (BL And, GW Tau, RU UMi, GSC3658-0076, UU Lyn, AS Ser, IR Cas, EP Aur). Our results show that the orbital periods of BL And, GW Tau, RU UMi and UU Lyn are decreasing while that of IR Cas is decreasing and oscillating. The mechanisms that could explain the period variations are discussed. Combining the photometric solutions with period variations of these systems, we divide them into four types: BL And is a semi-detached system with the lobe filling primary, RU UMi and EP Aur are the semi-detached system with the lobe filling secondary, GW Tau, UU Lyn and AS Ser are the marginal contact system while GSC3658-0076 is the marginal detached system. Finally, the evolutionary stage of each system is discussed and some statistical relations of NCBs are presented.

  10. 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.

  11. 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.

  12. Planetary Dynamics and Evolution in Evolved Binary Systems

    NASA Astrophysics Data System (ADS)

    Perets, Hagai; Kratter, K.; Kenyon, S.

    2011-09-01

    Exo-planets typically form in protoplanetary disks left over from the formation of their host star. We discuss additional evolutionary routes which may may exist in old evolved binary systems. Stellar evolution in binaries could lead to the formation of symbiotic stars, where mass is lost from one star and (partially) transferred to its binary companion, forming an accretion disk. Planetary orbits around the mass losing star can expand and destabilize, and may result in chaotic evolution. Possible outcomes include exchange of the planet to the companion star, ejection, collision, or tidal capture by one of the binary components. We show that the conditions in the newly formed accretion disk could be very similar to protoplanetary disks. Planets around the accreting companion may interact with the disk, leading to (re)growth and (re)migration of the planets. The disk may also provide the necessary environment for the formation of a new, second generation of planets in both circumstellar or circumbinary configurations. Pre-existing planets and/or planetesimals may serve as seeds for the formation of the second generation planets. Such systems should be found in white dwarf binary systems, and may show various unique observational signatures. Most notably, second generation planets could form in environments which are unfavorable for first generation planets. The phase space available for these planets could be forbidden (unstable) to first generation planets in the pre-evolved progenitor binaries. Planets may also form in double compact object binaries and in metal poor environments. Observations of exo-planets in such unfavorable regions could possibly serve to uniquely identify their second generation character. Finally, we point out a few observed candidate second generation planetary systems (Gl 86, HD 27442 and observed circumbinary planet candidates). A second generation origin for these systems could explain their unique configurations.

  13. 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.

  14. 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

  15. 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.

  16. VERITAS Observations of Gamma-ray Binary Systems

    NASA Astrophysics Data System (ADS)

    Holder, Jamie; VERITAS Collaboration

    2016-01-01

    Gamma-ray emitting binary systems constitute a small fraction of the high-energy catalogue, with only five objects confirmed to emit photons above 100 GeV. They comprise a compact object (black hole or neutron star) and a high-mass stellar companion, with gamma-ray emission arising as the result of particle acceleration within the system. The details of how and where this acceleration takes place, and the mechanisms which modulate the subsequent emission, remain unclear. We report here on recent observations of gamma-ray binary systems with the VERITAS observatory.

  17. Extinct radionuclides. [in solar system

    NASA Technical Reports Server (NTRS)

    Podosek, F. A.; Swindle, T. D.

    1988-01-01

    Extinct radionuclides, or radioactive isotopes with lifetimes of the order of 1 to 100 Myr that are now extinct in the solar system are discussed. Evidence is presented for the presence of such radionuclides in the early solar system, including Al-26, Mn-53, Pd-107, I-129, Pu-244, and Sm-146. It is suggested that the abundances of these species provide constraints on nucleosynthetic time scales and the history of solar system materials before they became the solar system. The shortest-lived species is Al-26, which may have been sufficiently abundant to be the major heat source for meteorite parent-body metamorphism or igneous differentiation.

  18. 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.

  19. 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. PMID:26113154

  20. 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

  1. 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.

  2. Confronting Numerical Relativity With Nature: A model-independent characterization of binary black-hole systems in LIGO

    NASA Astrophysics Data System (ADS)

    Jani, Karan; Clark, James; Shoemaker, Deirdre; LIGO Scientific Collaboration; Virgo Collaboration

    2016-03-01

    Stellar and Intermediate mass binary black hole systems (10-1000 solar masses) are likely to be among the strongest sources of gravitational wave detection in Advanced LIGO. In this talk we discuss the prospects for the detection and characterization of these extreme astrophysical system using robust, morphology-independent analysis techniques. In particular, we demonstrate how numerical relativity simulations of black hole collisions may be combined with waveform reconstructions to constrain properties of a binary black-hole system using only exact solutions from general relativity and any potential gravitational wave signal in the data.

  3. Hydrodynamic Simulations of Close and Contact Binary Systems using Bipolytropes

    NASA Astrophysics Data System (ADS)

    Kadam, Kundan

    2016-01-01

    I will present the results of hydrodynamic simulations of close and contact bipolytropic binary systems. This project is motivated by the peculiar case of the red nova, V1309 Sco, which is indeed a merger of a contact binary. Both the stars are believed to have evolved off the main sequence by the time of the merger and possess a small helium core. In order to represent the binary accurately, I need a core-envelope structure for both the stars. I have achieved this using bipolytropes or composite polytropes. For the simulations, I use an explicit 3D Eulerian hydrodynamics code in cylindrical coordinates. I will discuss the evolution and merger scenarios of systems with different mass ratios and core mass fractions as well as the effects due to the treatment of the adiabatic exponent.

  4. 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 motivate…

  5. 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.

  6. Solar Heating Systems: Student Manual.

    ERIC Educational Resources Information Center

    Green, Joanne; And Others

    This Student Manual for a Solar Heating System curriculum contains 22 units of instructional materials for students to use in a course or courses on solar heating systems (see note). For each unit (task), objectives, assignment sheets, laboratory assignments, information sheets, checkpoints (tests), and job sheets are provided. Materials are set…

  7. Solar Heating Systems: Instructor's Guide.

    ERIC Educational Resources Information Center

    Green, Joanne; And Others

    This Instructor's Guide for a Solar Heating System Curriculum is designed to accompany the Student Manual and the Progress Checks and Test Manual for the course (see note), in order to facilitate the instruction of classes on solar heating systems. The Instructor's Guide contains a variety of materials used in teaching the courses, including…

  8. Binary systems, star clusters and the Galactic-field population. Applied stellar dynamics

    NASA Astrophysics Data System (ADS)

    Kroupa, Pavel

    2002-01-01

    This book contains the results of recent theoretical work on the evolution of primordial binary systems in young star clusters, their effect on the evolution of their host clusters, implications for the distribution of young stars in the Milky Way, and the formation of bound star clusters. This work shows that if the Galactic-field binary population is a dynamically evolved version of the Taurus-Auriga pre-main sequence population, then most stars form in clusters with typically a few hundred binaries within a radius of about 0.5-1 pc. The results also suggest that the population I primordial binary-star orbital-parameter distribution functions may be universal, much like the initial mass function. Most solar-like planetary systems can survive in such clusters. The work presented here also establishes that most observed triple and quadruple systems must be primordial, but that α Cen A/B-Proxima Cen-like systems can form in clusters through dynamical capture. Precise N-body calculations using Aarseth's N-body codes of clusters containing up to 104 stars are used to create an extensive young-cluster library. These data demonstrate that the primordial binary systems are disrupted on a crossing-time scale, and that the truncation of the surviving period distribution measures the maximum concentration the cluster ever experienced. The N-body calculations demonstrate that Galactic star clusters form readily as nuclei of expanding OB associations despite a star-formation efficiency of typically 30 per cent and gas-expulsion over a time-span shorter than the cluster crossing time.

  9. 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)

  10. The new Wolf-Rayet binary system WR62a

    NASA Astrophysics Data System (ADS)

    Collado, A.; Gamen, R.; Barbá, R. H.

    2013-04-01

    Context. A significant number of the Wolf-Rayet stars seem to be binary or multiple systems, but the nature of many of them is still unknown. Dedicated monitoring of WR stars favours the discovery of new systems. Aims: We explore the possibility that WR62a is a binary system. Methods: We analysed the spectra of WR62a, obtained between 2002 and 2010, to look for radial-velocity and spectral variations that would suggest there is a binary component. We searched for periodicities in the measured radial velocities and determined orbital solutions. A period search was also performed on the "All-Sky Automated Survey" photometry. Results: We find that WR62a is a double-lined spectroscopic binary with a WN5 primary star and an O 5.5-6 type secondary component in orbit with a period of 9.1447 d. The minimum masses range between 21 and 23 M⊙ for the WN star and between 39 and 42 M⊙ for the O-type star, thus indicating that the WN star is less massive than the O-type component. We detect a phase shift in the radial-velocity curve of the He ii λ4686 emission line relative to the other emission line curves. The equivalent width of this emission line shows a minimum value when the WN star passes in front of the system. The analysis of the ASAS photometry confirms the spectroscopic periodicity, presenting a minimum at the same phase.

  11. 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

    2015-02-01

    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.

  12. 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.

  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. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Orbital Motions in Binary Protostellar Systems

    NASA Astrophysics Data System (ADS)

    Rodríguez, L. F.

    2004-08-01

    Using high-resolution ( ˜ 0to z @. hss ''1), multi-epoch Very Large Array observations, we have detected orbital motions in several low-luminosity protobinary systems in the Taurus and ρ Ophiuchus molecular complexes. The masses obtained from Kepler's third law are of the order of 0.5 to 2 M⊙, as expected for such low-mass protostars. The relatively large bolometric luminosities of these young systems corroborates the notion that protostars obtain most of their luminosity from accretion and not from nuclear reactions. In addition, in one of the sources studied (a multiple system in Taurus), a low-mass young star has shown a drastic change in its orbit after a close approach with another component of the system, presumed to be a double star. The large proper motion achieved by this low mass protostar (20 km s-1), suggests an ejection from the system.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Views of the solar system

    NASA Astrophysics Data System (ADS)

    Hamilton, C.

    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.

  8. 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.

  9. 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.

  10. GRAVITATIONAL CONUNDRUM? DYNAMICAL MASS SEGREGATION VERSUS DISRUPTION OF BINARY STARS IN DENSE STELLAR SYSTEMS

    SciTech Connect

    De Grijs, Richard; Li, Chengyuan; Zheng, Yong; Kouwenhoven, M. B. N.; Deng, Licai; Hu, Yi; Wicker, James E.

    2013-03-01

    Upon their formation, dynamically cool (collapsing) star clusters will, within only a few million years, achieve stellar mass segregation for stars down to a few solar masses, simply because of gravitational two-body encounters. Since binary systems are, on average, more massive than single stars, one would expect them to also rapidly mass segregate dynamically. Contrary to these expectations and based on high-resolution Hubble Space Telescope observations, we show that the compact, 15-30 Myr old Large Magellanic Cloud cluster NGC 1818 exhibits tantalizing hints at the {approx}> 2{sigma} level of significance (>3{sigma} if we assume a power-law secondary-to-primary mass-ratio distribution) of an increasing fraction of F-star binary systems (with combined masses of 1.3-1.6 M {sub Sun }) with increasing distance from the cluster center, specifically between the inner 10''-20'' (approximately equivalent to the cluster's core and half-mass radii) and the outer 60''-80''. If confirmed, then this will offer support for the theoretically predicted but thus far unobserved dynamical disruption processes of the significant population of 'soft' binary systems-with relatively low binding energies compared to the kinetic energy of their stellar members-in star clusters, which we have access to here by virtue of the cluster's unique combination of youth and high stellar density.

  11. 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.

  12. Formation and Evolution of Hypernova Progenitors in Massive Binary Systems

    NASA Astrophysics Data System (ADS)

    Joss, P. C.; Becker, J. A.

    If long γ-ray bursts are produced by hypernovae, a problem that must be confronted is how the core of the hypernova progenitor retains or acquires sufficient angular momentum to produce the requisite axisymmetric collapse. Physical processes during the evolution of an isolated massive star will tend to extract any initial angular momentum from the stellar core, rendering it difficult for such a star to become a hypernova. However, a substantial fraction of massive stars are members of binary systems. Tidal locking, mass transfer, or stellar merger in an evolved massive binary may lead to the transfer of orbital angular momentum to the core of one of the stars (or the merged star), sufficient to produce the progenitor of a hypernova. We have developed a new binary stellar-evolution code that includes the effects of mass and angular-momentum transfer between the component stars and the subsequent transport of angular momentum through one of the stars. This transport is affected by dynamical and secular shear instabilities, convective motions, the critical layer instability, and gravity waves. Our code treats in a self-consistent way the dynamical distortion of the star resulting from the induced rapid differential rotation. The results of our numerical computations indicate that late main-sequence or early post-mainsequence accretion from a binary companion onto a star with an initial mass ≥ 20M⊙ may produce a stellar core that is rotating sufficiently rapidly when it collapses to provide the initial conditions necessary for a hypernova event. Our results also indicate that the merger of a late post-main-sequence star with its binary companion, as considered by Ivanova, Podsiadlowski & Spruit (2002), may also lead to a hypernova event in the stellar core but is unlikely to produce an observable γ-ray burst.

  13. Deep, Low Mass Ratio Overcontact Binary Systems. XIV. A Statistical Analysis of 46 Sample Binaries

    NASA Astrophysics Data System (ADS)

    Yang, Yuan-Gui; Qian, Sheng-Bang

    2015-09-01

    A sample of 46 deep, low mass ratio (DLMR) overcontact binaries (i.e., q≤slant 0.25 and f≥slant 50%) is statistically analyzed in this paper. It is found that five relations possibly exist among some physical parameters. The primary components are little-evolved main sequence stars that lie between the zero-age main sequence line and the terminal-age main sequence (TAMS) line. Meanwhile, the secondary components may be evolved stars above the TAMS line. The super-luminosities and large radii may result from energy transfer, which causes their volumes to expand. The equations of M-L and M-R for the components are also determined. The relation of P-Mtotal implies that mass may escape from the central system when the orbital period decreases. The minimum mass ratio may preliminarily be {q}{min}=0.044(+/- 0.007) from the relations of q-f and q-Jspin/Jorb. With mass and angular momentum loss, the orbital period decreases, which finally causes this kind of DLMR overcontact binary to merge into a rapid-rotating single star.

  14. 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.

  15. Kepler eclipsing binary stars. IV. Precise eclipse times for close binaries and identification of candidate three-body systems

    SciTech Connect

    Conroy, Kyle E.; Stassun, Keivan G.; Prša, Andrej; Orosz, Jerome A.; Welsh, William F.; Fabrycky, Daniel C.

    2014-02-01

    We present a catalog of precise eclipse times and analysis of third-body signals among 1279 close binaries in the latest Kepler Eclipsing Binary Catalog. For these short-period binaries, Kepler's 30 minute exposure time causes significant smearing of light curves. In addition, common astrophysical phenomena such as chromospheric activity, as well as imperfections in the light curve detrending process, can create systematic artifacts that may produce fictitious signals in the eclipse timings. We present a method to measure precise eclipse times in the presence of distorted light curves, such as in contact and near-contact binaries which exhibit continuously changing light levels in and out of eclipse. We identify 236 systems for which we find a timing variation signal compatible with the presence of a third body. These are modeled for the light travel time effect and the basic properties of the third body are derived. This study complements J. A. Orosz et al. (in preparation), which focuses on eclipse timing variations of longer period binaries with flat out-of-eclipse regions. Together, these two papers provide comprehensive eclipse timings for all binaries in the Kepler Eclipsing Binary Catalog, as an ongoing resource freely accessible online to the community.

  16. Stability of a planet in the HD 41004 binary system

    NASA Astrophysics Data System (ADS)

    Satyal, S.; Musielak, Z. E.

    2016-03-01

    The Hill stability criterion is applied to analyse the stability of a planet in the binary star system of HD 41004 AB, with the primary and secondary separated by 22 AU, and masses of 0.7 M_⊙ and 0.4 M_⊙, respectively. The primary hosts one planet in an S-type orbit, and the secondary hosts a brown dwarf (18.64 M_J) on a relatively close orbit, 0.0177 AU, thereby forming another binary pair within this binary system. This star-brown dwarf pair (HD 41004 B+Bb) is considered a single body during our numerical calculations, while the dynamics of the planet around the primary, HD 41004 Ab, is studied in different phase-spaces. HD 41004 Ab is a 2.6 M_J planet orbiting at the distance of 1.7 AU with orbital eccentricity 0.39. For the purpose of this study, the system is reduced to a three-body problem and is solved numerically as the elliptic restricted three-body problem (ERTBP). The {Hill stability} function is used as a chaos indicator to configure and analyse the orbital stability of the planet, HD 41004 Ab. The indicator has been effective in measuring the planet's orbital perturbation due to the secondary star during its periastron passage. The calculated Hill stability time series of the planet for the coplanar case shows the stable and quasi-periodic orbits for at least ten million years. For the reduced ERTBP the stability of the system is also studied for different values of planet's orbital inclination with the binary plane. Also, by recording the planet's {ejection time} from the system or {collision time} with a star during the integration period, stability of the system is analysed in a bigger phase-space of the planet's orbital inclination, ≤ 90o, and its semimajor axis, 1.65-1.75 AU. Based on our analysis it is found that the system can maintain a stable configuration for the planet's orbital inclination as high as 65o relative to the binary plane. The results from the Hill stability criterion and the planet's dynamical lifetime map are found to be

  17. 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…

  18. 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

  19. 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.

