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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. Tidal Evolution of Solar System Binaries

    NASA Astrophysics Data System (ADS)

    Taylor, Patrick A.; Margot, J. L.

    2007-10-01

    We approximate tidal evolution timescales for small (radius < 200 km), rocky bodies [1, 2] following a fission event, interpreted here as any process resulting in the placement of mass into orbit above the synchronous height, and explicitly calculate timescales for well-characterized systems. Binaries with nearly equal mass components orbit within 6 primary radii and have likely fully despun rapidly while smaller secondaries despin more slowly and end their tidal evolution at wider separations. The final separation of the components is limited by the conversion of spin to orbital angular momentum. Binary systems with separations beyond this limit require a different formation mechanism such as n-body capture. The product μQ, where μ is the rigidity and Q is the tidal dissipation factor, combines the idealized elastic properties of the asteroid that affect the tidal strength. Since binaries in the Main Belt must evolve to their current configuration within the age of the Solar System, a binary near this limit would place an upper bound on μQ for the system. Precise orbit, density, and component size information are required because ten percent errors in primary radius and density can cause approximately 20 and 25 percent changes in μQ, respectively. Assuming μQ of 1011 N/m2, many near-Earth binaries, if produced through fission, have tidally evolved for longer than their typical dynamical lifetime of 10 My [3]. This implies that either these binaries were formed prior to injection into the near-Earth region or μQ is at least an order of magnitude smaller than assumed, which might occur for highly fractured or rubble pile bodies. The effect of a non-spherical primary is also analyzed. [1] A. W. Harris and W. R. Ward, AREPS, 10, 1982. [2] S. J. Weidenschilling et al., in Asteroids II, 1989. [3] B. J. Gladman et al., Science, 277, 1997.

  3. Solar Type Binary Systems with Impacting Gas Streams

    NASA Astrophysics Data System (ADS)

    Samec, Ronald G.; Hube, Doug; Faulkner, Danny R.; van Hamme, W.

    2002-02-01

    Our quest is the discovery of near-contact solar type eclipsing binaries which show evidence of stream impacts. The existence of stream impacts would provide evidence of dynamic mass transfer possibly leading to coalescence into contact. This would lend strong support to the theoretical scenarios of 1) Angular Momentum Loss (AML) via magnetic breaking and 2) Thermal Relaxation Oscillations (TRO) ,ie., oscillations between a near-contact and shallow contact modes. We hypothesize that many F to early K spectral type binaries formerly classified as ''thermally decoupled'' contact binaries and other binaries with large differences in eclipse depths formerly classified as contact binaries in the 0.33 to 0.5d period range will reveal such stream impacts when they are subjected to precision UBVRI multi-band photometry, since these fall in the pre-contact period range for F to K dwarf binaries. Modern light curve synthesis techniques will be used to simultaneously model the multi-band light curves. Impact spots will be adjusted numerically along with the stellar atmosphere parameters. Spectroscopic work will follow to verify stream activity in emission lines and to obtain radial velocity curves for calculating orbital parameters and fundamental physical characteristics. Our larger goal is to understand close binary evolution in general, in detached, semi-detached and contact modes. This study could supply an important piece to the puzzle. We now have found four stream system candidates: CN And, BE Cep, ZZ Eri and V343 Cen giving us an encouraging 40 % rate of recovery.

  4. Solar-Type Eclipsing Binary Systems with Impacting Gas Streams

    NASA Astrophysics Data System (ADS)

    Samec, Ronald G.; Hube, Doug; Faulkner, Danny R.; van Hamme, W.

    2002-08-01

    Our quest is the recovery of near contact solar type eclipsing binaries with evidence for stream impacts. Their existence will provide strong support of dynamic mass transfer leading to coalescence into a state of contact. This will lend strong support to the theoretical scenarios of 1) angular momentum loss(AML)via magnetic breaking scenario and 2)Thermal Relaxation Oscillations (TRO)or oscillations between a near­contact and shallow contact modes. We hypothesize that many F to early K spectral type binaries formerly classified as ''thermally decoupled'' contact binaries and other binaries with large differences in eclipse depths formerly classified as contact binaries in the 0.33 to 0.5d period range will reveal evidence for stream impacts when they are subjected to precision UBVRI multi­band photometry, since these fall in the pre­contact period range for F to K dwarf binaries. Modern light curve synthesis techniques will be used to simultaneously model the multi­band light curves. Impact spots will be adjusted numerically along with the stellar atmosphere parameters. Spectroscopic work will follow to verify stream activity and to obtain fundamental physical characteristics. Our larger goal is to understand close binary evolution in general. This study could supply an important piece to the puzzle. We now have found four candidates, CN And, BE Cep, ZZ Eri and V343 Cen giving us an encouraging 40 percent recovery thus far.

  5. The solar-type eclipsing binary system LL Aquarii

    NASA Astrophysics Data System (ADS)

    Southworth, J.

    2013-09-01

    The eclipsing binary LL Aqr consists of two late-type stars in an eccentric orbit with a period of 20.17 d. We use an extensive light curve from the SuperWASP survey augmented by published radial velocities and UBV light curves to measure the physical properties of the system. The primary star has a mass of 1.167 ± 0.009 M⊙ and a radius of 1.305 ± 0.007 R⊙. The secondary star is an analogue of the Sun, with a mass and radius of 1.014 ± 0.006 M⊙ and 0.990 ± 0.008 R⊙ respectively. The system shows no signs of stellar activity: the upper limit on spot-induced rotational modulation is 3 mmag, it is slowly rotating, has not been detected at X-ray wavelengths, and the calcium H and K lines exhibit no emission. Theoretical stellar models provide a good match to its properties for a sub-solar metal abundance of Z = 0.008 and an age of 2.5 Gyr. Most low-mass eclipsing binary systems are found to have radii larger than expected from theoretical predictions, blamed on tidally-enhanced magnetic fields in these short-period systems. The properties of LL Aqr support this scenario: it exhibits negligible tidal effects, shows no signs of magnetic activity, and matches theoretical models well. Full Tables 1 and 7 are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/557/A119

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

    NASA Technical Reports Server (NTRS)

    Hale, Alan

    1994-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Hale, Alan

    1994-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2007-10-01

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

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

    SciTech Connect

    Kumar, Rohitash; Kumar, Ravindra; Dixit, Ambesh

    2016-05-06

    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.

  10. 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.

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

    NASA Astrophysics Data System (ADS)

    Laughlin, Gregory; Adams, Fred C.

    2000-06-01

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

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

    NASA Astrophysics Data System (ADS)

    Ipatov, S.

    2014-07-01

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

  13. Planetary systems in binaries

    NASA Astrophysics Data System (ADS)

    Takeda, Genya

    In this thesis we investigate the orbital evolution of planets in binaries. Unlike our own Solar System, at least one out of five planetary systems known to date is associated with additional stellar companions. Despite their large distances from the planetary systems, these stellar companions play an important role in significantly altering the planetary architecture over very long timescales. Most of the planets in binaries are found in hierarchical configurations in which a planet orbits around a component of a wide stellar binary. The evolution of such hierarchical triples has been analytically understood through the framework of the Kozai mechanism, in which the orbital eccentricity of a planet secularly grows through angular momentum exchange with the stellar companion. The aim of our first study is to investigate the global effect of stellar companions in exciting planetary eccentricities through the Kozai mechanism, using synthetic eccentricity distributions computed numerically from various initial assumptions motivated by observational studies. As inferred from observations and theoretical planet formation simulations, newly formed planetary systems are more likely to be oligarchic, containing multiple giant planets. However, the long-term evolution of gravitationally coupled planets perturbed by a stellar companion has been little understood in the previous studies. From a large ensemble of numerical integrations of double-planet systems in binaries, we have found that there are various evolutionary classes of multiple planets in binaries compared to simple hierarchical triple systems containing only one planet. Using the Kozai mechanism and the Laplace-Lagrange secular theory, we also provide analytic criteria that can readily predict the secular evolutionary behavior of a pair of planetary orbits in binaries. In the last part of this thesis we discuss an alternative channel of planetary migration induced by a combined effect of dissipative tidal forces

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  15. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  17. 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.

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

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  19. 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.

  20. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  2. 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.

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

    PubMed

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

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I2) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, JSC of 17.29mAcm(-2), open circuit voltage, VOC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Can binary stars test solar models?

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  6. Can binary stars test solar models?

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  7. 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.

  8. 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.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

  12. Multi-Planets in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Pilat-Lohinger, Elke; Haghighipour, Nader; Bazso, Akos

    2017-06-01

    Space missions like Cheops, Tess or Plato will explore the solar neighborhood when searching for other Earth-like worlds. Moreover, observations have shown that many stars build binary or multi-stellar systems which might influence the dynamical behavior of planets moving in such systems where gravitational interactions play an important role. Phenomena like mean motion resonances and secular resonances can be sources of both stability and instability and influence therefore the architecture of a planetary system significantly. In our solar system the two giant planets Jupiter and Saturn also influence the inner part of the planetary system. In this presentation we will show the dynamics of Jupiter-Saturn like configurations in binary stars and we analyse the changes in the dynamical behavior of the planets.

  13. 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.

  14. 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.

  15. Distances to Four Solar Neighborhood Eclipsing Binaries from Absolute Fluxes

    NASA Astrophysics Data System (ADS)

    Wilson, R. E.; Van Hamme, W.

    2009-07-01

    Eclipsing binary (EB)-based distances are estimated for four solar neighborhood EBs by means of the Direct Distance Estimation (DDE) algorithm. Results are part of a project to map the solar neighborhood EBs in three dimensions, independently of parallaxes, and provide statistical comparisons between EB and parallax distances. Apart from judgments on adopted temperature and interstellar extinction, DDE's simultaneous light-velocity solutions are essentially objective and work as well for semidetached (SD) and overcontact binaries as for detached systems. Here, we analyze two detached and two SD binaries, all double lined. RS Chamaeleontis is a pre-main-sequence (MS), detached EB with weak δ Scuti variations. WW Aurigae is detached and uncomplicated, except for having high metallicity. RZ Cassiopeiae is SD and has very clear δ Scuti variations and several peculiarities. R Canis Majoris (R CMa) is an apparently simple but historically problematic SD system, also with weak δ Scuti variations. Discussions include solution rules and strategies, weighting, convergence, and third light problems. So far there is no indication of systematic band dependence among the derived distances, so the adopted band-calibration ratios seem consistent. Agreement of EB-based and parallax distances is typically within the overlapped uncertainties, with minor exceptions. We also suggest an explanation for the long-standing undermassiveness problem of R CMa's hotter component, in terms of a fortuitous combination of low metallicity and evolution slightly beyond the MS.

  16. Binaries and Multiple Stellar Systems

    NASA Astrophysics Data System (ADS)

    Horch, Elliott

    Binary and multiple stellar systems have importance in three main areas of astronomy and astrophysics. First, because of the relatively simple gravitational interaction at work in the case of binary stars, these systems provide a basic check on stellar structure and evolution theory since the masses may be determined through observation. When these masses can be linked to other properties of the two stars, such as luminosity, color, and radius, they can provide very stringent constraints on stellar models. Second, the statistics of binary and multiple star systems provide clues to star formation mechanisms and environmental effects in the galactic gravitational potential and in clusters. Although a number of good results have been obtained in nearby star clusters and associations, knowledge of the field population has been somewhat limited until recently by a lack of large, complete samples of binaries. However, there appears to be a great deal of promise in this area for the coming decade in part due to astrometric satellites such as Hipparcos and Gaia. Third, the binary scenario is invoked to explain several important types of astrophysical phenomena such as Type Ia supernovae, cataclysmic variables, and stellar x-ray sources. Since the first of these mentioned is a standard candle for the extragalactic distance scale, it may even be said binary stars play a minor role in field of cosmology. However, in this chapter, the focus will mainly be on normal stars in binary and multiple-stellar systems. The basic physics of binaries will be reviewed, and the observational methods in use today will be discussed together with their limitations and prospects for the future. Finally, an overview of the current science in the three main areas mentioned where binaries have a significant impact will be given.

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

    NASA Astrophysics Data System (ADS)

    Drobyshevski, Edward M.

    2008-09-01

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

  18. 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.

  19. Trojan Binary Asteroid Systems as Future Mission Targets

    NASA Astrophysics Data System (ADS)

    Bellerose, Julie; Yano, Hajime

    To date, the Jupiter-Sun Lagrangian points are populated with almost 4500 asteroids, for which their formation and history are still debated. In the current work, we look at rationales for a mission to Jovian Trojan asteroids, and discuss the scientific benefits to investigate binary systems and contact binary systems. We summarized the dynamics for a solar sail mission, which is currently thought to go along the Europa Jupiter System Mission (EJSM), and we show a case study of the contact binary Hektor, and its moon S/2006, which offer the most suitable conditions for spacecraft operations. Trojans asteroids offer many opportunities, and we list some of the targets in time.

  20. 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.

  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. 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.…

  3. 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.…

  4. 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

  5. Close binary neutron star systems

    NASA Astrophysics Data System (ADS)

    Marronetti, Pedro

    1999-12-01

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

  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. 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

  8. Formation and Evolution of Binary Systems Containing Collapsed Stars

    NASA Technical Reports Server (NTRS)

    Rappaport, Saul; West, Donald (Technical Monitor)

    2003-01-01

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

  9. Formation and Evolution of Binary Systems Containing Collapsed Stars

    NASA Technical Reports Server (NTRS)

    Rappaport, Saul; West, Donald (Technical Monitor)

    2003-01-01

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

  10. 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.

  11. 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

  12. 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.

  13. New RR Lyrae variables in binary systems

    NASA Astrophysics Data System (ADS)

    Hajdu, G.; Catelan, M.; Jurcsik, J.; Dékány, I.; Drake, A. J.; Marquette, J.-B.

    2015-04-01

    Despite their importance, very few RR Lyrae (RRL) stars have been known to reside in binary systems. We report on a search for binary RRL in the OGLE-III Galactic bulge data. Our approach consists in the search for evidence of the light-travel time effect in so-called observed minus calculated (O-C) diagrams. Analysis of 1952 well-observed fundamental-mode RRL in the OGLE-III data revealed an initial sample of 29 candidates. We used the recently released OGLE-IV data to extend the baselines up to 17 yr, leading to a final sample of 12 firm binary candidates. We provide O-C diagrams and binary parameters for this final sample, and also discuss the properties of eight additional candidate binaries whose parameters cannot be firmly determined at present. We also estimate that ≳ 4 per cent of the RRL reside in binary systems.

  14. 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.

  15. 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.

  16. Orbital Architectures of Planet-Hosting Binary Systems

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    SciTech Connect

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

    2016-03-01

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

  18. The Dusty, Solar Type Spectroscopic Binary BD +20 307

    SciTech Connect

    Fekel, Francis C.; Williamson, Michael H.; Henry, Gregory W.; Zuckerman, B.; Muno, M. P.

