Related papers: Multi-Mode Oscillations in Classical Cepheids and …

Detailed knowledge of the variability of classical Cepheids, in particular their modulations and mode composition, provides crucial insight into stellar structure and pulsation. However, tiny modulations of the dominant radial-mode…

The long-term behaviours of the pulsation and Blazhko periods of RR Lyr are investigated by means of Kepler and ground-based observations. The difficulties in detecting additional modes in the Cepheids monitored with CoRoT are discussed.

We report the discovery of a new case of an RR Lyrae star that experienced a switching of its pulsation mode. We detected USNO-B1.0 1171-0309158 as a double-mode RR Lyrae star from observations of the Catalina surveys (CSS) that showed…

It is shown that the oscillations of brightness in classical Cepheids and other 'pulsating' variable stars are caused rather by the passing of radial solitary waves through the photosphere of a star, than by pulsations of a star. Radial…

Photometric observations from the last decade have revealed additional low-amplitude periodicities in many classical pulsators that are likely due to pulsations in non-radial modes. One group of multi-mode RR Lyrae stars, the so-called 0.61…

We present a sample of the most interesting classical Cepheids selected from the OGLE collection of classical Cepheids in the Magellanic System. The main selection criterion for this sample was the presence of non-standard, unique…

Thanks to the space missions CoRoT and Kepler new oscillation frequencies have been discovered in the Fourier spectra of Blazhko RR Lyrae stars. The period doubling (PD) yields half-integer frequencies between the fundamental mode and its…

We present a collection of classical, type II, and anomalous Cepheids detected in the OGLE fields toward the Galactic center. The sample contains 87 classical Cepheids pulsating in one, two or three radial modes, 924 type II Cepheids…

The Blazhko effect is the conspicuous amplitude and phase modulation of the pulsation of RR Lyrae stars that was discovered in the early 20th century. The field of study of this mysterious modulation has recently been invigorated thanks to…

We report the discovery of an RR Lyrae star that experienced a switching of its pulsation mode. OGLE-BLG-RRLYR-12245 was discovered as a double-mode RRd star from the observations conducted in years 2001-2006 during the third phase of the…

A nonlinear development of radial pulsation instability to a resonant excitation of nonradial modes is studied. The theory covers the cases of axisymmetric (m=0) modes as well as (m,-m) pairs. Adopting a simplified treatment of the mode…

We analyse photometry of $\sim$2000 Galactic Cepheids available in the OGLE Collection of Variable Stars. We analyse both Galactic disk and Galactic bulge fields; stars classified both as single- and multi-periodic. Our goal was to search…

We analyse photometry for 138 first overtone Cepheids from the Small Magellanic Cloud, in which Optical Gravitational Lensing Experiment (OGLE) team discovered additional variability with period shorter than first overtone period, and…

$\omega$ Centauri (NGC~5139) contains many variable stars of different types, including the pulsating type II Cepheids, RR Lyrae and SX Phoenicis stars. We carried out a deep, wide-field, near-infrared (IR) variability survey of $\omega$…

42 RRab, 46 RRc and 7 previously unidentified double-mode RR Lyrae stars were found in the publicly available data of the WASP archive. The Galactic double-mode RR Lyrae stars appear to show a bimodal period distribution.

Over two dozen early F-type variable stars have been identified which constitute a new class of pulsating stars. These stars typically have periods between 0.5 and 3 days with V-band variability of several hundredths of a magnitude. Given…

We have analysed Optical Gravitational Lensing Experiment photometry for first overtone classical Cepheids in the Large and Small Magellanic Clouds in search for additional periodicities beyond radial modes. We have used standard…

Double-mode RR Lyrae variables (i.e. radial variables which are simultaneously pulsating in both fundamental and first overtone modes) appear a fundamental tool for investigating the mass of old Population II Horizontal Branch (HB) stars.…

The popularity of pulsating stars resides in their capacity of determining several crucial and relevant parameters such as heliocentric distances, ages, metallicity gradients and reddening. RR Lyrae stars are old stellar tracers and have…

Data on multimode Cepheids from OGLE-III catalog of the LMC Cepheids are confronted with results from model calculations. Models whose radial mode periods are consistent with observation are not always in agreement with published…