  20. Solar tracking system

    SciTech Connect

    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. Official Gazette of the U.S. Patent and Trademark Office

  1. Counter electrodes from binary ruthenium selenide alloys for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Li, Pinjiang; Cai, Hongyuan; Tang, Qunwei; He, Benlin; Lin, Lin

    2014-12-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, cost-effectiveness, relatively high efficiency, and easy fabrication. However, the reduction of fabrication cost without sacrifice of power conversion efficiencies of the DSSCs is a golden rule for their commercialization. Here we design a new binary ruthenium selenide (Ru-Se) alloy counter electrodes (CEs) by a low-temperature hydrothermal reduction method. The electrochemical behaviors are evaluated by cyclic voltammogram, electrochemical impedance, and Tafel measurements, giving an optimized Ru/Se molar ratio of 1:1. The DSSC device with RuSe alloy CE achieves a power conversion efficiency of 7.15%, which is higher than 5.79% from Pt-only CE based DSSC. The new concept, easy process along with promising results provide a new approach for reducing cost but enhancing photovoltaic performances of DSSCs.

  2. On the Nb-Ge Binary System

    NASA Astrophysics Data System (ADS)

    Papadimitriou, Ioannis; Utton, Claire; Tsakiropoulos, Panos

    2015-12-01

    First-principles calculations were used to study intermetallic compounds in the Nb-Ge system, to gain a better understanding of the phase diagram and resolve conflicts reported in the literature. The enthalpy of formation with regard to temperature was calculated for all the intermetallic compounds, to investigate phase stabilities and phase equilibria at low and elevated temperatures. These results, combined with the electronic DOS, suggest that the tI32 (W5Si3-type) Nb5Ge3 and NbGe2 compounds are stable over the whole temperature range. The stoichiometric cP8 Nb3Ge becomes stable close to its melting temperature. Regarding different compositions of the cP8 Nb3Ge, the calculations suggest the (Nb)0.75(Nb,Ge)0.25 model for the Nb3Ge phase instead of the proposed model, (Nb)0.75(Nb,Ge,Va)0.25, where Va represents vacancy. The calculations show that the tI32 (Cr5B3-type) Nb5Ge3, hP16 (Mn5Si3-type) Nb5Ge3 and Nb10Ge7 compounds should be considered metastable. The elastic constants, bulk, shear, and Young's modulus, Poisson's ratio, and Debye temperature of the Nb, Ge, cP8 Nb3Ge, tP32 Nb3Ge, tI32 (Cr5B3-type) Nb5Ge3, tI32 (W5Si3-type) Nb5Ge3, hP16 (Mn5Si3-type) Nb5Ge3, Nb10Ge7 and NbGe2 were calculated. These phases were found to be mechanically stable. Using the Cauchy pressure, Pugh's index of ductility, and the Poisson's ratio as criteria, the calculations suggest that the tI32 (Cr5B3-type) Nb5Ge3 and NbGe2 intermetallics should be brittle (with the latter being the most brittle) and the cP8 Nb3Ge, tP32 Nb3Ge, hP16 Nb5Si3 and Nb10Ge7 ductile (with cP8 Nb3Ge being the most ductile).

  3. Phase equilibrium behavior of the carbon dioxide + benzophenone binary system

    SciTech Connect

    Tarantino, D.E.; Kohn, J.P.; Brennecke, J.F. . Dept. of Chemical Engineering)

    1994-01-01

    Phase equilibrium behavior of various binary CO[sub 2] + hydrocarbon mixtures has been studied by many researchers, providing data which are useful in the design of economically attractive separation processes using carbon dioxide as a solvent. Pressure, liquid-phase composition, and liquid-phase molar volumes are presented for the binary vapor-liquid system CO[sub 2] + benzophenone at 25, 35, and 50 C. Also, pressure, liquid-phase compositions, and liquid-phase molar volumes on the S[sub 1]-L[sub 1]-V curve and L[sub 1]-L[sub 2]-V curve are presented. The termination points of these loci are located and characterized.

  4. Photometric study of the binary system NN Del

    NASA Astrophysics Data System (ADS)

    Gómez-Forrellad, J. M.; Sánchez-Bajo, F.; Corbera-Subirana, M.; GarcÍa-Melendo, E.; Vidal-Sainz, J.

    We present the results of the differential V light curve analysis of NN Del. We show that NN Del is an EA eclipsing binary system with a period of 99.27 days and a highly eccentric orbit. Photometric solutions obtained using the Russell and the Wilson-Devinney models seem to indicate that both components are very similar in radii and luminosities (assuming a F5 spectral type). Constraints imposed on the V luminosity of the system by the HIPPARCOS data suggest that the components of the system could be subgiants instead of main sequence stars.

  5. Chaos in the Solar System

    NASA Technical Reports Server (NTRS)

    Lecar, Myron; Franklin, Fred A.; Holman, Matthew J.; Murray, Norman J.

    2001-01-01

    The physical basis of chaos in the solar system is now better understood: In all cases investigated so far, chaotic orbits result from overlapping resonances. Perhaps the clearest examples are found in the asteroid belt. Overlapping resonances account for its kirkwood gaps and were used to predict and find evidence for very narrow gaps in the outer belt. Further afield, about one new "short-peroid" comet is discovered each year. They are believed to come from the "Kuiper Belt" (at 40 AU or more) via chaotic orbits produced by mean-motion and secular resonances with Neptune. Finally, the planetary system itself is not immune from chaos. In the inner solar system, overlapping secular resonances have been identified as the possible source of chaos. For example, Mercury in 1012 years, may suffer a close encounter with Venus or plunge into the Sun. In the outer solar system, three-body resonances have been identified as a source of chaos, but on an even longer time scale of 109 times the age of the solar system. On the human time scale, the planets do follow their orbits in a stately procession, and we can predict their trajectories for hundreds of thousands of years. That is because the mavericks, with shorter instability times, have long since been ejected. The solar system is not stable; it is just old!

  6. 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.

  7. Searching Planets Around Some Selected Eclipsing Close Binary Stars Systems

    NASA Astrophysics Data System (ADS)

    Nasiroglu, Ilham; Slowikowska, Agnieszka; Krzeszowski, Krzysztof; Zejmo, M. Michal; Er, Hüseyin; Goździewski, Krzysztof; Zola, Stanislaw; Koziel-Wierzbowska, Dorota; Debski, Bartholomew; Ogloza, Waldemar; Drozdz, Marek

    2016-07-01

    We present updated O-C diagrams of selected short period eclipsing binaries observed since 2009 with the T100 Telescope at the TUBITAK National Observatory (Antalya, Turkey), the T60 Telescope at the Adiyaman University Observatory (Adiyaman, Turkey), the 60cm at the Mt. Suhora Observatory of the Pedagogical University (Poland) and the 50cm Cassegrain telescope at the Fort Skala Astronomical Observatory of the Jagiellonian University in Krakow, Poland. All four telescopes are equipped with sensitive, back-illuminated CCD cameras and sets of wide band filters. One of the targets in our sample is a post-common envelope eclipsing binary NSVS 14256825. We collected more than 50 new eclipses for this system that together with the literature data gives more than 120 eclipse timings over the time span of 8.5 years. The obtained O-C diagram shows quasi-periodic variations that can be well explained by the existence of the third body on Jupiter-like orbit. We also present new results indicating a possible light time travel effect inferred from the O-C diagrams of two other binary systems: HU Aqr and V470 Cam.

  8. Cross-sections for planetary systems interacting with passing stars and binaries

    NASA Astrophysics Data System (ADS)

    Li, Gongjie; Adams, Fred

    2015-08-01

    Most planetary systems are formed within stellar clusters, and these environments can shape their properties. This paper considers scattering encounters between solar systems and passing cluster members, and calculates the corresponding interaction cross-sections. The target solar systems are generally assumed to have four giant planets, with a variety of starting states, including circular orbits with the semimajor axes of our planets, a more compact configuration, an ultracompact state with multiple mean motion resonances, and systems with massive planets. We then consider the effects of varying the cluster velocity dispersion, the relative importance of binaries versus single stars, different stellar host masses, and finite starting eccentricities of the planetary orbits. For each state of the initial system, we perform an ensemble of numerical scattering experiments and determine the cross-sections for eccentricity increase, inclination angle increase, planet ejection, and capture. This paper reports results from over 2 million individual scattering simulations. Using supporting analytic considerations, and fitting functions to the numerical results, we find a universal formula that gives the crosssections as a function of stellar host mass, cluster velocity dispersion, starting planetary orbital radius, and final eccentricity. The resulting cross-sections can be used in a wide variety of applications. As one example, we revisit constraints on the birth aggregate of our Solar system due to dynamical scattering and find N ≤104 (consistent with previous estimates).

  9. 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.

  10. Solar liquid heating system

    SciTech Connect

    Finn, D.J.

    1990-05-08

    This patent describes a solar heater for heating liquids. It comprises: a heatable bag, a support means supporting the heatable bag, a heatable body of liquid in the heatable bag, the heatable bag being disposed in sunlight so as to become heated thereby, a topside gas bag above the heatable bag, the topside gas bag containing a gas for serving as insulation, a topside fluid bag disposed above the topside gas bag and containing a fluid for further insulation. The bags being substantially gasproof and waterproof and also being flexible whereby the gravity pull on the bags and the flexibility thereof causes the upper sides of the bags to seek horizontal levels.

  11. Photometric Analysis of the Contact Binary System V829 Hercules

    NASA Astrophysics Data System (ADS)

    Özkardeş, B.; Erdem, A.

    2007-05-01

    New BVR light curves and photometric analysis of the contact binary star V829 Her are presented. The light curves were obtained at the çanakkale Onsekiz Mart University Observatory in 2005. All the times of minimum light were collected and combined with the new ones presented in this work. The variation of the orbital period of the system was then analysed. Sinusoidal and secular changes were found. These variations were examined in terms of two plausible mechanisms, namely (i) mass transfer, and (ii) a light-time effect due to an unseen component in the system. The instrumental differential magnitudes of the system were converted into standard magnitudes. So, we calculate BVR standard magnitudes of the system and obtain the mean color indices of B-V=0.59±0.01 for V829 Her, which indicates the spectral type of the system to be G0-1. The light curves are generally those of contact binaries, but there are large asymmetries between maxima. New BVR light curves and radial velocity curves available from the literature were analysed, simultaneously. Light curve asymmetries of the system were explained in terms of a large dark starspot on the more massive component. Absolute parameters of the system were also derived.

  12. SELF-CONSISTENT MAGNETIC STELLAR EVOLUTION MODELS OF THE DETACHED, SOLAR-TYPE ECLIPSING BINARY EF AQUARII

    SciTech Connect

    Feiden, Gregory A.; Chaboyer, Brian E-mail: Brian.Chaboyer@Dartmouth.edu

    2012-12-10

    We introduce a new one-dimensional stellar evolution code, based on the existing Dartmouth code, that self-consistently accounts for the presence of a globally pervasive magnetic field. The methods involved in perturbing the equations of stellar structure, the equation of state, and the mixing-length theory of convection are presented and discussed. As a first test of the code's viability, stellar evolution models are computed for the components of a solar-type, detached eclipsing binary (DEB) system, EF Aquarii, shown to exhibit large disagreements with stellar models. The addition of the magnetic perturbation corrects the radius and effective temperature discrepancies observed in EF Aquarii. Furthermore, the required magnetic field strength at the model photosphere is within a factor of two of the magnetic field strengths estimated from the stellar X-ray luminosities measured by ROSAT and those predicted from Ca II K line core emission. These models provide firm evidence that the suppression of thermal convection arising from the presence of a magnetic field is sufficient to significantly alter the structure of solar-type stars, producing noticeably inflated radii and cooler effective temperatures. The inclusion of magnetic effects within a stellar evolution model has a wide range of applications, from DEBs and exoplanet host stars to the donor stars of cataclysmic variables.

  13. 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.

  14. 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.

  15. Solar hot-water system

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design data brochure describes domestic solar water system that uses direct-feed system designed to produce 80 gallons of 140 F hot water per day to meet needs of single family dwelling. Brochure also reviews annual movements of sun relative to earth and explains geographic considerations in collector orientation and sizing.

  16. Observation of asteroids with GRAVITY - Physical characterization of binary systems

    NASA Astrophysics Data System (ADS)

    Matter, A.; Delbo, M.; Carry, B.; Tanga, P.

    2014-12-01

    Density and internal structures are among the most important characteristics of asteroids, yet these properties are also some of the least known. For distant asteroids (in the Main Belt and beyond) these properties were up to now accessible only for the largest (>100 km in size) asteroids. Going to smaller and fainter asteroids can revolutionize our understanding because we will be sampling a new regime in physical properties. Here we discuss how ground-based optical interferometry with the GRAVITY instrument can be used to observe the motion of asteroid satellites to determine the mass of small binary systems. Following the expected sensitivity performances in K-band of GRAVITY, we present a sample of binary targets potentially observable in single-field mode. The feasibility of such observations will strongly be dependent on the ability of the control software of GRAVITY to track objects moving at high rate on the sky (differential motion ˜f 10 mas.s^{-1}). Although the dual-field mode could allow to increase the sample of small binary asteroids observable, it seems to be currently unfeasible given the high differential motion of asteroids.

  17. Water delivery to the Habitable zone and impact probabilities in the early phases of planetary systems in binary star systems

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    By now, observations of exoplanets have found more than 50 binary star systems hosting 71 planets. We expect these numbers to increase as more than 70Â % of the main sequence stars in the solar neighbourhood are members of binary or multiple systems. The planetary motion in binary star systems depends strongly on both the parameters of the stellar system (stellar separation and eccentricity) and the architecture of the planetary system (number of planets and their orbital behaviour). In case a terrestrial planet moves in the so-called habitable zone (HZ) of its host star, the habitability of such a planet depends on many parameters. A crucial factor is certainly the amount of water. Water is the main ingredient defining an habitable planet. Therefore, the main question we would like to answer in our study is if a dry or almost dry planet can be fed with water by a bombardement of wet small bodies in such binary systems. First simulations of planetary formation in such systems show the stochastic behaviour of the water to mass ratio of planetary embryos (Haghighipour and Raymond 2007). After the embryo formation, a remnent disc of small bodies can be found around the main star. It mainly contains asteroids and comets whose initial water distribution depends on their position relative to the snow-line. After the gas dissipation, the disc is free to move under gravitation. They can interact with embryos located in the habitable zone and thus alter their initial water content. In our study, we consider different binary star configurations of G, K and M for the secondary star (the primary is a G-type), with various ranges of semi-major axis (from 25 AU to 100 AU) and eccentricity (from 0.1 to 0.5), and analyse the dynamics of small bodies moving under the gravitational perturbation of the binary star system, a Jupiter-like planet and an Earth-like planet, where the latter is randomly placed in the habitable zone. We mainly focus on water-rich asteroids with semi

  18. 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.

  19. 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. PMID:26406745

  20. 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.

  1. 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.

  2. 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%. PMID:27355523

  3. 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.

  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. 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).

  6. 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)

  7. 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.

  8. Solar desalination system and method

    SciTech Connect

    Kruse, C.L.

    1985-03-12

    A solar desalination system in which fresh water is derived from sea water by focussing solar ray energy from a collecting reflector onto an evaporator tube located at substantially the focal apex of the reflector. The reflector/evaporator tube assembly is mounted on a horizontal open grid platform which may support a plurality of parallel reflector/evaporator tube assemblies. The reflectors may serve as pontoons to support the desalination system unit on a body of sea water. The solar heat generated vapor is condensed in condenser tubes immersed in the sea water. Intermittently sea water concentrate is withdrawn from the evaporator tubes. Velocity of the vapor passing from the evaporator tubes to the condensers may be utilized for generating power.

  9. 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.

  10. ROSAT x ray survey observations of active chromospheric binary systems and other selected sources

    NASA Technical Reports Server (NTRS)

    Ramsey, Lawrence W.

    1993-01-01

    The connection between processes that produce optical chromospheric activity indicators and those that produce x-rays in RS CVn binary systems by taking advantage of the ROSAT All-Sky Survey (RASS) results and our unique ground-based data set was investigated. In RS CVn systems, excess emission in the Ca 2 resonance (K & H) and infrared triplet (IRT) lines and in the Balmer lines of hydrogen is generally cited as evidence for chromospheric activity, which is usually modeled as scaled up solar-type activity. X-ray emission in RS CVn systems is believed to arise from coronal loop structures. Results from spectra data obtained from RASS observations are discussed and presented.

  11. Colliding winds from early-type stars in binary systems

    NASA Technical Reports Server (NTRS)

    Stevens, Ian R.; Blondin, John M.; Pollock, A. M. T.

