Over the past decade we observed a sample of late-type stars (supergiants, semi-regular variables, OH/IR stars, and Mira's) 3–4 times per year in the 1.3-cm line of H 2 O. The observations were carried out with the Medicina 32-m and the Effelsberg 100-m telescopes. In addition, a sub-sample of these stars was observed at several epochs with the VLA. In our analysis we also use data from the lit...

We present period-luminosity relations for more than 23,000 red giants in the Large Magellanic Cloud observed by the OGLE-II microlensing project. The OGLE period values were combined with the 2MASS single-epoch JHKS photometric data. For the brighter stars we find agreement with previous results (four different sequences corresponding to different modes of pulsation in AGB stars). We also disc...

We present period-luminosity relations for more than 23,000 red giants in the Large Magellanic Cloud observed by the OGLE-II microlensing project. The OGLE period values were combined with the 2MASS single-epoch JHKS photometric data. For the brighter stars we find agreement with previous results (four different sequences corresponding to different modes of pulsation in AGB stars). We also disc...

We discuss visual observations spanning nearly 70 years of the nearby semiregular variable R Doradus. Using wavelet analysis, we show that the star switches back and forth between two pulsation modes having periods of 332 days and about 175 days, the latter with much smaller amplitude. Comparison with model calculations suggests that the two modes are the first and third radial overtone, with t...

We present a collection of 65,981 Mira-type variable stars found in the Optical Gravitational Lensing Experiment (OGLE) project database. Two-thirds our sample (40,356 objects) are located Galactic bulge fields, whereas 25,625 disk. The vast majority (47,532 new discoveries. provide basic observational parameters Mira variables: equatorial coordinates, pulsation periods, $I$-band and $V$-band m...

Hipparcos observations of some variable stars, and especially of long-period (e.g. Mira) variables, reveal a motion of the photocenter correlated with the brightness variation (variability-induced mover – VIM), suggesting the presence of a binary companion. A re-analysis of the Hipparcos photometric and astrometric data does not confirm the VIM solution for 62 among the 288 VIM objects (21%) in...

This article presents the study of the light–curves extracted from the MACHO database of a sample of stars observed by the Infrared Space Observatory in the Small Magellanic Cloud. These stars belong to the ISO–Mini-Survey catalogue of the Magellanic Clouds (ISO–MCMS, Loup et al. in preparation). Most of them are in the asymptotic giant branch (AGB) and supergiant phases. The dominant period an...

This article presents the study of the light–curves extracted from the MACHO database of a sample of stars observed by the Infrared Space Observatory in the Small Magellanic Cloud. These stars belong to the ISO–Mini-Survey catalogue of the Magellanic Clouds (ISO–MCMS, Loup et al. in preparation). Most of them are in the asymptotic giant branch (AGB) and supergiant phases. The dominant period an...

King, Modjaz, & Li (1999) discovered Nova 1999 in IC 1613 at Lick Observatory. Both Fugazza et al. (2000) and Borissova et al. (2000) questioned this classification, because they were able to detect the star on images obtained in previous years. In infrared frames taken on Oct. 15, 1998, the Nova 1999 has (J −K) = 1.14 and K = 14.69 mag. Our light curve study, based primarily on 92 unfiltered L...