    2009-02-16

    The dustiest known main-sequence star, BD +20 307, is actually a double-lined binary with a period of 3.4202 days and a circular orbit. The system is also metal poor with [Fe/H] = -0.4. The components are late-F and early-G dwarfs and have a mass ratio of 1.07. The photometric period of about 3.5 days indicates that the components are synchronously rotating. The metal poor, binary nature invalidates the idea that the object is a very young single star with a warm planet-making dust disk. Instead, the metal poor nature of the system and the lithium abundances of the components argue that the system is likely several billion years old, and so the dust disk results from the recent collision of two planetary mass rocky objects. Thus, BD +20 307 may well be the first known system with planets orbiting a close binary star.

  19. 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.

  20. Terrestrial Planet Formation in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Quintana, Elisa V.; Lissauer, Jack J.

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

  1. 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.

  2. Planet Formation in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Martin, Rebecca

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

  3. Stability of multiplanet systems in binaries

    NASA Astrophysics Data System (ADS)

    Marzari, F.; Gallina, G.

    2016-10-01

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

  4. 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.

  5. The Evolution of Compact Binary Star Systems.

    PubMed

    Postnov, Konstantin A; Yungelson, Lev R

    2014-01-01

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

  6. Classification of close binary systems by Svechnikov

    NASA Astrophysics Data System (ADS)

    Dryomova, G. N.

    The paper presents the historical overview of classification schemes of eclipsing variable stars with the foreground of advantages of the classification scheme by Svechnikov being widely appreciated for Close Binary Systems due to simplicity of classification criteria and brevity.

  7. Mass flow in close binary systems

    NASA Technical Reports Server (NTRS)

    Kondo, Y.; Mccluskey, G. E.

    1976-01-01

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

  8. 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.

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

    PubMed

    Boroson, Todd A; Lauer, Tod R

    2009-03-05

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

  10. Solar ADEPT: Efficient Solar Energy Systems

    SciTech Connect

    2011-01-01

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

  11. 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.

  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. 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.

  14. Stacking Analysis of Binary Systems with HAWC

    NASA Astrophysics Data System (ADS)

    Brisbois, Chad; HAWC Collaboration

    2017-01-01

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

  15. A New Merging Double Degenerate Binary in the Solar Neighborhood

    NASA Astrophysics Data System (ADS)

    Debes, John H.; Kilic, Mukremin; Tremblay, Pier-Emmanuel; López-Morales, Mercedes; Anglada-Escude, Guillem; Napiwotzki, Ralph; Osip, David; Weinberger, Alycia

    2015-05-01

    Characterizing the local space density of double degenerate (DD) binary systems is a complementary approach to broad sky surveys of DDs to determine the expected rates of WD binary mergers, in particular those that may evolve into other observable phenomena such as extreme helium stars, Am CVn systems, and SNe Ia. However, there have been few such systems detected in local space. We report here the discovery that WD 1242-105, a nearby bright WD, is a double-line spectroscopic binary consisting of two degenerate DA WDs of similar mass and temperature, despite it previously having been spectroscopically characterized as a single degenerate. Follow-up photometry, spectroscopy, and trigonometric parallax have been obtained in an effort to determine the fundamental parameters of each component of this system. The binary has a mass ratio of 0.7 and a trigonometric parallax of 25.5 mas, placing it at a distance of 39 pc. The system’s total mass is 0.95 {{M}⊙ } and has an orbital period of 2.85 hr, making it the strongest known gravitational wave source (log h=-20.78) in the mHz regime. Because of its orbital period and total mass, WD 1242-105 is predicted to merge via gravitational radiation on a timescale of 740 Myr, which will most likely not result in a catastrophic explosion. This paper includes data gathered with the 6.5 m Magellan telescopes and the 2.5 m Dupont telescope located at Las Campanas Observatory, Chile.

  16. On the Habitability of Planets in Binary Star Systems

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  17. 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.

  18. Comprehensive Gravity and Dynamics Model Determination of Binary Asteroid Systems

    NASA Astrophysics Data System (ADS)

    Fahnestock, Eugene G.

    2009-09-01

    I present the development of additional tools within the framework of JPL's in-house Mirage / Orbit Determination Program (ODP) software to allow the determination of a comprehensive gravity and dynamics model for any binary asteroid system potentially visited by a spacecraft rendezvous mission. This involves a concurrent global solution for the gravity fields of both components, sufficient parametric description of their fully-coupled translational and rotational dynamics, the spacecraft state, and all other relevant force model parameters. This estimation process primarily uses spacecraft radio tracking data (range and Doppler measurements), supplemented by in-situ imaging observations data types. A solution for the gravity field (gravity analysis) and a simultaneous solution for the spacecraft motion and other system properties has been performed before using the ODP for solitary irregular small solar system bodies (e.g. Eros, visited by the NEAR mission), but never for any closely gravitationally bound pair of irregular small solar system bodies. I am expanding NASA's tool set to allow the latter, in preparation for potential future spacecraft rendezvous missions. This is nontrivial, because of the need to incorporate propagation of the binary system's fully-coupled rigid-body dynamical model either along with the spacecraft state within Mirage/ODP or "offline", followed by interpolating an appropriate "binary dynamics ephemeris” representation. Further, this model optionally incorporates formulations for body gravity fields not previously used in this context, and it can be computationally very expensive. However, successfully performing this model determination at a binary asteroid yields valuable science results concerning internal mass distributions and structures of the components and insight into the system's formation and evolution. In this poster I present my current progress in the development of this capability and results for the quality of science

  19. 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.

  20. 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.

  1. The evolution of ultrashort period binary systems

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  2. Solar energy systems cost

    SciTech Connect

    Lavender, J.A.

    1980-01-01

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

  3. Gravitational wave background from binary systems

    SciTech Connect

    Rosado, Pablo A.

    2011-10-15

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

  4. 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.

  5. New Eclipsing Contact Binary System in Auriga

    NASA Astrophysics Data System (ADS)

    Austin, S. J.; Robertson, J. W.; Justice, C.; Campbell, R. T.; Hoskins, J.

    2004-05-01

    We present data on a newly discovered eclipsing binary system. The serendipitous discovery of this variable star was made by J.W. Robertson analyzing inhomogeneous ensemble photometry of stars in the field of the cataclysmic variable FS Aurigae from Indiana University RoboScope data. We obtained differential time-series BVR photometry during 2003 of this field variable using an ensemble of telescopes including the university observatories at ATU, UCA and joint ventures with amateur observatories in the state of Arkansas (Whispering Pines Observatory and Nubbin Ridge Observatory). The orbital period of this eclipsing system is 0.2508 days. The B-V light curve indicates colors of 1.2 around quadrature, to nearly 1.4 at primary eclipse. Binary star light curve models that best fit the BVR differential photometry suggest that the system is a contact binary overfilling the inner Roche Lobe by 12%, a primary component with a temperature of 4350K, a secondary component with a temperature of 3500K, a mass ratio of 0.37, and an inclination of 83 degrees. We present BVR light curves, an ephemeris, and best fit model parameters for the physical characteristics of this new eclipsing binary system.

  6. 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

  7. 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

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Solar System Dynamics

    NASA Astrophysics Data System (ADS)

    Murray, Carl D.; Dermott, Stanley F.

    2000-02-01

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

  15. Transit Timing Variations In Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Sansone, Eric; Haghighipour, N.

    2012-01-01

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

  16. Solar photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Forney, R. G.

    1978-01-01

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

  17. Parabolic solar systems

    NASA Astrophysics Data System (ADS)

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

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

  18. Solar Electric System

    NASA Technical Reports Server (NTRS)

    1987-01-01

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

  19. Formation of Binaries from Triple Systems

    PubMed Central

    Szebehely, Victor

    1972-01-01

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

  20. 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…

  1. 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…

  2. 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.

  3. 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.

  4. Asteroidal binary systems - Detection and formation

    NASA Astrophysics Data System (ADS)

    Zappala, V.; Scaltriti, F.; Farinella, P.; Paolicchi, P.

    1980-04-01

    Recent occultation data and an analysis of some photometric light curves have shown the possible existence of asteroidal binary systems. A simple geometrical model taking into account mutual shadowing effects shows some peculiar features of the light curve which can be recovered in several previously observed objects. On the other hand, while the rotational period distribution of large asteroids (diameter greater than 200 km) is sharply peaked at about 5-8 hours, the surprisingly higher dispersion towards longer periods for intermediate size objects (diameters between 50 and 150 km) could be connected with a larger probability of binary nature within this class. From a theoretical point of view, the collisional fragmentation of asteroids could originate gravitationally bound fragments, with a tidal transfer of rotational into orbital angular momentum, causing a rapid synchronization of the system. This kind of processes could more easily occur for intermediate objects since: (1) for large ones, very massive colliding bodies are needed for fragmentation, that means a very rare event; and (2) for smaller asteroids, solid state interactions are stronger than the gravitational ones, so that breakage probably causes a complete disruption of the gravitational binding. Further collisional events could disintegrate some systems, so that the present frequency of binary asteroids could be lower than that of the objects whose rotational period was increased by such processes.

  5. 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).

  6. BVRI Photometric Analysis and Spectra of the Dwarf Solar Type Algol Binary, V500 Pegasi

    NASA Astrophysics Data System (ADS)

    Caton, Daniel B.; Samec, Ronald G.; Robb, Russell; Faulkner, Danny R.; Van Hamme, Walter; Clark, Jimmy D.; Shebs, Travis

    2017-06-01

    Observations and analyses of V500 Pegasi taken at the Dark Sky Observatory (DSO), the SARA North Observatory and the Dominion Astrophysical Observatory are presented. V500 Peg is an eclipsing binary with a period of 0.57983 d. The light curves have the appearance of a detached or semi-detached binary. Spectroscopy reveals that it is of F5V-type. A continuous 14-year period study may show an orbital period increase is occurring. This may be due to weak matter transfer with the primary component as the gainer. The light curve has a large difference in primary and secondary amplitudes that is typical of this class of binary. The final solution shows a total secondary eclipse. The solution is that of a classical Algol system (semi-detached with the secondary component filling its Roche lobe), but it is of solar type, with a magnetic spot. This may mean that magnetic braking is interfering in the nuclear evolution. The secondary component has a temperature of ˜4700 K (K3), which means it is somewhat overluminous for its mass.

  7. 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.

  8. 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.

  9. 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.

  10. Solar System: Lethal billiards

    NASA Astrophysics Data System (ADS)

    Claeys, Philippe; Goderis, Steven

    2007-09-01

    A huge collision in the asteroid belt 160 million years ago sent fragments bagatelling around the inner Solar System. One piece might have caused the mass extinction that wiped out the dinosaurs 65 million years ago.

  11. Solar energy control system

    NASA Astrophysics Data System (ADS)

    Currie, J. R.

    1981-12-01

    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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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?

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. The Algol binary system KZ Pavonis revisited

    NASA Astrophysics Data System (ADS)

    Sürgit, D.; Erdem, A.; Budding, E.

    2010-09-01

    We present results from analysing new spectroscopic and photometric observations of the KZ Pav (IDS 20490-7048 A-BC) multiple system. High-resolution spectra were taken at the Mt John University Observatory in 2007 and 2008. Radial velocities for the close binary were determined from cross-correlation and spectral disentangling methods. The resulting orbital elements are a1 sin i = 0.0103 +/- 0.0001au, a2 sin i = 0.0158 +/- 0.0001 au, M1 sin3i = 1.598 +/- 0.006 Msolar and M2 sin3i = 1.045 +/- 0.006 Msolar. The close binary components rotated synchronously according to their MgI (5183.6 Å) line profiles. Four photometric data sets (1988-89 BV, 1998 V, Hipparcos and 2006 BVRI) were modelled with modern light-curve synthesis methods. The radial velocity models, including proximity effects, give the close binary mass ratio as 0.641 +/- 0.003. The combination of the photometric light and radial velocity data gives the following absolute parameters: M1 = 1.70 +/- 0.02 Msolar, M2 = 1.09 +/- 0.03 Msolar, R1 = 1.74 +/- 0.01 Rsolar, R2 = 1.94 +/- 0.02 Rsolar, L1 = 5.86 +/- 0.81 Lsolar and L2 = 2.32 +/- 0.40 Lsolar. The distance to KZ Pav is 115 +/- 8 pc from our analysis, taking into account interstellar extinction. The orbital period of the close binary, from times of minimum data covering nearly one century, indicates a quasi-sinusoidal form superimposed on a downward parabola. The secular period decrease was interpreted in terms of the combined effects of mass transfer and loss. The sinusoidal component may reflect a light-time effect from either an unseen component or higher order terms in perturbations from the BC system, or perhaps an internal magnetic field rearrangement (Applegate type) mechanism. The orbits of the A-BC and B-C systems are considered against historic astrometric measurements.

  3. 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.

  4. 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.

  5. 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.

  6. Binary-metal perovskites toward high-performance planar-heterojunction hybrid solar cells.

    PubMed

    Zuo, Fan; Williams, Spencer T; Liang, Po-Wei; Chueh, Chu-Chen; Liao, Chien-Yi; Jen, Alex K-Y

    2014-10-08

    A simple, low temperature solution process for Pb/Sn binary-metal perovskite planar-heterojunction solar cells is demonstrated. Sn inclusion substantially influences the band-gap, crystallization kinetics, and thin-film formation leading to a broadened light absorption and enhanced film coverage on ITO/PEDOT:PSS. As a result, the optimized device shows a PCE exceeding 10%, which is the best result for binary-metal perovskite solar cells so far. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 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.

  8. Radio emission from RS CVn binary systems

    SciTech Connect

    Doiron, D.J.

    1984-01-01

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

  9. Solar 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.

  10. A detached binary system BK Pegasi

    NASA Astrophysics Data System (ADS)

    Demircan, Osman; Kaya, Yalcin; Tufekcioglu, Zeki

    1994-12-01

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

  11. 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.

  12. 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.

  13. 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.

  14. A solution for the binary system V1373 Orionis

    NASA Astrophysics Data System (ADS)

    Hauck, Norbert

    2016-02-01

    Binary system V1373 Ori (HD 36107) has been investigated in the photometric passbands VIc and by spectroscopy (radial velocities). Modelling of the data delivered a single and consistent solution for a detached configuration consisting of a large K-type giant primary component having a radius of 39.40 ± 0.43 Rsun and a mass of 1.132 ± 0.043 Msun, and an invisible dwarf secondary component having a mass of 0.661 ± 0.025 Msun. The red giant fits into a stellar model for a moderately sub-solar metallicity of Z = 0.008. [English and German online-version available under www.bav-astro.eu/rb/rb2016-2/4.html].

  15. 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…

  16. 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…

  17. 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.

  18. The organic Solar System

    NASA Astrophysics Data System (ADS)

    Gibb, Bruce C.

    2015-05-01

    In the second of two essays looking at organic chemistry that can be found in the Solar System, Bruce C. Gibb focuses on the gas and ice giants as well as their satellites -- concluding the tour on Saturn's fascinating moon Titan.

  19. Solar System Speculations

    NASA Astrophysics Data System (ADS)

    Comins, Neil F.

    2002-05-01

    This is an excerpt from Neil F. Comins' book titled Heavenly Errors. The author describes some common misconceptions about astronomy, many of which pertain to objects in our solar system. Evidence from recent space missions dispels the mistakes. The author is a professor of physics and astronomy at the University of Maine.

