Related papers: Possible spatial asymmetry in semi-regular variabl…

The uniform disk (UD) angular diameter measurements of two oxygen-rich Mira variables (AW Aur and BS Aur) and three semiregular (SRb) variables (GP Tau, RS Cap, RT Cap), in near Infrared K-band (2.2 micron) by lunar occultation observations…

Semi-regular variables (SRVs) are similar to Miras in brightness, and they also follow PLRs, though not necessarily the same as Miras. As potential standard candles they are more challenging than Miras due to their smaller variability…

We report the angular diameters of two Mira variables (U Ari and Z Sco), three semiregular (SR) and irregular variables (SW Vir, eta Gem and mu Gem) and a supergiant SR variable (TV Gem) by lunar occultation observations in the near-IR…

Aims: We present J, H, K interferometry with a spectral resolution of 35 for the Mira variable S Orionis. We aim at measuring the diameter variation as a function of wavelength that is expected due to molecular layers lying above the…

(abridged) Variability is a key property of stars on the asymptotic giant branch (AGB). Their pulsation period is related to the luminosity and mass-loss rate (MLR) of the star. Long-period variables (LPVs) and Mira variables are the most…

The spectrophotometric variability of the magnetic CP star 56 Arietis (56 Ari) in the ultraviolet spectral region from 1950 to 3200 A is investigated. This study is based on the archival International Ultraviolet Explorer data obtained at…

Dynamic model atmospheres of Mira stars predict variabilities in the photospheric radius and in atmospheric molecular layers which are not yet strongly constrained by observations. Here we measure the variability of the oxygen-rich Mira…

We present the results of a near-infrared monitoring programme of a selected sample of stars, initially suspected to be Mira variables and OH/IR stars, covering more than a decade of observations. The objects monitored cover the typical…

Context. A number of RR Lyrae stars show variable mean magnitudes in the OGLE survey light curves of the Galactic bulge. Hitherto this phenomenon was not studied, as it was generally assumed to be related to problems with the photometry.…

In this work, a sample of luminous M-type giants in the Baade's Windows towards the inner Galactic Bulge is investigated in the near-infrared. The ISOGAL survey at 7 and 15 micron has given information concerning the mass-loss rates of…

We present the results of a massive variability search based on a photometric survey of a six square degree region along the Galactic plane at ($l = 305^\circ$, $b = -0.8^\circ$) and ($l = 330^\circ$, $b = -2.5^\circ$). This survey was…

Mira and semi-regular variable stars have been studied for centuries but continue to be enigmatic. One unsolved mystery is the presence of polarization from these stars. In particular, we present 40 years of polarization measurements for…

We describe a new RR Lyrae identification technique based on out-of-phase single-epoch photometric and spectroscopic observations contained in SDSS Data Release 6 (DR-6). This technique detects variability by exploiting the large disparity…

We present a detailed period analysis for 93 red semiregular variables by means of Fourier and wavelet analyses of long-term visual observations carried out by amateur astronomers. The results of this analysis yield insights into the mode…

We use the OGLE-II and OGLE-III data in conjunction with the 2MASS near-infrared (NIR) photometry to identify and study Miras and Semiregular Variables (SRVs) in the Large Magellanic Cloud. We found in total 3221 variables of both types,…

In this paper we present radial velocity curves of AGB variables that exhibit various kinds of anomalies: Semiregular variables (SRVs) with typical mira periods, SRVs exceeding the mira 2.5 mag amplitude limit, miras with secondary maxima…

Variability is a fundamental signature for active galactic nuclei (AGN) activity, and serve as an unbiased indicator for rapid instability happened near the center supermassive black hole (BH). Previous studies showed that AGN variability…

The spectrophotometric variability of the mCP star 56 Ari in the far-UV spectral region from 1150 \AA\ to 1980 \AA\ is investigated. This study is based on the archival {\it IUE} data obtained at different phases of the rotational cycle.…

We report on recent observations of AGB stars obtained with the VLT Interferometer (VLTI). We illustrate in general the potential of interferometric measurements to study stellar atmospheres and circumstellar envelopes, and demonstrate in…

We explore mid-infrared (MIR) variability in local ultraluminous infrared galaxies (ULIRGs; infrared luminsoity $L_{\rm IR}>10^{12}\ L_\odot$) utilizing the $\sim$11 years of photometry from the NEOWISE multi-epoch catalog of {\it…