Related papers: Blue Horizontal Branch Stars in M92

Motivated by the historical identification of runaway main-sequence (MS) stars of early spectral type at high Galactic latitudes, we test the capability of Gaia at identifying new such stars. We have selected ~2300 sources with Gaia…

We report the results for rotational velocities, Vrot sin i, and macroturbulence dispersion, zeta(RT), for 12 metal-poor field red giant branch stars and 7 metal-poor field red horizontal branch stars. The results are based on Fourier…

Intermediate resolution spectra at the Ca II triplet have been obtained for 55 candidate red giants in the field of the globular cluster M22 with the VLT/FORS instrument. Spectra were also obtained for a number of red giants in standard…

Most inhomogeneities in the chemical composition of GC stars are due to primordial enrichment. The model today most credited is that the winds lost by high mass Asymptotic Giant Branch (AGB) stars, evolving during the first $\simlt$200Myr…

The aim of this study is to search for observational evidence of vertical iron stratification in the atmosphere of fourteen blue horizontal-branch (BHB) stars. We have found from our numerical simulations that five BHB stars: B22, B186 in…

An exciting recent finding regarding scaling relations among globular clusters is the so-called 'blue tilt': clusters of the blue sub-population follow a trend of redder colour with increasing luminosity. In this paper we evaluate to which…

We present the velocity dispersion of red giant branch (RGB) stars in M31's halo, derived by modeling the line of sight velocity distribution of over 5000 stars in 50 fields spread throughout M31's stellar halo. The dataset was obtained as…

We present a detailed analysis of stellar rotation along the main sequences of NGC 1866 and NGC 1856, two young (~200-300 Myr) massive clusters in the Large Magellanic Cloud, using MUSE integral field spectroscopy. Differences in stellar…

We present the deepest near-UV image of M32 to date, which for the first time resolves hot HB stars in an elliptical galaxy. Given the near-solar metallicity of M32, much larger than that of globular clusters, the existence of an extended…

We analyse complementary HST and SUBARU data for the globular cluster NGC 2419. We make a detailed analysis of the horizontal branch (HB), that appears composed by two main groups of stars: the luminous blue HB stars ---that extend by…

This study presents the rotational distribution of red giant stars (RGs) in eleven old to intermediate age open clusters. The masses of these stars are all above the Kraft break, so that they lose negligible amounts of their birth angular…

We have used HST imaging of the central regions (R<100 arcsec, about 5 core radii) of the globular cluster 47 Tucanae to derive proper motions and U- and V-band magnitudes for 14,366 cluster members. We also present a catalogue of…

Blue Straggler stars are present in all the properly observed Globular Clusters. They mimic a rejuvenated stellar population and their existence has been a puzzle for many years. We performed an extensive spectroscopic survey of the surface…

We continue our studies on stellar latitudinal differential rotation. The presented work is a sequel of the work of Reiners et al. who studied the spectral line broadening profile of hundreds of stars of spectral types A through G at high…

We present initial results from a large spectroscopic survey of stars throughout M33's stellar disk. We analyze a sample of 1667 red giant branch (RGB) stars extending to projected distances of $\sim 11$ kpc from M33's center ($\sim 18$…

Recent high-quality Hubble Space Telescope (HST) photometry shows that the main sequences (MS) stars of young star clusters form two discrete components in the color-magnitude diagram (CMD). Based on their distribution in the CMD, we show…

The Horizontal Branch (HB) second parameter of Globular Clusters (GCs) is a major open issue in stellar evolution. Large photometric and spectroscopic databases allow a re-examination of this issue. We derive median and extreme (90% of the…

We analyze the reddening, surface helium abundance and mass of 115 horizontal branch (HB) and blue hook (BH) stars in OmegaCentauri, spanning the HB from the blue edge of the instability strip to Teff~50000K. The mean cluster reddening is…

We used FLAMES+GIRAFFE (Medusa mode) at the VLT to obtain moderately high resolution spectra for 30 red horizontal branch (RHB) stars, 4 RR Lyrae variables, and 17 blue horizontal branch (BHB) stars in the low-concentration, moderately…

We report the analysis of the rotational properties of our sample of Herbig Ae/Be (HAeBe) and related stars for which we have obtained high-resolution spectropolarimetric observations. Using the projected rotational velocities measured at…