The space-borne missions CoRoT and Kepler opened up a new opportunity for better understanding stellar evolution by probing interiors with unrivalled high-precision photometric data. has observed oscillation four years, which gave access to excellent frequency resolution that enables deciphering the spectrum of evolved red giant branch asymptotic stars. internal structure stars in upper parts b...

Abstract We have gathered near-infrared zyJ -band high-resolution spectra of nearly 300 field red giant stars with known lithium abundances in order to survey their He i ? 10830 absorption strengths. This transition is an indicator chromospheric activity and/or mass loss giants. The majority our sample reside the clump or horizontal branch based on V ? J , M color–magnitude diagram, and Gaia T ...

Red clump giants in the Galactic bulge are approximate standard candles and hence they can be used as distance indicators. We compute the proper motion dispersions of RCG stars in the Galactic bulge using the proper motion catalogue from the second phase of the Optical Gravitational Microlensing Experiment (OGLE-II, Sumi et al. 2004) for 45 fields. The proper motion dispersions are measured to ...

Chemical abundances of about fifteen elements from oxygen to europium are measured in seven red giants of the two open clusters NGC 2360 and NGC 2447. The effective temperatures of the giants are determined spectroscopically by taking advantage of their known masses (∼ 2M in NGC 2360 and ∼ 3M in NGC 2447) and bolometric magnitudes. The average iron abundances we obtain for the two clusters are ...

We investigate the observed depletion of red giants in the cores of post-core-collapse globular clusters. In particular, the evolutionary scenario we consider is a binary consisting of two lowmass stars which undergoes two common-envelope phases. The first common-envelope phase occurs when the primary is a red giant resulting in a helium white dwarf and main-sequence star in a detached binary. ...

We have used high-resolution, high signal-to-noise spectra obtained with the VLT and UVES to determine abundances of 17 elements in 4 red giants in the Sculptor dwarf spheroidal galaxy. Our [Fe/H] values range from –2.10 to –0.97, confirming previous findings of a large metallicity spread. We have combined our data with similar data for five Sculptor giants studied recently by Shetrone et al. t...

Aims. The distribution of RR Lyrae stars (RRLS) in the inner Large Magellanic Cloud (LMC), and the structure of the halo of the LMC delineated by these stars are studied here. Methods. RRLS identified by the OGLE II survey are used to estimate their number density distribution in the bar region of the LMC. To find their location, I estimated the scale-height of their distribution in the LMC usi...

Recent, and older accurate, data on (limb-darkened) angular diameters is compiled for 221 stars, as well as BV RIJK[12][25] magnitudes for those objects, when available. Nine stars (all M-giants or supergiants) showing excess in the [12− 25] colour are excluded in the analysis as this may indicate the present of dust influencing the optical and near-infrared colours as well. Based on this large...

ABSTRACT Red giant asteroseismology can provide valuable information for studying the Galaxy as demonstrated by space missions like CoRoT and Kepler. However, previous observations have been limited to small data sets fields of view. The TESS mission provides far larger samples and, first time, opportunity perform asteroseimic inference from full-frame images full-sky, instead narrow pre-select...

The solar system formed 4.5–4.6 billion years ago (Patterson 1956) by collapse of a portion of a molecular cloud of gas and dust rather like the Eagle or Orion nebulae. Some of the star dust from the solar nebula has now been isolated from primitive meteorites. The isotopic compositions of many elements in these grains are vastly different from those of our solar system and provide fingerprints...