Related papers: CX Lyrae 2008 Observing Campaign

We report the discovery of amplitude and phase modulations typical of the Blazhko effect in 22 RRc and 9 RRab type RR Lyrae stars in NGC 5024 (M53). This brings the confirmed Blazhko variables in this cluster to 23 RRc and 11 RRab, that…

We present the analysis of the CoRoT star 105288363, a new Blazhko RR Lyrae star of type RRab (f0 = 1.7623 c/d), observed with the CoRoT space craft during the second long run in direction of the galactic center (LRc02, time base 145 d).…

BL Lacertae was the target of an extensive multiwavelength monitoring campaign in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio (UMRAO and Metsaehovi) and optical(WEBT collaboration)…

We selected a sample of a dozen blazars which are the prime candidates for simultaneous multi-wavelength observing campaigns in their outburst phase. We searched for optical outbursts, intra-day variability and short term variability in…

In this paper it is shown that the mathematical form which most precisely describes the Blazhko RR Lyrae light curves is connected to almost periodic functions and not to the mathematics of modulation. That is, the Blazhko effect is more…

Hydrogen emissions of RR Lyrae variables are the imprints of shock waves traveling through their atmospheres. We develop a pattern recognition algorithm, which is then applied to single-epoch spectra of SDSS and LAMOST. These two…

The \textit{Kepler} space telescope observed thousands of RR Lyrae stars in the K2 mission. In this paper we present our photometric solutions using extended apertures in order to conserve the flux of the stars to the highest possible…

This study investigates periodic modulation of the light curve of the RRc star TV Boo and its physical parameters based on photometric data. This phenomenon, known as Blazhko effect, is quite rare among RRc stars. Frequency analysis based…

A significant fraction of RR Lyrae stars exhibits amplitude and/or phase modulation known as the the Blazhko effect. The oscillation spectra suggest that, at least in most of the cases, excitation of nonradial modes in addition to the…

The results of 8-year R-band photopolarimetric data of blazar Mrk 421 collected from February 2008 to May 2016 are presented, along with extensive multiwavelength observations covering from radio to TeV $\gamma$-rays around the flares…

This paper summarizes the main results of our recent study of the non-Blazhko RR Lyrae stars observed with the Kepler space telescope. These stars offer the opportunity for studying the stability of the pulsations of RR Lyrae stars and for…

We present the hydrodynamic BL Herculis-type models which display a long-term modulation of pulsation amplitudes and phases. The modulation is either strictly periodic or it is quasi-periodic, with the modulation period and modulation…

We analyzed 151 variables previously classified as fundamental mode RR Lyrae stars from Campaigns 01-04 of the Kepler two wheel (K2) archive. By employing a method based on the application of systematics filtering with the aid of…

In this paper it is shown that the Blazhko effect may result from a near-resonant type of multi-mode pulsation, where two (or sometimes more) periodic oscillations with slightly different frequencies gradually slip in phase, producing a…

We examined the complete short cadence sample of Kepler RR Lyrae stars to further investigate the recently discovered dynamical effects such as period doubling and additional modes. Here we present the findings on four stars. V450 Lyr may…

We present the optical (V, R, and I) photometry for BL Lacertae, which was observed from 1997 through 1999, with the 1.56-m telescope at the Shanghai astronomical observatory (SHAO). After the 1997 outburst, it dimmed to a low state and…

Context. RR Gem is one of the few Blazhko RR Lyrae that has photometric observations available extended enough to study the long-term courses of its pulsation and modulation properties in detail. Aims. We investigate the pulsation and…

We have performed a structure function analysis of the Rossi X-ray Timing Explorer All Sky Monitor data to search for variability in 24 blazars using data trains that each exceed 12 years. Although 20 of them show nominal periods though…

More than 1300 variables classified provisionally as first overtone RR Lyrae pulsators in the MACHO variable star database of the Large Magellanic Cloud (LMC) have been subjected to standard frequency analysis. Based on the remnant power in…

We present the results of extensive multi-band intra-night optical monitoring of BL Lacertae during 2010--2012. BL Lacertae was very active in this period and showed intense variability in almost all wavelengths. We extensively observed it…