Related papers: Eleven New DAVs from the Sloan Survey
The pulsating DA white dwarfs are the coolest degenerate stars that undergo self-driven oscillations. Understanding their interior structure will help to understand the previous evolution of the star. To this end, we report the analysis of…
Results of nonradial, nonadiabatic pulsation calculations on hydrogen-rich white dwarf models are presented. In contrast to earlier attempts, the modeling builds on hydrodynamically simulated convective surface layers supplemented with…
A photometric variability study of a sample of northern field stars, which previously classified as either PMS or Herbig Ae/Be objects, has been undertaken with the purpose of detecting {\delta} Scuti-type pulsations. Determination of…
The {\sl TESS} space mission has recently demonstrated its great potential to discover new pulsating white dwarf and pre-white dwarf stars, and to detect periodicities with high precision in already known white-dwarf pulsators. We report…
Ultraviolet observations using the Solar Blind Channel on the Hubble Space Telescope provide light curves and low resolution spectra of three pulsating white dwarfs in the cataclysmic variables SDSS013132.39-090122.3,…
The mean pulsation period of ZZ Ceti stars increases with decreasing effective temperature as we traverse from the blue to the red edge of the instability strip. This well-established correlation between the mean period and spectroscopic…
As part of the NASA Kepler Guest Observer program, we requested and obtained long-cadence data on about 2700 faint (magnitude 14-16) Kepler stars with effective temperatures and surface gravities that lie near or within the pulsation…
We introduce the first results from an ongoing, systematic survey for new symbiotic stars selected from the AAO/UKST SuperCOSMOS H$\alpha$ Survey (SHS). The survey aims to identify and characterise the fainter population of symbiotic stars…
There are different classes of pulsating stars in the H-R diagram. While many of those classes are undisputed, some remain a mystery such as the objects historically called "Maia variables". Whereas the presence of such a class was…
Using an image subtraction method we have searched for variable stars in the globular cluster M14. We confirmed 62 previously known catalogued variables. In addition to the previoulsy known variables we have identified 71 new variables. We…
As white-dwarf (WD) stars cool, they go through one or more stages of $g$(gravity)-mode pulsational instability, becoming multiperiodic variable stars. Stars passing through these instability domains allow astronomers to study their…
Coordinates, magnitudes and spectra are presented for 39 cataclysmic variables found in Sloan Digital Sky Survey spectra that were primarily obtained in 2006. Of these, 12 were CVs identified prior to the SDSS spectra (GY Cnc, GO Com, ST…
We present an asteroseismological analysis of four ZZ Ceti stars observed with \emph{Kepler}: GD 1212, SDSS J113655.17+040952.6, KIC 11911480 and KIC 4552982, based on a grid of full evolutionary models of DA white dwarf stars. We employ a…
The search was performed for cataclysmic variable stars with outlying infrared magnitudes in USNO-B1.0 catalog. The selection was limited to objects in the Northern hemisphere with (B1-R1) < 1 and (R2-I) > 3.5. The search method is…
The New Luyten Two-Tenths catalog contains a large number of high-proper motion white dwarf candidates that remain to be spectroscopically confirmed. We present new spectroscopic observations as well as SDSS archival spectra of 49 white…
We report the detection of 1143 variable stars towards the Galactic bulge, including 320 previously uncatalogued variables, using time-series photometry extracted from data obtained with the VIMOS imager at the Very Large Telescope.…
We initiated digitization of the Moscow collection of astronomical plates using flatbed scanners. Techniques of photographic photometry of the digital images were applied, enabling an effective search for new variable stars. Our search for…
Variability is examined in over 2.6 million stars covering 11 square degrees of the core of the Sagittarius dwarf spheroidal galaxy (Sgr dSph) from VISTA Z-band observations. Generally, pulsation on the Sgr dSph giant branches appears to be…
We present accurate trigonometric parallaxes for 20 new members of the 25 pc white dwarf sample as part of the DENSE project (Discovery and Evalution of Nearby Stellar Embers, http://www.DenseProject.com). Previously, there were a total of…
Hot DQ white dwarfs constitute a new class of white dwarf stars, uncovered recently within the framework of the SDSS project. Recently, three hot DQ white dwarfs have been reported to exhibit photometric variability with periods compatible…