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Distributions of Wide Binary Stars in Theory and in Gaia Data. I. Generalized Ambartsumian (1937) Approach and the Family of Power-law Distributions of Eccentricity
Makarov, Valeri V.
The orbital parameter space of wide, weakly bound binary stars has been shaped by the still poorly known circumstances of their formation, as well as by subsequent dynamical evolution in parent clusters and in the field. The advance of the Gaia mission astrometry takes statistical studies of wide stellar systems to an unprecedented level of precis…
Demographics of M Dwarf Binary Exoplanet Hosts Discovered by TESS
Lester, Kathryn V.; Schlieder, Joshua E.; Howell, Steve B. +15 more
M dwarfs have become increasingly important in the detection of exoplanets and the study of Earth-sized planets and their habitability. However, 20%–30% of M dwarfs have companions that can impact the formation and evolution of planetary systems. We use high-resolution imaging and Gaia astrometry to detect stellar companions around M dwarf exoplan…
Unveiling the binary nature of NGC 2323
Wang, Long; Chen, Li; Zhong, Jing +9 more
Context. As a well-known open cluster, NGC 2323 (also called M50) has been widely investigated for over a hundred years and has always been considered a classical single cluster. Aims. We studied the binary structure nature of NGC 2323 with Gaia Data Release 3 (DR3). Methods. We discovered the binary structure of NGC 2323 by the HDBSCAN algorithm …
Finite-lens Effect on Self-lensing in Detached White Dwarfs-main Sequence Binary Systems
Sajadian, Sedighe; Fatheddin, Hossein
In edge-on and detached binary systems, including a white dwarf (WD) and a main-sequence (MS) star system (or WDMS), when the source star is passing behind the compact companion its light is bent and magnified. Meanwhile, some part of its image's area is obscured by the WD's disk. These two effects occur simultaneously, and the observer receives t…
Estimating the Mass Escaping Rates of Radius-valley-spanning Planets in the TOI-431 System via X-Ray and Ultraviolet Evaporation
Zhu, Zong-Hong; Jiang, Xiaoming; Jiang, Jonathan H. +1 more
The TOI-431 system has three close-in exoplanets, which gives an ideal lab to study gas escape. In this study, we measure the X-ray and ultraviolet luminosity for TOI-431 with XMM-Newton's European Photon Imaging Camera-pn and Optical/UV Monitor Telescope data, then calculate the fluxes for the planets in the system. We find TOI-431 b's
IXPE observation of the low-synchrotron peaked blazar S4 0954+65 during an optical-X-ray flare
Kaaret, Philip; Wu, Kinwah; Enoto, Teruaki +135 more
The X-ray polarization observations, made possible with the Imaging X-ray Polarimetry Explorer (IXPE), offer new ways of probing high-energy emission processes in astrophysical jets from blazars. Here, we report the first X-ray polarization observation of the blazar S4 0954+65 in a high optical and X-ray state. During our multi-wavelength (MWL) ca…
The TW Hydrae Association is a cluster chain of Sco-Cen
Miret-Roig, N.; Bouy, H.; Figueras, F. +9 more
The TW Hydrae Association (TWA) is a young local association (YLA) about 50 pc from the Sun, offering a unique opportunity to study star and planet formation processes in detail. We characterized TWA's location, kinematics, and age, investigating its origin within the Scorpius-Centaurus (Sco-Cen) OB association. Using Gaia DR3 astrometric data and…
Spherical bias in the 3D reconstruction of the ICM density profile in galaxy clusters
Rossetti, M.; Veronesi, I.; Bartalucci, I. +9 more
Context. X-ray observations of galaxy clusters are routinely used to derive radial distributions of intracluster medium (ICM) thermodynamical properties, such as density and temperature. However, observations only allow access to quantities projected on the celestial sphere, so an assumption on the three-dimensional distribution of the ICM is nece…
A Time-dependent Spectral Analysis of γ Cassiopeiae
Nichols, Joy S.; Huenemoerder, David P.; Ignace, Richard +7 more
We investigated the temporal and spectral features of γ Cassiopeiae's X-ray emission within the context of the white dwarf (WD) accretion hypothesis. We find that the variabilities present in the X-ray data show two different signals, one primarily due to absorption and the other due to flickering like in nonmagnetic cataclysmic variables. We then…
The lithium-rich giant stars puzzle: New observational trends for a general-mass-loss scenario
de la Reza, R.
The existence of one percent of lithium-rich giant stars among normal, lithium-poor giant stars continues to be poorly explained. By merging two catalogues – one containing 10,535 lithium-rich giant stars with lithium abundances ranging from 1.5 to 4.9 dex, and the other detecting infrared sources – we have found 421 clump giant stars and 196 firs…