Search Publications
The explosive life of massive binaries
Renzo, M.; Zapartas, E.
Massive stars are born predominantly as members of binary (or higher multiplicity) systems, and the presence of a companion can significantly alter their life and final fate. Therefore, any observed sample of massive stars or associated transients is likely to be significantly influenced by the effects of binarity. Here, we focus on the relationsh…
Close eclipsing binary BD And: a triple system
Perdelwitz, V.; Kundra, E.; Guenther, E. +5 more
BD And is a fairly bright (V = 10.8), active and close (P ∼ 0.9258 days) eclipsing binary. The cyclic variability of the apparent orbital period as well as third light in the light curves indicate the presence of an additional late-type component. The principal aim is the spectroscopic testing of the third-body hypothesis and determination of abso…
The importance of studying active giant stars in eclipsing binaries - and the role of citizen scientists in finding them
Derekas, A.; Vanderburg, A.; Rappaport, S. +2 more
Red giant stars with deep convection zones and rapid rotation maintain a strong surface magnetic field which may alter their observable astrophysical parameters. The resulting lower surface temperature due to spots makes the inferred masses and ages from evolutionary tracks uncertain. Eclipsing binaries having an active giant component can help in…
An investigation of low-mass-ratio EW systems from the Catalina Sky Survey
Papageorgiou, A.; Catelan, M.; Christopoulou, P. E. +1 more
We have conducted a survey of overcontact binary systems (EW) with mass ratio ≤ 0.25 from the Catalina Sky Survey (CSS) that are considered strong merger candidates and are probable progenitors of FK Com-type stars and blue stragglers. The discovery of such extreme mass ratio overcontact binaries is vital to resolve the critical mass ratio ambigui…
CPCS 2.0 — new automatic tool for time-domain astronomy
Rybicki, K.; Wyrzykowski, Ł.; Zieliński, P. +3 more
The Cambridge Photometric Calibration Server (CPCS) has been designed to respond to the need of automated rapid photometric data calibration and dissemination for transient events, primarily from Gaia space mission. The Calibration Server has been in operation since 2013 and has been used to calibrate around 50 000 observations of hundreds of tran…
Improvement of positional accuracy of Solar system bodies ground-based observations with CCD-imaging of close approaches of them with Gaia stars
Bikulova, D. A.
Current release of the Gaia mission provides representation of a new reference frame on an unprecedent level of accuracy. This astrometric catalogue is practically free of systematic errors with respect to astrometric ground-based observations. First applications Gaia DR1 and Gaia DR2 as a reference in an analysis of CCD-observations of asteroids …
Independent study and spectral classification of a sample of poorly studied high proper motion M-dwarf candidate stars
Merc, J.; Csörnyei, G.; Cabello, C. +2 more
We report an independent spectral classification of a sample of poorly studied M-dwarf candidate stars observed with the OSIRIS instrument at GTC. Our project was carried out as an independent test of the spectral classification. It is crucial for the studies of extrasolar planets orbiting M-dwarfs, since properties of the host star are directly r…
Photometric and spectroscopic investigation of nine Cepheids in the Cassiopeia constellation
Handler, G.; Zejda, M.; Paunzen, E. +3 more
We present new multicolor BVRI photometry and low-resolution spectroscopy of 9 fundamental mode Cepheids in the Cassiopeia constellation. Observations were carried out during the 2017/2018 observing season. We investigated each particular light curve in detail using Fourier decomposition techniques which we compare with the Cepheids from the OGLE …
Galactic astronomy and small telescopes
Zwitter, T.
The second data release of ESA's Gaia satellite (Gaia DR2) revolutionised astronomy by providing accurate distances, proper motions, apparent magnitudes, and in many cases temperatures and radial velocities for an unprecedented number of stars. These new results, which are freely available, need to be considered in virtually any stellar research p…
Analysis of exoplanetary system WASP-118
Fedurco, M.; Vaňko, M.; Parimucha, Š. +1 more
We present a new study of a recently discovered exoplanetary system WASP-118. The system consists of an F-type star and a close-in giant planet (an inflated hot Jupiter). Using Kepler-K2 observations, we re-determined the orbital and physical parameters of the system. Our results are in good agreement with the values published in the literature. T…