Related papers: New tools for finding and testing of weak periodic…
Stars exhibit a bewildering variety of variable behaviors ranging from explosive magnetic flares to stochastically changing accretion to periodic pulsations or rotations. The principal LSST surveys will have cadences too sparse and…
We present a sample of 59 periodic variables from the Palomar Transient Factory, selected from published catalogues of white dwarf (WD) candidates. The variability can likely be attributed to ellipsoidal variation of the tidally distorted…
We consider the estimation of a common period for a set of functions sampled at irregular intervals. The problem arises in astronomy, where the functions represent a star's brightness observed over time through different photometric…
Aims. We analyze the population of periodic variable stars in the open cluster NGC 3766 based on a 7-year multi-band monitoring campaign conducted on the 1.2 m Swiss Euler telescope at La Silla, Chili. Methods. The data reduction, light…
The growing number of multi-epoch optical and infrared sky surveys are uncovering unprecedented numbers of new variable stars, of an increasing number of types. The short interval between observations in adjacent near infrared filters in…
We present new periodograms that are effective in distinguishing Doppler shift from spectral shape variability in astronomical spectra. These periodograms, building upon the concept of partial distance correlation, separate the periodic…
The magnetic field of the CP star HD 14437 was discovered by Glagolevskij et al. (1985) using the 6-m telescope of the Special Astrophysical Observatory. No polarity changes have been found during 2 years of observations. A very long (> 3-4…
Context. A thousand new magnetic candidate CP stars have been identified with LAMOST, among which about 700 prime targets have rotational modulation determined from TESS. Aims. We aim to check for the presence of a magnetic field in a…
We report time-series photometry for 16 variable stars located in the central part of the globular cluster NGC 6752. The sample includes 13 newly identified objects. The precision of our differential photometry ranges from 1 mmag at V=14.0…
We performed R-band time series observations of the young, metal rich open cluster NGC 2301 for 12 nights in Feb. 2004. B images were also obtained and color magnitude diagrams, having limits of R=19.5 and B=21.5, were produced. Only asmall…
Magnetic chemically peculiar (mCP) stars of the upper part of the main sequence usually exhibit strictly periodic variations of their light, spectrum and magnetic field. These changes can be well explained using the oblique rotator model of…
The search for radio signals from exoplanets or star-planet interactions is a topic of major scientific interest, as it is likely the best way to detect and measure a planetary magnetic field and, therefore, to probe the inner structure of…
Spectra of four non-magnetic chemically peculiar late B type stars (HgMn) stars are analysed to detect periodic spectral line variations (LPVs). A procedure developed to study LPVs in Slowly Pulsating B stars has been adopted as pulsational…
An automatic Bayesian Kepler periodogram has been developed for identifying and characterizing multiple planetary orbits in precision radial velocity data. The periodogram is powered by a parallel tempering MCMC algorithm which is capable…
We have monitored four fields containing nine previously identified members of the MBM 12 association to search for photometric variability and periodicity in these pre-main sequence stars. Seven of the nine are found to be variable and…
Recently the OGLE experiment has provided accurate light curves and colours for about 2 millions stars in the Small Magellanic Cloud. We have examined this database for its content of Be stars, applying some selection criteria, and we have…
Optical spectroscopic monitoring has been conducted of two O stars in the Small and one in the Large Magellanic Cloud, the spectral characteristics of which place them in the Of?p category, which has been established in the Galaxy to…
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have been analyzed in search of variable…
We present a methodology to discover outliers in catalogs of periodic light-curves. We use cross-correlation as measure of ``similarity'' between two individual light-curves and then classify light-curves with lowest average ``similarity''…
Many astrophysical phenomena are time-varying, in the sense that their brightness change over time. In the case of periodic stars, previous approaches assumed that changes in period, amplitude, and phase are well described by either…