Search Publications
A photometric study of NSVS 7453183: a probable quadruple system with long-term surface activity
Wolf, M.; Zejda, M.; Kučáková, H. +5 more
The VRC light curves were regularly measured for the eclipsing binary NSVS 7453183 as a part of our long-term observational project for studying of low-mass eclipsing binaries with a short orbital period and surface activity. The TESS light curve solution in PHOEBE results to the detached configuration, where the temperature of primary component w…
General relativistic pulsations of ultra-massive ZZ Ceti stars
Kepler, S. O.; Córsico, Alejandro H.; Althaus, Leandro G. +4 more
Ultra-massive white dwarf stars are currently being discovered at a considerable rate, thanks to surveys such as the Gaia space mission. These dense and compact stellar remnants likely play a major role in Type Ia supernova explosions. It is possible to probe the interiors of ultra-massive white dwarfs through asteroseismology. In the case of the …
XGAPS: a sub-arcsec cross-match of galactic plane surveys
Knigge, C.; Groot, P. J.; Monguió, M. +5 more
We present a sub-arcsec cross-match of Gaia Data Release 3 (DR3) against the INT Galactic Plane Surveys (IGAPS) and the United Kingdom Infrared Deep Sky Survey (UKIDSS). The resulting cross-match of Galactic Plane Surveys (XGAPS) provides additional precise photometry (URGO, g, r, i, Hα, J, H, and K) to the Gaia photometry. In building …
VLBI astrometry on the white dwarf pulsar AR Scorpii
Zhang, Bo; Yang, Jun; An, Tao +12 more
AR Scorpii (AR Sco), the only-known radio-pulsing white dwarf binary, shows unusual pulsating emission at the radio, infrared, optical, and ultraviolet bands. To determine its astrometric parameters at the radio band independently, we conducted multi-epoch Very Long Baseline Interferometry (VLBI) phase-referencing observations with the European VL…
A non-detection of red supergiant convection in Gaia
Kochanek, C. S.
Large-scale surface convection on red supergiants (RSGs) can lead to shifts in the photocentre of the star that might be measured by Gaia and used as a new probe of the surface dynamics of these rare but important stars. Unlike brightness variations, photocentre motions would provide information on the physical scale of the convective cells. The s…
Cross-matching the General Catalogue of Variable Stars with the Gaia DR3 source catalogue
Eyer, L.; Kerschbaum, F.; Ansari, S. G.
The most recent release of the General Catalogue of Variable Stars (GCVS) (Samus et al. 2017) contains 518 different variable types, in eight different variable categories. The catalogue has now reached its 5th version available via the VizieR service and can be considered one of the primary catalogues on the subject. The Gaia Data Release 3 (DR3)…
Constraints on star formation in Orion A from Gaia
Kounkel, Marina; Hartmann, Lee; Calvet, Nuria +4 more
We develop statistical methods within a Bayesian framework to infer the star formation history from photometric surveys of pre-main-sequence populations. Our procedures include correcting for biases due to extinction in magnitude-limited surveys, and using distributions from subsets of stars with individual extinction measurements. We also make mo…
Spectroscopic follow-up of a subset of the Gaia/IPHAS catalogue of Hα-excess sources
Knigge, C.; Pala, A. F.; Monguió, M. +5 more
State-of-the-art techniques to identify Hα emission-line sources in narrow-band photometric surveys consist of searching for Hα excess with reference to nearby objects in the sky (position-based selection). However, while this approach usually yields very few spurious detections, it may fail to select intrinsically faint and/or rare Hα-excess sour…
Lack of influence of the environment in the earliest stages of massive galaxy formation
Barro, Guillermo; Pérez-González, Pablo G.; Costantin, Luca +5 more
We investigate how the environment affects the assembly history of massive galaxies. For that purpose, we make use of Survey for High-z Absorption Red and Dead Sources (SHARDS) and HST spectrophotometric data, whose depth, spectral resolution, and wavelength coverage allow to perform a detailed analysis of the stellar emission as well as obtaining…
A small survey for massive stars in the LMC/SMC: binaries and pulsations
Çakırlı, Ömür; Hoyman, Barış; Özdarcan, Orkun
Binarity and pulsations are two notable properties that frequently appear together in massive stars. To place constraints on how binarity affects stellar evolution, the exact parameters of massive stars in binary systems must be known. Their exact and accurate masses and radii, which were calculated from binary dynamics, present model-independent …