    1992-01-01

    The dynamics of the wind and shock structure formed by the wind collision in early-type binary systems is examined by means of a 2D hydrodynamics code, which self-consistently accounts for radiative cooling, and represents a significant improvement over previous attempts to model these systems. The X-ray luminosity and spectra of the shock-heated region, accounting for wind attenuation and the influence of different abundances on the resultant level and spectra of X-ray emission are calculated. A variety of dynamical instabilities that are found to dominate the intershock region is examined. These instabilities are found to be particularly important when postshock material is able to cool. These instabilities disrupt the postshock flow and add a time variability of order 10 percent to the X-ray luminosity. The X-ray spectrum of these systems is found to vary with the nuclear abundances of winds. These theoretical models are used to study several massive binary systems, in particular V444 Cyg and HD 193793.

  12. The low mass ratio contact binary system V728 Herculis

    NASA Astrophysics Data System (ADS)

    Erkan, N.; Ulaş, B.

    2016-07-01

    We present the orbital period study and the photometric analysis of the contact binary system V728 Her. Our orbital period analysis shows that the period of the system increases (dP / dt = 1.92 ×10-7 dyr-1) and the mass transfer rate from the less massive component to more massive one is 2.51 ×10-8 M⊙y-1 . In addition, an advanced sinusoidal variation in period can be attributed to the light-time effect by a tertiary component or the Applegate mechanism triggered by the secondary component. The simultaneous multicolor BVR light and radial velocity curves solution indicates that the physical parameters of the system are M1 = 1.8M⊙ , M2 = 0.28M⊙ , R1 = 1.87R⊙ , R2 = 0.82R⊙ , L1 = 5.9L⊙ , and L2 = 1.2L⊙ . We discuss the evolutionary status and conclude that V728 Her is a deep (f = 81%), low mass ratio (q = 0.16) contact binary system.

  13. Secular resonances in circumstellar systems in binary stars

    NASA Astrophysics Data System (ADS)

    Bazso, A.; Pilat-Lohinger, E.; Eggl, S.; Funk, B.; Bancelin, D.

    2016-02-01

    Planet formation around single stars is already a complicated matter, but extrasolar planets are also present in binary and multiple star systems. We investigate circumstellar planets in binary star systems with stellar separations below 100 astronomical units. For a selection of 11 systems with at least one detected giant planet we determine the location and extension of the habitable zone (HZ), subject to the incident stellar flux from both stars. We work out the stability of additional hypothetical terrestrial planets in or close to the HZ in these systems. To study the secular dynamics we apply a semi-analytical method. This method employs a first-order perturbation theory to determine the secular frequencies of objects moving under the gravitational influence of two much more massive perturbers. The other part uses a single numerical integration of the equations of motion and a frequency analysis of the obtained time-series to determine the apsidal precession frequencies of the massive bodies. By combining these two parts we are able to find the location of the most important secular resonances and the regions of chaotic motion. We demonstrate that terrestrial planets interior to the giant planet’s orbit may suffer from a linear secular resonance that could prevent the existence of habitable planets. Contrary to this, close-in giant planets are less of a problem, but one has to take into account the general relativistic precession of the pericenter that can also lead to resonances.

  14. 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.

  15. Properties of the components in young binary systems

    NASA Astrophysics Data System (ADS)

    Woitas, Jens

    1999-10-01

    Using near-infrared speckle-interferometry we have obtained resolved JHK-photometry for the components of 58 young binary systems. By placing the components into a color-color diagram we identify some unusual red objects that are candidates for infrared companions or substellar objects. We place a subsample that consists of the components of 14 weak-lined TTS systems (where no significant circumstellar excess emission is expected) into a color-magnitude diagram and show that in all these systems the components are coeval within the uncertainties. Particularly this is the case for the triple system HBC 358. Using the J-magnitude as an indicator for the stellar luminosity, the optical spectral type of the system and the previously justified assumption that all components are coeval we can place the components into the HRD and derive their masses by comparison with theoretical pre-main sequence evolutionary tracks. The results are the following: The distribution of mass ratios is neither clustered towards M2 / M1 = 1 nor is it a function of the primary's mass or the components' projected separation. Comparison of these results with predictions of theoretical multiple star formation models suggests that most of the systems have formed by fragmentation during protostellar collapse, and that the components' masses are principally determined by fragmentation and not by the following accretion processes. Furthermore the infrared source HV Tau C is discussed using new observational data. We show that this source is no Herbig-Haro object, but an active T Tauri star. So the HV Tau-system does not impose a problem on current models of T Tauri stars and their environment. From relative positions of the components at different epochs we derive their relative velocities and show that in most close systems orbital motion can be proved. The analysis of this orbital motion leads to an empirical mass estimate for T Tauri-stars which is larger than the masses one would expect from the

  16. Decentralized solar photovoltaic energy systems

    NASA Astrophysics Data System (ADS)

    Krupka, M. C.

    1980-09-01

    Emphasis was 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 percent efficiency at 28 C and 100 mW/sq cm insolation are used to generate 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. 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.

  17. 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,…

  18. 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…

  19. 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.

  20. 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…

  1. Synergistic Effects of Binary-Solvent Annealing for Efficient Polymer-Fullerene Bulk Heterojunction Solar Cells.

    PubMed

    Wu, Fu-Chiao; Li, Yi-Hao; Tsou, Chieh-Jen; Tung, Kuo-Cheng; Yen, Chia-Te; Chou, Fang-Sheng; Tang, Fu-Ching; Chou, Wei-Yang; Ruan, Jrjeng; Cheng, Horng-Long

    2015-09-01

    Conjugated polymer-fullerene-based bulk-heterojunction (BHJ) organic solar cells (OSCs) have attracted tremendous attention over the past two decades because of their potential to develop low-cost and easy methods to produce energy from light. The complicated microstructure and morphology with randomly organized architecture of these polymer-fullerene-based active layers (ALs) is a key factor that limits photovoltaic performance. In this study, a binary-solvent annealing (BSA) approach was established to improve the poly(3-hexylthiophene):indene-C60 bisadduct-based AL for efficient BHJ-type OSCs by varying the second solvents with different boiling points (BP). Thus, we were able to change the evaporation behavior of cosolvents and consequently obtain the various microstructural properties of the AL. An in-depth study was conducted on the solvent-evaporation driven morphology of the active layer under various cosolvent conditions and its effect on the photovoltaic parameters of OSCs. Under the BSA processes, we found that the specimens with low-BP second solvents allows us to observe a more ideal AL for increasing photon absorption and efficient charge transport and collection at the respective electrodes, resulting in enhanced PCE of the corresponding OSCs. By contrast, the specimens with high-BP second solvents exhibit random microstructures, which are detrimental to charge transport and collection and lead to diminished PCE of the corresponding OSCs. By appropriately selecting the composition of a binary solvent, BSA can be employed as an easy method for the effective manipulation of the microstructures of ALs. BSA is a promising technique for the performance enhancement of not only OSCs but also other organic/polymeric-based electronic devices. PMID:26267758

  2. 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

  3. 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.

  4. 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.

  5. The Quasi-Roche Lobe Overflow State in the Evolution of Close Binary Systems Containing a Radio Pulsar

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; De Vito, M. A.; Horvath, J. E.

    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.

  6. Geologic exploration of solar system

    SciTech Connect

    Wood, C.A.

    1987-11-01

    The processes that must have operated on the early Earth have been deduced from evidence from ancient surfaces of the Moon and planets. In particular, such comparative studies have demonstrated that only two geologic processes have been widespread throughout the history of the solar system: impact cratering and volcanism. Impact craters have formed throughout solar system history, indeed the planets themselves were formed by the accumulation of millions of smaller planetesimals, each of which formed an impact crater. Earth could not have escaped the intense bombardment that churned the surfaces of Mars, Mercury, and the Moon. The impact cratering rate dramatically declined about 3.9 billion years ago, but craters 10 km across still form on the Earth on the average of one every 140,000 years, and the 1.5-km wide Meteor Crater in Arizona formed only about 25,000 years ago. Volcanic flows and cones have been observed on nearly all planets and moons in the solar system; the variety and duration of volcanism are directly related to planet mass. Thus, a relatively large planet like the Earth has a wide range of volcanic morphologies and compositions, with activity continuing throughout Earth history. In contrast, the smaller Moon produced a narrow compositional range of basaltic lava flows, with most of the lavas having erupted about 3 billion years ago. Water and sulfur volcanism have also been discovered on the cold satellites of the outer solar system, thus expanding their terrestrial concept of volcanism. Many other processes and materials exist in the solar system, but the Earth remains unique in its richness of resources to support humans. Discovery and exploitation of extraterrestrial resources are beginning and must be greatly increased to prepare for their future as a space-faring race.

  7. 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.

  8. Revisiting the O'Connell Effect in Eclipsing Binary Systems

    NASA Astrophysics Data System (ADS)

    Wilsey, Nicholas J.; Beaky, Mathew M.

    2009-05-01

    Many eclipsing binary light curves exhibit a feature known as the O'Connell effect, where the two out-of-eclipse maxima are unequally high. The effect is entirely unexpected, because the two side-by-side configurations of the components should appear equally bright from our line of sight. Several theories have been proposed to explain the effect, including asymmetrically distributed starspots, clouds of circumstellar dust and gas, or a hot spot caused by the impact of a mass-transferring gas stream. Currently, most published models of systems with asymmetric maxima incorporate starspots to rectify their models to fit the observational data. However, the limitations of starspot solutions, as well as other possible explanations for the asymmetry, are rarely discussed. In order to revitalize the study the O'Connell effect, the astronomy program at Truman State University in Kirksville, Missouri has initiated a project to construct complete BVRI light curves of poorly studied eclipsing binary systems exhibiting the O'Connell effect, including V573 Lyr and UV Mon. We are also exploring methods of applying Fourier analysis to large, all-sky databases to extract correlations that may help to evaluate competing theories for explaining the effect.

  9. 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

  10. 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.

  11. Stability of the Solar System

    NASA Astrophysics Data System (ADS)

    Leubner, I. H.

    2008-12-01

    It is a well established myth that the solar system is stable. The argument is generally based on the fact that the rate of the radiative plus solar wind mass loss of the Sun has a relatively small value of 8.81E-05 (1/Byr = 1/Ma) (radiative: 6.63E-05 (1/By)). Experimental results, e.g., that the Earth is separating from the Sun (10m/100year)(1), put the concept of stability of solar planetary orbits into doubt. An understanding of the stability of the solar system is a critical step towards the understanding of the stability of galaxies and the Universe.(2,3) The stability of planetary orbits, which is the other factor determining the stability of the solar system, has until recently not been modeled.(4) A model is presented which shows that the planetary orbits are weakly bound relative to orbital separation, ranging from 0.6 percent for Mercury to 0.006 for Pluto, and 0.0011 percent for CR105, the furthest reported planetesimal. These values are in the order of solar mass/gravity loss, and as a consequence, the model predicts that the solar system is expanding since its formation. The present separation rate of Earth is calculated to 3.0 m/year. Eventually orbital separation of planets will occur, e.g., at 133.8, 1.30, and 0.23 Billion years for Mercury, Pluto, Cr105, respectively under current conditions. The model shows that Mars was previously closer to the Sun and exposed to higher radiation, and that the transition from water to ice on its surface occurred 3.6 Billion years ago.(4) Predictions of the model are reported for all planets and dwarf planets. References: 1. C. Laemmerzahl, 2006, 70th Annual Meeting, German Physical Society, (DPG); Note: indirect measurements, quote: The cause for the drifting apart of Sun and Earth cannot be explained by present knowledge and methods of gravitation physics' 2. I. H. Leubner, 2003, 'The Formation of the universe (Big Bang) as a Crystallization Process', Rochester Academy of Science, 30th Fall Paper Session

  12. Solar System Analog; WMO Statement

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Scientists searching for extra-solar planets have discovered the closest known analog to our own Solar System. A planet with a mass about twice that of Jupiter is in a near-circular orbit of the star HD70642, a team of astronomers from Australia, the United Kingdom, and the United States announced on 3 July at a conference in Paris on extra-solar planets.The planet measures about three-fifths the size of Jupiter, circles its star about every six years, and is in an orbit equivalent to being about halfway between Mars and Jupiter if it were located in our Solar System, according to the astronomers. The star is about 90 light years away from Earth in the constellation Puppis.Public concern about a spate of well-publicized, extreme weather events around the world this year has prompted the World Meteorological Organization to issue a statement that, as global temperatures continues to rise due to climate change, the number and intensity of extreme events might increase. The July 2 statement is based on scientific assessments by the Intergovernmental Panel on Climate Change and others, rather than on any new studies, according to Ken Davidson, director orf WMO's World Climate Program Department. The statement cites record high termperatures so far this summer in southern France and in Switzerland, an abnormally high number of tornadoes in the U.S. in May, and particularly heavy rains from tropical cyclones in Sri Lanka.

  13. 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.

  14. 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.

  15. The solar system's invariable plane

    NASA Astrophysics Data System (ADS)

    Souami, D.; Souchay, J.

    2012-07-01

    Context. The dynamics of solar system objects, such as dwarf planets and asteroids, has become a well-established field of celestial mechanics in the past thirty years, owing to the improvements that have been made in observational techniques and numerical studies. In general, the ecliptic is taken as the reference plane in these studies, although there is no dynamical reason for doing so. In contrast, the invariable plane as originally defined by Laplace, seems to be a far more natural choice. In this context, the latest study of this plane dates back to Burkhardt. Aims: We define and determine the orientation of the invariable plane of the solar system with respect to both the ICRF and the equinox-ecliptic of J2000.0, and evaluate the accuracy of our determination. Methods: Using the long-term numerical ephemerides DE405, DE406, and INPOP10a over their entire available time span, we computed the total angular momentum of the solar system, as well as the individual contribution to it made by each of the planets, the dwarf planets Pluto and Ceres, and the two asteroids Pallas and Vesta. We then deduced the orientation of the invariable plane from these ephemerides. Results: We update the previous results on the determination of the orientation of the invariable plane with more accurate data, and a more complete analysis of the problem, taking into account the effect of the dwarf planet (1) Ceres as well as two of the biggest asteroids, (4) Vesta and (2) Pallas. We show that the inclusion of these last three bodies significantly improves the accuracy of determination of the invariable plane, whose orientation over a 100 y interval does not vary more than 0.1 mas in inclination, and 0.3 mas in longitude of the ascending node. Moreover, we determine the individual contributions of each body to the total angular momentum of the solar system, as well as the inclination and longitude of the node with respect to this latter plane. Conclusions: Owing to the high accuracy

  16. 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.

  17. 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.

  18. Goldstone solar system radar

    NASA Technical Reports Server (NTRS)

    Jurgens, Raymond F.

    1988-01-01

    Planning, direction, experimental design, and coordination of data-acquisition and engineering activities in support of all Goldstone planetary radar astronomy were performed. This work demands familiarity with the various components of a planetary radar telescope (transmitter, receiver, antenna, computer hardware and software) as well as knowledge of how the entire system must function as a cohesive unit to meet the particular scientific objectives at hand in a given observation. Support radar data-processing facilities, currently being used for virtually all Goldstone data reduction includes: a VAX 11/780 computer system, an FPS 5210 array processor, terminals, tape drives, and image-display devices, as well as a large body of data-reduction software to accommodate the variety of data-acquisition formats and strategems. Successful 113-cm radar observation of Callisto and the near-Earth asteroid 1981 Midas and Goldstone/VLA radar observations of Saturn's rings were obtained. Quick-look verification programs from data taken with phase-coded cw (i.e., ranging) waveforms, applicable to Venus, the Moon, and small bodies were completed. Definition of scientific and engineering requirements on instrument performance, radar system configuration, and personnel, for all 1988 Goldstone radar investigations was accomplished.

  19. 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.

  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. Glass transition and mixing thermodynamics of a binary eutectic system.

    PubMed

    Tu, Wenkang; Chen, Zeming; Gao, Yanqin; Li, Zijing; Zhang, Yaqi; Liu, Riping; Tian, Yongjun; Wang, Li-Min

    2014-02-28

    A quantitative evaluation of the contribution of mixing thermodynamics to glass transition is performed for a binary eutectic benzil and m-nitroaniline system. The microcalorimetric measurements of the enthalpy of mixing give small and positive values, typically ~200 J mol(-1) for the equimolar mixture. The composition dependence of the glass transition temperature, T(g), is found to show a large and negative deviation from the ideal mixing rule. The Gordon-Taylor and Couchman-Karasz models are subsequently applied to interpret the T(g) behavior, however, only a small fraction of the deviation is explained. The analyses of the experimental results manifest quantitatively the importance of the mixing thermodynamics in the glass transition in miscible systems.

  2. PG 1346+082 - An interacting binary white dwarf system

    NASA Technical Reports Server (NTRS)

    Wood, M. A.; Winget, D. E.; Nather, R. E.; Liebert, James; Wesemael, F.

