Related papers: Long-Period Variability in o Ceti

Our goal is to assess Gaia's performance on the period recovery of short period (p < 2 hours) and small amplitude variability. To reach this goal first we collected the properties of variable stars that fit the requirements described above.…

The properties of accretion disks around stars and brown dwarfs in the SOri cluster (age 3 Myr) are studied based on NIR time series photometry supported by MIR spectral energy distributions. We monitor ~30 young low-mass sources over 8…

We investigate the variability properties of main sequence stars in the first month of Kepler data, using a new astrophysically robust systematics correction, and find that 60% of stars are more variable then the active Sun. We define low…

The location of the red edge of the ZZ Ceti instability strip is defined observationally as being the lowest temperature for which a white dwarf with a H-rich atmosphere (DA) is known to exhibit periodic brightness variations. Whether this…

Context. The post-main-sequence evolution of massive stars remains poorly understood, particularly for blue supergiants. These objects play a crucial role in the dynamical and chemical evolution of galaxies and exhibit pronounced…

We present the results of analysing the long-term radio variability of active galactic nuclei at 37 GHz using data of 123 sources observed in the Aalto University Mets\"ahovi Radio Observatory. Our aim was to constrain the characteristic…

We present a detailed period analysis of the bright Cepheid-type variable star V1154 Cygni (V =9.1 mag, P~4.9 d) based on almost 600 days of continuous observations by the Kepler space telescope. The data reveal significant cycle-to-cycle…

Results of the long-term monitoring observations of the 6.7 GHz Class II methanol masers associated with the four high-mass star-forming regions by Hitachi 32-m radio telescope are presented. We detected periodic flux variability in…

Classical Be stars, regardless of spectral subtype, display multiperiodic light modulations in the frequency range 0.1-12 d$^{-1}$, when observed with high-cadence and long duration. This behaviour is attributed to non-radial pulsations…

We have observed S4 0954+658 in the BVRI bands in 2001, and in the BI bands in 2002. The observations resulted in almost evenly sampled light curves, 3-8 hours long, with an average sampling interval of ~5-15 min. Because of the dense…

We present the results of a search for short-period variable stars in Leo A. We have found 92 candidate variables, including eight candidate RR Lyrae stars. From the RR Lyraes, we measure a distance modulus of (m-M)_0 = 24.51 +/- 0.12, or…

We present the results of a short time scale monitoring of SiO maser emission (v=1 J=1-0 transition) in four known strong sources. These sources were monitored nightly for a period of about a month. The aim of these observations is to…

We analyze sparsely-sampled near-infrared (JHKs) light curves of a sample of 1781 Mira variable candidates in M33, originally discovered using I-band time-series observations. We extend our single-band semi-parametric Gaussian process…

We have obtained discrete Fourier power spectra of a sample of persistent low-mass neutron-star X-ray binaries using long-term light curves from the All Sky Monitor on board the Rossi X-ray Timing Explorer. Our aim is to investigate their…

Using extensive HST imaging, combined with Chandra X-ray and Parkes radio data, we have detected the optical binary companion to a second millisecond pulsar (MSP) in the globular cluster 47 Tucanae. This faint (V=22.3) blue (V-I=0.7) star…

We investigate the line-profile variability (lpv) of H-alpha for a large sample of O-type supergiants. We used the Temporal Variance Spectrum (TVS) analysis, developed by Fullerton et al 1996 and modified by us to take into account the…

We present a study of OGLE light curves of red giant stars exhibiting long secondary periods (LSPs) - an enigmatic phenomenon commonly observed in stars on the upper red giant branch and asymptotic giant branch. We show that the light…

The fifteenth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains 232,406 long-period variables (LPVs) detected in the OGLE-II and OGLE-III fields toward the Galactic bulge. The sample consists of 6528 Mira stars, 33,235…

The classical T Tauri star RW Aur A is an irregular variable with a large amplitude in all photometric bands. In an extended series of photometric data we found small-amplitude periodic variations in the blue colours of the star, with a…

We present the first multi-epoch study that includes concurrent mid-infrared and radio interferometry of an oxygen-rich Mira star. We obtained mid-infrared interferometry of S Ori with VLTI/MIDI at four epochs between December 2004 and…