  20. 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…

  1. 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…

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

    Atmospheric Science Data Center

    2016-06-14

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

  3. Our Solar System

    NASA Astrophysics Data System (ADS)

    Coates, Andrew

    2005-10-01

    Up until the dark ages, humankind knew of six planets including our own. The invention of the telescope, and the beginnings of scientific thought on orbits and planetary motion, were in the seventeenth century. The next three centuries added Uranus, Neptune and Pluto to the known list as well as the many moons, asteroids and comets that we know today. It is only in the latter part of the 20th century that we have been privileged to carry out in-situ exploration of the planets, comets and the solar wind's realm and to begin to understand the special conditions on Earth which meant that life started here. This is leading to a detailed view of the processes which have shaped our solar system. Here, we briefly review our current knowledge of the solar system we inhabit. We discuss the current picture of how the solar system began. Important processes at work, such as collisions and volcanism, and atmospheric evolution, are discussed. The planets, comets and asteroids are all discussed in general terms, together with the important discoveries from space missions which have led to our current views. For each of the bodies we present the current understanding of the physical properties and interrelationships and present questions for further study. The significance of recent results, such as proof that there were one standing bodies of water on Mars, and the discovery of what appears to be an Oort cloud comet, are put into context. What is in store for planetary exploration and discoveries in the future? Already a sequence of Mars exploration missions, a landing on a comet, further exploration of Saturn and the Jovian system and the first flyby of Pluto are planned. We examine the major scientific questions to be answered. We also discuss the prospects for finding other Earth-like planets elsewhere, and for finding extraterrestrial life both within and beyond our own solar system.

  4. WISE Solar System Science

    NASA Astrophysics Data System (ADS)

    McMillan, Robert S.; WISE Team

    2009-05-01

    WISE will survey the solar system to unprecedented sensitivity and resolution in its wavelength bands. Corresponding to the peak of thermal emission of many solar system bodies and particles, the 12 and 23 micron bands will detect asteroids, comets, comet debris trails, and zodiacal dust to several AU from the sun. Some of the objects and material will be too dark to have been detected by visible-light surveys, and previous infrared telescopes in space have either not covered the whole sky or have had far less sensitivity. As a consequence, WISE will explore the spatial distributions and thermal properties of the objects and material populating the inner solar system efficiently and without bias favoring bright albedos. At the temperatures dominant in the inner solar system, IR flux is more directly related to the size of the emitter than is visible flux, so the detections of asteroids by WISE will be closer to a diameter-limited census. Yet combined with visual magnitudes, WISE data can yield albedos. Orbital migration driven by thermal reradiation of absorbed sunlight depends on size and albedo, and affects the evolution of the orbits of asteroids. The distributions of sizes of asteroids, and the dependences of those distributions with orbital parameters to be uncovered by WISE will therefore be evidence of the processes that brought the solar system to its current arrangement. Dark asteroids that approach Earth are especially menacing if they have evaded detection by ground-based surveys, so WISE will refine knowledge of the impact hazard. WISE data will help the study of the formation of cometary comae, tails, and dust trails, and the rate of mass loss from comets. Finally, the zodiacal dust bands, being the asteroidal component of the zodiacal dust, hold the key to determining the magnitude of the asteroid component.

  5. 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.

  6. 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

  7. Future solar system missions

    NASA Technical Reports Server (NTRS)

    Briggs, Geoffrey A.

    1990-01-01

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

  8. 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

  9. 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.

  10. Solar System, in Perspective

    NASA Image and Video Library

    2017-09-27

    This artist's concept puts solar system distances in perspective. The scale bar is in astronomical units, with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the sun to the Earth, which is about 93 million miles or 150 million kilometers. Neptune, the most distant planet from the sun, is about 30 AU. Informally, the term "solar system" is often used to mean the space out to the last planet. Scientific consensus, however, says the solar system goes out to the Oort Cloud, the source of the comets that swing by our sun on long time scales. Beyond the outer edge of the Oort Cloud, the gravity of other stars begins to dominate that of the sun. The inner edge of the main part of the Oort Cloud could be as close as 1,000 AU from our sun. The outer edge is estimated to be around 100,000 AU. NASA's Voyager 1, humankind's most distant spacecraft, is around 125 AU. Scientists believe it entered interstellar space, or the space between stars, on Aug. 25, 2012. Much of interstellar space is actually inside our solar system. It will take about 300 years for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it. Alpha Centauri is currently the closest star to our solar system. But, in 40,000 years, Voyager 1 will be closer to the star AC +79 3888 than to our own sun. AC +79 3888 is actually traveling faster toward Voyager 1 than the spacecraft is traveling toward it. The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif. Caltech manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington. For more information about Voyager, visit: www.nasa.gov/voyager and voyager.jpl.nasa.gov . Image credit: NASA/JPL-Caltech NASA image use policy. NASA Goddard Space Flight Center enables

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

    NASA Astrophysics Data System (ADS)

    Chambers, John E.

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

  12. 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.

  13. The Evolution of Compact Binary Star Systems.

    PubMed

    Postnov, Konstantin A; Yungelson, Lev R

    2006-01-01

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

  14. 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).

  15. 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.

  16. On solar system nomenclature

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1976-01-01

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

  17. On solar system nomenclature

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1976-01-01

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

  18. Fixed solar collection system

    SciTech Connect

    Tipton, H.R.

    1984-07-31

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

  19. 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.

  20. NASA Solar System Exploration Website

    NASA Astrophysics Data System (ADS)

    Sohus, A. M.

    2000-10-01

    The NASA Solar System Exploration website, http://solarsystem.nasa.gov, sponsored by the Science Director for Solar System Exploration, Office of Space Science, NASA, is a gateway to information about our solar system and NASA's missions and research to understand it. The site has been designed for easy navigation and is becoming known as a resource for educators, students, media, and publishers. Major subsections include latest news, newest images, a link to NASA research opportunities in space science, technology, missions, information on solar system bodies, the people who are involved in solar system exploration, and the history of solar system exploration in the space age. There is also a link to the NASA Solar System Exploration Education and Public Outreach Forum. Members of the planetary science community are invited to contribute suggestions, comments, and content to the website, including links to their own institutions and research.

  1. HD 50975: a yellow supergiant in a spectroscopic binary system

    NASA Astrophysics Data System (ADS)

    Sperauskas, J.; Začs, L.; Raudeliūnas, S.; Musaev, F.; Puzin, V.

    2014-10-01

    Context. Recent detection of a yellow supergiant star as a possible progenitor of a supernova has posed serious questions about our understanding of the evolution of massive stars. Aims: The spectroscopic binary star HD 50975 with an unseen hot secondary was studied in detail with the main goal of estimating fundamental parameters of both components and the binary system. Methods: A comprehensive analysis and modeling of collected long-term radial velocity measurements, photometric data, and spectra was performed to calculate orbital elements, atmospheric parameters, abundances, and luminosities. The spectrum in an ultraviolet region was studied to clarify the nature of an unseen companion star. Results: The orbital period was found to be 190.22 ± 0.01 days. The primary star (hereafter HD 50975A) is a yellow supergiant with an effective temperature Teff = 5900 ± 150 K and a surface gravity of log (g) = 1.4 ± 0.3 (cgs). The atmosphere of HD 50975 A is slightly metal deficient relative to solar, [Fe/H] = -0.26 ± 0.06 dex. Abundances of Si and Ca are close to the scaled solar composition. The r-process element europium is enhanced, [Eu/H] = + 0.61 ± 0.07. The bolometric magnitude of the primary was estimated to be Mbol = -5.5 ± 0.3 mag and its mass to be 10.7 ± 2.0 M⊙. The secondary (hereafter HD 50975B) is a hot star of spectral type ~B2 near ZAMS with an effective temperature of Teff ≃ 21 000 K and a mass M ≃ 8.6 M⊙. The distance between HD 50975A and B is about 370 R⊙. The binary star is near a semi-detached configuration with a radius, RA ≃ 107 R⊙, and a radius of Roche lobe of about 120 R⊙ for the primary star. The reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/570/A3

  2. Mass transfer and disc formation in AGB binary systems

    NASA Astrophysics Data System (ADS)

    Chen, Zhuo; Frank, Adam; Blackman, Eric G.; Nordhaus, Jason; Carroll-Nellenback, Jonathan

    2017-07-01

    We investigate mass transfer and the formation of discs in binary systems using a combination of numerical simulations and theory. We consider six models distinguished by binary separation, secondary mass and outflow mechanism. Each system consists of an asymptotic giant branch (AGB) star and an accreting secondary. The AGB star loses its mass via a wind. In one of our six models, the AGB star incurs a short period of outburst. In all cases, the secondary accretes part of the ejected mass and also influences the mass-loss rate of the AGB star. The ejected mass may remain gravitationally bound to the binary system and form a circumbinary disc, or contribute to an accretion disc around the secondary. In other cases, the ejecta will escape the binary system. The accretion rate on to the secondary changes non-linearly with binary separation. In our closest binary simulations, our models exemplify the wind Roche lobe overflow while in our wide binary cases, the mass transfer exhibits Bondi-Hoyle accretion. The morphologies of the outflows in the binary systems are varied. The variety may provide clues to how the late AGB phase influences planetary nebula shaping. We employ the adaptive-mesh-refinement code astrobear for our simulations and include ray tracing, radiation transfer, cooling and dust formation. To attain the highest computational efficiency and the most stable results, all simulations are run in the corotating frame.

  3. 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.

  4. 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.

  5. Solar Powered Refrigeration System

    NASA Astrophysics Data System (ADS)

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

    2002-09-01

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

  6. 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.

  7. 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.

  8. High Efficiency Pb-In Binary Metal Perovskite Solar Cells.

    PubMed

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

    2016-08-01

    Mixed Pb-In perovskite solar cells are fabricated by using lead(II) chloride and indium(III) chloride with methylammonium iodide. A maximum power conversion efficiency as high as 17.55% is achieved owing to the high quality of perovskites with multiple ordered crystal orientations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Early Solar System Chronology

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  10. 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.

  11. 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.

  12. Concentrating Solar Power Systems

    NASA Astrophysics Data System (ADS)

    Pitz-Paal, R.

    2017-07-01

    Development of Concentrating Solar Power Systems has started about 40 years ago. A first commercial implementation was performed between 1985 and 1991 in California. However, a drop in gas prices caused a longer period without further deployment. It was overcome in 2007 when new incentive schemes for renewables in Spain and the US enabled a commercial restart. In 2016, almost 100 commercial CSP plants with more than 5GW are installed worldwide. This paper describes the physical background of CSP technology, its technical characteristics and concepts. Furthermore, it discusses system performances, cost structures and the expected advancement.

  13. 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.

  14. 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.

  15. 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

  16. 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

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

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-Chul

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

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

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-CHul

    2015-08-01

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

  19. Detection of X-ray emission from the PSR 1259-63/SS 2883 binary system

    NASA Technical Reports Server (NTRS)

    Cominsky, Lynn; Roberts, Mallory; Johnston, Simon

    1994-01-01

    Nonpulsed but variable X-ray emission has been detected from the binary system containing the radio pulsar PSR 1259-63 during two pointed ROSAT observations, taken 5 months apart. This 47.7 ms radio pulsar is in a highly eccentric (epsilon approximately 0.85) binary system with the 10-15 solar mass Be star SS 2883. It is the first radio pulsar found to be in a binary system with a massive main-sequence companion; it is also the most highly eccentric binary system known to contain a neutron star. The level of X-ray flux detected in the ROSAT observations has increased with orbital phase by a factor of at least 10 between 1992 February and 1993 February. The X-ray flux is significantly greater than expected from the Be star's corona and seems likely to originate either from low-level stellar wind accretion onto the neutron star or from the shock between the stellar wind and the relativistic pulsar wind. The system may be the progenitor of the more slowly rotating Be X-ray binary pulsar systems.

  20. 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.

  1. Solar-System Ephemeris Toolbox

    NASA Technical Reports Server (NTRS)

    Walker, Charles F.

    2005-01-01

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

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

    SciTech Connect

    Gullikson, Kevin; Dodson-Robinson, Sarah

    2013-01-01

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

  3. Photometric studies of close binary systems

    NASA Astrophysics Data System (ADS)

    Varricatt, Watson P.

    2000-06-01

    Two eclipsing binary stars of the Algol type, RZ Cassiopeiae and R Canis Majoris, are observed in the near IR photometric bands J and K and the light curves are analysed using the Wilson - Devinney light curve synthesis program. Existing light curves of these systems in the optical bands are also analysed with the same program. In the case of RZ Cas, the J & K band light curves gave higher values of bolometric albedo of the secondary star, compared to what is expected theoretically. Also the near IR light curves yielded lower values of derived values of the temperature of the secondary star T2. These two factors are considered as the indication of the presence of a dark spot on the back side of the secondary star and the values of the spot parameter are derived using the model. For R CMa, T2 was found to increase towards the near IR wavelengths, from the optical bands. This is interpreted as due to the presence of localized gas in the system. Also T2 derived from the Hα light curves is found to be higher than that derived from the neighbouring bands. This is explained as due to the difference in the photospheric absorption of Hα in the photospheres of the primary and the secondary. The moments of primary minima follow the periodic O-C curve observed for R CMa, giving more faith in the presence of a third body in the system, which was proposed before. But the nature of the third body, if present, is still uncovered.

  4. Planetesimal Accretion in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Marzari, F.; Scholl, H.

    2000-11-01

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

  5. 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.

  6. 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.

  7. 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.

  8. WISE Solar System Science

    NASA Astrophysics Data System (ADS)

    Mainzer, Amanda K.; Wright, E. L.; Bauer, J. M.; Cutri, R.; Dailey, J.; Grav, T.; Masiero, J.; McMillan, R. S.; Tholen, D.; Walker, R.

    2010-10-01

    In early January, 2010, the Wide-field Infrared Survey Explorer (WISE) began imaging the entire sky with sensitivities in the mid-IR hundreds of times greater than previous surveys. WISE consists of a 40 cm cryogenically-cooled telescope taking simultaneous images at 3.4, 4.6, 12 and 22 microns. WISE has recently completed its first full survey of the sky and is expected to continue flight operations through November. Although WISE itself is an astrophysics mission, NASA's Planetary Science Mission Directorate has funded an enhancement to the WISE project, called "NEOWISE", that is dedicated to serving the individual exposures and extracted source lists, providing an interface for small bodies based on orbital elements, and discovering new moving objects. The WISE bandpasses sample the flux from most inner-Solar System bodies near the peak of their thermal emission, making the survey extremely efficient at detecting and discovering solar system objects. Infrared observations are sensitive to the low albedo objects that are preferentially missed by optical surveys. By the time the cryogen is depleted, NEOWISE will observe 700 Near-Earth Objects (NEOs), 200,000 Main Belt Asteroids, 200 comets, and 1500 Trojan asteroids. The NEOWISE dataset represents a treasure trove of new information on small bodies in our Solar System that will leave a legacy for decades to come. We will present preliminary results of the NEOWISE survey from the first six months of flight operations and will offer an introduction to the community on how to access the data when they become available next year. This research was funded in part by the NASA (ROSES) NEOO program. This work makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of UCLA and JPL/Caltech, funded by NASA.

  9. 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.

  10. Equilibrium, stability, and orbital evolution of close binary systems

    NASA Technical Reports Server (NTRS)

    Lai, Dong; Rasio, Frederic A.; Shapiro, Stuart L.