    1987-01-01

    PG 1346+082 is both a photometric and a spectroscopic variable, spanning the B-magnitude range 13.6-17.2. High-speed photometric data reveal rapid flickering in the low-state light curve. The system also shows spectroscopic variations, displaying broad shallow He I absorption lines at maximum light and a weak emission feature at He I (4471 A) at minimum light. Hydrogen lines are conspicuous by their absence. Is is concluded that PG 1346+082 is an interacting binary white dwarf system. Furthermore, because continuum fits to IUE high-state data suggest temperatures consistent with membership in the DB white dwarf instability strip, it is suggested that some of the photometric variations may arise from pulsations.

  3. Flux distribution in the Algol binary system RW Persei

    NASA Technical Reports Server (NTRS)

    Dobias, Jan J.; Plavec, Mirek J.

    1987-01-01

    IUE low-dispersion spectra and optical TIS scans of the Algol-type binary system RW Persei show that the primary has a spectrral type of B9.6 and that it is a Be star. The cooler component has a spectral type that is less accurately determined to as K2 III-IV, and it is probably a star of very low mass. The system is heavily reddened, with an E(B-V) color excess of 0.40 + or - 0.05 mag. The present results suggest that the hotter component is actually an opticaly thick accretion disk. The expected W Serpentis-type emission lines are not found in the UV spectrum near mideclipse, although two very broad emissions and several weaker ones seem to be present.

  4. Orbital period variation of the eclipsing binary system TT Herculis

    NASA Astrophysics Data System (ADS)

    Selam, S. O.; Albayrak, B.

    2007-02-01

    % New photoelectric U BV observations were obtained for the eclipsing binary TT Her at the Ankara University Observatory (AUO) and three new times of minima were calculated from these observations. The (O-C) diagram constructed for all available times of minima of TT Her exhibits a cyclic character superimposed on a quadratic variation. The quadratic character yields an orbital period decrease with a rate of dP/dt=-8.83×10-8 day yr-1 which can be attributed to the mass exchange/loss mechanism in the system. By assuming the presence of a gravitationally bound third body in the system, the analysis of the cyclic nature in the (O-C) diagram revealed a third body with a mass of 0.21 M\\sun orbiting around the eclipsing pair. The possibility of magnetic activity cycle effect as a cause for the observed cyclic variation in the (O-C) diagram was also discussed.

  5. 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.

  6. Shock waves in the solar system.

    NASA Technical Reports Server (NTRS)

    Spreiter, J. R.

    1972-01-01

    Review of the role of gasdynamic processes involving shock waves in the transfer of solar material and energy to the earth and elsewhere in the solar system. The role of shock waves in maintaining the high temperature of the solar corona and in establishing the steady-state solar wind is discussed. An approximate hydromagnetic theory is developed to explain the flow of a supersonic solar wind past planets and the moon. Data concerning the passage of interplanetary shock waves and the ability of a solar flare to produce such a wave are reviewed, and some terrestrial consequences of solar activity are cited.

  7. Volcanoes of the Solar System

    NASA Astrophysics Data System (ADS)

    Frankel, Charles

    1996-09-01

    Nothing can be more breathtaking than the spectacle of a volcano erupting. Space-age lunar and planetary missions offer us an unprecedented perspective on volcanism. Starting with the Earth, Volcanoes of the Solar System takes the reader on a guided tour of the terrestrial planets and moons and their volcanic features. We see lunar lava fields through the eyes of the Apollo astronauts, and take an imaginary hike up the Martian slopes of Olympus Mons--the tallest volcano in the solar system. Complemented by over 150 photographs, this comprehensive and lucid account of volcanoes describes the most recent data on the unique and varied volcanic features of Venus and updates our knowledge on the prodigiously active volcanoes of Io. A member of the Association of European Volcanologists, Charles Frankel has directed documentary films on geology, astronomy and space exploration and has authored a number of articles on the earth sciences.

  8. Water in the Solar System

    NASA Astrophysics Data System (ADS)

    Encrenaz, Thérèse

    2008-09-01

    Water is ubiquitous in the Universe, and also in the Solar System. By setting the snow line at its condensation level in the protosolar disk, water was responsible for separating the planets into the terrestrial and the giant ones. Water ice is a major constituent of the comets and the small bodies of the outer Solar System, and water vapor is found in the giant planets, both in their interiors and in the stratospheres. Water is a trace element in the atmospheres of Venus and Mars today. It is very abundant on Earth, mostly in liquid form, but it was probably also abundant in the primitive atmospheres of Venus and Mars. Water is found in different states on the three planets, as vapor on Venus and ice (or permafrost) on Mars. Most likely, this difference has played a major role in the diverging destinies of the three planets.

  9. 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.

  10. Goldstone Solar System Radar (GSSR)

    NASA Technical Reports Server (NTRS)

    Renzetti, N. A.

    1991-01-01

    The primary objective of the Goldstone Solar System Radar is the investigation of solar system bodies by means of Earth-based radar. Targets of primary interest include the Galilean moons, Saturn's rings and moons, and Earth-approaching asteroids and comets. Planets are also of interest, particularly Mercury and the planets to which NASA has not yet planned spacecraft visits. Based on a history of solid achievement, including the definition of the Astronomical Unit, imaging and topography of Mars, Venus, and Mercury, and contributions to the general theory of relativity, the program will continue to support flight project requirements and its primary objectives. The individual target objectives are presented, and information on the following topics are presented in tabular form: Deep Space Network support, compatibility tests, telemetry, command, and tracking support responsibility.

  11. The disruption of multiplanet systems through resonance with a binary orbit.

    PubMed

    Touma, Jihad R; Sridhar, S

    2015-08-27

    Most exoplanetary systems in binary stars are of S-type, and consist of one or more planets orbiting a primary star with a wide binary stellar companion. Planetary eccentricities and mutual inclinations can be large, perhaps forced gravitationally by the binary companion. Earlier work on single planet systems appealed to the Kozai-Lidov instability wherein a sufficiently inclined binary orbit excites large-amplitude oscillations in the planet's eccentricity and inclination. The instability, however, can be quenched by many agents that induce fast orbital precession, including mutual gravitational forces in a multiplanet system. Here we report that orbital precession, which inhibits Kozai-Lidov cycling in a multiplanet system, can become fast enough to resonate with the orbital motion of a distant binary companion. Resonant binary forcing results in dramatic outcomes ranging from the excitation of large planetary eccentricities and mutual inclinations to total disruption. Processes such as planetary migration can bring an initially non-resonant system into resonance. As it does not require special physical or initial conditions, binary resonant driving is generic and may have altered the architecture of many multiplanet systems. It can also weaken the multiplanet occurrence rate in wide binaries, and affect planet formation in close binaries. PMID:26310763

  12. The disruption of multiplanet systems through resonance with a binary orbit.

    PubMed

    Touma, Jihad R; Sridhar, S

    2015-08-27

    Most exoplanetary systems in binary stars are of S-type, and consist of one or more planets orbiting a primary star with a wide binary stellar companion. Planetary eccentricities and mutual inclinations can be large, perhaps forced gravitationally by the binary companion. Earlier work on single planet systems appealed to the Kozai-Lidov instability wherein a sufficiently inclined binary orbit excites large-amplitude oscillations in the planet's eccentricity and inclination. The instability, however, can be quenched by many agents that induce fast orbital precession, including mutual gravitational forces in a multiplanet system. Here we report that orbital precession, which inhibits Kozai-Lidov cycling in a multiplanet system, can become fast enough to resonate with the orbital motion of a distant binary companion. Resonant binary forcing results in dramatic outcomes ranging from the excitation of large planetary eccentricities and mutual inclinations to total disruption. Processes such as planetary migration can bring an initially non-resonant system into resonance. As it does not require special physical or initial conditions, binary resonant driving is generic and may have altered the architecture of many multiplanet systems. It can also weaken the multiplanet occurrence rate in wide binaries, and affect planet formation in close binaries.

  13. 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.

  14. An investigation of the eclipsing binary star system, CK Bootes

    NASA Astrophysics Data System (ADS)

    Gershon, Kae Pearson

    Photoelectrically observed light curves of the eclipsing binary star system CK Bootes was obtained using the sixteen inch reflecting telescope at Kitt Peak National Observatory. The data was gathered during June of 1983. A total of 258, 240, and 240 usable observations were obtained in ultraviolet, blue, and visual light respectively, corresponding to the colors in the (UBV) system of Johnson and Morgan (ApJ.117,313,1953). Computer programs were written to reduce the data to light curves. The primary eclipse was found to be a transit. The light curves were reduced to system parameters using three methods of analysis; the Russell - Merrill Method, the Wood Model, (WINK), and the Wilson-DeVinney Model. The results from these models were then compared. The parameters of the systems were found, and they were compared between the three models. The system was found to be a very close system, only about four stellar radii apart. Mass streaming was indicated by the light curve. The derived parameters suggested that the larger star had filled its Roche Lobe, and it was spilling mass onto the smaller and brighter star. This, combined with a mass ratio about equal one, indicated that the system consists of one unevolved star and one star just beginning to evolve.

  15. 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

  16. 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.

  17. 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…

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Energy distribution in the strongly interacting binary system SX Cassiopeiae

    NASA Technical Reports Server (NTRS)

    Plavec, M. J.; Weiland, J. L.; Koch, R. H.

    1982-01-01

    IUE spectra and optical scans covering the 110-680 nm interval were obtained in a search for a source which would resolve the anomalous presence of strong Balmer emission lines in the SX Cas eclipsing binary system, which is inconsistent with the usual spectral classification of the components as A6 III + G6 III. The IUE spectra unexpectedly show such strong emission lines as those of C IV, N V and Si IV, which require higher temperatures that the already anomalously high Balmer lines, and a continuum several magnitudes higher than the extrapolated continuum of an A6 star. A model in which the UV continuum originates in the transition zone between the A6 star and an accretion disk fails to reproduce the observed energy distribution. A revision of component spectral types to B7 + K3 III removes the UV excess.

  3. 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.

  4. 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.

  5. Precipitation Modeling in Nitriding in Fe-M Binary System

    NASA Astrophysics Data System (ADS)

    Tomio, Yusaku; Miyamoto, Goro; Furuhara, Tadashi

    2016-10-01

    Precipitation of fine alloy nitrides near the specimen surface results in significant surface hardening in nitriding of alloyed steels. In this study, a simulation model of alloy nitride precipitation during nitriding is developed for Fe-M binary system based upon the Kampmann-Wagner numerical model in order to predict variations in the distribution of precipitates with depth. The model can predict the number density, average radius, and volume fraction of alloy nitrides as a function of depth from the surface and nitriding time. By a comparison with the experimental observation in a nitrided Fe-Cr alloy, it was found that the model can predict successfully the observed particle distribution from the surface into depth when appropriate solubility of CrN, interfacial energy between CrN and α, and nitrogen flux at the surface are selected.

  6. Monte Carlo simulation of binary surfactant/contaminant/water systems.

    PubMed

    Khodadadi, Zahra; Mousavi-Khoshdel, S Morteza; Gharibi, Hussein; Hashemianzadeh, Seyed Majid; Javadian, Sohaila

    2012-06-01

    Surfactant-enhanced remediation (SER) is an effective approach for the removal of absorbed hydrophobic organic compounds (HOCs) from contaminated soils. The solubilization of contaminants by mixed surfactants with attractive and repulsive head-head interactions was studied by measuring the micelle-water partition coefficient (K(C)) and molar solubilization ratio (MSR) using the lattice Monte Carlo method. The effect of surfactant mixing on the MSR and K(C) of contaminants displayed the following trend: C₄ > C₃ > C₂. Synergistic binary surfactant mixtures showed greater solubilization capacities for contaminants than the corresponding individual surfactants. Mixed micellization parameters, including the interaction parameter β, and activity coefficient f(i), were evaluated with Rubingh's approach. Synergistic mixed-surfactant systems can improve the performance of surfactant-enhanced remediation of soils and groundwater by decreasing the amount of applied surfactant and the cost of remediation.

  7. The FUSE Survey of Algol-Type Interacting Binary Systems

    NASA Astrophysics Data System (ADS)

    Peters, Geraldine J.; Andersson, B.; Ake, T. B.; Sankrit, R.

    2006-12-01

    A survey of Algol binaries at random phases is currently being carried through with the FUSE spacecraft as part of the FUSE survey and supplemental program. A similar program was undertaken in FUSE Cycle 3. Both programs have produced multiple observations of 12 Algol systems with periods ranging from 1.2 37 d and include direct-impact and disk systems. We report on the status of the program. The absence of O VI absorption in the systems observed to date allows us to place an upper limit on the column density and temperature of the High Temperature Accretion Region, HTAR ( 100,000 K) confirmed in some Algols from earlier IUE data. The HTAR plasma component appears to be distinct from an O VI-emitting polar plasma discovered in FUSE totality observations of RY Per, V356 Sgr, and TT Hya. New observations of the direct-impact system U Cep have provided more information on the geometry and mass flow (including a splash plasma) in the vicinity of a hot spot at phase 0.90 that was discovered earlier. The extent of disk asymmetries in the long period ( 33 d) systems SX Cas and RX Cas is discussed. Models for direct-impact and the disk systems will be presented. The authors appreciate support from NASA grants NAG5-12253, NNG04GL17G, and NAS5-32985.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Properties of the components in close T Tauri binary systems

    NASA Astrophysics Data System (ADS)

    Woitas, Jens; Leinert, Christoph

    Using near-infrared speckle-interferometry we have obtained resolved JHK-photometry for the components of T Tauri binary systems. By placing the components into a color-color diagram we identify some unusually red objects that are candidates for infrared companions or substellar objects. We place a subsample that consists of the components of 17 WTTS systems (where no significant circumstellar excess emission is expected) into a color-magnitude diagram and show that in almost all of these systems the components are coeval within the uncertainties. Particularly this is the case for the triple system HBC 358. We use the J-magnitude as an indicator for the stellar luminosity and assign the optical spectral type of the system to the primary. Together with the previously justified assumption that all components are coeval we can place them independently into the HRD and derive their masses by comparison with theoretical pre-main sequence evolutionary tracks. The results are the following: The distribution of mass ratios is flat and is neither a function of the primary's mass nor the components' projected separation. Comparison of these results with predictions of theoretical multiple star formation models suggests that most of the systems have formed by fragmentation during protostellar collapse. From relative positions of the components in 34 systems at different epochs we derive their relative velocities and show that in most close systems orbital motion can be proved. The analysis of this orbital motion leads to an empirical mass estimate for T Tauri-stars which is larger than the masses one would expect from the HRD.

  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. 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.

  2. Life in the solar system.

    NASA Astrophysics Data System (ADS)

    McKay, C. P.

    Liquid water is the quintessential requirement for life. Thus, the presence of liquid water provides the most useful environmental criteria for searching for life on other planets. In the present solar system, liquid water, and hence life, is definitely found only on Earth. There is convincing evidence that liquid water existed on Mars early in its history. While there may be no life on Mars at present it may hold the key to understanding the origin of life in Earth-like environments and provide a basis for estimates of the distribution of life in the universe.

  3. 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.

  4. 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.

  5. Exceptional Solar-System Objects

    NASA Astrophysics Data System (ADS)

    Zellner, Benjamin

    1990-12-01

    This is a target-of-opportunity proposal for HST observations to be executed if a previously unknown, truly exceptional solar-system object or phenomenon is discovered either in the normal course of HST work or by anyone, anywhere. Trails due to unknown moving objects will often appear on HST images made for other purposes. A short trail seen near the opposition point or at high ecliptic latitude could represent a major addition to our knowledge of the solar system. Thus we further propose that all short trials seen on HST images taken in favorable regions of the sky be given a quick analysis in the Observation Support System for their possible significance. If an unusual object is found we propose to: (1) Seek from the owner of data rights permission to proceed as may be appropriate; (2) Contact the Minor Planet Center for an evaluation of the significance of the discovery; and (3) For an object that appears to be of great significance where effective groundbased followup appears unlikely, request the HST schedule be replanned for followup images and physical studies using HST.

  6. 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

  7. 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).

  8. Modulated gamma-ray emission from compact millisecond pulsar binary systems

    NASA Astrophysics Data System (ADS)

    Bednarek, W.

    2014-01-01

    Context. A significant number of the millisecond pulsars (MSPs) have been discovered within binary systems. Tens of these MSPs emit γ-rays that are modulated with the pulsar period since this emission is produced in the inner pulsar magnetosphere. In several such binary systems, the masses of the companion stars have been derived allowing two classes of objects to be distinguished, which are called the black widow and the redback binaries. Pulsars in these binary systems are expected to produce winds that create conditions for acceleration of electrons, when colliding with stellar winds. These electrons should interact with the anisotropic radiation from the companion stars producing γ-ray emission modulated with the orbital period of the binary system, similar to what is observed in the massive TeV γ-ray binary systems. Aims: We consider the interaction of a MSP wind with a very inhomogeneous stellar wind from the companion star within binary systems of the black widow and redback types. Our aim is to determine the features of γ-ray emission produced in the collision region of the winds from a few typical MSP binary systems. Methods: It is expected that the pulsar wind should mix efficiently with the inhomogeneous stellar wind. The mixed winds move outside the binary with relatively low velocity. Electrons accelerated in such mixed, turbulent winds can interact with the magnetic field and strong radiation from the companion star, producing not only synchrotron radiation but also γ-rays in the inverse Compton process, fluxes of which are expected to be modulated on the periods of the binary systems. Applying numerical methods, we calculated the GeV-TeV gamma-ray spectra and the light curves expected from some MSP binary systems. Results: Gamma-ray emission, produced within the binary systems, is compared with the sensitivities of the present and future gamma-ray telescopes. It is concluded that energetic MSP binary systems create a new class of TeV

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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.

