相关论文: AGB Variables and the Mira Period-Luminosity Relat…

The 3.6 and 4.5 micron characteristics of AGB variables in the LMC and IC1613 are discussed. For C-rich Mira variables there is a very clear period-luminosity-colour relation, where the [3.6]-[4.5] colour is associated with the amount of…

(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…

Spectroscopic measurements of Mira variable stars, as a function of phase, probe the stellar atmospheres and underlying pulsation mechanisms. For example, measuring variations in TiO, VO, and ZrO with phase can be used to help determine…

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…

Period-luminosity (PL) relations of variable red giants in the Large (LMC) and Small Magellanic Clouds (SMC) are presented. The PL diagrams are plotted in three planes: logP-K_S, logP-W_{JK}, and logP-W_I. Fourteen PL sequences are…

The fourth part of the OGLE-III Catalog of Variable Stars presents 91 995 long-period variables (LPVs) in the Large Magellanic Cloud (LMC). This sample consists of 79 200 OGLE Small Amplitude Red Giants (OSARGs), 11 128 semiregular…

We report on the succesful search for CO (2-1) and (3-2) emission associated with OH/IR stars in the Galactic Bulge. We observed a sample of eight extremely red AGB stars with the APEX telescope and detected seven. The sources were selected…

TThe Period-Luminosity (PL) relation for Cepheid variable stars in the Large Magellanic Cloud (LMC) is crucial for distance measurements in astronomy. This study analyzes the impact of using the median rather than the mean on the PL…

In an era of extensive photometric observations, the catalogs of RR Lyr type variable stars number tens of thousands of objects. The relation between the iron abundance [Fe/H] and the Fourier parameters of the stars light curve allows us to…

The galactic kinematics of Mira variables derived from radial velocities, Hipparcos proper motions and an infrared period-luminosity relation are reviewed. Local Miras in the 145-200day period range show a large asymmetric drift and a high…

For nine Mira-type stars (o Cet, R Leo, S Car, U Her, X Oph, R Aql, RR Aql, S Ori, S Scl,) and one semi-regular star (L2 Pup), the mean light curves have been obtained. The initial values of the brightness (observations) were fitted by a…

We find that AGB stars separate in the 25-12 vs. 12-K color-color diagram according to their chemistry (O, S vs. C) and variability type (Miras vs. SRb/Lb). While discrimination according to the chemical composition is not surprising, the…

The kinematic and Period-Luminosity-Colour distribution of O-rich Long-Period Variable stars of the solar neighbourhood is interpreted in terms of pulsation modes, masses and metallicities. It is first shown that, because of input physics…

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…

The characteristics of light variation of RSGs in SMC are analyzed based on the nearly 8-10 year long data collected by the ASAS and MACHO projects. The identified 126 RSGs are classified into five categories accordingly: 20 with poor…

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…

JHKL observations of the mass-losing carbon Mira variable IRAS 15194-5115 (II Lup) extending over about 18 years are presented and discussed. The pulsation period is 575 days and has remained essentially constant over this time span. The…

Many studies have shown that there are clear sequences in the period-luminosity relationship (PLR) for Mira variables and semiregular variables (SRVs) in the Large Magellanic Cloud (LMC). To investigate the PLR for SRVs in our galaxy, we…

We analysed 30 RR Lyrae stars (RRLs) located in the Large Magellanic Cloud (LMC) globular cluster Reticulum that were observed in the 3.6 and 4.5 $\mu$m passbands with the Infrared Array Camera (IRAC) on board of the Spitzer Space…

(abridged) New photometry and spectroscopy for more than a hundred RR Lyrae stars in two fields located close to the bar of the Large Magellanic Cloud (LMC) are used to derive new accurate estimates of the average magnitude, the local…