    1994-01-01

    We present a new analytic study of the equilibrium and stability properties of close binary systems containing polytropic components. Our method is based on the use of ellipsoidal trial functions in an energy variational principle. We consider both synchronized and nonsynchronized systems, constructing the compressible generalizations of the classical Darwin and Darwin-Riemann configurations. Our method can be applied to a wide variety of binary models where the stellar masses, radii, spins, entropies, and polytropic indices are all allowed to vary over wide ranges and independently for each component. We find that both secular and dynamical instabilities can develop before a Roche limit or contact is reached along a sequence of models with decreasing binary separation. High incompressibility always makes a given binary system more susceptible to these instabilities, but the dependence on the mass ratio is more complicated. As simple applications, we construct models of double degenerate systems and of low-mass main-sequence star binaries. We also discuss the orbital evoltuion of close binary systems under the combined influence of fluid viscosity and secular angular momentum losses from processes like gravitational radiation. We show that the existence of global fluid instabilities can have a profound effect on the terminal evolution of coalescing binaries. The validity of our analytic solutions is examined by means of detailed comparisons with the results of recent numerical fluid calculations in three dimensions.

  11. RR Lyrae binary systems in the Galactic bulge

    NASA Astrophysics Data System (ADS)

    Hajdu, Gergely; Catelan, Márcio

    2017-09-01

    The possibility of a direct mass measurement of RR Lyrae variable stars in binary systems has remained elusive for many years, due to the apparent paucity of such systems. Motivated by our recent success of finding a population of high confidence candidates, we have been continuing the search for RR Lyrae variables in binary systems towards the Galactic bulge. We describe the preliminary results of our project in these proceedings.

  12. Solar System Ambassadors Program

    NASA Astrophysics Data System (ADS)

    Ferrari, K.

    2004-11-01

    The Solar System Ambassadors Program is an informal education program designed to work with motivated volunteers across the nation. These competitively selected volunteers communicate information about NASA and JPL's space exploration plans and discoveries to members of their local communities. Currently, there are 375 volunteer Solar System Ambassadors in all 50 states, Puerto Rico and the District of Columbia who seek to inspire general public audiences with information about NASA's space exploration missions. Each Ambassador participates in web-based telecon 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. In addition to on-line information, Ambassadors are given DVDs, slides, pamphlets, posters, postcards and lithographs in support of their public engagement.. In addition to participating in on-line trainings with Ambassadors, scientists have the opportunity to partner with, and mentor Ambassadors to strengthen their knowledge of space science and exploration, thereby improving the message that goes out to the general public through these enthusiastic volunteers. Integrating volunteers across the country in an informal education program helps optimize project funding set aside for education and outreach purposes and establishes a nationwide network of regional contacts.

  13. Solar heat storage system

    SciTech Connect

    Thomason, H.E.; Thomason, H.J.

    1983-01-25

    In a solar heating system, using liquid for heat-transfer or heat-storage or both, the liquid may be lost slowly due to a leaky pipe connection, or a cracked or split absorber plate or collector pipes attached to the absorber of a closed type of collector, by evaporation through broken solar collector glazing of a trickle-flow collector, or such. A number of schemes have been proposed to provide makeup liquid. One is to allow makeup liquid, such as water, to flow backward from a large heat-storage vessel used during the winter to a smaller one which is the only one in use during the summer. That scheme was disclosed in a patent application filed by dr. Harry E. Thomason way back in 1961. However, the backflow-connecting pipe had no check valve in it and therefore was of limited value. The present invention resides in several features including placing a check valve in the connecting pipe, and/or placing a flow-restricting device in the interconnecting pipes, and/or using a hole semi-check valve or lightly-loaded pressure-relief valve in the piping, or such, to increase the value of the system as will become apparent hereinafter.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Fuzzy rank functions in the set of all binary systems.

    PubMed

    Kim, Hee Sik; Neggers, J; So, Keum Sook

    2016-01-01

    In this paper, we introduce fuzzy rank functions for groupoids, and we investigate their roles in the semigroup of binary systems by using the notions of right parallelisms and [Formula: see text]-shrinking groupoids.

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

    NASA Astrophysics Data System (ADS)

    De Donder, E.; Vanbeveren, D.

    2002-03-01

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

  20. 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.

  1. 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

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

    PubMed

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

    2016-11-09

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  4. Milankovitch cycles of terrestrial planets in binary star systems

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan

    2016-12-01

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

  5. 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

  6. 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…

  7. 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…

  8. 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.

  9. Resolving sdB Binary Systems with Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Ostensen, R.; Heber, U.; Maxted, P.

    2005-07-01

    A snapshot survey of spectroscopic subdwarf B plus main sequence binaries is underway, using high resolution infrared imaging with the NAOMI adaptive optics system at the William Herschel Telescope on La Palma. It is well known that a disproportionally large fraction of the field sdB stars are found in binary systems, and both interacting binary and single star evolutionary scenarios have been proposed for their origin. In the first case, all spectroscopic binaries containing sdBs need to have small separations of the order of 0.1 AU or less, in the other the binaries should have about the same distribution of separations as found for normal stars, i.e. they should be mostly in wide systems. About 100 sdB binary systems brighter than MV=14.5 are known and have spectroscopic distances between 200 pc and 1200 pc. More than 30% of them should be resolvable on short exposure J-band AO images if the non-interacting evolutionary scenario holds, none in the alternative case. Hence a snapshot survey should yield decisive constraints for the origin of sdB stars.

  10. 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.

  11. 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.

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

    SciTech Connect

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

    2016-03-01

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

  13. 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.

  14. 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.

  15. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1981-01-01

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

  16. 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.

  17. Towards A Complete Census of the Solar-Type Binaries in the Young Open Cluster M37

    NASA Astrophysics Data System (ADS)

    Geller, Aaron M.; Meibom, Soren; Barnes, Sydney A.; Mathieu, Robert D.

    2012-08-01

    Binary stars govern the dynamical evolution of star clusters and determine the formation rates and mechanisms for exotic stars like blue stragglers and X-ray sources. Understanding the near-primordial (after removal of the natal gas) binary population of star clusters is of primary importance for dynamical models of star clusters, which have the potential to revolutionize our understanding of star cluster evolution. Yet the binary frequencies and distributions of binary orbital parameters (period, eccentricity, etc.) for young coeval stellar populations are poorly known, due to a lack of necessary observations. Time-series radial-velocity surveys are essential for identifying and characterizing binary populations. Using WIYN/Hydra data, we have already identified a nearly complete sample of 329 solar-type (1.5 <=M [M_⊙] <=1.0) candidate members in the young (~540 Myr) open cluster M37. Of these stars, 82 show significant radial-velocity variability, indicative of a binary companion. Kinematic orbital solutions are crucial to define the initial binary conditions critical for dynamical star cluster models, and to understand how binaries affects stellar rotational evolution. As we have already identified the binaries in M37, we have a unique opportunity to add significantly to our knowledge of young binaries with minimal additional telescope time. We propose to initiate a WIYN/Hydra multi-epoch radial-velocity survey of the 82 velocity variables in M37.

  18. 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.

  19. ABSOLUTE PROPERTIES OF THE HIGHLY ECCENTRIC, SOLAR-TYPE ECLIPSING BINARY HD 74057

    SciTech Connect

    Sowell, James R.; Henry, Gregory W.; Fekel, Francis C. E-mail: gregory.w.henry@gmail.com

    2012-01-15

    We have obtained Stroemgren b and y differential photometric observations of the solar-type eclipsing binary HD 74057 plus follow-up high-resolution, red wavelength spectroscopic observations. The system has an orbital period of 31.2198 days, a high eccentricity of 0.47, and is seen almost exactly edge on with an inclination of 89.{sup 0}8. The two main-sequence G0 stars are nearly identical in all physical characteristics. We used the Wilson-Devinney program to obtain a simultaneous solution of our photometric and spectroscopic observations. The resulting masses of the components are M{sub 1} = 1.138 {+-} 0.003 M{sub Sun} and M{sub 2} = 1.131 {+-} 0.003 M{sub Sun }, and the radii are R{sub 1} = 1.064 {+-} 0.002 R{sub Sun} and R{sub 2} = 1.049 {+-} 0.002 R{sub Sun }. The effective temperatures are 5900 K (fixed) and 5843 K, and the iron abundance, [Fe/H], is estimated to be +0.07. A comparison with evolutionary tracks suggests that the system may be even more metal rich. The components rotate with periods of 8.4 days, significantly faster than the predicted pseudosynchronous period of 12.7 days. We see evidence that one or both components have cool spots. Both stars are close to the zero-age main sequence and are about 1.0 Gyr old.

  20. 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.

  1. 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.

  2. 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.

  3. Constraining the orbits of young binary systems with ALMA

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  4. The formation and evolution of eccentric binary systems

    NASA Astrophysics Data System (ADS)

    Davis, Philip

    2014-09-01

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

  5. 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.

  6. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  9. Solar Radiation Alert System

    DTIC Science & Technology

    2005-07-01

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

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

    PubMed

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

    2015-02-04

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

  11. 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

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

    NASA Astrophysics Data System (ADS)

    Antelis, Javier M.; Moreno, Claudia

    2017-01-01

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

  13. Electrical Resistivity of Ten Selected Binary Alloy Systems.

    DTIC Science & Technology

    1981-04-01

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

  14. 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.

  15. 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.

  16. Exobiology in Solar System Exploration

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  17. 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.

  18. 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; hide

    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.

  19. Period change of a contact binary system RW Comae Berenices

    NASA Astrophysics Data System (ADS)

    Maithong, Wiraporn; Phao-ai, Parinda

    2017-08-01

    In this work, we studied about the period change of a contact binary system RW Comae Berenices. The binary system was observed on March 9th, 2016 by the 105 mm diameter of a refraction telescope with the DSLR digital camera at the Regional Observatory for the Public Nakhon Ratchasima, Thailand. The photometry used the IRIS program. The period change was analyzed by used the O-C diagram. The result shows that the period of the RW Comae Berenices is increasing with 1.89×10-3 seconds/year.

  20. Orbital evolution of eccentric interacting binary star systems

    NASA Astrophysics Data System (ADS)

    Sepinsky, Jeremy Francis

    2009-06-01

    We provide a comprehensive description of the long-term (secular) orbital evolution of eccentric interacting binary systems. The evolution of circular interacting binary systems is a well studied phenomenon, but observations have shown the existence of a small but significant number of eccentric interacting binary systems. We begin by extending the commonly accepted Roche formalism for binary interacting to include eccentric orbits and asynchronously rotating stars. Using this, we calculate orbital trajectories for particles ejected from a Roche lobe-filling donor star at the periastron of the eccentric orbit. These particles admit of three possible trajectories: direct impact onto the secondary star, self accretion back onto the donor star, and the formation of a disk about the accretor. We provide a proscription for determining a priorithe trajectory of the particle given the initial system parameters, as well as describe the secular evolution of the system for each of the three cases described above. We find that these orbital evolution timescales are comparable to the mass transfer timescale which can be significantly longer than expected from the literature. Furthermore, while it is commonly assumed that any mass transfer interactions will act to circularize the orbit, we find that there are regimes of parameter space where mass transfer can cause an increase in eccentricity, and can do so at a timescale comparable to the circularization timescale created by tidal interactions. The formalism presented here can be incorporated into binary evolution and population synthesis models to create a self-consistent treatment of mass transfer in eccentric binaries.

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  2. Orbit determination of close binary systems using lucky imaging

    NASA Astrophysics Data System (ADS)

    Rica, F. M.; Barrena, R.; Vázquez, G.; Henríquez, J. A.; Hernández, F.

    2012-01-01

    We present relative positions of visual binaries observed in 2009 with the FastCam 'lucky-imaging' camera mounted on the 1.5-m Carlos Sánchez Telescope at the Observatorio del Teide. We obtained 424 CCD observations (averaged in 198 mean relative positions) of 157 binaries with angular separations in the range 0.14-15.40 arcsec, with a median separation of 0.51 arcsec. For a given system, each CCD image represents the sum of the best 10-25 per cent images from 1000-5000 short-exposure frames. Derived internal errors were 7 mas in ρ and 1?2 (9 mas) in θ. When comparing to systems with very well known orbits, we find that the rms deviation in ρ residuals is 23 mas, while the rms deviation in θ residuals is 0?73/ρ. We confirmed 18 Hipparcos binaries and we report new companions to BVD 36 A and J 621 B. For binaries with preliminary orbital parameters, the relative radial velocity was estimated as well. We also present four new revised orbits computed for LDS 873, BU 627 A-BC, BU 628 and HO 197 AB. This work discusses the first results on visual binaries using the FastCam lucky-imaging camera.

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

    NASA Astrophysics Data System (ADS)

    Barman, S. K.

    1993-03-01

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

  4. Binary systems: implications for outflows & periodicities relevant to masers

    NASA Astrophysics Data System (ADS)

    Singh, Nishant K.; Deshpande, Avinash A.

    2012-07-01

    Bipolar molecular outflows have been observed and studied extensively in the past, but some recent observations of periodic variations in maser intensity pose new challenges. Even quasi-periodic maser flares have been observed and reported in the literature. Motivated by these data, we have tried to study situations in binary systems with specific attention to the two observed features, i.e., the bipolar flows and the variabilities in the maser intensity. We have studied the evolution of spherically symmetric wind from one of the bodies in the binary system, in the plane of the binary. Our approach includes the analytical study of rotating flows with numerical computation of streamlines of fluid particles using PLUTO code. We present the results of our findings assuming simple configurations, and discuss the implications.

  5. Binary systems: implications for outflows and periodicities relevant to masers

    NASA Astrophysics Data System (ADS)

    Singh, Nishant K.; Deshpande, Avinash A.

    Bipolar molecular outflows have been observed and studied extensively in the past, but some recent observations of periodic variations in maser intensity pose new challenges. Even quasi-periodic maser flares have been observed and reported in the literature. Motivated by these data, we have tried to study situations in binary systems with specific attention to the two observed features, i.e., the bipolar flows and the variabilities in the maser intensity. We have studied the evolution of spherically symmetric wind from one of the bodies in the binary system, in the plane of the binary. Our approach includes the analytical study of rotating flows with numerical computation of streamlines of fluid particles using PLUTO code. We present the results of our findings assuming simple configurations, and discuss the implications.