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

    PubMed

    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

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

    PubMed

    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.

  13. Meteorites and the early solar system

    SciTech Connect

    Kerridge, J.F.; Matthews, M.S.

    1988-01-01

    The present work discusses topics in the source regions for meteorites, their secondary processing, irradiation effects on meteorites, solar system chronology, the early solar system, the chemistry of chondrites and the early solar system, magnetic fields in the early solar system, the nature of chondrules, micrometeorites, inhomogeneity of the nebula, the survival of presolar material in meteorites, nucleosynthesis, and the relationship between extinct radionuclides and nucleocosmochronology. Attention is given to igneous activity in the early solar system, principles of radiometric aging, the cosmochemical classification of the elements, highly labile elements, the potential significance of pristine material, the astrophysical implications of presolar grains, boundary conditions for the origin of the solar system, and iodine-xenon dating.

  14. 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.

  15. Solving integral equations for binary and ternary systems

    NASA Astrophysics Data System (ADS)

    Nader Lotfollahi, Mohammad; Modarress, Hamid

    2002-02-01

    Solving integral equations is an effective approach to obtain the radial distribution function (RDF) of multicomponent mixtures. In this work, by extending Gillan's approach [M. J. Gillan, Mol. Phys. 38(6), 1781 (1979)], the integral equation was solved by numerical method and was applied to both binary and ternary mixtures. The Lennard-Jones (LJ) potential function was used to express the pair molecular interactions in calculating the RDF and chemical potential. This allowed a comparison with available simulation data, on the RDF and the chemical potential, since the simulation data have been reported for the LJ potential function. The RDF and the chemical potential results indicated good agreement with the simulation data. The calculations were extended to the ternary system and the RDFs for carbon dioxide-octane-naphthalene were obtained. The numerical method used in solving integral equation was rapidly convergent and not sensitive to the first estimation. The method proposed in this work can be easily extended to more than the three-component systems.

  16. A binary system in the Kuiper Belt: 1998_WW31

    NASA Astrophysics Data System (ADS)

    Veillet, Christian

    2002-07-01

    1998_WW31 is the first Kuiper Belt Object, outside the pair Pluto/Charon, to be discovered as a binary object. Though only preliminary results are available from two orbits of HST DDT observation when this proposal is submitted, the pair exhibits a very high eccentricity {larger than 0.5} and a period of 570 days. The purpose of this proposal is to complete the monitoring of the pair on a full orbit, up to February 2003. Monitoring will then have to cease {Sun too close}. The binarity of an asteroid allows the determination of the total mass of the system and provides important information on the past Kuiper Belt environment {formation/collisions/capture processes}. If size can be obtained from albedo determination, the mass will give the density, a key parameter for any study of the origin and evolution of the Kuiper Belt. Hubble's unparalleled resolution provides the unique way to acquire observations of the pair good enough to access the physical characteristics of this system with a high degree of confidence, as the high eccentricity of the orbit keeps the two components less than 1 arc-second apart for most of the orbit. The observations would be made public immediately to allow the continuation of the education program offering to follow the pair on a regular basis to illustrate the prediction/verification iterative process of science and the direct use of simple laws for the determination of key parameters.

  17. 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

  18. 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.

  19. Solar System Science with ALMA

    NASA Astrophysics Data System (ADS)

    Butler, Bryan J.; Gurwell, Mark A.

    1999-10-01

    Observations of solar system bodies with the ALMA array will undoubtedly allow significant progress to be made on our understanding of the individual bodies therein, their interactions, and possibly their formation. With its fantastic resolution, sensitivity, and speed, ALMA will be one of the most important ground based observatories for planetary science. While it is nearly impossible to predict what will be learned about the solar system and its bodies, we can predict some general areas where we expect that ALMA will make significant contributions. We will concentrate here on 2 such areas: observations of small bodies, and observations of the solid surfaces of the larger bodies. Small bodies Observations of comets will help disentangle the story of their formation and history, and shed light on the physical processes occuring in their atmospheres. Observations of NEAs by ALMA will contribute to knowledge of their properties and orbits (ALMA can observe in daytime). Observations of KBOs will help to determine their properties and origin. Larger bodies We imagine that observations of Mercury, Mars, the larger asteroids, the moons of Jupiter, Saturn, Uranus, and Neptune, and the Pluto/Charon will be undertaken to determine properties and physical processes of their surfaces and subsurfaces.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. The photometric investigation of the newly discovered W UMa type binary system GSC 03122-02426

    NASA Astrophysics Data System (ADS)

    Zhou, X.; Qian, S.-B.; He, J.-J.; Zhang, J.; Zhang, B.

    2016-10-01

    The B V Rc Ic bands light curves of the newly discovered binary system GSC 03122-02426 are obtained and analyzed using the Wilson-Devinney (W-D) code. The solutions suggest that the mass ratio of the binary system is q = 2.70 and the less massive component is 422 K hotter than the more massive one. We conclude that GSC 03122-02426 is a W-subtype shallow contact (with a contact degree of f = 15.3 %) binary system. It may be a newly formed contact binary system which is just under geometrical contact and will evolve to be a thermal contact binary system. The high orbital inclination (i = 81 .6∘) implies that GSC 03122-02426 is a total eclipsing binary system and the photometric parameters obtained by us are quite reliable. We also estimate the absolute physical parameters of the two components in GSC 03122-02426, which will provide fundamental information for the research of contact binary systems. The formation and evolutionary scenario of GSC 03122-02426 is discussed.

  6. 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

  7. 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.

  8. 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.

  9. Gravitational Radiation Reaction of Inspiralling Compact Binary Systems

    NASA Astrophysics Data System (ADS)

    Pati, Michael E.; Will, Clifford M.

    1998-04-01

    We outline a technique for obtaining the spacetime metric and local equations of motion for compact binary systems to high post-Newtonian (PN) order. Our approach is based upon direct integration of the ``relaxed Einstein equations'' (DIRE) and casts its solution as a retarded flat-spacetime integral involving a non-compact source. Although mathematical ambiguities have accompanied similar approaches in the past, we obtain results manifestly free of divergences to high PN orders using a method first introduced by Will and Wiseman(C.M. Will and A.G. Wiseman, Phys. Rev. D 54), 4813 (1996).. To 3.5 PN ((v/c)^7 beyond Newtonian) order we calculate the radiation reaction terms in the equations of motion and compare our results with other treatments (B.R. Iyer and C.M. Will, Phys. Rev. Lett. 70), 113 (1993); Phys. Rev. D 52, 6882 (1995); L. Blanchet, Phys. Rev. D 47, 4392 (1993); ibid. 55 714 (1997). We discuss the status of obtaining the non-dissipative, 3PN terms in the equations of motion.

  10. Discovery of a Binary System in IRAM 04191+1522

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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 7farcs8 ± 0farcs2. The two continuum sources are located in the southeast-northwest direction, with total gas masses of ~0.011 M ⊙ and ~0.005 M ⊙, 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 ~0.08 L ⊙. The newly discovered northwestern continuum source is not visible in the Spitzer images at wavelengths from 3.6 to 70 μm and has an extremely low bolometric luminosity (<0.03 L ⊙). Complementary IRAM N2H+ (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 βrot > 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. Prototype solar-heating system design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design package for complete residential solar-heating system is given. Includes documents and drawings describing performance design, verification standards, and analysis of system with sufficient information to assemble working system.

  16. 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.

  17. 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

  18. Radar-Derived Shape Model of Near-Earth Binary Asteroid System (285263) 1998 QE2

    NASA Astrophysics Data System (ADS)

    Springmann, Alessondra; Taylor, Patrick A.; Nolan, Michael C.; Howell, Ellen S.; Brozovi?, Marina; Benner, Lance A.; Giorgini, Jon D.; Busch, Michael W.; Margot, Jean-Luc; Lee, Clement; Jao, Joseph S.; Lauretta, Dante S.

    2014-11-01

    We report on shape modeling of binary asteroid 1998 QE2, a 3.2-km asteroid with a 800-m moon. We observed this asteroid with both Arecibo Observatory planetary radar (2380 MHz, 12.6 cm) and Goldstone Solar System Radar (8560 MHz, 3.5 cm) between May 31-Jun 9, 2013. The close approach on May 31, 2013 (0.039 au) presented an outstanding opportunity for radar delay-Doppler imaging with resolutions as fine as 7.5 m of both objects. The extensive radar dataset was used for shape modeling of both components. Our SHAPE 3D modeling software (Hudson, 1993 and Magri et al., 2007) uses a constrained, weighted least-squares minimization procedure to invert radar delay-Doppler images.The rotation rate of the primary, 4.749 ± 0.002 h, was well constrained from optical lightcurves (P. Pravec, pers. comm.) and rotates prograde as determined from radar data. The primary is roughly spheroidal, showing prominent concavities and surface features, with effective diameter 3.2 ± 0.3 km.The secondary is irregularly shaped, with an effective diameter of 800 ± 80 m and significant elongation. The radar data suggest it is tidally locked, with an orbital period of 31.31 ± 0.01 h hours and a semi-major orbital axis of 6.2 ± 0.1 km. The orbit is approximately circular (e < 0.01), which is typical of most near-Earth asteroid binary system orbits. We estimate a preliminary density for the primary of 0.7 ± 0.2 g/cm^3. The low density is consistent with a "rubble pile" structure.

  19. Gravitational radiation from binary systems in alternative metric theories of gravity - Dipole radiation and the binary pulsar

    NASA Technical Reports Server (NTRS)

    Will, C. M.

    1977-01-01

    The generation of gravitational radiation in several currently viable metric theories of gravitation (Brans-Dicke, Rosen, Ni, and Lightman-Lee) is analyzed, and it is shown that these theories predict the emission of dipole gravitational radiation from systems containing gravitationally bound objects. In the binary system PSR 1913 + 16, this radiation results in a secular change in the orbital period of the system with a nominal magnitude of 3 parts in 100,000 per year. The size of the effect is proportional to the reduced mass of the system, to the square of the difference in (self-gravitational energy)/(mass) between the two components of the system, and to a parameter, xi, whose value varies from theory to theory. In general relativity xi equals 0, in Rosen's (1973) theory xi equals -20/3, and in Ni's (1973) theory xi equals -400/3. The current upper limit on such a secular period change is one part in 1 million per year. It is shown that further observations of the binary system that tighten this limit and that establish the masses of the components and the identity of the companion may provide a crucial test of otherwise viable alternatives to general relativity.

  20. 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.

    2016-08-01

    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 neighborhood, 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 Gyrs).

  1. The Solar System Origin Revisited

    NASA Astrophysics Data System (ADS)

    Johnson, Fred M.

    2016-10-01

    A novel theory will be presented based in part on astronomical observations, plasma physics experiments, principles of physics and forensic techniques. The new theory correctly predicts planetary distances with a 1% precision. It accounts for energy production mechanism inside all of the planets including our Earth. A log-log mass-luminosity plot of G2 class stars and solar system planets results in a straight line plot, whose slope implies that a fission rather than a proton-proton fusion energy production is operating. Furthermore, it is a confirmation that all our planets had originated from within our Sun. Other still-born planets continue to appear on the Sun's surface, they are mislabeled as sunspots.

  2. 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.

  3. Solar System Searches for Life

    NASA Astrophysics Data System (ADS)

    Chyba, C. F.

    1998-12-01

    Exobiology--the search for extraterrestrial life and the study of conditions relevant to its origins--has been reborn in the past decade. This rebirth has been driven largely by discoveries related to Earth's deep biosphere, and the recognition that there may be several extraterrestrial environments within our own Solar System that could provide plausible environments for subsurface ecologies. Most prominent among these are Mars and Jupiter's moon Europa. In 2003 NASA intends to launch an orbiting spacecraft to Europa, to determine whether a subsurface ocean does in fact exist beneath that world's ice layer. A subsequent lander mission is in the initial planning stages. Lessons learned from the Viking spacecrafts' search for life on Mars over 25 years ago need to be carefully considered. More broadly, the interrelationships between planetary exploration and our understanding of the origin of life are becoming increasingly important.

  4. Micellar solubilization in strongly interacting binary surfactant systems. [Binary surfactant systems of: dodecyltrimethylammonium chloride + sodium dodecyl sulfate; benzyldimethyltetradecylammonium chloride + tetradecyltrimethylammonium chloride

    SciTech Connect

    Treiner, C. ); Nortz, M.; Vaution, C. )

    1990-07-01

    The apparent partition coefficient P of barbituric acids between micelles and water has been determined in mixed binary surfactant solutions from solubility measurements in the whole micellar composition range. The binary systems chosen ranged from the strongly interacting system dodecyltrimethylammonium chloride + sodium dodecyl sulfate to weakly interacting systems such as benzyldimethyltetradecylammonium chloride + tetradecyltrimethyammonium chloride. In all cases studied, mixed micelle formation is unfavorable to micellar solubilization. A correlation is found between the unlike surfactants interaction energy, as measured by the regular solution parameter {beta} and the solute partition coefficient change upon surfactant mixing. By use of literature data on micellar solubilization in binary surfactant solutions, it is shown that the change of P for solutes which are solubilized by surface adsorption is generally governed by the sign and amplitude of the interaction parameter {beta}.

  5. WZ CYGNI: A MARGINAL CONTACT BINARY IN A TRIPLE SYSTEM?

    SciTech Connect

    Lee, Jae Woo; Kim, Seung-Lee; Lee, Chung-Uk; Kim, Ho-Il; Park, Jang-Ho; Hinse, Tobias Cornelius E-mail: slkim@kasi.re.kr E-mail: hikim@kasi.re.kr E-mail: tobiash@kasi.re.kr

    2011-07-15

    We present new multiband CCD photometry for WZ Cyg made on 22 nights in two observing seasons of 2007 and 2008. Our light-curve synthesis indicates that the system is in poor thermal contact with a fill-out factor of 4.8% and a temperature difference of 1447 K. Including our 40 timing measurements, a total of 371 times of minimum light spanning more than 112 yr were used for a period study. Detailed analysis of the O-C diagram showed that the orbital period has varied by a combination of an upward parabola and a sinusoid. The upward parabola means continuous period increase and indicates that some stellar masses are thermally transferred to the more massive primary star at a rate of about 5.80 x 10{sup -8} M{sub sun} yr{sup -1}. The sinusoidal variation with a period of 47.9 yr and a semi-amplitude of 0.008 days can most likely be interpreted as the light-travel-time effect due to the existence of a low-mass M-type tertiary companion with a projected mass of M{sub 3}sin i{sub 3} = 0.26 M{sub sun}. We examined the evolutionary status of WZ Cyg from the absolute dimensions of the eclipsing pair. It belongs to the marginal contact binary systems before the broken contact phase, consisting of a massive primary star with spectral type F4 and a secondary star with type K1.

  6. Working With Solar System Ambassadors

    NASA Astrophysics Data System (ADS)

    Ferrari, K.

    2001-11-01

    The Solar System Ambassadors Program is a public outreach program designed to work with motivated volunteers across the nation. These competitively selected volunteers organize and conduct public events that communicate exciting discoveries and plans in Solar System research, exploration and technology through non-traditional forums; e.g. community service clubs, libraries, museums, planetariums, "star parties," mall displays, etc. Each Ambassador participates in on-line (web-based) training sessions that provide interaction with NASA scientists, engineers and project team members. As such, each Ambassador's experience with the space program becomes personalized. Training sessions provide Ambassadors with general background on each mission and educate them concerning specific mission milestones, such as launches, planetary flybys, first image returns, arrivals, and ongoing key discoveries. Additionally, projects provide limited supplies of videos, slide sets, booklets, pamphlets, posters, postcards, lithographs, on-line materials, resource links and information. In addition to participating in on-line trainings with Ambassadors, scientists will be given the opportunity to interact with, and mentor volunteer Ambassadors at regional, weekend conferences designed to strengthen the Ambassadors' knowledge of space science and exploration, thereby improving the space science message that goes out to the general public through these enthusiastic volunteers. Integrating volunteers across the country in a public-engagement program helps optimize project funding set aside for education and outreach purposes, establishing a nationwide network of regional contacts. At the same time, members of communities across the country become an extended part of each mission's team and an important interface between the space exploration community and the general public at large.

  7. From wide to close binaries?

    NASA Astrophysics Data System (ADS)

    Eggleton, Peter P.

