Related papers: Red giant variables: OGLE--II and MACHO

With recent advances in asteroseismology it is now possible to peer into the cores of red giants, potentially providing a way to study processes such as nuclear burning and mixing through their imprint as sharp structural variations --…

Mass loss on the red giant branch (RGB) influences stellar evolution, properties of stellar populations, and Galactic chemical enrichment, yet remains poorly constrained observationally. Current models provide limited insight into how…

We present an analysis of the 3-D structure of the Magellanic Clouds, using period-luminosity (P-L) relations of pulsating red giants in the OGLE-II sample. By interpreting deviations from the mean P-L relations as distance modulus…

Thanks to the high quality data of space missions, the detection of mixed modes has become possible in numerous stars. In this work, we investigate how the mixing character of dipolar mixed modes changes with stellar evolution, as well as…

Context. The large quantity of high-quality asteroseismic data that obtained from space-based photometric missions and the accuracy of the resulting frequencies motivate a careful consideration of the accuracy of computed oscillation…

Many decades ago a search for variable stars was one of the main areas of astrophysical research. Such searches, conducted with CCD detectors rather than with photographic plates, became a by-product of several projects seeking…

Over the recent years, the Petersen diagram for classical pulsators, Cepheids and RR Lyr stars, populated with a few hundreds of new multiperiodic variables. We review our analyses of the OGLE data, which resulted in the significant…

Stars are massive resonators that may be used as gravitational-wave (GW) detectors with isotropic sensitivity. New insights on stellar physics are being made possible by asteroseismology, the study of stars by the observation of their…

We have used long-term AAVSO visual observations and Fourier and wavelet analysis to identify periods and study long-term amplitude variations in 44 red supergiants. Of these, 12 stars had data which were too sparse and/or had low amplitude…

Red-giant stars are an incredible source of information for testing models of stellar evolution, as asteroseismology has opened up a window into their interiors. Such insights are a direct result of the unprecedented data from space…

We briefly review the phenomenon of long secondary periods (LSPs) in red giants, and the LSP variable stars classification introduced in the All-Sky Automated Survey for Supernovae (ASAS-SN) variable star catalog; they are red giant Long…

The influence of rotation on the properties of red giants is studied in the context of the asteroseismic modelling of these stars. While red giants exhibit low surface rotational velocities, we find that the rotational history of the star…

When a star evolves into a red giant, the enhanced coupling between core-based gravity modes and envelope-based pressure modes forms mixed modes, allowing its deep interior to be probed by asteroseismology. The ability to obtain information…

So far, solar-like oscillations have been studied using radial velocity and/or light curve variations, which reveal frequencies of the oscillation modes. Line-profile variations, however, are also a valuable diagnostic to characterise…

Red-giant stars are emerging as one of the most interesting areas of space asteroseismology. Even a relatively basic analysis leads to the determination of the global parameters of the stars, such as their mass and radius, and the very…

Independent of stellar modelling, global seismic parameters of red giants provide unique information on the individual stellar properties as well as on stellar evolution. They allow us to measure key stellar parameters, such as the stellar…

Pulsation influences atmospheric structures of variable AGB stars (Miras) considerably. Spectral lines of the CO dv=3 vibration-rotation bands (at 1.6mue) therefore have a very characteristic appearance in time series of high-resolution…

Stellar rotation, a key factor influencing stellar structure and evolution, also drives magnetic activity, which is manifested as spots or flares on stellar surface. Here, we present a collection of 18 443 rotating variables located toward…

Theoretical predictions of Red Giant Branch stars' effective temperatures, colors, luminosities and surface chemical abundances are a necessary tool for the astrophysical interpretation of the visible--near infrared integrated light from…

In spite of the great effort made in the last decades to improve our understanding of stellar evolution, significant uncertainties still remain due to our poor knowledge of some complex physical processes that still require an empirical…