  6. Dynamical Evolution and Momentum Transfer for Binary Asteroid Systems

    NASA Astrophysics Data System (ADS)

    Bellerose, Julie

    Over the past decade, robotic missions have been sent to small bodies, providing a basic understanding of their environment. Some of these small systems are found to be in pairs, orbiting each other, which are thought to represent about 16% of the near-Earth asteroid population. It is fair to assume that a mission will target a binary asteroid system in the near future as they can enable scientific insight into both the geology and dynamics of asteroids. In previous work, the dynamical evolution of binary systems was investigated for an ellipsoidsphere model. From the dynamics of two celestial bodies, equilibrium configurations and their stability were analyzed. For a given value of angular momentum, it was shown that there are in general two relative equilibrium configurations which are opposite in stability. When perturbations are introduced, we found that the equilibrium states are the minimum energy points of nearby periodic families. General dynamics from unstable to stable configurations were investigated for binaries in close proximity. Accounting for the dynamics of binaries, the dynamics of particles in this gravitational field were also studied. The location of the analogue Lagrangian points and energy associated with them were characterized. The L1 region is a key element for transfers between the bodies. It was shown that L1 can be situated between or inside the bodies depending on the free parameters of the system modifying the transfer possibilities since L1 has a hyperbolic manifold associated with it. In the current work, we look at the L1 region for binary system where the bodies are in relative equilibrium, close to each other. We find that L1 transits from outside to inside the ellipsoid when the mass ratio is larger than 0.6. For binary systems in close proximity with L1 being inside the ellipsoidal body, simulations show that particles on the surface tend to move away from the ellipsoid, toward the spherical primary. We can relate this to the

  7. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  9. K2 & Solar System Science

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack

    2015-01-01

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

  10. Lattice animals in diffusion limited binary colloidal system

    NASA Astrophysics Data System (ADS)

    Shireen, Zakiya; Babu, Sujin B.

    2017-08-01

    In a soft matter system, controlling the structure of the amorphous materials has been a key challenge. In this work, we have modeled irreversible diffusion limited cluster aggregation of binary colloids, which serves as a model for chemical gels. Irreversible aggregation of binary colloidal particles leads to the formation of a percolating cluster of one species or both species which are also called bigels. Before the formation of the percolating cluster, the system forms a self-similar structure defined by a fractal dimension. For a one component system when the volume fraction is very small, the clusters are far apart from each other and the system has a fractal dimension of 1.8. Contrary to this, we will show that for the binary system, we observe the presence of lattice animals which has a fractal dimension of 2 irrespective of the volume fraction. When the clusters start inter-penetrating, we observe a fractal dimension of 2.5, which is the same as in the case of the one component system. We were also able to predict the formation of bigels using a simple inequality relation. We have also shown that the growth of clusters follows the kinetic equations introduced by Smoluchowski for diffusion limited cluster aggregation. We will also show that the chemical distance of a cluster in the flocculation regime will follow the same scaling law as predicted for the lattice animals. Further, we will also show that irreversible binary aggregation comes under the universality class of the percolation theory.

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

    NASA Astrophysics Data System (ADS)

    Marzari, F.

    2012-04-01

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

  12. Radiation reaction in binary systems in general relativity

    NASA Astrophysics Data System (ADS)

    Kennefick, Daniel John

    1997-09-01

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

  13. Origins of Inner Solar Systems

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah Ilene

    2017-06-01

    Over the past couple decades, thousands of extra-solar planetshave been discovered orbiting other stars. The exoplanets discovered to date exhibit a wide variety of orbital and compositional properties; most are dramatically different from the planets in our own Solar System. Our classical theories for the origins of planetary systems were crafted to account for the Solar System and fail to account for the diversity of planets now known. We are working to establish a new blueprint for the origin of planetary systems and identify the key parameters of planet formation and evolution that establish the distribution of planetary properties observed today. The new blueprint must account for the properties of planets in inner solar systems, regions of planetary systems closer to their star than Earth’s separation from the Sun and home to most exoplanets detected to data. I present work combining simulations and theory with data analysis and statistics of observed planets to test theories of the origins of inner solars, including hot Jupiters, warm Jupiters, and tightly-packed systems of super-Earths. Ultimately a comprehensive blueprint for planetary systems will allow us to better situate discovered planets in the context of their system’s formation and evolution, important factors in whether the planets may harbor life.

  14. 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

  15. 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

  16. Experiences in solar cooling systems

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Astrophysics Data System (ADS)

    Leão, I. C.; de Medeiros, J. R.

    2003-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  1. 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)

  2. MAGIC VHE gamma-ray observations of binary systems

    NASA Astrophysics Data System (ADS)

    Bednarek, W.; Blanch, O.; Cortina, J.; de Oña Wilhelmi, E.; Hadasch, D.; López-Coto, R.; López-Oramas, A.; Munar-Adrover, P.; Paredes, J. M.; Pérez-Torres, M. A.; Ribó, M.; Sitarek, J.; Torres, D. F.; Zanin, R.

    2017-01-01

    There are several types of Galactic sources that can potentially accelerate charged particles up to GeV and TeV energies. These accelerated particles can produce Very High Energy (VHE, E >100 GeV) γ-ray emission through different processes like for example inverse Compton scattering of ambient photon fields by accelerated electrons. We present here the results of our obser-vations of the source class of γ-ray binaries and the subclass of binary systems known as novae with the MAGIC telescopes. The focus lies on the five sources: nova V339 Del, AE Aquarii, SS 433, MWC 656 and LS I +61°303. The binary system LS I +61◦303 was observed in a long-term monitoring campaign for 8 years. We show the newest results on our search for superorbital variability also in context with contemporaneous optical observations. MWC 656 is a unique detected high-mass X-ray binary system, since it is up to now the only one known composed of a Be star and a black hole. Furthermore, we present the observations of the only super-critical accretion system known in our galaxy: SS 433. Finally, results of our multiwavelength observation campaign regarding the cataclysmic variable AE Aquarii and the results of the follow-up observations of the nova V339 Del will be discussed in these proceedings.

  3. 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)

  4. 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.

  5. An ultramassive, fast-spinning white dwarf in a peculiar binary system.

    PubMed

    Mereghetti, S; Tiengo, A; Esposito, P; La Palombara, N; Israel, G L; Stella, L

    2009-09-04

    White dwarfs typically have masses in a narrow range centered at about 0.6 solar mass (M(o)). Only a few ultramassive white dwarfs (mass > 1.2 M(o)) are known. Those in binary systems are of particular interest, because a small amount of accreted mass could drive them above the Chandrasekhar limit, beyond which they become gravitationally unstable. Using data from the x-ray multimirror mission (XMM)-Newton satellite, we show that the x-ray pulsator RX J0648.0-4418 is a white dwarf with mass > 1.2 M(o), based on dynamical measurements only. This ultramassive white dwarf in a post-common envelope binary with a hot subdwarf can reach the Chandrasekhar limit, and possibly explode as a type Ia supernova, when its helium-rich companion will transfer mass at an increased rate through Roche lobe overflow.

  6. Solar tracking system

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  7. Solar tracking system

    NASA Astrophysics Data System (ADS)

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

    1981-04-01

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

  8. Solar Radiation Alert System

    DTIC Science & Technology

    2009-03-01

    accessed: 20 February 2008). 21. Smart, D.F. and Shea, M.A. The local tme depen- dence of the ansotropc solar cosmc ray flux. Advances in Space Research 32...c cutoff rgdtes for earth orbtng spacecraft. Advances in Space Research 36: 2012-2020 (2005) (Regons were selected based on boundares of... in Space Research 42: 1008-29 (2008). 12. ICRU, Internatonal Commsson on Radaton Unts and Measurements. Stopping Powers and Ranges for

  9. 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!

  10. Passive solar heating system

    NASA Astrophysics Data System (ADS)

    Mingenbach, W.

    1981-08-01

    The Toas State Office Building is a single-story office building in New Mexico which incorporates passive collection and storage of solar energy along with natural lighting for general illumination. The building is oriented to take advantage of early morning sunlight and is designed to supply 70% of the heating load by solar heat. The site is equipped with clerestory windows, totaling 2695 square feet, 296 square feet of south facing windows, and east and west window scoops totaling 218 square feet. The collected solar energy is stored in 14,080 gallons of water contained in drums located in the clerestory area, as well as in the masonry construction mass. Auxiliary heat is provided via electric strips in the supply ducts. Movable, insulated shutters are provided to reduce the loss from the clerestory window area at night. The project is described with pictures and diagrams of the final installation provided. An updated performance data report is included, and functional problems, general comments, maintenance and refurbishment recommendations are discussed.

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

    NASA Astrophysics Data System (ADS)

    Rabinowitz, David L.; Owainati, Yasi

    2014-11-01

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

  12. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  14. Estimating gravitational radiation from super-emitting compact binary systems

    NASA Astrophysics Data System (ADS)

    Hanna, Chad; Johnson, Matthew C.; Lehner, Luis

    2017-06-01

    Binary black hole mergers are among the most violent events in the Universe, leading to extreme warping of spacetime and copious emission of gravitational radiation. Even though black holes are the most compact objects they are not necessarily the most efficient emitters of gravitational radiation in binary systems. The final black hole resulting from a binary black hole merger retains a significant fraction of the premerger orbital energy and angular momentum. A nonvacuum system can in principle shed more of this energy than a black hole merger of equivalent mass. We study these super-emitters through a toy model that accounts for the possibility that the merger creates a compact object that retains a long-lived time-varying quadrupole moment. This toy model may capture the merger of (low mass) neutron stars, but it may also be used to consider more exotic compact binaries. We hope that this toy model can serve as a guide to more rigorous numerical investigations into these systems.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

  17. 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.

  18. Physics of Solar System Plasmas

    NASA Astrophysics Data System (ADS)

    Hughes, W. Jeffrey

    Anyone who has taught an introductory course in space physics faces an insolvable dilemma. Space physics is the common name for the physics of the plasma regions in the solar system. The dilemma is, do you introduce the topics in plasma physics in an ordered progression and illustrate them with examples drawn from the solar system, in which case you are teaching a course in plasma physics with applications to the solar system? Or do you describe the various regions and environments found in the solar system in a coherent order and introduce the plasma physics as it is needed, in which case you are teaching a course in geophysics? I have tried both approaches, and neither works well. The first approach gives students an understanding of plasma physics and its hierarchy of approximations, but they usually do not get a coherent understanding of geospace. The second approach gives students a good grasp of the Sun/solar wind/magnetosphere/ionosphere as a single complex system, but they invariably end up with a poorer grasp of what physics applies in various situations. For programs that can accommodate it, two separate courses is clearly the best approach. Not all programs have that luxury.

  19. Modular passive solar heating system

    SciTech Connect

    Hunter, B.D.

    1985-03-19

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

  20. 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.

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

    SciTech Connect

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

    2014-05-01

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

  2. Binary Minor Planets

    NASA Astrophysics Data System (ADS)

    Richardson, Derek C.; Walsh, Kevin J.

    2006-05-01

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

  3. Determination of the Period of Binary Asteroid Systems

    NASA Astrophysics Data System (ADS)

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

    2008-09-01

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

  4. 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.

  5. 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.

  6. Solar-powered cooling system

    SciTech Connect

    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.

  7. Solar thermophotovoltaic system using nanostructures

    DOE PAGES

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

    2015-08-20

    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 bothmore » easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.« less

  8. 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.

  9. Solar thermophotovoltaic system using nanostructures

    SciTech Connect

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

    2015-08-20

    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.

  10. Origin of Outer Solar System

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  11. 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.

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

    NASA Technical Reports Server (NTRS)

    Gies, Douglas R.

    1991-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Alexander, M. E.

    1988-12-01

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

  14. 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.

  15. Solar and stellar system tests of the cosmological constant

    SciTech Connect

    Sereno, Mauro; Jetzer, Philippe

    2006-03-15

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

  16. The Solar-Type Hard-Binary Frequency and Distributions of Orbital Parameters in the Open Cluster M37

    NASA Astrophysics Data System (ADS)

    Geller, Aaron M.; Meibom, Soren; Barnes, Sydney A.; Mathieu, Robert D.

    2014-02-01

    Binary stars, and particularly the short-period ``hard'' binaries, govern the dynamical evolution of star clusters and determine the formation rates and mechanisms for exotic stars like blue stragglers and X-ray sources. Understanding the near-primordial hard-binary population of star clusters is of primary importance for dynamical models of star clusters, which have the potential to greatly advance our understanding of star cluster evolution. Yet the binary frequencies and distributions of binary orbital parameters (period, eccentricity, etc.) for young coeval stellar populations are poorly known, due to a lack of necessary observations. The young (~540 Myr) open cluster M37 hosts a rich binary population that can be used to empirically define these initial conditions. Importantly, this cluster has been the target of a comprehensive WIYN/Hydra radial-velocity (RV) survey, from which we have already identified a nearly complete sample of 329 solar-type (1.5 <=M [M_⊙] <=1.0) members in M37. Of these stars, 82 show significant RV variability, indicative of a binary companion. We propose to build upon these data with a multi-epoch RV survey using WIYN/Hydra to derive kinematic orbital solutions for these 82 binaries in M37. This project was granted time in 2013B and scheduled for later this year. We anticipate that about half of the detected binaries in M37 will acquire enough RV measurements (>=10) in 2013B to begin searching for orbital solutions. With this proposal and perhaps one additional semester we should achieve >=10 RV measurements for the remaining binaries.

  17. 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.

  18. 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.

  19. 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.

  20. Advances in Solar Heating and Cooling Systems

    ERIC Educational Resources Information Center

    Ward, Dan S.

    1976-01-01

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

  1. Percolation of binary disk systems: Modeling and theory

    DOE PAGES

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

    2017-01-12

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

  2. Percolation of binary disk systems: Modeling and theory

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  3. 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.

  4. 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.

  5. Periodic orbits of planets in binary systems

    NASA Astrophysics Data System (ADS)

    Voyatzis, G.

    2017-03-01

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

  6. Solar rocket system concept analysis

    NASA Technical Reports Server (NTRS)

    Boddy, J. A.

    1980-01-01

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

  7. Solar energy decision support system

    NASA Astrophysics Data System (ADS)

    Ramachandra, T. V.; Rajeev Kumar, J.; Vamsee Krishna, S.; Shruthi, B. V.

    2006-03-01

    Energy plays a prominent role in human society. As a result of technological and industrial developments, the demand for energy is rapidly increasing. Existing power sources that are mainly fossil fuel based are leaving an unacceptable legacy of waste and pollution apart from diminishing stock of fuels. Hence, the focus is now shifted to large-scale propagation of renewable energy. Renewable energy technologies are clean sources of energy that have a much lower environmental impact than conventional energy technologies. Solar energy is one such renewable energy. Most renewable energy comes either directly or indirectly from the sun. Estimation of solar energy potential of a region requires detailed solar radiation climatology, and it is necessary to collect extensive radiation data of high accuracy covering all climatic zones of the region. In this regard, a decision support system (DSS) would help to estimate solar energy potential considering the regions’ energy requirement. This article explains the design and implementation of DSS for assessment of solar energy. The DSS with executive information systems and reporting tools helps to tap vast data resources and deliver information. The main hypothesis is that this tool can be used to form a core of practical methodology that is resilient and can be used by decision-making bodies to assess various scenarios. It also offers means of entering, accessing and interpreting the information for the purpose of sound decision-making.

  8. Solar energy decision support system

    NASA Astrophysics Data System (ADS)

    Ramachandra, T. V.; Jha, Rajeev Kumar; Vamsee Krishna, S.; Shruthi, B. V.