    The mechanisms by which the periods of wide binaries (mass 8 solar mass or less and period 10-3000 d) are lengthened or shortened are discussed, synthesizing the results of recent theoretical investigations. A system of nomenclature involving seven evolutionary states, three geometrical states, and 10 types of orbital-period evolution is developed and applied; classifications of 71 binaries are presented in a table along with the basic observational parameters. Evolutionary processes in wide binaries (single-star-type winds, magnetic braking with tidal friction, and companion-reinforced attrition), late case B systems, low-mass X-ray binaries, and triple systems are examined in detail, and possible evolutionary paths are shown in diagrams.

  8. 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.

  9. 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.

  10. 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.

  11. Solar-heating system design package

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Report describes solar heating system composed of warm-air solar collector, logic control unit, and switching and transport unit, that meets government standards for installation in residential dwellings. Text describes system operation and performance specifications complemented by comprehensive set of subcomponent design drawings.

  12. Open cluster evolutions in binary system: How they dissolved

    NASA Astrophysics Data System (ADS)

    Priyatikanto, R.; Arifyanto, M. I.; Wulandari, H. R. T.

    2014-03-01

    Binarity among stellar clusters in galaxy is such a reality which has been realized for a long time, but still hides several questions and problems to be solved. Some of binary star clusters are formed by close encounter, but the others are formed together from similar womb. Some of them undergo separation process, while the others are in the middle of merger toward common future. The products of merger binary star cluster have typical characteristics which differ from solo clusters, especially in their spatial distribution and their stellar members kinematics. On the other hand, these merger products still have to face dissolving processes triggered by both internal and external factors. In this study, we performed N-body simulations of merger binary clusters with different initial conditions. After merging, these clusters dissolve with greater mass-loss rate because of their angular momentum. These rotating clusters also experience more deceleration caused by external tidal field.

  13. Doublet 2800 MgII in close binary systems

    NASA Technical Reports Server (NTRS)

    Gurzadian, G. A.; Perez, M.

    1991-01-01

    The origin of the intercomponent ultraviolet emission from binary radio stars is discussed following an examination of observed emission parameters. Observations are used to consider four arguments which suggest that the Mg emission originates in the space between the components of the binary and not in the chromosphere. Parameters examined include the ratio of Mg emission to that of other binaries, the direct variation of emission with brightness strength, the derivation and nature of the radial velocity, and comparisons of absolute luminosities. Emission (A) and absorption (B) streams or clouds generate the emission, and the observed wavelength distortions are caused by B. An examination of the nature of the emission yields both qualitative and quantitative criteria, including the notion of weak ionization of the hydrogen atoms in B clouds relative to the ionization in A clouds.

  14. 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.

  15. 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.

  16. Formation, Evolution, and Population Synthesis of Binary Systems Containing Collapsed Stars

    NASA Technical Reports Server (NTRS)

    West, Donald (Technical Monitor); Rappaport, Saul

    2004-01-01

    During the period September 1, 2002 through August 31, 2003 we have been supported in part by a small NASA 'bridge" grant NAG5-12522 to continue our theoretical investigations of the "Formation, Evolution, and Population Synthesis of Binary Systems Containing Collapsed Stars". This research includes theoretical studies of the formation and evolution of several different types of interacting binary systems containing collapsed stars. Four papers were completed under the auspices of this grant: 1. Theoretical Consideration on the Properties of Accreting Millisecond Pulsars. 2. Accretion Onto Fast X-Ray Pulsars. 3. The Effects of Binary Evolution on the Dynamics of Core Collapse and Neutron-Star.

  17. 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

    2012-11-01

    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. PMID:23139326

  18. 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

    2012-11-01

    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  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 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.

  6. 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. PMID:23222523

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    Reipurth, Bo; Mikkola, Seppo

    2012-12-01

    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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Solar System Science with LSST

    NASA Astrophysics Data System (ADS)

    Jones, R. L.; Chesley, S. R.; Connolly, A. J.; Harris, A. W.; Ivezic, Z.; Knezevic, Z.; Kubica, J.; Milani, A.; Trilling, D. E.

    2008-09-01

    The Large Synoptic Survey Telescope (LSST) will provide a unique tool to study moving objects throughout the solar system, creating massive catalogs of Near Earth Objects (NEOs), asteroids, Trojans, TransNeptunian Objects (TNOs), comets and planetary satellites with well-measured orbits and high quality, multi-color photometry accurate to 0.005 magnitudes for the brightest objects. In the baseline LSST observing plan, back-to-back 15-second images will reach a limiting magnitude as faint as r=24.7 in each 9.6 square degree image, twice per night; a total of approximately 15,000 square degrees of the sky will be imaged in multiple filters every 3 nights. This time sampling will continue throughout each lunation, creating a huge database of observations. Fig. 1 Sky coverage of LSST over 10 years; separate panels for each of the 6 LSST filters. Color bars indicate number of observations in filter. The catalogs will include more than 80% of the potentially hazardous asteroids larger than 140m in diameter within the first 10 years of LSST operation, millions of main-belt asteroids and perhaps 20,000 Trans-Neptunian Objects. Objects with diameters as small as 100m in the Main Belt and <100km in the Kuiper Belt can be detected in individual images. Specialized `deep drilling' observing sequences will detect KBOs down to 10s of kilometers in diameter. Long period comets will be detected at larger distances than previously possible, constrainting models of the Oort cloud. With the large number of objects expected in the catalogs, it may be possible to observe a pristine comet start outgassing on its first journey into the inner solar system. By observing fields over a wide range of ecliptic longitudes and latitudes, including large separations from the ecliptic plane, not only will these catalogs greatly increase the numbers of known objects, the characterization of the inclination distributions of these populations will be much improved. Derivation of proper elements for

  14. The Origin and Evolution of the Solar System.

    ERIC Educational Resources Information Center

    Woolfson, M. M.

    1987-01-01

    Describes the major components of the solar system and proposes several features that a theory about the solar system should include. Contains explanations of several theories about the origin of the solar system. (TW)

  15. 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.

  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. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Astrometric solar-system anomalies

    NASA Astrophysics Data System (ADS)

    Anderson, John D.; Nieto, Michael Martin

    2010-01-01

    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 reportedly increasing by about 15 cm yr-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, including us, 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 prudent 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.

  3. Low Mass Ratio Contact Binary Systems HN UMa and II UMa - III

    NASA Astrophysics Data System (ADS)

    Lee, Woo-Baik; Kim, Ho-Il; Kang, Young Woon; Oh, Kyu-Dong

    2006-09-01

    We present newly observed BVRI CCD light curves for low mass ratio contact binaries, HN UMa and II UMa. The absolute dimensions of these objects were obtained by applying the Wilson-Devinney program to previously published spectroscopic analysis and to our observed photometric data. The evolutionary status of all 21 low mass ratio contact binary system including HN UMa and II UMa was then considered. The secondaries of all low mass ratio contact binaries are located below the zero age main sequence in HR diagram. This phenomenon could be explained by mass loss from the secondary component in the low mass contact binary system because even small mass loss affects luminosity decrease in the low mass stars.

  4. 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

  5. Solar- and wind-powered irrigation systems

    NASA Astrophysics Data System (ADS)

    Enochian, R. V.

    1982-02-01

    Five different direct solar and wind energy systems are technically feasible for powering irrigation pumps. However, with projected rates of fossil fuel costs, only two may produce significant unsubsidied energy for irrigation pumping before the turn of the century. These are photovoltaic systems with nonconcentrating collectors (providing that projected costs of manufacturing solar cells prove correct); and wind systems, especially in remote areas where adequate wind is available.

  6. Prototype solar domestic hot water systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Construction of a double wall heat exchanger using soft copper tube coiled around a hot water storage tank was completed and preliminary tests were conducted. Solar transport water to tank potable water heat exchange tests were performed with a specially constructed test stand. Work was done to improve the component hardware and system design for the solar water heater. The installation of both a direct feed system and a double wall heat exchanger system provided experience and site data to enable informative decisions to be made as the solar market expands into areas where freeze protection is required.

  7. 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.

  8. Database of candidates for RR Lyrae stars in binary systems - RRLyrBinCan

    NASA Astrophysics Data System (ADS)

    Liska, J.; Skarka, M.

    2016-05-01

    A new on-line database with RR Lyrae stars bound in binary systems is presented. Its purpose is to give a quick overview about known and suspected RR Lyrae stars in binaries on the basis of available literature. The first released version of the catalogue contains information about 61 double-star candidates, their orbital periods, method of detection, comments and active links to published papers.

  9. The Closest Known Flyby of a Star to the Solar System

    NASA Astrophysics Data System (ADS)

    Mamajek, Eric E.; Barenfeld, Scott A.; Ivanov, Valentin D.; Kniazev, Alexei Y.; Väisänen, Petri; Beletsky, Yuri; Boffin, Henri M. J.

    2015-02-01

    Passing stars can perturb the Oort Cloud, triggering comet showers and potentially extinction events on Earth. We combine velocity measurements for the recently discovered, nearby, low-mass binary system WISE J072003.20-084651.2 (“Scholz’s star”) to calculate its past trajectory. Integrating the Galactic orbits of this ˜0.15 M⊙ binary system and the Sun, we find that the binary passed within only 52+23-14 kAU (0.25+0.11-0.07 pc) of the Sun 70+15-10 kya (1σ uncertainties), i.e., within the outer Oort Cloud. This is the closest known encounter of a star to our solar system with a well-constrained distance and velocity. Previous work suggests that flybys within 0.25 pc occur infrequently (˜0.1 Myr-1). We show that given the low mass and high velocity of the binary system, the encounter was dynamically weak. Using the best available astrometry, our simulations suggest that the probability that the star penetrated the outer Oort Cloud is ˜98%, but the probability of penetrating the dynamically active inner Oort Cloud (<20 kAU) is ˜10-4. While the flyby of this system likely caused negligible impact on the flux of long-period comets, the recent discovery of this binary highlights that dynamically important Oort Cloud perturbers may be lurking among nearby stars.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Photometric Observations of the Totally Eclipsing, Solar Type Eclipsing Binary, DK Andromedae

    NASA Astrophysics Data System (ADS)

    Samec, Ronald G.; Faulkner, D. R.; Van Hamme, W. V.; Kring, J.

    2013-06-01

    We present the first precision BVRI light curves, synthetic light curve solutions and a period study for the Sonneberg variable, DK And. Observations were taken with the NURO 0.81-m Lowell reflector on 24, 25 and 27 September and 26 October and 01 November 2011 with the SARA 0.9-m reflector. Our light curves were premodeled with Binary Maker 3.0, and solved with the Wilson-Devinney program. Our observations included 374 B, 372 V, 392 R and 394 I individual and calibrated observations. These were taken with the NURO, Lowell 2KX2K NASACAM, and the SARA 1KX1K Apogee camera. Six mean times of minimum light were determined, includingHJDMin I= 2455866.8222(±0.0003), 2455828.6632(±0.0001), 2455829.6405(±0.0097), and HJDMin II=2455866.5782(±0.0007), 2455860.6970(±0.0053) and 2455828.9081(±0.0004). Thirty-one timings taken over 73 years are included in our ephemeris calculation: J.D. Hel Min I = 2451435.4330(±0.0011)d + 0.48922346(±0.00000015)×E + 2.4(±0.4)×10-11×E2 For conservative mass transfer, the positive quadratic term means that the more massive star is the gainer. Our light curves shows a time of constant light in the secondary eclipse of 28 minutes making this an A-type W UMa system. The amplitude of the light curves are about 0.5 mags in V. The light curve solution reveals a rather extreme mass ratio of 0.32, a component temperature difference of ~300K, and an inclination of 82.5°. The curves show the effects of dark spot activity. 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.

  15. 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

  16. 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. PMID:17943124

  17. 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.

  18. 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.

  19. 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.

  20. Solar System Visualization: Global Science Maps

    NASA Technical Reports Server (NTRS)

    DeJong, E. M.

    1994-01-01

    The goal of the Solar System Visualization (SSV) project is to re-explore the planets using the data from previous National Aeronautics and Space Administration (NASA) planetary missions on and public information.

  1. 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.

  2. Design information for solar-heating systems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report contains preliminary design information for two solar-heating and hot water systems presently under development. Information includes quality control data, special tooling specifications, hazard analysis, and preliminary training program for installation contractors.

  3. Modular solar-heating system - design package

    NASA Technical Reports Server (NTRS)

    Sinton, D. S.

    1979-01-01

    Compilation contains design, performance, and hardware specifications in sufficient detail to fabricate or procure materials and install, operate, and maintain complete modular solar heating and hot water system for single family size dwellings.

  4. Prototype solar-heating system - installation manual

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Manual for prototype solar-heating system gives detailed installation procedures for each of seven subsystems. Procedures for operation and maintenance are also included. It discusses architectural considerations, building construction considerations, and checkout-test procedures.

  5. Solar Heating System at a Racquetball Club

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Detailed 93-page report describes Arlington, Virginia racquetball club which obtains heat and hot water for its support area from solar collectors. Report explains modes of operation of system and details of acceptance-test plan.

  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. 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.

  8. Planetary science: Birth of a Solar System

    NASA Astrophysics Data System (ADS)

    Cameron, A. G. W.

    2002-08-01

    Radioisotope dating of meteorites suggests that planets formed in the Solar System over shorter timescales than had been thought. There are consequences for how the Moon formed, but is this the final word?

  9. Paleomagnetism of the Solar System.

    NASA Astrophysics Data System (ADS)

    Fuller, M.

    2005-12-01

    In addition to the paleomagnetic record from Earth, we have paleomagnetic results from samples from the Moon, Mars, and from a variety of meteorites. The record from the Moon involves numerous samples and appears to define a strong field interval from about 3.85 to 3.65 Ga. Subsequently the field may have turned off rapidly as some have advocated, or decayed over a period of billions of years as advocated by others. The record from Mars comes to us via the Martian meteorites, which include only one ancient rock ALH84001, a cataclastic pyroxenite. It has a crystallization age of 4.5 Ga. However, it was severely shocked at 4.0 Ga, from which time much of the magnetization probably originated. Estimates of the strength of the field in which it was magnetized vary, but it was probably at least a few microteslas. Younger volcanic rocks from Mars have given more reliable, but weaker field estimates. The paleomagnetic record from meteorites other than those from the Moon and Mars is probably the hardest of all records to interpret, but at least the achondrites may carry a record of fields on parent bodies. Besides the intrinsic interest in the paleomagnetism of samples from the solar system, the results provide some "groundtruth" to aid in the interpretation of the magnetic fields of the parent bodies. Such interpretations immediately encounter the role of shock on the magnetization of the recovered samples. Both on the Moon and Mars the effects of impacts and shock are pervasive on all scales. Indeed the least improbable model of lunar magnetism is related to giant impacts and on Mars the large impact basins play a key role.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. 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.

  16. 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. PMID:27511533

  17. 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.

  18. 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.

  19. 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.

  20. Chemical evolution: A solar system perspective

    NASA Technical Reports Server (NTRS)

    Oro, J.

    1989-01-01

    During the last three decades major advances were made in the understanding of the formation of carbon compounds in the universe and of the occurrence of processes of chemical evolution in the solar system and beyond. This was made possible by the development of new astronomical techniques and by the exploration of the solar system by means of properly instrumented spacecraft. Some of the major findings made as a result of these observations are summarized.

  1. 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.

  2. 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.

  3. Solar-heating system performance tests

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report contains results of performance tests on complete system for solar space and hot-water heating system that uses commercially available components. Results were used to determine system suitability for field installation and to generate performance data base for comparison with future tests on field installed systems.

  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. 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

  6. Photometric observations and analysis of the close binary system DV Aquarii

    SciTech Connect

    Okazaki, A.; Yamasaki, A.; Nurwendaya, C.

    1985-01-01

    Photoelectric BV light curves of the close binary system DV Aqr are presented. These light curves are analyzed with a synthesis method to determine the photometric elements. Physical properties of the system are briefly discussed. It is found that DV Aqr is a detached system consisting of a late-A and a K subgiant star. 12 references.

  7. 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.

  8. Generalized Roche potential for misaligned binary systems - Properties of the critical lobe

    NASA Technical Reports Server (NTRS)

    Avni, Y.; Schiller, N.

    1982-01-01

    The paper considers the Roche potential for binary systems where the stellar rotation axis is not aligned with the orbital revolution axis. It is shown that, as the degree of misalignment varies, internal Lagrangian points and external Lagrangian points may switch their roles. A systematic method to identify the internal Lagrangian point and to calculate the volume of the critical lobe is developed, and numerical results for a wide range of parameters of binary systems with circular orbits are presented. For binary systems with large enough misalignment, discrete changes occur in the topological structure of the equipotential surfaces as the orbital phase varies. The volume of the critical lobe has minima, as a function of orbital phase, at the two instances when the secondary crosses the equatorial plane of the primary. In semidetached systems, mass transfer may be confined to the vicinity of these two instances.

  9. 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. PMID:24784245

  10. 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)

  11. Desalting system utilizing solar energy

    SciTech Connect

    Iida, T.

