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The Solar Neighborhood. LII. M Dwarf Twin Binaries—Presumed Identical Twins Appear Fraternal in Variability, Rotation, Hα, and X-Rays
Henry, Todd J.; Osten, Rachel A.; Jao, Wei-Chun +4 more
We present an investigation into the rotation and stellar activity of four fully convective M dwarf "twin" wide binaries. Components in each pair have (1) astrometry confirming they are common-proper-motion binaries, (2) Gaia BP, RP, and 2MASS J, H, and K s magnitudes matching within 0.10 mag, and (3) presumably the same age and compo…
Light Curves and Period Analysis of Beta Lyrae Stars
Mennickent, R. E.; Garcés, J.; Cortés, C. C. +1 more
We present the light-curve period analysis of 36 Beta Lyrae stars from the OMC Archive. We check the reference period of the sample by applying the phase dispersion minimization periodogram. From our research, we determine the orbital period of five stars in the sample. One of them is CP Psc, showing a prominent hump in the light curve before the …
ELM of ELM-WD: An Extremely-low-mass Hot Star Discovered in LAMOST Survey
Chen, Xuefei; Li, Zhenwei; Zhang, Haotong +7 more
The extremely-low-mass white dwarfs (ELM WDs) and pre-ELM WDs are helium-core white dwarfs with mass <~ 0.3M ⊙. Evolution simulations show that a lower mass limit for ELM WDs exists at ≈0.14M ⊙ and no ELM WD is proposed by observation to be less massive than that. Here we report the discovery of a binary system, LAMOST J22…
Feasibility of Observing Gamma-Ray Polarization from Cygnus X-1 Using a CubeSat
Chang, Hsiang-Kuang; Laurent, Philippe; Rodriguez, Jerome +7 more
Instruments flown on CubeSats are small. Meaningful applications of CubeSats in astronomical observations rely on the choice of a particular subject that is feasible for CubeSats. Here we report the result of a feasibility study for observing gamma-ray polarization from Cygnus X-1 using a small Compton polarimeter on board a 3U CubeSat. Silicon de…
V348 And and V572 Per: Bright Triple Systems with Eccentric Eclipsing Binaries
Wolf, M.; Uhlař, R.; Zasche, P. +5 more
The eclipsing binaries are still important objects for our understanding of the universe. Especially these ones located within the more complex multiple systems can help us solving the problem of their origin and subsequent evolution of these higher order multiples. Photometry and spectroscopy spanning over more than 25 yr were used for the first …
The Period Analysis of V418 Aql, SU Boo, RV CVn, CR Cas, GV Cyg, V432 Per, and BD+42 2782
Wolf, M.; Kučáková, H.; Uhlař, R. +1 more
The minimum timings of eclipsing binaries V418 Aql, SU Boo, RV CVn, CR Cas, GV Cyg, V432 Per, and BD+42 2782 were collected and analyzed. Their long-term behavior was studied via period analysis, revealing a periodic term in eclipse times. We derived 576 new times of minimum. Hence, to describe the periodic variation, a third-body hypothesis was p…
The Photometric Study of a Neglected Near Contact Binary: BS Vulpeculae
Zejda, M.; Liška, J.; Qian, S. -B. +3 more
We present a detailed study of the close eclipsing binary BS Vulpeculae. Although it is relatively bright (V: 10.9-11.6 mag) and belongs to short-periodic variable stars (P = 0.48 days), it is rather neglected. To perform a thorough period analysis, we collected all available photometric observations that span the time interval of 1898-2010. Obser…
Early Optical Observations of Gamma-Ray Bursts by the TAROT Telescopes: Period 2001-2008
Klotz, A.; Gendre, B.; Atteia, J. L. +1 more
The Télescopes à Action Rapide pour les Objets Transitoires telescopes are two robotic observatories designed to observe the prompt optical emission counterpart and the early afterglow of gamma-ray bursts (GRBs). We present data acquired between 2001 and 2008 and discuss the properties of the optical emission of GRBs, noting various interesting re…
A Catalog of Visual Double and Multiple Stars With Eclipsing Components
Wolf, M.; Gazeas, K.; Liakos, A. +4 more
A new catalog of visual double systems containing eclipsing binaries as one component is presented. The main purpose of this catalog is to compile a complete list of all known multiples of this variety, both for current analysis and to highlight those in need of additional observations. All available photometric and astrometric data were analyzed,…
Accretion Properties of a Sample of Hard X-Ray (<60 keV) Selected Seyfert 1 Galaxies
Wang, J.; Wei, J. Y.; Mao, Y. F.
We examine the accretion properties in a sample of 42 hard (3-60 keV) X-ray selected nearby broad-line active galactic nuclei (AGNs). The energy range in the sample is harder than that usually used in similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey, and complemented by the released INTEGRAL AGN catalog. The bl…