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121.
《New Astronomy》2015
An updated period analysis for the overcontact eclipsing binary ER Orionis is presented. Featured is an improved derivation of parameters for the light time effect (LTE) due to the third star (in actuality, a pair of stars) utilising the latest set of eclipse timings. The very good fit between the eclipse timing differences (ETD) plot (otherwise known as an O–C diagram) and the theoretical ETD curve makes possible an improved determination of the rate of mass interchange between the binary pair, dm1/dt = +1.83(6) × 10−7 Mʘ/year. In addition, the mass of the companion system (in actuality, m3 sin i) and the elements of its orbit were computed. A suggestion is made for a method of future determination of the inclination of the orbit of the companion system. 相似文献
124.
127.
《New Astronomy》2015
In this article, a period analysis of the late-type eclipsing binary VV UMa is presented. This work is based on the periodic variation of eclipse timings of the VV UMa binary. We determined the orbital properties and mass of a third orbiting body in the system by analyzing the light-travel time effect. The O−C diagram constructed for all available minima times of VV UMa exhibits a cyclic character superimposed on a linear variation. This variation includes three maxima and two minima within approximately 28,240 orbital periods of the system, which can be explained as the light-travel time effect (LITE) because of an unseen third body in a triple system that causes variations of the eclipse arrival times. New parameter values of the light-time travel effect because of the third body were computed with a period of 23.22 ± 0.17 years in the system. The cyclic-variation analysis produces a value of 0.0139 day as the semi-amplitude of the light-travel time effect and 0.35 as the orbital eccentricity of the third body. The mass of the third body that orbits the eclipsing binary stars is 0.787 ± 0.02 M⊙, and the semi-major axis of its orbit is 10.75 AU. 相似文献
128.
《New Astronomy》2015
We present a photometric study of a weak-contact binary V873 Per. New observations in BVR filter bands showed asymmetric light curves to be a negative type of the O’Connell effect, which can be described by magnetic activity of a cool spot on the more massive component. Our photometric solutions showed that V873 Per is a W-type with a mass ratio of q = 2.504(±0.0029), confirming the results of Samec et al. (2009). The derived contact degree was found to be f = 18.10%(±1.36%). Moreover, our analysis found the cyclic variation with the period of about 4 yr that could be due to existence of the third companion in the system or the mechanism of magnetic activity cycle in the binary. While available data indicated that the long-term orbital period tends to be stable rather than decreasing. 相似文献
129.
Two CCD epochs of light minimum and a complete R light curve of SS Ari are presented. The light curve obtained in 2007 was
analyzed with the 2003 version of the W-D code. It is shown that SS Ari is a shallow contact binary system with a mass ratio
q=3.25 and a degree of contact factor f=9.4%(±0.8%). A period investigation based on all available data shows that there may exist two distinct solutions about the
assumed third body. One, assuming eccentric orbit of the third body and constant orbital period of the eclipsing pair, results
in a massive third body with M
3=1.73M
⊙ and P
3=87.0 yr. On the contrary, assuming continuous period changes of the eclipsing pair the orbital period of tertiary is 37.75
yr and its mass is about 0.278M
⊙. Both of the cases suggest the presence of an unseen third component in the system. 相似文献
130.
Half of the energy ever emitted by stars and accreting objects comes to us in the far-infrared (FIR) waveband and has yet
to be properly explored. We propose a powerful Far-InfraRed Interferometer mission, FIRI, to carry out high-resolution imaging spectroscopy in the FIR. This key observational capability is essential to reveal how
gas and dust evolve into stars and planets, how the first luminous objects in the Universe ignited, how galaxies formed, and
when super-massive black holes grew. FIRI will disentangle the cosmic histories of star formation and accretion onto black holes and will trace the assembly and evolution
of quiescent galaxies like our Milky Way. Perhaps most importantly, FIRI will observe all stages of planetary system formation and recognise the birth of planets via its ability to image the dust
structures in planetary systems. FIRI is an observatory-class mission concept: three cold, 3.5-m apertures, orbiting a beam-combining module, with separations
of up to 1 km, free-flying or tethered, operating between 25 and 385 μm, using the interferometric direct-detection technique
to ensure μJy sensitivity and 0.02” resolution at 100 μm, across an arcmin2 instantaneous field of view, with a spectral resolution, R ~ 5,000 and a heterodyne system with R ~ 1 million. Although FIRI is an ambitious mission, we note that FIR interferometry is appreciably less demanding than at shorter wavelengths.
