Search Publications
Ground-Based Observations of the ZZ Ceti Star HS 1625+1231
Sódor, Á.; Kalup, Cs; . Bognár, Zs.
We present the results of our detailed light curve analysis of the ZZ Ceti star HS 1625+1231. We collected photometric time series data at Konkoly Observatory on 14 nights, and performed Fourier analysis of these data sets. We detected 11 significant frequencies, where six of them are found to be independent pulsation modes in the 514-881 s period…
Photometric and Spectroscopic Investigations of the Galactic Field RRc Candidates V764 Mon and HY Com
Pál, A.; Sódor, Á.; Benkő, J. M.
By analyzing photometric and spectroscopic time series, we show that the pulsator V764 Mon, assumed to be the brightest RR Lyr star in the sky, is in fact a rapidly rotating δ Sct star with an unusually long dominant period (P1=0.29 d). Our spectroscopy confirmed the binarity of V764 Mon discovered by the Gaia satellite. In the case of …
Search for Planets in Hot Jupiter Systems with Multi-Sector TESS Photometry. I. No Companions in Planetary Systems KELT-18, KELT-23, KELT-24, Qatar-8, WASP-62, WASP-100, WASP-119, and WASP-126
Maciejewski, G.
Origins of giant planets on tight orbits, so called hot Jupiters, are a long-lasting question in the planetary formation and evolution theory. The answer seems to be hidden in architectures of those systems that remain only partially understood. Using multi-sector time-series photometry from the Transiting Exoplanet Survey Satellite, we searched f…
Properties of the Milky Way's Old Populations Based on Photometric Metallicities of the OGLE RR Lyrae Stars
Soszyński, I.; Udalski, A.; Szymański, M. K. +11 more
We have used photometric data on almost 91 000 fundamental-mode RR Lyr stars (type RRab) detected by the OGLE survey to investigate properties of old populations in the Milky Way. Based on their metallicity distributions, we demonstrate that the Galaxy is built from three distinct old components: halo, bulge, and disk. The distributions reach thei…
Orbital Period Analysis of Four Eclipsing Binaries XY Boo, RW Com, MR Del and AK Her
Yılmaz, M.; Selam, S. O.; Özavcı, İ. +9 more
The orbital period variations of the eclipsing binaries XY Boo, RW Com, MR Del, and AK Her are investigated. This study includes the first orbital period analysis of the detached eclipsing binary MR Del and necessary updates for the remaining stars with addition of new mid-eclipse times calculated from our recent observations carried out at Ankara…
A Newtonian Model for the WASP-148 Exoplanetary System Enhanced with TESS and Ground-based Photometric Observations
Fernández, M.; Maciejewski, G.; Sota, A. +1 more
The WASP-148 planetary system has a rare architecture with a transiting Saturn-mass planet on a tight orbit which is accompanied by a slightly more massive planet on a nearby outer orbit. Using new space-born photometry and ground-based follow-up transit observations and data available in literature, we performed modeling that accounts for gravita…
On the Pulsations of the δ Scuti Star of the Binary System KIC 6629588
Liakos, A.
This work includes a comprehensive analysis of the Kepler detached eclipsing binary system KIC 6629588 that aims at the detailed study of the oscillation properties of its pulsating component. Ground-based spectroscopic observations were obtained and used to classify the components of the system. The spectroscopic results were used as constraints …
Photocenter Shift Effect in Double Stars of Gaia DR2 Database
Ling, J. F.; López Oriona, A.; Sánchez Sellero, C.
In order to check the performance of the Gaia satellite when detecting double stars, we attempted to discover a photocenter shift affecting Gaia's second data release (Gaia DR2). We analyzed data of bona-fide double stars from "Double and Multiple System Annex" catalog and matched them with the Gaia DR2 catalog. We tried to derive a relationship b…
High-Velocity Moving Groups in the Solar Neighborhood in Gaia DR2
Baluev, R. V.; Shaidulin, V. Sh.; Veselova, A. V.
We use an improved wavelet analysis technique to reconstruct the (U,V,W) velocity distribution for ≈250 000 stars from Gaia DR2, located in the solar neighborhood of 200 pc. The 2D wavelet transforms for three bivariate distributions (U,V), (U,W), and (V,W) were investigated. Though most of currently known (low-velocity) stellar moving groups are …
The Clusters AgeS Experiment (CASE). Variable Stars in the Field of the Globular Cluster NGC 3201 - a Supplement
Thompson, I. B.; Rozyczka, M.; Pych, W. +1 more
We report the detection of 20 new variables in the field of NGC 3201. Among them there are 15 confirmed cluster members. Follow-up observations are desirable for two blue stragglers with variable light curves (probably resulting from magnetic activity), and for a yellow straggler coinciding with a Chandra X-ray source. Two of the eclipsing binarie…