    1985-06-25

    A heat-transfer medium is heated by a solar heat collector and then adiabatically compressed. The heat-transfer medium thus compressed exchanges heat with the seawater to heat it, and is then adiabatically expanded with the heated seawater being evaporated and the steam thus produced, upon heat exchange with the seawater, changed into fresh water.

  12. 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

  13. 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...

  14. 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...

  15. 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...

  16. Physical Identification of Binary System of Gliclazide-Hydrophilic Polymers Using X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Rachmawati, H.; Yatinasari, Faizatun, Syarie, S. A.

    2008-03-01

    The formation of binary system in pharmaceutical solid state is aimed to improve the physicochemical characteristics of active compound, such as its solubility. To identify the physical change of the binary system including crystallinity or particle morphology, there are many methods can be applied. In present report, we study the physical interaction of the binary system of gliclazide and hydrophilic polymers. In this binary system, gliclazide was either dispersed or mixed with polyvinyl pirrolidone (PVP K30) or polyethylene glycol (PEG 6000). The dispersion system of gliclazide in the polymeric carriers was prepared by solvation-evaporation method, using dichloromethane/methylene chloride as an organic solvent. The physical characterization of both dispersed and mixed of gliclazide was studied using X-ray diffraction at interval 6-50 °/2θ. As a comparison, the same procedure was performed for pure gliclazide. To confirm the diffractogram of this binary system, Fourier Transform Infrared (FT-IR) spectroscopy was carried out as well. Both diffarctogram and FT-IR spectra revealed that there was no new compound formed in the solid dispersion system of gliclazide:PEG 6000 and gliclazide:PVP K30. In contrast, the solubility as well as the dissolution rate of gliclazide in the presence of both hydrophilic polymers was increased as compared to pure gliclazide. We conclude therefore that solvatation followed by evaporation of gliclazide in the presence of either PEG 6000 or PVP K30 did not alter its crystalline characteristic. The improved of gliclazide solubility in the binary system might due to other mechanism such as increased in the wettability and the hydrophylicity effect of the polymers.

  17. 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.

  18. Solar System Exploration, 1995-2000

    NASA Technical Reports Server (NTRS)

    Squyres, S.; Varsi, G.; Veverka, J.; Soderblom, L.; Black, D.; Stern, A.; Stetson, D.; Brown, R. A.; Niehoff, J.; Squibb, G.

    1994-01-01

    Goals for planetary exploration during the next decade include: (1) determine how our solar system formed, and understand whether planetary systems are a common phenomenon through out the cosmos; (2) explore the diverse changes that planets have undergone throughout their history and that take place at present, including those that distinguish Earth as a planet; (3) understand how life might have formed on Earth, whether life began anywhere else in the solar system, and whether life (including intelligent beings) might be a common cosmic phenomenon; (4) discover and investigate natural phenomena that occur under conditions not realizable in laboratories; (5) discover and inventory resources in the solar system that could be used by human civilizations in the future; and (6) make the solar system a part of the human experience in the same way that Earth is, and hence lay the groundwork for human expansion into the solar system in the coming century. The plan for solar system exploration is motivated by these goals as well as the following principle: The solar system exploration program will conduct flight programs and supporting data analysis and scientific research commensurate with United States leadership in space exploration. These programs and research must be of the highest scientific merit, they must be responsive to public excitement regarding planetary exploration, and they must contribute to larger national goals in technology and education. The result will be new information, which is accessible to the public, creates new knowledge, and stimulates programs of education to increase the base of scientific knowledge in the general public.

  19. 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.

  20. Prototype solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A collection of monthly status reports are given on the development of eight prototype solar heating and cooling systems. This effort calls for the development, manufacturing, test, system installation, maintenance, problem resolution, and performance evaluation. The systems are 3-, 25-, and 75-ton size units.

  1. Residential solar-heating/cooling system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Report documents progress of residential solar-heating and cooling system development program at 5-month mark of anticipated 17-month program. System design has been completed, and development and component testing has been initiated. Report includes diagrams, operation overview, optimization studies of subcomponents, and marketing plans for system.

  2. 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.

  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 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.

  5. 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.

  6. The Birth Environment of the Solar System

    NASA Astrophysics Data System (ADS)

    Adams, Fred C.

    2010-09-01

    This review examines our current understanding of the possible birth environments of our Solar System. Because most stars form within groups and clusters, the question becomes one of determining the nature of the birth aggregate of the Sun. This discussion starts by reviewing Solar System properties that provide constraints on our environmental history. We then outline the range of star-forming environments that are available in the Galaxy and discuss how they affect star and planet formation. The nature of the solar birth cluster is constrained by many physical considerations, including radiation fields provided by the background environment, dynamical scattering interactions, and by the necessity of producing the short-lived radioactive nuclear species inferred from meteoritic measurements. Working scenarios for the solar birth aggregate can be constructed, as discussed herein, although significant uncertainties remain.

  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. 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.

  9. 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.

  10. Chaos and stability of the solar system

    PubMed Central

    Malhotra, Renu; Holman, Matthew; Ito, Takashi

    2001-01-01

    Over the last two decades, there has come about a recognition that chaotic dynamics is pervasive in the solar system. We now understand that the orbits of small members of the solar system—asteroids, comets, and interplanetary dust—are chaotic and undergo large changes on geological time scales. Are the major planets' orbits also chaotic? The answer is not straightforward, and the subtleties have prompted new questions. PMID:11606772

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Time-Dependent Behavior of the O'Connell Effect in Eclipsing Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Beaky, Matthew M.; Koju, V.

    2012-05-01

    The characteristic shape of an eclipsing binary light curve consists of two out-of-eclipse maxima and two mid-eclipse minima. Many eclipsing binary light curves exhibit unequally high maxima, a feature known as the O'Connell effect. So far, this asymmetry has not been convincingly explained aside from a few individual systems. Most theories attribute the O'Connell effect to phenomena such as starspots, clouds of circumstellar gas and dust, or a hot spot caused by the impact of a mass-transferring gas stream. The high precision and nearly continuous temporal coverage of light curves produced by the Kepler Space Mission make it possible to detect variations in the O'Connell effect within individual systems that have not previously been observed via ground-based observations. Our analysis of Kepler light curves of eclipsing binary systems reveals that in most cases the size and even the sign of the O'Connell effect changes significantly over time scales of weeks or months. Moreover, the magnitude difference between the eclipse minima also varies, usually lagging behind the variations in the difference between the out-of-eclipse maxima by several orbital cycles. We have created models of eclipsing binary systems using Binary Maker 3 that include starspots that migrate slowly in longitude, and have analyze the light curves generated by these model systems. Models with constant starspots at fixed latitude and models with starspots that vary in size and latitude both reproduce the qualitative behavior of the time-dependent O'Connell effect in the Kepler light curves very closely. These results provide support for the notion that the O'Connell effect, at least in some cases, is caused by migrating starspots on the surface of one or both components of the binary star system.

  17. The Gibbs Energy Basis and Construction of Boiling Point Diagrams in Binary Systems

    ERIC Educational Resources Information Center

    Smith, Norman O.

    2004-01-01

    An illustration of how excess Gibbs energies of the components in binary systems can be used to construct boiling point diagrams is given. The underlying causes of the various types of behavior of the systems in terms of intermolecular forces and the method of calculating the coexisting liquid and vapor compositions in boiling point diagrams with…

  18. Recognition of binary x-ray systems utilizing the doppler effect

    NASA Technical Reports Server (NTRS)

    Novak, B. L.

    1980-01-01

    The possibility of recognizing the duality of a single class of X-ray systems utilizing the Doppler effect is studied. The procedure is based on the presence of a period which coincides with the orbital period at the intensity of the radiation in a fixed energy interval of the X-ray component of a binary system.

  19. MAXI/GSC detection of a possible X-ray flare from an dMe binary system YY Gem

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Kanetou, S.; Tsuboi, Y.; Sasaki, R.; Ueno, S.; Tomida, H.; Nakahira, S.; Kimura, M.; Ishikawa, M.; Nakagawa, Y. E.; Mihara, T.; Sugizaki, M.; Serino, M.; Shidatsu, M.; Sugimoto, J.; Takagi, T.; Matsuoka, M.; Kawai, N.; Arimoto, M.; Yoshii, T.; Tachibana, Y.; Ono, Y.; Fujiwara, T.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Ohtsuki, H.; Tsunemi, H.; Imatani, R.; Negoro, H.; Nakajima, M.; Tanaka, K.; Masumitsu, T.; Ueda, Y.; Kawamuro, T.; Hori, T.; Yamauchi, M.; Itoh, D.; Yamaoka, K.; Morii, M.

    2015-09-01

    MAXI/GSC observed a possible X-ray flare from a dMe binary system YY Gem. The MAXI/GSC nova alert system triggered on the flare-like event from the position consistent with the active binary system YY Gem during a scan transit at 01:29:00 UT on September 24th 2015.

  20. Experimental determination of systems suitable for study as monotectic binary metallic alloy solidification models

    NASA Technical Reports Server (NTRS)

    Smith, J. E., Jr.

    1985-01-01

    Transparent binary metallic alloy solidification models are important in attempts to understand the processes causing liquid-liquid and solid-liquid phase transformations in metallic alloy systems. These models permit visual observation of the phase transformation and the processes proceding solidification. The number of these transparent monotectic binary models needs to be expanded to distinguish between the unique and general phenomena observed. The expansion of the number of accurately determined monotectic phase diagrams of model systems, and contribution to a data base for eventual use with UNIFAC group contribution methods is examined.

  1. Southern RS CVn systems - Candidate list. [spectral catalog of variable binary stars

    NASA Technical Reports Server (NTRS)

    Weiler, E. J.; Stencel, R. E.

    1979-01-01

    A list of 43 candidate RS CVn binary systems in the far southern hemisphere of the sky (south of -40 deg declination) is presented. The candidate systems were selected from the first two volumes of the Michigan Spectral Catalog (1975, 1978), which provides MK classifications for southern HD stars and identifies any unusual characteristics noted for individual stellar spectra. The selection criteria used were: (1) the occurrence of Ca II H and K emission; (2) known or suspected binary nature; (3) regular light variations of zero to one magnitude; and (4) spectral type between F0 and K2 and luminosity less than bright giant (II).

  2. 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…

  3. Photometric and Spectroscopic Analysis for the Determination of Physical Parameters of an Eclipsing Binary Star System

    NASA Astrophysics Data System (ADS)

    Reid, Piper

    2013-01-01

    A binary star system is a pair of stars that are bound together by gravity. Most of the stars that we see in the night sky are members of multiple star systems. A system of stars where one star passes in front of the other (as observed from Earth) on a periodic basis is called an eclipsing binary. Eclipsing binaries can have very short rotational periods and in all cases these pairs of stars are so far away that they can only be resolved from Earth as a single point of light. The interaction of the two stars serves to produce physical phenomena that can be observed and used to study stellar properties. By careful data collection and analysis is it possible for an amateur astronomer using commercial, low cost equipment (including a home built spectroscope) to gather photometric (brightness versus time) and spectroscopic (brightness versus wavelength) data, analyze the data, and calculate the physical properties of a binary star system? Using a CCD camera, tracking mount and telescope photometric data of BB Pegasi was collected and a light curve produced. 57 Cygni was also studied using a spectroscope, tracking mount and telescope to prove that Doppler shift of Hydrogen Balmer absorption lines can be used to determine radial velocity. The orbital period, orbital velocity, radius of each star, separation of the two stars and mass of each star was calculated for the eclipsing binary BB Pegasi using photometric and spectroscopic data and Kepler’s 3rd Law. These data were then compared to published data. By careful use of consumer grade astronomical equipment it is possible for an amateur astronomer to determine an array of physical parameters of a distant binary star system from a suburban setting.

  4. 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

  5. Orbital Evolution of Mass-transferring Eccentric Binary Systems. I. Phase-dependent Evolution

    NASA Astrophysics Data System (ADS)

    Dosopoulou, Fani; Kalogera, Vicky

    2016-07-01

    Observations reveal that mass-transferring binary systems may have non-zero orbital eccentricities. The time evolution of the orbital semimajor axis and eccentricity of mass-transferring eccentric binary systems is an important part of binary evolution theory and has been widely studied. However, various different approaches to and assumptions on the subject have made the literature difficult to comprehend and comparisons between different orbital element time evolution equations not easy to make. Consequently, no self-consistent treatment of this phase has ever been included in binary population synthesis codes. In this paper, we present a general formalism to derive the time evolution equations of the binary orbital elements, treating mass loss and mass transfer as perturbations of the general two-body problem. We present the self-consistent form of the perturbing acceleration and phase-dependent time evolution equations for the orbital elements under different mass loss/transfer processes. First, we study the cases of isotropic and anisotropic wind mass loss. Then, we proceed with non-isotropic ejection and accretion in a conservative as well as a non-conservative manner for both point masses and extended bodies. We compare the derived equations with similar work in the literature and explain the existing discrepancies.

  6. Looking for light pseudoscalar bosons in the binary pulsar system J0737-3039.

    PubMed

    Dupays, Arnaud; Rizzo, Carlo; Roncadelli, Marco; Bignami, Giovanni F

    2005-11-18

    We present numerical calculations of the photon-light-pseudoscalar-boson (LPB) production in the recently discovered binary pulsar system J0737-3039. Light pseudoscalar bosons oscillate into photons in the presence of strong magnetic fields. In the context of this binary pulsar system, this phenomenon attenuates the light beam emitted by one of the pulsars, when the light ray goes through the magnetosphere of the companion pulsar. We show that such an effect is observable in the gamma-ray band since the binary pulsar is seen almost edge-on, depending on the values of the LPB mass and on the strength of its two-photon coupling. Our results are surprising in that they show a very sharp and significant (up to 50%) transition probability in the gamma-ray (> tens of MeV) domain. The observations can be performed by the upcoming NASA GLAST mission.

  7. 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.

  8. Exoplanets bouncing between binary stars

    NASA Astrophysics Data System (ADS)

    Moeckel, Nickolas; Veras, Dimitri

    2012-05-01

    Exoplanetary systems are found not only among single stars, but also among binaries of widely varying parameters. Binaries with separations of 100-1000 au are prevalent in the solar neighbourhood; at these separations, planet formation around a binary member may largely proceed as if around a single star. During the early dynamical evolution of a planetary system, planet-planet scattering can eject planets from a star's grasp. In a binary, the motion of a planet ejected from one star has effectively entered a restricted three-body system consisting of itself and the two stars, and the equations of motion of the three-body problem will apply as long as the ejected planet remains far from the remaining planets. Depending on its energy, escape from the binary as a whole may be impossible or delayed until the three-body approximation breaks down, and further close interactions with its planetary siblings boost its energy when it passes close to its parent star. Until then, this planet may be able to transition from the space around one star to the other, and chaotically 'bounce' back and forth. In this paper, we directly simulate scattering planetary systems that are around one member of a circular binary, and quantify the frequency of bouncing in scattered planets. We find that a great majority (70-85 per cent) of ejected planets will pass at least once through the space of it's host's binary companion, and depending on the binary parameters about 35-75 per cent will begin bouncing. The time spent bouncing is roughly lognormally distributed with a peak at about 104 yr, with only a small percentage bouncing for more than 1 Myr. This process may perturb and possibly incite instability among existing planets around the companion star. In rare cases, the presence of multiple planets orbiting both stars may cause post-bouncing capture or planetary swapping.

  9. 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.

  10. SMA OBSERVATIONS OF CLASS 0 PROTOSTARS: A HIGH ANGULAR RESOLUTION SURVEY OF PROTOSTELLAR BINARY SYSTEMS

    SciTech Connect

    Chen Xuepeng; Arce, Hector G.; Dunham, Michael M.; Zhang Qizhou; Bourke, Tyler L.; Launhardt, Ralf; Henning, Thomas; Jorgensen, Jes K.; Lee, Chin-Fei; Foster, Jonathan B.; Pineda, Jaime E. E-mail: xuepeng.chen@yale.edu

    2013-05-10

    We present high angular resolution 1.3 mm and 850 {mu}m dust continuum data obtained with the Submillimeter Array toward 33 Class 0 protostars in nearby clouds (distance < 500 pc), which represents so far the largest survey toward protostellar binary/multiple systems. The median angular resolution in the survey is 2.''5, while the median linear resolution is approximately 600 AU. Compact dust continuum emission is observed from all sources in the sample. Twenty-one sources in the sample show signatures of binarity/multiplicity, with separations ranging from 50 AU to 5000 AU. The numbers of singles, binaries, triples, and quadruples in the sample are 12, 14, 5, and 2, respectively. The derived multiplicity frequency (MF) and companion star fraction (CSF) for Class 0 protostars are 0.64 {+-} 0.08 and 0.91 {+-} 0.05, respectively, with no correction for completeness. The derived MF and CSF in this survey are approximately two times higher than the values found in the binary surveys toward Class I young stellar objects, and approximately three (for MF) and four (for CSF) times larger than the values found among main-sequence stars, with a similar range of separations. Furthermore, the observed fraction of high-order multiple systems to binary systems in Class 0 protostars (0.50 {+-} 0.09) is also larger than the fractions found in Class I young stellar objects (0.31 {+-} 0.07) and main-sequence stars ({<=}0.2). These results suggest that binary properties evolve as protostars evolve, as predicted by numerical simulations. The distribution of separations for Class 0 protostellar binary/multiple systems shows a general trend in which CSF increases with decreasing companion separation. We find that 67% {+-} 8% of the protobinary systems have circumstellar mass ratios below 0.5, implying that unequal-mass systems are preferred in the process of binary star formation. We suggest an empirical sequential fragmentation picture for binary star formation, based on this work and

  11. 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.

