Related papers: Long-Period Variability in o Ceti
We have performed an optical observation campaign on PKS 2155-304, whose aim was to determine the variability properties of this object on very short time scales in several photometric bands. We detected variability on time scales as short…
We present time series analyses of three-decade long radio observations of the BL Lacertae object AO 0235+164 made at the University of Michigan Radio Astronomical Observatory operating at three central frequencies of 4.8 GHz, 8.0 GHz and…
We present a period-luminosity-amplitude analysis of 5899 red giant and binary stars in the Large Magellanic Cloud, using publicly available observations of the MACHO project. For each star, we determined new periods, which were…
We have identified 22 new variable red giants in 47 Tuc and determined periods for another 8 previously known variables. All red giants redder than V-I_c=1.8 are variable at the limits of our detection threshold, which corresponds to delta…
We present photometric light curves for a sample of 21 ultra cool M and L dwarfs in the field and in the young open clusters sigma Orionis and the Pleiades. Evidence for variability with RMS amplitudes (in the I band) of 0.01 to 0.055…
We present new light curves covering 14 to 19 years of observations of four bright proto-planetary nebulae (PPNs), all O-rich and of F spectral type. They each display cyclical light curves with significant variations in amplitude. All four…
(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 of the star. The long-period variables (LPVs) and Mira variables are the most…
The Period--Luminosity relation (PLR) of Mira variable stars is an important tool to determine astronomical distances. The common approach of estimating the PLR is a two-step procedure that first estimates the Mira periods and then runs a…
We have used the COBE DIRBE database to derive near- and mid-infrared light curves for a well-defined sample of 38 infrared-bright Mira variable stars, and compared with optical data from the AAVSO. In general, the 3.5 micron and 4.9 micron…
Consistent stellar evolution and nonlinear radial stellar pulsation calculations were carried out for models of asymptotic giant branch stars with initial masses $1.5M_\odot\le M_\mathrm{ZAMS}\le 3M_\odot$ and initial metal abundance…
The properties of the Milky Way's nuclear stellar disc give crucial information on the epoch of bar formation. Mira variables are promising bright candidates to study the nuclear stellar disc, and through their period-age relation dissect…
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,…
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…
Previous studies on the stellar content of the two nearby dwarf galaxies NGC147 and NGC185 reveal a rich population of late-type giants in both systems, including a large number of carbon-rich objects. These stars are known to show…
Previous studies of GD 244 revealed seven pulsation frequencies (two doublets and three single periods) in the light variations of the star. The data obtained at McDonald Observatory between 2003 and 2006, and our additional measurements in…
We analyzed the light curves of 165 AGB variables, mostly Miras, in the sky area centered between M16 and M17 (l=16, b=0), using the OGLE GVS database in the I_C band. Comparison with the published light curves, derived about 50 years…
We present the results of a long-term monitoring campaign of the H\alpha line in a sample of bright OB-supergiants (O7.5-B9) that aims at detecting rotationally modulated changes potentially related to the existence of large-scale wind…
Stars in the Asymptotic Giant Branch (AGB) phase, dominated by low to intermediate-mass stars in the late stage of evolution, undergo periodic pulsations, with periods of several hundred days, earning them the name Long Period Variables…
We present near infrared velocity curves for 12 long period variables (LPVs) in the globular cluster 47 Tuc (NGC 104). New light curves are also presented for these variables. Results are compared with the period-luminosity sequences…
Context. Stars on the asymptotic giant branch (AGB) are long-period variables that present strong flux variations at almost all wavelengths, including the SiO maser lines. The periods of these variations are of 300-500 days in Mira-type…