    2005-12-01

    Energy plays a prominent role in human society. As a result of technological and industrial development, the demand for energy is rapidly increasing. Existing power sources that are mainly fossil fuel based are leaving an unacceptable legacy of waste and pollution apart from diminishing stock of fuels. Hence, the focus is now shifted to large-scale propagation of renewable energy. Renewable energy technologies are clean sources of energy that have a much lower environmental impact than conventional energy technologies. Solar energy is one such renewable energy. Most renewable energy comes either directly or indirectly from the sun. Estimation of solar energy potential of a region requires detailed solar radiation climatology, and it is necessary to collect extensive radiation data of high accuracy covering all climatic zones of the region. In this regard, a decision support system (DSS) would help in estimating solar energy potential considering the region's energy requirement. This article explains the design and implementation of DSS for assessment of solar energy. The DSS with executive information systems and reporting tools helps to tap vast data resources and deliver information. The main hypothesis is that this tool can be used to form a core of practical methodology that will result in more resilient in time and can be used by decision-making bodies to assess various scenarios. It also offers means of entering, accessing, and interpreting the information for the purpose of sound decision making.

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

    PubMed

    Ibrahim, Mohamed Abbas

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

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

  11. Evidence for compact binary systems around Kepler red giants

    NASA Astrophysics Data System (ADS)

    Colman, Isabel L.; Huber, Daniel; Bedding, Timothy R.; Kuszlewicz, James S.; Yu, Jie; Beck, Paul G.; Elsworth, Yvonne; García, Rafael A.; Kawaler, Steven D.; Mathur, Savita; Stello, Dennis; White, Timothy R.

    2017-08-01

    We present an analysis of 168 oscillating red giants from NASA's Kepler mission that exhibit anomalous peaks in their Fourier amplitude spectra. These peaks result from ellipsoidal variations that are indicative of binary star systems, at frequencies such that the orbit of any stellar companion would be within the convective envelope of the red giant. Alternatively, the observed phenomenon may be due to a close binary orbiting a red giant in a triple system, or chance alignments of foreground or background binary systems contaminating the target pixel aperture. We identify 87 stars in the sample as chance alignments using a combination of pixel Fourier analysis and difference imaging. We find that in the remaining 81 cases, the anomalous peaks are indistinguishable from the target star to within 4 arcsec, suggesting a physical association. We examine a galaxia model of the Kepler field of view to estimate background star counts and find that it is highly unlikely that all targets can be explained by chance alignments. From this, we conclude that these stars may comprise a population of physically associated systems.

  12. Stripped red giant cores in eclipsing binary star systems

    NASA Astrophysics Data System (ADS)

    Maxted, P. F. L.; Heber, U.; Smalley, B.; Marsh, T. R.

    2013-02-01

    Red giant stars can be stripped of their outer layers by stellar collisions or mass transfer in binary star systems such as low mass X-ray binaries. If the star is stripped on or before its first ascent of the red giant branch it will eventually become a very low mass white dwarf composed almost entirely of helium. Very low mass white dwarfs are well known in binary milli-second pulsars and many have recently been found in surveys such as the Sloan Digital Sky Survey, but the precursor phase during which the remnant evolves to higher effective temperature at nearly constant luminosity has rarely been observed. The cooling timescale for very low mass white dwarfs is very uncertain because they are thought to be born with thick hydrogen envelopes which can sustain weak but stable p-p shell burning, but unstable phases of CNO burning (shell flashes) can remove this hydrogen envelope. The predicted number of shell flashes (if any) is dependent on the mass and composition of the star and other details of the models used. In this talk I present new observations of a bright eclipsing binary star recently discovered in the WASP archive in which a stripped red giant is eclipsed by an A-type dwarf star. These observations were used to derive precise masses and radii for both stars and have be used to test the formation scenario outlined above. In addition, I present the main characteristics of 17 new eclipsing binary stars that are also likely to contain the precursors of very low mass white dwarfs.

  13. Near Infrared Excess Energy in Binary System V367 Cygni

    NASA Astrophysics Data System (ADS)

    Gunasekera, Saraj

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

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

    PubMed

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

    2016-09-30

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

  16. 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.

  17. 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.

  18. Maximum collectible solar energy by different solar tracking systems

    SciTech Connect

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

    2000-01-01

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

  19. Magnetospheres in the solar system

    SciTech Connect

    Mcnutt, R.L.

    1984-11-01

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

  20. Solar system: Sandcastles in space

    NASA Astrophysics Data System (ADS)

    Scheeres, Daniel J.

    2014-08-01

    Analysis of a kilometre-sized, near-Earth asteroid shows that forces weaker than the weight of a penny can keep it from falling apart. This has implications for understanding the evolution of the Solar System. See Letter p.174

  1. 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,…

  2. 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.

  3. 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…

  4. 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…

  5. 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,…

  6. 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…

  7. 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.

  8. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    SciTech Connect

    Smullen, Rachel A.; Kobulnicky, Henry A.

    2015-08-01

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

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

    SciTech Connect

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

    2012-03-10

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

  12. Solar System Science with WISE

    NASA Astrophysics Data System (ADS)

    McMillan, Robert S.; WISE Team

    2011-01-01

    WISE has surveyed the solar system to unprecedented sensitivity and resolution in its wavelength bands. Corresponding to the peak of thermal emission of many solar system bodies and particles, the 12 and 22 micron bands detected asteroids, comets, comet debris trails, and zodiacal dust to several AU from the sun. Some of the objects and material are too dark to have been detected by visible-light surveys, and previous infrared telescopes in space have either not covered the whole sky or have had far less sensitivity. As a consequence, WISE explores the spatial distributions and thermal properties of the objects and material populating the inner solar system efficiently and without bias favoring bright albedos. At the temperatures dominant in the inner solar system, IR flux is more directly related to the size of the emitter than is visible flux, so the detections of asteroids by WISE are relatively insensitive to albedo. Yet combined with visual magnitudes, WISE data yield albedos. Orbital migration driven by asymmetrical thermal reradiation of absorbed sunlight depends on size and albedo, and affects the evolution of the orbits of asteroids. The distributions of sizes of asteroids, and the dependences of those distributions with orbital parameters to be uncovered by WISE are therefore evidence of the processes that brought the solar system to its current state. Dark asteroids that approach Earth are especially menacing if they have evaded detection by ground-based surveys, so WISE has refined knowledge of the impact hazard. WISE data help the study of the formation of cometary comae, tails, and dust trails, and the rate of mass loss from comets. Finally, the zodiacal dust bands, being the asteroidal component of the zodiacal dust, hold the key to determining the magnitude of the asteroid component.

  13. 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.

  14. 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.

  15. 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.

  16. 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%.

  17. Challenges in Solar System Ionospheres

    NASA Astrophysics Data System (ADS)

    Mendillo, M.

    2001-12-01

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

  18. Our Solar System, from the Outside

    NASA Image and Video Library

    2011-04-28

    This graphic, based on data from NASA Voyager spacecraft, shows a model of what our solar system looks like to an observer outside in interstellar space, watching our solar system fly towards the observer.

  19. V Sge: a Hot, Peculiar Binary System

    NASA Astrophysics Data System (ADS)

    Smak, Jozef I.; Belczynski, K.; Zola, S.

    2001-06-01

    Five sets of mean UBV light curves of V Sge covering 2 mag of its large scale variations are analyzed. The mass ratio adopted in the analysis q=M_2/M_1=3.76 is that obtained by Herbig etal (1965) from radial velocity curves based on fluorescent OIII lines (arising from the surfaces of the two components). Models with an accretion disk around the white dwarf primary (or a very massive neutron star secondary) fail completely to reproduce the shapes of the observed light curves. Successful solutions are obtained with a model involving contact configuration, modified by the presence of a hot, gaseous envelope (needed to explain the behavior of colors and the variable depth of the primary eclipse). At inclination i approx 71 arcd the resulting masses of the components are: M_1 approx 0.9 M_odot and M_2 approx 3.3 M_odot. In the faintest state the secondary is a main sequence star with R_2 approx 1.2 R_odot and T_2 approx 12000 K, while the main parameters of the primary are: R_1 approx 2.1 R_odot, T_1 approx 70000 K, and L_1 approx 1038 erg/s. Due to the high radiation pressure from the primary an expanding gaseous envelope is formed, leading to the mass outflow from the system. Large scale variations involve significant increase of the temperatures of both components, up to about 140000 K for the primary and about 50000 K for the secondary, and a considerable thickening of the gaseous envelope, which contributes up to 20-30% of the total UBV flux. These variations are interpreted as being due - in part - to the instability and large variations in the rate of mass outflow from the secondary. No obvious explanation, however, is offered for the major increase of the temperature and luminosity of the primary component in the brightest state. The temperature of the primary in the faint and intermediate states (T_1 approx 70000 K) is too low to explain the supersoft X-ray flux (observed only during those states), the only alternative being that it must come from the envelope

  20. Binary nanoparticle superlattices of soft-particle systems

    PubMed Central

    Travesset, Alex

    2015-01-01

    The solid-phase diagram of binary systems consisting of particles of diameter σA=σ and σB=γσ (γ≤1) interacting with an inverse p = 12 power law is investigated as a paradigm of a soft potential. In addition to the diameter ratio γ that characterizes hard-sphere models, the phase diagram is a function of an additional parameter that controls the relative interaction strength between the different particle types. Phase diagrams are determined from extremes of thermodynamic functions by considering 15 candidate lattices. In general, it is shown that the phase diagram of a soft repulsive potential leads to the morphological diversity observed in experiments with binary nanoparticles, thus providing a general framework to understand their phase diagrams. Particular emphasis is given to the two most successful crystallization strategies so far: evaporation of solvent from nanoparticles with grafted hydrocarbon ligands and DNA programmable self-assembly. PMID:26195799

  1. Binary nanoparticle superlattices of soft-particle systems

    DOE PAGES

    Travesset, Alex

    2015-08-04

    The solid-phase diagram of binary systems consisting of particles of diameter σA=σ and σB=γσ (γ≤1) interacting with an inverse p = 12 power law is investigated as a paradigm of a soft potential. In addition to the diameter ratio γ that characterizes hard-sphere models, the phase diagram is a function of an additional parameter that controls the relative interaction strength between the different particle types. Phase diagrams are determined from extremes of thermodynamic functions by considering 15 candidate lattices. In general, it is shown that the phase diagram of a soft repulsive potential leads to the morphological diversity observed inmore » experiments with binary nanoparticles, thus providing a general framework to understand their phase diagrams. In addition, particular emphasis is shown to the two most successful crystallization strategies so far: evaporation of solvent from nanoparticles with grafted hydrocarbon ligands and DNA programmable self-assembly.« less

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

    SciTech Connect

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

    2015-12-01

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

  3. 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.

  4. Numerical Simulations of Binary Systems with Matter Companions

    NASA Astrophysics Data System (ADS)

    Etienne, Zachariah

    2011-04-01

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

  5. 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.

  6. Simulating binary inspirals in a corotating spherical coordinate system

    NASA Astrophysics Data System (ADS)

    Garrett, Travis Marshall

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

  7. Solar system: Interplanetary kidnap

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro

    2006-05-01

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

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

    NASA Astrophysics Data System (ADS)

    Mudryk, Lawrence R.; Wu, Yanqin

    2006-03-01

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

  9. 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.

  10. Observations of Hierarchical Solar-type Multiple Star Systems

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  11. 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.

  12. High performance solar Stirling system

    NASA Technical Reports Server (NTRS)

    Stearns, J. W.; Haglund, R.

    1981-01-01

    A full-scale Dish-Stirling system experiment, at a power level of 25 kWe, has been tested during 1981 on the Test Bed Concentrator No. 2 at the Parabolic Dish Test Site, Edwards, CA. Test components, designed and developed primarily by industrial contractors for the Department of Energy, include an advanced Stirling engine driving an induction alternator, a directly-coupled solar receiver with a natural gas combustor for hybrid operation and a breadboard control system based on a programmable controller and standard utility substation components. The experiment demonstrated practicality of the solar Stirling application and high system performance into a utility grid. This paper describes the design and its functions, and the test results obtained.

  13. High performance solar Stirling system

    NASA Astrophysics Data System (ADS)

    Stearns, J. W.; Haglund, R.

    1981-12-01

    A full-scale Dish-Stirling system experiment, at a power level of 25 kWe, has been tested during 1981 on the Test Bed Concentrator No. 2 at the Parabolic Dish Test Site, Edwards, CA. Test components, designed and developed primarily by industrial contractors for the Department of Energy, include an advanced Stirling engine driving an induction alternator, a directly-coupled solar receiver with a natural gas combustor for hybrid operation and a breadboard control system based on a programmable controller and standard utility substation components. The experiment demonstrated practicality of the solar Stirling application and high system performance into a utility grid. This paper describes the design and its functions, and the test results obtained.

  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. Steamy Solar System

    NASA Technical Reports Server (NTRS)

    2007-01-01

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

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

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

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

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

  16. 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.

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

    NASA Astrophysics Data System (ADS)

    Chernov, S. V.

    2017-03-01

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

  18. System-size resonance in a binary attractor neural network.

    PubMed

    de la Casa, M A; Korutcheva, E; Parrondo, J M R; de la Rubia, F J

    2005-09-01

    System size resonance (SSR) is a phenomenon in which the response of a system is optimal for a certain finite size, but poorer as the size goes to zero or infinity. In order to show SSR effects in binary attractor neural networks, we study the response of a network, in the ferromagnetic phase, to an external, time-dependent stimulus. Under the presence of such a stimulus, the network shows SSR, as is demonstrated by the measure of the signal amplification both analytically and by simulation.

  19. Inhabiting the solar system

    NASA Astrophysics Data System (ADS)

    Sherwood, Brent

    2011-03-01

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

  20. 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.

  1. 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.

  2. 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

  3. Analysis of hybrid solar systems

    NASA Astrophysics Data System (ADS)

    Swisher, J.

    1980-10-01

    The TRNSYS simulation program was used to evaluate the performance of active charge/passive discharge solar systems with water as the working fluid. TRNSYS simulations are used to evaluate the heating performance and cooling augmentation provided by systems in several climates. The results of the simulations are used to develop a simplified analysis tool similar to the F-chart and Phi-bar procedures used for active systems. This tool, currently in a preliminary stage, should provide the designer with quantitative performance estimates for comparison with other passive, active, and nonsolar heating and cooling designs.

  4. From Binaries to Triples

    NASA Astrophysics Data System (ADS)

    Freismuth, T.; Tokovinin, A.

    2002-12-01

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

  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. Analytic orbit propagation of planets in binary star systems

    NASA Astrophysics Data System (ADS)

    Eggl, Siegfried; Georgakarakos, Nikolaos

    2015-08-01

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

  7. Studying binary asteroids with NGS and LGS AO systems

    NASA Astrophysics Data System (ADS)

    Marchis, Franck; Berthier, Jerome; Descamps, Pascal; Hestroffer, Daniel; Vachier, Frederic; Laver, Conor; de Pater, Imke; Gavel, Don T.

    2004-10-01

    Since the discovery of Dactyl orbiting around Ida by the Galileo spacecraft in 1993, over twenty-five binary asteroid systems have been discovered using radar, direct imaging and Adaptive Optics observations. Asteroidal moon discoveries dramatically increased with the advent of this last technique on ground based telescopes. Our group focuses on the search and study of double asteroids in the main-belt, in the Trojan population and beyond Neptune's orbit. We have been using several of the AO systems available (Lick-3m, Palomar-5m, VLT-8m, Keck-10m) and related techniques such as Appulse and Laser Guide Star observations to broaden the sample of asteroids observed from the main-belt out to the Kuiper Belt. We will present a quality comparison between various techniques and different AO systems with NGS and will detail our first successful observations with the Lick LGS system. Precise orbital elements of the secondary can be determined by multiple observations spanning large periods of time (several months). Our group developed a method to predict the ephemeris of a secondary companion. Without any assumptions, this method, tested successfully on 22 Kalliope and 121 Hermione binary systems, leads to the direct determination of important physical parameters of the targets, such as their mass and the interior structure, as well as gives direct insights on their formation processes that may be otherwise only be speculated on from spacecraft mission flybys.

