Search Publications
Detection of Eclipses in the Cataclysmic Variable LAMOST J035913.61 + 405035.0
Kozhevnikov, V. P.
I conducted photometric observations of the cataclysmic variable LAMOST J035913.61 + 405035.0 and detected eclipses. During these observations, I recorded 14 eclipses over two groups of nights separated by 13 months. I accurately determined the orbital period of the system to be $$ {P}_{\mathrm{orb}}=0.228\kern0.1em 343\kern0.1em 85\pm 0.000\kern0…
Revisiting Variable Stars Near Globular Clusters South of ‑29° Declination
Layden, Andrew C.; Evangelista, Julia; Gupta, Sakshi +5 more
We review an often-cited but seldom-accessed catalogue by Fourcade and Laborde (1966) of 785 variable stars near 47 southern Galactic globular clusters, and recover the locations of 85 stars that were not incorporated into subsequent variable star catalogues and hence have become "lost" to the literature. We match the positions of these stars with…
The HST Large Programme on NGC 6752 - V. Differences in luminosity and mass function among stellar populations
Vesperini, Enrico; Anderson, Jay; Salaris, Maurizio +8 more
We exploit the astro-photometric dataset of the multi-epoch infrared parallel field of a Hubble Space Telescope Large Programme aimed at studying the faintest stars of the globular cluster NGC 6752 to determine the luminosity and mass functions of the multiple stellar populations of this cluster. Thanks to the measurement of proper motions and dee…
HST astrometry of the closest brown dwarfs-II. Improved parameters and constraints on a third body
Apai, D.; Pourbaix, D.; Bedin, L. R. +5 more
Located at less than two pc away, Luhman 16 AB (WISE J104915.57-531906.1) is the closest pair of brown dwarfs and the third closest "stellar" system to Earth. An exoplanet candidate in the Luhman 16 binary system was reported in 2017 based on a weak astrometric signature in the analysis of 12 HST epochs. An additional epoch collected in 2018 and r…
Constraining stellar tidal quality factors from planet-induced stellar spin-up
Chiappini, Cristina; Poppenhaeger, Katja; Ilić, Nikoleta +1 more
The dynamical evolution of tight star-planet systems is influenced by tidal interactions between the star and the planet, as was shown recently. The rate at which spins and orbits in such a system evolve depends on the stellar and planetary tidal dissipation efficiency. Here, we present a method to constrain the modified tidal quality factor Q
Spectroscopic and dynamic orbital analyses of metal‑poor and high proper‑motion stars: I. HD 8724 and HD 195633
Bilir, S.; Şahin, T.; Plevne, O. +2 more
In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal‑poor and high proper‑motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar neighborhood. This analysis combines detailed abundance measurements, kinematics, and orbital dynamics to determine their origin. Standard 1D local thermodynamic equ…
Photometric and Kinematic Studies of Open Clusters Ruprecht 1 and Ruprecht 171
Bilir, Selçuk; Yontan, Talar; Banks, Timothy S. +5 more
This study outlines a detailed investigation using CCD UBV and Gaia DR3 data sets of the two open clusters Ruprecht 1 (Rup-1) and Ruprecht 171 (Rup-171). Fundamental astrophysical parameters such as color excesses, photometric metallicities, ages, and isochrone distances were based on UBV-data analyses, whereas membership probability calculations,…
Orbit of the visual binary star 61 Cyg
Izmailov, I. S.; Apetyan, A. A.
We present the orbit and the mass estimates for the components of the visual binary star 61 Cyg obtained with the positional observations, including the high-precision Gaia data, and the measurements of differences in the radial velocities and the radial accelerations of the components. Since the orbital period of this star significantly exceeds t…
Radial Metallicity Gradients for the Chemically Selected Galactic Thin Disc Main-Sequence Stars
Seabroke, G. M.; Bilir, S.; Ak, T. +3 more
We present the radial metallicity gradients within the Galactic thin disc population through main-sequence stars selected on the chemical plane using GALAH DR3 accompanied with Gaia DR3 astrometric data. The [Fe/H], [α/Fe] and [Mg/H] radial gradients are estimated for guiding radius as -0.074±0.006, +0.004±0.002, -0.074±0.006 dex kpc -1…
Updated absolute parameters and kinematics of IS CMa
Alan, Neslihan; Canbay, Remziye; Evcil, Serkan +2 more
Eclipsing binary systems are significant objects for astrophysics in that direct observations can determine the fundamental parameters of stars. In this study, we precisely determined the fundamental parameters of the binary component stars obtained by simultaneous analysis of radial velocities and the TESS light curve using the Wilson and Devinne…