On behalf of the following scientists: Javier Alcolea, David Alexander, Philippe Andre, Rafael Bachiller, Mike Barlow, Andrey
Baryshev, Alain Baudry, Carlton Baugh, Dominic Benford, Ted Bergin, Frank Bertoldi, Geoffrey Blake, Andrew Blain, Sylvain
Bontemps, Franois Bouchet, Francois Boulanger, Jeroen Bouwman, Jonathan Braine, Bernhard Brandl, Valentin Bujarrabal, Sylvie
Cabrit, Martin Caldwell, Daniela Calzetti, John Carpenter, Emmanuel Caux, Cecilia Ceccarelli, Jose Cernicharo Quintanilla,
Pierre Chanial, Andrea Cimatti, John Conway, Pierre Cox, Dave Clements, Bill Dent, Gianfranco De Zotti, Carsten Dominik, Loretta
Dunne, Steve Eales, Nicholas Elias, Duncan Farrah, Mike Fich, Jacqueline Fischer, Alberto Franceschini, David Frayer, Carlos
Frenk, Gary Fuller, Maryvonne Gerin, Martin Giard, Thijs de Graauw, Gian Luigi Granato, Jane Greaves, Matt Griffin, Rolf Guesten,
Stephane Guilloteau, Martin Harwit, Thomas Henning, Eric Herbst, Michiel Hogerheijde, Kate Isaak, Christine Joblin, Eelco
van Kampen, Hubert Klahr, Kirsten Kraiberg Knudsen, Oliver Krause, Cedric Lacey, Robert Laing, Jean-Michel Lamarre, Huib Jan
van Langevelde, David Leisawitz, Simon Lilly, Darek Lis, Rene Liseau, Enrico Lorenzini, Dieter Lutz, Michael Macintyre, Suzanne
Madden, Roberto Maiolino, Jesus Martin-Pintado, Karine Mercier, Karl Menton, Vincent Minier, Raphael Moreno, Harvey Moseley,
Takao Nakagawa, David Neufeld, Michael Olberg, Seb Oliver, Luca Olmi, Goran Olofsson, Hans Olofsson, Mat Page, Pantelis Papadopoulos,
Juan Pardo, John Pearson, Ismael Perez-Fournon, Sabine Philipp, Rene Plume, Albrecht Poglitsch, Jean-Loup Puget, John Richer,
Dimitra Rigopoulou, Stephen Rinehart, Peter Roelfsema, Paolo Saraceno, Rudolf Schieder, Karl-Friedrich Schuster, Gene Serabyn,
Stephen Serjeant, Robert Simon, Ian Smail, Luigi Spinoglio, Jason Stevens, Eckhard Sturm, Juergen Stutzki, Bruce Swinyard,
Emma Taylor, Floris van der Tak, Leonardo Testi, Wing-Fai Thi, Mattia Vaccari, Lars Venema, Laurent Vigroux, Serena Viti,
Catherine Vlahakis, Christoffel Waelkens, Malcolm Walmsley, Fabian Walter, Rens Waters, Paul van der Werf, Paul Wesselius,
Glenn White, Wolfgang Wild, Tom Wilson, Adam Woodcraft, Gillian Wright, FriedrichWyrowski, Harold Yorke, Min Yun, Jonas Zmuidzinas 相似文献