  8. 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…

  9. 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…

  10. 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.

  11. Hybrid solar lighting distribution systems and components

    DOEpatents

    Muhs, Jeffrey D [Lenoir City, TN; Earl, Dennis D [Knoxville, TN; Beshears, David L [Knoxville, TN; Maxey, Lonnie C [Powell, TN; Jordan, John K [Oak Ridge, TN; Lind, Randall F [Lenoir City, TN

    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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  2. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  3. High efficiency and stable dye-sensitized solar cells with an organic chromophore featuring a binary pi-conjugated spacer.

    PubMed

    Zhang, Guangliang; Bala, Hari; Cheng, Yueming; Shi, Dong; Lv, Xueju; Yu, Qingjiang; Wang, Peng

    2009-04-28

    We employed a binary spacer of orderly conjugated 3,4-ethyldioxythiophene and thienothiophene to construct a wide-spectral response organic chromophore for dye-sensitized solar cells, exhibiting a high power conversion efficiency of 9.8% measured under irradiation of 100 mW cm(-2) air mass 1.5 global (AM1.5G) sunlight and an excellent stability.

  4. 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.

  5. 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.

  6. 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.

  7. Solar-Powered Refrigeration System

    NASA Astrophysics Data System (ADS)

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

    2002-10-01

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

  8. Preparation And Study Of Electrodeposited Silver-Nickel Binary System

    NASA Astrophysics Data System (ADS)

    Santhi, Kalavathy; Narmatha, R.; Narayanan, V.; Stephen, A.

    2011-06-01

    Ag-Ni binary system was prepared by the method of pulsed electrodeposition from an electrolyte that consisted of silver nitrate and nickel sulfate along with the complexing agents thiourea and sodium gluconate. The depositions were carried out by applying short current pulses of different current densities through electrolytes of same composition. The deposits were characterized using X-ray diffraction, vibrating sample magnetometer, energy dispersive X-ray analysis and SEM. The samples in their as prepared form exhibit ferromagnetic properties. This study shows that it is possible to simultaneously deposit the two immiscible constituents Ag and Ni with desired magnetic properties in pulsed electrolysis.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  10. Solar system employing ground level heliostats and solar collectors

    SciTech Connect

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

    1981-07-07

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

  11. 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.

  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. On stress relaxation timescales for dense binary particulate systems

    NASA Astrophysics Data System (ADS)

    Mao, Shaolin

    2015-06-01

    We study contact stress relaxation timescales, especially the temporal correlation involved in dense binary particulate systems, which offers insight into the intriguing relationship between the contact stresses and the contact time of particle interactions under non-equilibrium state. The contact time (also referred to as contact age) of a pair of particles is defined by the duration between current time and the instant when the contact was formed. The interspecies inter-particles contact stresses are derived from Liouville's theorem. We apply particle dynamics methods (e.g. molecular dynamics, discrete element method) to simulate 3D dense binary particulate systems with periodic boundary conditions. External perturbation is exerted on the system to balance the dissipation of energy due to the viscoelastic collisions. The contact stresses, Reynolds stresses, and the probability density function of the contact time of particles are predicted at different volume fraction of particles. The obtained stress-strain rate data are used to examine the constitutive relation of macroscopic materials. The study targets the impact of the short-term and the long-term contact/collision on the contact stress relaxation. The simulation results reveal distinct effects of the short-term and the long-term contact/collision on the contact stresses, which have been treated by only an averaged expression of particle interactions in discrete element methods before.

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

    NASA Technical Reports Server (NTRS)

    Dobias, Jan J.; Plavec, Mirek J.

    1987-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Dobias, Jan J.; Plavec, Mirek J.

    1987-01-01

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

  16. 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.

  17. Young binary systems and their nearby environment: high-angular resolution observations

    NASA Astrophysics Data System (ADS)

    Duchêne, Gaspard

    2000-07-01

    The high frequency of binary systems among main sequence stars as well as in star-forming regions has been largely documented in the last ten years. This raised the issue of the mechanism responsible for the preferred occurence of multiple systems. Moreover, interactions between a companion and the complex environment of a T Tauri star are only poorly understood. The work conducted during this thesis fits in this framework; the main goals of the thesis are: i) to estimate the binary frequency in various populations of pre-main sequence stars, ii) to study quantitatively the accretion phenomenon in binary T Tauri stars, and iii) to get direct observations and to model circumstellar and circumbinary disks in these systems. Using the Canada-France-Hawaii Telescope adaptive optics system to search for visual binaries, I took part in the observations of several hundreds objects located in various young stellar clusters. Here, I detail the analysis and results concerning two two-million years-old clusters, IC 348 and NGC 6611. When considering all populations studied to date, we find that the visual binary frequency among solar-type stars is the same in all stellar clusters as on the main sequence. Furthermore, this property does not depend on the age of the cluster, indicating that the binary frequency does not evolve after the first million years in these clusters. On the other hand, the extremely young loose star-forming regions display a significatively enhanced binary frequency. The models that best fit these observations are those where the binary frequency resulting from the gravitational collapse is close to 100%. In the densest clusters, this frequency can be subsequently decreased due to the numerous disrupting gravitational encounters between systems. OB stars in NGC 6611 retain significantly more companions in the separation range 200--2000 AU than low-mass objects in closer similarly-aged clusters, when one tries to account for uncompleteness in the

  18. 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.

  19. 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.

  20. Thermodynamic modeling of the Ge-La binary system

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

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

  1. Non-tracking solar energy collector system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1978-01-01

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

  2. PHASES: A Search for Planets in Binary Systems

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Moorman, Sarah; Cuntz, Manfred

    2017-01-01

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

  4. Determination of Individual Temperatures and Luminosities in Eclipsing Binary Star Systems.

    DTIC Science & Technology

    1983-06-20

    REPORT 1NO. W DETERMINATION OF INDIVIDUAL TEMPERATURES AND LUMINOSITIES IN ECLIPSING BINARY STAR SYSTEMS UNITED STATES NAVAL ACADEMY ANNAPOLIS, MARYLAND...U.S.N.A. - Trident Scholar project report; no. 122 (1983) DETERMINATION OF INDIVIDUAL TEMPERATURES AND LUMINOSITIES IN ECLIPSING BINARY STAR SYSTEMS A...the temperatures and luminosities of the individual components of eclipsing binary star systems. -’r. Richard L. Walker of the U.S. Naval Observatory

  5. Solar-gas systems impact analysis study

    NASA Astrophysics Data System (ADS)

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

    1984-07-01

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

  6. Planetary Nebulae that Cannot Be Explained by Binary Systems

    NASA Astrophysics Data System (ADS)

    Bear, Ealeal; Soker, Noam

    2017-03-01

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

  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. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Cuntz, M.

    2014-01-01

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

  15. Chemical Composition of RR Lyn - an Eclipsing Binary System with Am and λ Boo Type Components

    NASA Astrophysics Data System (ADS)

    Jeong, Yeuncheol; Yushchenko, Alexander V.; Doikov, Dmytry N.; Gopka, Vira F.; Yushchenko, Volodymyr O.

    2017-06-01

    High-resolution spectroscopic observations of the eclipsing binary system RR Lyn were made using the 1.8 m telescope at the Bohuynsan Optical Astronomical Observatory in Korea. The spectral resolving power was R = 82,000, with a signal to noise ratio of S/N > 150. We found the effective temperatures and surface gravities of the primary and secondary components to be equal to Teff = 7,920 & 7,210 K and log(g) = 3.80 & 4.16, respectively. The abundances of 34 and 17 different chemical elements were found in the atmospheric components. Correlations between the derived abundances with condensation temperatures and the second ionization potentials of these elements are discussed. The primary component is a typical metallic line star with the abundances of light and iron group elements close to solar values, while elements with atomic numbers Z > 30 are overabundant by 0.5-1.5 dex with respect to solar values. The secondary component is a λ Boo type star. In this type of stars, CNO abundances are close to solar values, while the abundance pattern shows a negative correlation with condensation temperatures.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2004-07-01

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

  18. 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.

  19. Small Solar Power Systems /SSPS/

    NASA Astrophysics Data System (ADS)

    Grasse, W.

    1981-05-01

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

  20. 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.

  1. 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

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

  3. 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.

  4. Be discs in binary systems - II. Misaligned orbits

    NASA Astrophysics Data System (ADS)

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

    2017-10-01

    We use a smoothed particle hydrodynamics (SPH) code to examine the effects of misaligned binary companions on Be star discs. We systematically vary the degree of misalignment between the disc and the binary orbit, as well as the disc viscosity and orbital period to study their effects on the density in the inner and outer parts of the disc. We find that varying the degree of misalignment, the viscosity and the orbital period affects both the truncation radius and the density structure of the outer disc, while the inner disc remains mostly unaffected. We also investigate the tilting of the disc in the innermost part of the disc and find the tilt increases with radius until reaching a maximum around 5 stellar radii. The direction of the line of nodes, with respect to the equator of the central star, is found to be offset compared to the orbital line of nodes, and to vary periodically in time, with a period of half a orbital phase. We also compare the scaleheight of our discs with the analytical scaleheight of an isothermal disc, which increases with radius as r1.5. We find that this formula reproduces the scaleheight well for both aligned and misaligned systems but underestimates the scaleheight in regions of the disc where density enhancements develop.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  8. 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.

  9. Tidal formation of Hot Jupiters in binary star systems

    NASA Astrophysics Data System (ADS)

    Bataille, M.; Libert, A.-S.; Correia, A. C. M.

    2015-10-01

    More than 150 Hot Jupiters with orbital periods less than 10 days have been detected. Their in-situ formation is physically unlikely. We need therefore to understand the migration of these planets from high distance (several AUs). Three main models are currently extensively studied: disk-planet interactions (e.g. [3]), planet-planet scattering (e.g. [4]) and Kozai migration (e.g. [2]). Here we focus on this last mechanism, and aim to understand which dynamical effects are the most active in the accumulation of planetary companions with low orbital periods in binary star systems. To do so, we investigate the secular evolution of Hot Jupiters in binary star systems. Our goal is to study analytically the 3-day pile-up observed in their orbital period. Our framework is the hierarchical three-body problem, with the effects of tides, stellar oblateness, and general relativity. Both the orbital evolution and the spin evolution are considered. Using the averaged equations of motion in a vectorial formalism of [1], we have performed # 100000 numerical simulations of well diversified three-body systems, reproducing and generalizing the numerical results of [2]. Based on a thorough analysis of the initial and final configurations of the systems, we have identified different categories of secular evolutions present in the simulations, and proposed for each one a simplified set of equations reproducing the evolution. Statistics about spin-orbit misalignements and mutual inclinations between the orbital planes of the Hot Jupiter and the star companion are also provided. Finally, we show that the extent of the 3 day pile-up is very dependent on the initial parameters of the simulations.

  10. Near-Infrared Observations of Compact Binary Systems

    NASA Astrophysics Data System (ADS)

    Khargharia, Juthika

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

  11. Intelligence in the solar system

    NASA Astrophysics Data System (ADS)

    Tough, A.

    Could extraterrestrial intelligence have already reached our solar system--in the form of an interstellar probe, for instance? If any other civilizations exist in our galaxy, they are likely thousands of years older than us. With such advanced science and technology, interstellar exploration is likely easy and attractive for them. If they launched interstellar probes thousands of years ago, at least one may have already reached our solar system. What scientific strategies might detect evidence of such probes? Two strategies are especially promising. (1) Astronomy and space missions could, with very little additional expense, look for evidence of ETI in addition to the observations already scheduled. They could search for derelict probes, exhaust or heat from active probes, ancient mining, monuments, or other artifacts. (2) If a super-smart probe has reached our planet, it is likely monitoring our radio broadcasts, television broadcasts, and World Wide Web. Consequently we could use these media to invite contact. A group of eighty scientists already uses the Web to issue an invitation to ETI.

  12. Biotechnology for Solar System Exploration

    NASA Astrophysics Data System (ADS)

    Steele, A.; Maule, J.; Toporski, J.; Parro-Garcia, V.; Briones, C.; Schweitzer, M.; McKay, D.

    With the advent of a new era of astrobiology missions in the exploration of the solar system and the search for evidence of life elsewhere, we present a new approach to this goal, the integration of biotechnology. We have reviewed the current list of biotechnology techniques, which are applicable to miniaturization, automatization and integration into a combined flight platform. Amongst the techniques reviewed are- The uses of antibodies- Fluorescent detection strategies- Protein and DNA chip technology- Surface plasmon resonance and its relation to other techniques- Micro electronic machining (MEMS where applicable to biologicalsystems)- nanotechnology (e.g. molecular motors)- Lab-on-a-chip technology (including PCR)- Mass spectrometry (i.e. MALDI-TOF)- Fluid handling and extraction technologies- Chemical Force Microscopy (CFM)- Raman Spectroscopy We have begun to integrate this knowledge into a single flight instrument approach for the sole purpose of combining several mutually confirming tests for life, organic and/or microbial contamination, as well as prebiotic and abiotic organic chemicals. We will present several innovative designs for new instrumentation including pro- engineering design drawings of a protein chip reader for space flight and fluid handling strategies. We will also review the use of suitable extraction methodologies for use on different solar system bodies.

  13. 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.

  14. Fast Imaging Solar Spectrograph System in New Solar Telescope

    NASA Astrophysics Data System (ADS)

    Park, Y.-D.; Kim, Y. H.; Chae, J.; Goode, P. R.; Cho, K. S.; Park, H. M.; Nah, J. K.; Jang, B. H.

    2010-12-01

    In 2004, Big Bear Solar Observatory in California, USA launched a project for construction of the world's largest aperture solar telescope (D = 1.6m) called New Solar Telescope(NST). University of Hawaii (UH) and Korea Astronomy and Space Science Institute(KASI) partly collaborate on the project. NST is a designed off-axis parabolic Gregorian reflector with very high spatial resolution(0.07 arcsec at 5000A) and is equipped with several scientific instruments such as Visible Imaging Magnetograph (VIM), InfraRed Imaging Magnetograph IRIM), and so on. Since these scientific instruments are focused on studies of the solar photosphere, we need a post-focus instrument for the NST to study the fine structures and dynamic patterns of the solar chromosphere and low Transition Region (TR) layer, including filaments/prominences, spicules, jets, micro flares, etc. For this reason, we developed and installed a fast imaging solar spectrograph(FISS) system on the NST withadvantages of achieving compact design with high spectral resolution and small aberration as well as recording many solar spectral lines in a single and/or dual band mode. FISS was installed in May, 2010 and now we carry out a test observation. In this talk, we introduce the FISS system and the results of the test observation after FISS installation.