  12. 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.

  13. NLTE spectral analysis of the sdOB primary of the eclipsing binary system LB 3459 (AA Dor)

    NASA Astrophysics Data System (ADS)

    Rauch, T.

    2000-04-01

    We present a spectral analysis of the sdOB primary star of the binary system LB 3459 based on high-resolution high-S/N optical and UV spectra. The metal abundances are determined by means of state-of-the-art NLTE model atmospheres. We determined Teffw42 and log gw{5.2} within very small error limits. The He (1/125 solar), C (1/265), N (1/33), O (1/12), and Si (1/5) abundances appear strongly depleted while that of Fe and Ni are roughly solar and Mg is strongly enriched by a factor of 6. The spectroscopic distance to LB 3459 is d = 396 pc. The mass of the primary component of LB 3459 is 0.330 M_sun derived from comparisons with theoretical models for sdO stars in the log T_eff - \\log g plane. The mass of the secondary is then 0.066 M_sun derived from the mass function. There remains some disagreement between the radius derived from log g and the above mass, and that derived from analysis of the radial-velocity curve and the eclipse curves. LB 3459 is a close binary system which had experienced a common envelope (CE) phase during its evolution. It fits in the ``low mass case B'' scenario of Iben & Livio (1993) and the secondary is a brown dwarf. The spectroscopically determined rotational velocity of the primary is v_rot = 34 ± 10 km* sec-1. Thus even bound rotation (v_rot = 45.7 km* sec-1) cannot be ruled out. Based on observations collected at the European Southern Observatory, La Silla, Chile (proposals 55.D-0319, 56.C-0165) and on data retrieved from the International Ultraviolet Explorer (IUE) Final Archive.

  14. 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.

  15. The Cambridge Guide to the Solar System

    NASA Astrophysics Data System (ADS)

    Lang, Kenneth R.

    2011-03-01

    Part I. Changing Views and Fundamental Concepts: 1. Evolving perspectives: a historical prologue; 2. The new, close-up view from space; 3. The invisible buffer zone with space: atmospheres, magnetospheres and the solar wind; Part II. The Inner System - Rocky Worlds: 4. Third rock from the Sun: restless Earth; 5. The Moon: stepping stone to the planets; 6. Mercury: a dense battered world; 7. Venus: the veiled planet; 8. Mars: the red planet; Part III. The Giant Planets, Their Satellites and Their Rings - Worlds of Liquid, Ice and Gas: 9. Jupiter: a giant primitive planet; 10. Saturn: lord of the rings; 11. Uranus and Neptune; Part IV. Remnants of Creation - Small Worlds in the Solar System: 12. Asteroids and meteorites; 13. Colliding worlds; 14. Comets; 15. Beyond Neptune; Part V. Origin of the Solar System and Extrasolar Planets: 16. Brave new worlds; Index.

  16. 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.

  17. 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?

  18. 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

  19. Redox storage systems for solar applications

    NASA Technical Reports Server (NTRS)

    Hagedorn, N. H.; Thaller, L. H.

    1980-01-01

    The NASA Redox energy storage system is described. The system is based on soluble aqueous iron and chromium chloride redox couples. The needed technology advances in the two elements (electrodes and membranes) that are key to its technological feasibility have been achieved and system development has begun. The design, construction, and test of a 1 kilowatt system integrated with a solar photovoltaic array is discussed.

  20. Solar-Cell-Junction Processing System

    NASA Technical Reports Server (NTRS)

    Bunker, S. N.; Armini, A. J.

    1986-01-01

    System under development reduces equipment costs. Processing system will produce solar-cell junctions on 4 in. (10.2 cm) round silicon wafers at rate of 10 to seventh power per year. System includes non-mass-analyzed ion implanter, microcomputer-controlled, pulsed-electron-beam annealer, and wafertransport system with vacuum interlock. These features eliminate large, expensive magnet and plates, circuitry, and power source otherwise needed for scanning.

  1. Photometry of 20 eclipsing and ellipsoidal binary systems

    NASA Astrophysics Data System (ADS)

    Shobbrook, R. R.

    2004-12-01

    A total of almost 2000 V observations of 20 eclipsing and ellipsoidal bright binary stars was collected between 1991 and 2001 for the purpose of determining more recent epoch ephemerides for the light curves than are available in the literature. The original purpose was to provide the Sydney University Stellar Interferometer (SUSI) with orbital periods and particularly the accurate times of minimum separation (light curve minima), so that the SUSI observations need not be used to determine them. This paper provides the periods, the times of primary minima and the phases of secondary minima for the 20 stars at an epoch as near as possible to the year 2000. No attempt has been made in this report to determine other parameters such as {apsidal motion} or stellar radii. Since the program was started in 1991, data for these stars taken in the period from late 1989 to early 1993 has also been available from the Hipparcos satellite; the light curves shown here include both sets of observations.

  2. Photometry of 20 eclipsing and ellipsoidal binary systems

    NASA Astrophysics Data System (ADS)

    Shobbrook, R. R.

    2005-12-01

    ERRATUM: In the published paper the phase diagrams of pi Sco and AL Scl were ommitted. The version reproduced in JAD11, 7 is the complete version. A total of almost 2000 V observations of 20 eclipsing and ellipsoidal bright binary stars was collected between 1991 and 2001 for the purpose of determining more recent epoch ephemerides for the light curves than are available in the literature. The original purpose was to provide the Sydney University Stellar Interferometer (SUSI) with orbital periods and particularly the accurate times of minimum separation (light curve minima), so that the SUSI observations need not be used to determine them. This paper provides the periods, the times of primary minima and the phases of secondary minima for the 20 stars at an epoch as near as possible to the year 2000. No attempt has been made in this report to determine other parameters such as {apsidal motion} or stellar radii. Since the program was started in 1991, data for these stars taken in the period from late 1989 to early 1993 has also been available from the Hipparcos satellite; the light curves shown here include both sets of observations.

  3. 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].

  4. Stable Orbits in the Didymos Binary Asteroid System - Useful Platforms for Exploration

    NASA Astrophysics Data System (ADS)

    Damme, Friedrich; Hussmann, Hauke; Wickhusen, Kai; Enrico, Mai; Oberst, Jürgen

    2016-04-01

    We have analyzed particle motion in binary asteroid systems to search for stable orbits. In particular, we studied the motion of particles near the asteroid 1996 GT (Didymos), proposed as a target for the AIDA mission. The combined gravity fields of the odd-shaped rotating objects moving about each other are complex. In addition, orbiting spacecraft or dust particles are affected by radiation pressure, possibly exceeding the faint gravitational forces. For the numerical integrations, we adopt parameters for size, shape, and rotation from telescopic observations. To simulate the effect of radiation pressure during a spacecraft mission, we apply a spacecraft wing-box shape model. Integrations were carried out beginning in near-circular orbits over 11 days, during which the motion of the particles were examined. Most orbits are unstable with particles escaping quickly or colliding with the asteroid bodies. However, with carefully chosen initial positions, we found stable motion (in the orbiting plane of the secondary) associated with the Lagrangian points (L4 and L5), in addition to horseshoe orbits, where particles move from one of the Lagrangian point to the other. Finally, we examined orbits in 1:2 resonances with the motion of the orbital period of the secondary. Stable conditions depend strongly on season caused by the inclination of the mutual orbit plane with respect to Didymos solar orbit. At larger distance from the asteroid pair, we find the well-known terminator orbits where gravitational attraction is balanced against radiation pressure. Stable orbits and long motion arcs are useful for long tracking runs by radio or Laser instruments and are well-suited for modelling of the ephemerides of the asteroid pair and gravity field mapping. Furthermore, these orbits may be useful as observing posts or as platforms for approach. These orbits may also represent traps for dust particles, an opportunity for dust collection - or possibly a hazard to spacecraft

  5. Orbital parameters and variability of the emission spectrum for the massive binary system 103 Tau

    NASA Astrophysics Data System (ADS)

    Tarasov, A. E.

    2016-09-01

    Based on high-resolution spectra taken near the He I 6678 Å line for the massive binary system 103 Tau, we have detected a weak absorption component belonging to the binary's secondary component. We have measured the radial velocities of both components, improved the previously known orbital parameters, and determined the new ones. The binary has an orbital period P orb = 58.305d, an orbital eccentricity e = 0.277, a radial velocity semi-amplitude of the bright component K A = 44.8 km s-1, and a component mass ratio M A / M B = 1.77. The absence of photometric variability and the estimates of physical parameters for the primary component suggest that the binary most likely has a considerable inclination of the orbital plane to the observer, i ≈ 50°-60°. In this case, the secondary component is probably a normal dwarf of spectral type B5-B8. Based on the spectra taken near the H α line, we have studied the variability of the emission profile. It is shown to be formed in the Roche lobe of the secondary component, but no traces of active mass exchange in the binary have been detected.

  6. Near-Infrared Polarimetry of the GG Tauri A Binary System

    NASA Technical Reports Server (NTRS)

    Itoh, Yoichi; Oasa, Yumiko; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Hashimoto, Jun; Abe, Lyu; Brandner, Wolfgang; Brandt, Timothy D.; Carson, Joseph C.; Egner, Sebastian; Feldt, Markus; Grady, Carol A.; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiko; Hayashi, Saeko S.; Henning, Thomas; Hodapp, Klaus W.; Ishii, Miki; Iye, Masanori; Janson, Markus; Kandori, Ryo; Knapp, Gillian R.; Kuzuhara, Masayuki; Kwon, Jungmi; Matsuo, Taro; McElwain, Michael W.; Miyama, Shoken; Morino, Jun-Ichi; Moro-Martin, Amaya; Nishimura, Tetsuo; Pyo, Tae-Soo; Serabyn, Eugene; Suenaga, Takuya; Suto, Hiroshi

    2014-01-01

    A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.

  7. Spectroscopic observations of V443 Herculis - A symbiotic binary with a low mass white dwarf

    NASA Technical Reports Server (NTRS)

    Dobrzycka, Danuta; Kenyon, Scott J.; Mikolajewska, Joanna

    1993-01-01

    We present an analysis of new and existing photometric and spectroscopic observations of the symbiotic binary V443 Herculis. This binary system consists of a normal M5 giant and a hot compact star. These two objects have comparable luminosities: about 1500 solar for the M5 giant and about 1000 solar for the compact star. We identify three nebular regions in this binary: a small, highly ionized volume surrounding the hot component, a modestly ionized shell close to the red giant photosphere, and a less dense region of intermediate ionization encompassing both binary components. The system parameters for V443 Her suggest the hot component currently declines from a symbiotic nova eruption.

  8. Infrared observations of small solar system bodies

    NASA Technical Reports Server (NTRS)

    Brown, R. H.

    1991-01-01

    Infrared reflectance spectra were measured of dark primitive asteroids in the 2 to 5 micron wavelength region. The search was for organic complexes such and CN, CH, and NH in dark material on small bodies in the solar system. A search and study was made of volatiles such as nitrogen, methane, ammonia, and carbon monoxide, both as free ices and hydrates/clathrates, on icy surfaces in the outer solar system, using high resolution spectra obtained with a multichannel cooled grating, infrared spectrometer. An absorption that can be attributed to X-C (triple bond) N in the matrix of dark materials on the primitive asteroids.

  9. 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.

  10. Solar System dynamics with the Gaia mission

    NASA Astrophysics Data System (ADS)

    Hestroffer, D.; Berthier, J.; Carry, B.; David, P.; Lainey, V.; Rambaux, N.; Thuillot, W.; Arlot, J.-E.; Bancelin, D.; Colas, F.; Desmars, J.; Devillepoix, H.; Fouchard, M.; Ivantsov, A.; Kovalenko, I.; Robert, V.

    2014-12-01

    The Gaia mission is to be launched on December 19th, 2013 by the European Space Agency (ESA). Solar System science is well covered by the mission and has been included since the early stages of its concept and development. We present here some aspects on the astrometry and dynamics of Solar System Objects (SSO) - in particular asteroids, comets and satellites - as well as ground-based support. We also touch upon the future of SSO astrometry that will be achieved indirectly, after mission completion, from the Gaia astrometric catalogue.

  11. 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.

  12. Photometric Properties of Solar System Ices

    NASA Astrophysics Data System (ADS)

    Verbiscer, A. J.; Helfenstein, P.; Buratti, B. J.

    We present an overview of fundamental photometric properties of icy surfaces throughout the Solar System and investigate the extent to which these properties reflect the evolution of the bodies on which they reside. We review photometric models and their parameters and discuss the physical interpretability of those parameters. We focus on those fundamental photometric properties, primarily albedo and the near-opposition phase function, which are independent of any interpretation from the application of a photometric model. Finally, we offer suggestions for future work, both observational and laboratory measurements, which will enhance the scientific return from continued photometric studies of icy bodies in the Solar System.

  13. High throughput solar cell ablation system

    SciTech Connect

    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.

  14. 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.

  15. 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.

  16. Gravitational radiation, inspiraling binaries, and cosmology

    NASA Technical Reports Server (NTRS)

    Chernoff, David F.; Finn, Lee S.

    1993-01-01

    We show how to measure cosmological parameters using observations of inspiraling binary neutron star or black hole systems in one or more gravitational wave detectors. To illustrate, we focus on the case of fixed mass binary systems observed in a single Laser Interferometer Gravitational-wave Observatory (LIGO)-like detector. Using realistic detector noise estimates, we characterize the rate of detections as a function of a threshold SNR Rho(0), H0, and the binary 'chirp' mass. For Rho(0) = 8, H0 = 100 km/s/Mpc, and 1.4 solar mass neutron star binaries, the sample has a median redshift of 0.22. Under the same assumptions but independent of H0, a conservative rate density of coalescing binaries implies LIGO will observe about 50/yr binary inspiral events. The precision with which H0 and the deceleration parameter q0 may be determined depends on the number of observed inspirals. For fixed mass binary systems, about 100 observations with Rho(0) = 10 in the LIGO will give H0 to 10 percent in an Einstein-DeSitter cosmology, and 3000 will give q0 to 20 percent. For the conservative rate density of coalescing binaries, 100 detections with Rho(0) = 10 will require about 4 yrs.

  17. Enhancement of dark matter capture by neutron stars in binary systems.

    PubMed

    Brayeur, Lionel; Tinyakov, Peter

    2012-08-10

    We study the capture of dark matter particles by neutron stars in close binary systems. By performing a direct numerical simulation, we find that there is a sizable amplification of the rate of dark matter capture by each of the companions. In the case of the binary pulsar PSR J1906+0746 with the orbital period of 4 hours the amplification factor is approximately equal to 3.5. This amplification can be attributed to the energy loss by dark matter particles resulting from their gravitational scattering off moving companions.

  18. 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.

  19. Nearest Neighbor Searching in Binary Search Trees: Simulation of a Multiprocessor System.

    ERIC Educational Resources Information Center

    Stewart, Mark; Willett, Peter

    1987-01-01

    Describes the simulation of a nearest neighbor searching algorithm for document retrieval using a pool of microprocessors. Three techniques are described which allow parallel searching of a binary search tree as well as a PASCAL-based system, PASSIM, which can simulate these techniques. Fifty-six references are provided. (Author/LRW)

  20. Gamma rays and neutrinos from dense environment of massive binary systems in open clusters

    NASA Astrophysics Data System (ADS)

    Bednarek, Włodek; Pabich, Jerzy; Sobczak, Tomasz

    2014-11-01

    TeV gamma-ray emission has been recently observed from the direction of a few open clusters containing massive stars. We consider the high energy processes occurring within massive binary systems and in their dense environment by assuming that nuclei, from the stellar winds of massive stars, are accelerated at the collision region of the stellar winds. We calculate the rates of injection of protons and neutrons from fragmentation of these nuclei in collisions with stellar radiation and matter of the winds from the massive companions in a binary system. Protons and neutrons can interact with the matter, within the stellar wind cavity, and within the open cluster, producing pions which decay into γ rays and neutrinos. We discuss the detectability of such γ -ray emission by the present and future Cherenkov telescopes for the case of two binary systems Eta Carinae, within the Carina Nebula, and WR 20a, within the Westerlund 2 open cluster. We also calculate the neutrino fluxes produced by protons around the binary systems and within the open clusters. This neutrino emission is confronted with ANTARES upper limits on the neutrino fluxes from discrete sources and with the sensitivity of IceCube.