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

    SciTech Connect

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

    1993-07-01

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

  16. Masses of Early-type contact binary systems

    NASA Astrophysics Data System (ADS)

    Leung, K. C.

    2007-08-01

    In general, the mass ratio derived from photometric analyses, q(pe), agrees quite well with the value derived from double-line spectroscopic binary, q(sp), for wide pairs as well as for the close pairs. Therefore one wishes that masses could be determined for single-line systems with the help of photometric mass ratio. It is believed that the large masses determined for early type contact systems may be not reliable or quite wrong due to misleading photometric solution, mass ratios. Of course this includes some of my old published papers as well. The appearance of continuous light variation of their light curves resembles a system with contact configuration. In general, the temperature difference between the components is relatively well determined from the differential depths of the eclipses. Most of these systems have large temperature differences. In mode 3 (most popular) contact configuration of W-D method would automatically ends up with a very large temperature discontinuity at the interface. Even though some of our (with D. Q. Zhou of Peking University) model calculations on circulation in contact atmosphere did arrive at stable flow. (The mathematics just becomes too difficult to handle.) One can easily argue that such temperature discontinuity in a system can not be stable. If one utilizes the mode 1 configuration of the W-D method, there would not be a temperature discontinuity at the interface but than the temperature difference derived would not agree with the differential depths of eclipses. The key problem comes from the fact that there is only very slight difference in the shape of the light curves between a contact system and a very close semidetached system. Essentially there is no inflection point in the contact light curve while there is a slight inflection point for the latter. Since we are dealing with O and early B stars there are serious stellar winds and wind-wind interaction to be considered. These could well smooth out the slight the

  17. 2007 Mutual events within the binary system of (22) Kalliope

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

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

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

    PubMed

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

    2017-03-10

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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Solar thermal system engineering guidebook

    NASA Astrophysics Data System (ADS)

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

    1983-05-01

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

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

    NASA Astrophysics Data System (ADS)

    Touma, Jihad R.; Sridhar, S.

    2015-08-01

    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.

  8. 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.

  9. 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.

  10. Design of a Traditional Solar Tracking System

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader; Vasant, Pandian

    2010-06-01

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

  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. 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

  13. Density effects in a bulk binary Lennard-Jones system

    NASA Astrophysics Data System (ADS)

    Hernández-Rojas, Javier; Wales, David J.

    2003-10-01

    Properties of local minima as a function of density are studied in a binary Lennard-Jones system for temperatures T=1.0 (normal liquid), 0.5 (supercooled liquid), and 0.4 (glass), in reduced units. The number of different local minima sampled, energy, pressure, normal mode angular frequencies, and partial radial distribution functions are presented for simulation times of constant length. In agreement with previous studies by Sastry [Phys. Rev. Lett. 85, 590 (2000)] a limiting density is found at ρl=1.08 with negative pressure, below which the local structure of the glass and the supercooled phases are essentially the same, as evidenced by the partial radial distribution functions.

  14. Analytical estimates of secular frequencies for binary star systems

    NASA Astrophysics Data System (ADS)

    Bazsó, Á.; Pilat-Lohinger, E.

    2017-03-01

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

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

    PubMed

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

    2013-06-24

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

  16. Binary system of unequal counterrotating Kerr-Newman sources

    NASA Astrophysics Data System (ADS)

    Cabrera-Munguia, I.

    2015-02-01

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

  17. 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.

  18. Five New Low-Mass Eclipsing Binary Systems

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  7. 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.

  8. 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.

  9. Solar System Visualization (SSV) Project

    NASA Technical Reports Server (NTRS)

    Todd, Jessida L.

    2005-01-01

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

  10. EL CVn-type binaries - discovery of 17 helium white dwarf precursors in bright eclipsing binary star systems

    NASA Astrophysics Data System (ADS)

    Maxted, P. F. L.; Bloemen, S.; Heber, U.; Geier, S.; Wheatley, P. J.; Marsh, T. R.; Breedt, E.; Sebastian, D.; Faillace, G.; Owen, C.; Pulley, D.; Smith, D.; Kolb, U.; Haswell, C. A.; Southworth, J.; Anderson, D. R.; Smalley, B.; Collier Cameron, A.; Hebb, L.; Simpson, E. K.; West, R. G.; Bochinski, J.; Busuttil, R.; Hadigal, S.

    2014-01-01

    The star 1SWASP J024743.37-251549.2 was recently discovered to be a binary star in which an A-type dwarf star eclipses the remnant of a disrupted red giant star (WASP 0247-25 B). The remnant is in a rarely observed state evolving to higher effective temperatures at nearly constant luminosity prior to becoming a very low mass white dwarf composed almost entirely of helium, i.e. it is a pre-helium white dwarf (pre-He-WD). We have used the photometric database from the Wide Angle Search for Planets (WASP) to find 17 eclipsing binary stars with orbital periods P = 0.7-2.2 d with similar light curves to 1SWASP J024743.37-251549.2. The only star in this group previously identified as a variable star is the brightest one, EL CVn, which we adopt as the prototype for this class of eclipsing binary star. The characteristic light curves of EL CVn-type stars show a total eclipse by an A-type dwarf star of a smaller, hotter star and a secondary eclipse of comparable depth to the primary eclipse. We have used new spectroscopic observations for six of these systems to confirm that the companions to the A-type stars in these binaries have very low masses ({≈ } 0.2{ M_{⊙}}). This includes the companion to EL CVn which was not previously known to be a pre-He-WD. EL CVn-type binary star systems will enable us to study the formation of very low mass white dwarfs in great detail, particularly in those cases where the pre-He-WD star shows non-radial pulsations similar to those recently discovered in WASP0247-25 B.

  11. Solar heated fluidized bed gasification system

    SciTech Connect

    Frosch, R.A.; Qader, S.A.

    1981-09-22

    This solar-heated gasification system avoids the problems inherent in other solar processes (such as blackened solar-input windows and overheated zones on the reactor walls) by heating the fluidizing gas and steam in a solar-heat absorption zone before they enter the reactor. Energy to heat the gas and steam concentrates in high-heat-capacity refractory honeycomb that surrounds the fluidized-bed reactor zone. Solar concentrators focus the solar energy on the honeycomb through a solar window. The reaction zone is also heated directly and uniformly by thermal contact of the ceramic honeycomb with the walls of the reactor. The reactor handles such solids as coal and biomass.

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

    NASA Astrophysics Data System (ADS)

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

    1999-01-01

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

  13. Performance evaluation of solar water sterilization system

    SciTech Connect

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

    1998-07-01

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

  14. Small solar system bodies as granular systems

    NASA Astrophysics Data System (ADS)

    Hestroffer, Daniel; Campo Bagatín, Adriano; Losert, Wolfgang; Opsomer, Eric; Sánchez, Paul; Scheeres, Daniel J.; Staron, Lydie; Taberlet, Nicolas; Yano, Hajime; Eggl, Siegfried; Lecomte, Charles-Edouard; Murdoch, Naomi; Radjai, Fahrang; Richardson, Derek C.; Salazar, Marcos; Schwartz, Stephen R.; Tanga, Paolo

    2017-06-01

    Asteroids and other Small Solar System Bodies (SSSBs) are currently of great scientific and even industrial interest. Asteroids exist as the permanent record of the formation of the Solar System and therefore hold many clues to its understanding as a whole, as well as insights into the formation of planetary bodies. Additionally, SSSBs are being investigated in the context of impact risks for the Earth, space situational awareness and their possible industrial exploitation (asteroid mining). In all these aspects, the knowledge of the geophysical characteristics of SSSB surface and internal structure are of great importance. Given their size, constitution, and the evidence that many SSSBs are not simple monoliths, these bodies should be studied and modelled as self-gravitating granular systems in general, or as granular systems in micro-gravity environments in particular contexts. As such, the study of the geophysical characteristics of SSSBs is a multi-disciplinary effort that lies at the crossroads between Granular Mechanics, Celestial Mechanics, Soil Mechanics, Aerospace Engineering and Computer Sciences.

  15. Tidal stress and failure in the moon of binary asteroid systems: Application to asteroid (65803) Didymos

    NASA Astrophysics Data System (ADS)

    Sophal Pou, Laurent; Garcia, Raphael F.; Mimoun, David; Murdoch, Naomi; Karatekin, Ozgur

    2017-04-01

    Rocky remnants left over from the early formation of the Solar System, asteroids are a target of choice for planetary science since much about the history of planetary formation and small body evolution processes can be learnt by studying them. Here we consider the case of the binary asteroid (65803) Didymos, the target of several mission proposals e.g., AIM [1] and DART [2]. A mission to Didymos would be a great opportunity for in-situ geophysical investigation, providing information on the surface and interior of asteroids. Such studies would improve our knowledge of binary asteroid formation and subsequent evolution of asteroids, thus of the history of the Solar System. As Didymos is a binary asteroid [3] with the main 800-meter diameter asteroid named Didymain and a 150-meter sized moon named Didymoon, both are subject to tidal stress. Recent investigations suggest that Didymoon is tidally locked and moves in a retrograde motion around Didymain along an elliptic orbit with a 0.03 eccentricity at most. In the case of an eccentric orbit, the tidal stress varies periodically and may be strong enough to cause tidal quakes on Didymoon at some points of the orbit. For this study, we modelled Didymoon as a spherical, layered body with different internal structures: a homogeneous model, and two models with a 1-meter and 10-meter regolith layer on top of a stronger internal core. Simulations show that, for a cohesionless body with an internal friction angle of 30°, tidal stress is strong enough to cause failure at the surface of Didymoon. A maximal stress is reached around the poles and for a mean anomaly of 90°. These results would mean that if tidal quakes occur on Didymoon, then they are likely to happen at these locations. An extension of these results to an ellipsoidal model of Didymoon is also presented for comparison with the spherical case and for application to other bodies. [1]: P. Michel et al., Science case for the asteroid impact mission (aim): A

  16. Dense Random Packed Models for Amorphous Monatomic and Binary Systems.

    NASA Astrophysics Data System (ADS)

    Saw, Cheng Kiong

    In the last few years, computer simulated structure models have become very useful in predicting the density distribution functions of amorphous materials. However, no one model has every adequately described a physical amorphous system, with the result that many models have been proposed. These models may differ from each other in detail but the basic requirement that atoms are represented by spheres still remains. These proposed models can be characterized by either hard or soft spheres. Hard sphere refers to the situation where atoms are in contact with each other, while the latter to one where an energy function or many functions are applied resulting in the broadening of peaks. Hard sphere models are generally used with some kind of Gaussian broadenings in the distribution peaks in order for comparison with the experiments. Without broadening or "relaxation", these structural models possess anisotropy which reflects the inhomogeneity of the system. Periodicity is also observed in the interference function which suggests the existence of residual atomic lattices. Both of these effects are not observed in experiments therefore, the models cannot be used to represent physical systems. Relaxation using Morse and Lennard Jones potentials by Heimendahl on a single element computer simulated system makes the peak positions in the pair correlation function agree with the experiment, but the magnitudes do not compare well. Relaxation of binary systems has not yet been fully investigated. A new simplified model was developed here which uses less computer time than previously published models (approximately from half to an hour) in the structural simulations. The anisotropy and periodicity were investigated in this new unrelaxed model and, based on the correlation functions and the interference functions, were not observed. The average densities and distribution functions are comparable to previous published models and also to the experimental results on Co and TbFe2

  17. The Solar System: An Introductory Bibliography.

    ERIC Educational Resources Information Center

    Fraknoi, Andrew

    1987-01-01

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

  18. 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.

  19. 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.

  20. The formation of the solar system

    NASA Astrophysics Data System (ADS)

    Pfalzner, S.; Davies, M. B.; Gounelle, M.; Johansen, A.; Münker, C.; Lacerda, P.; Portegies Zwart, S.; Testi, L.; Trieloff, M.; Veras, D.

    2015-06-01

    The solar system started to form about 4.56 Gyr ago and despite the long intervening time span, there still exist several clues about its formation. The three major sources for this information are meteorites, the present solar system structure and the planet-forming systems around young stars. In this introduction we give an overview of the current understanding of the solar system formation from all these different research fields. This includes the question of the lifetime of the solar protoplanetary disc, the different stages of planet formation, their duration, and their relative importance. We consider whether meteorite evidence and observations of protoplanetary discs point in the same direction. This will tell us whether our solar system had a typical formation history or an exceptional one. There are also many indications that the solar system formed as part of a star cluster. Here we examine the types of cluster the Sun could have formed in, especially whether its stellar density was at any stage high enough to influence the properties of today’s solar system. The likelihood of identifying siblings of the Sun is discussed. Finally, the possible dynamical evolution of the solar system since its formation and its future are considered.

  1. The Solar System: An Introductory Bibliography.

    ERIC Educational Resources Information Center

    Fraknoi, Andrew

    1987-01-01

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

  2. 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.

  3. 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.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Li, Miao

    2017-02-01

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

  6. Spacecraft orbit lifetime within two binary near-Earth asteroid systems

    NASA Astrophysics Data System (ADS)

    Damme, Friedrich; Hussmann, Hauke; Oberst, Jürgen

    2017-10-01

    We studied the motion of medium-sized and small spacecraft orbiting within the binary asteroid systems 175,706 (1996 FG3) and 65,803 Didymos (1996 GT). We have considered spacecraft motion within the binary systems distance regimes between 0.4 and 2.5 km for Didymos and 0.8-4 km for 1996 FG3. Orbital motion of spacecraft, beginning from 20,000 initial conditions lying in the orbital planes of the secondary, were simulated and evaluated for lifespan. The simulations include the effects of (1) the asteroid's mass, shape, and rotational parameters, (2) the secondary's mass and orbit parameters, (3) the spacecraft mass, surface area, and reflectivity (representing large box-wing-shaped medium-sized spacecraft as well as small satellites), and (4) the time of the mission, and therefore the relative position of the system to the sun. Stable orbital motion (i.e., not requiring thrusting maneuvers) was achieved using the Lagrange points L4/L5 and orbital resonances. This allows for long motion arcs, e.g. of 90 days (L4) and 35 days (resonance) in the Didymos system. The accuracy necessary to deploy a probe into L4, so it can remain there for 35 day, is evaluated by comparisons. Retrograde orbits were found assuring 90 days of low eccentric orbiting for a compact small satellite for a great variety of initial conditions. The comparison of simulations at aphelion and perihelion as well as the different spacecraft show the critical impact of solar radiation pressure on orbital stability. 65,803 Didymos (1996 GT) is shown to be more suitable for orbit phases at the close distances we studied compared to 175,706 (1996 FG3). Two possible obliquities of the Didymos system were considered to study the effects of the inclination on perturbing forces at equinox and solstice, showing that cases of low obliquity or times of equinox are beneficial for spacecraft orbiting.

  7. 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.

  8. 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.

  9. Orbital Parameters for Two Young Spectroscopic Binary Systems

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Simulation of DKIST solar adaptive optics system

    NASA Astrophysics Data System (ADS)

    Marino, Jose; Carlisle, Elizabeth; Schmidt, Dirk

    2016-07-01

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

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  18. 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

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

    PubMed

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

    2014-09-05

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

  20. Solar powered desalination system using Fresnel lens

    NASA Astrophysics Data System (ADS)

    Sales, M. T. B. F.

    2016-11-01

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