100 datasets found

The red clump (RC) is found to be split into two components along several sightlines toward the Galactic bulge. This split is detected with high significance toward the areas...

Using the Advanced Camera for Surveys on Hubble Space Telescope, we have surveyed the far-ultraviolet (FUV) and near-ultraviolet (NUV) populations in the core region of M80. The...

We derive new constraints on the mass of the Milky Way's dark matter halo, based on 2401 rigorously selected blue horizontal-branch halo stars from SDSS DR6. This sample enables...

We present the results of 22GHz H2O maser observations of a sample of 85 post-asymptotic giant branch (post-AGB) candidate stars, selected on the basis of their OH 1612MHz maser...

Wide-field and deep DECam multiband photometry, combined with HST data for the core of the Galactic globular cluster NGC2808, allowed us to study the distribution of various...

We have observed their cyanogen CN features at ~3800 and 4120{AA} as well as the CH band at ~4300{AA} for 145 evolved stars in the Galactic globular cluster M71 using the...

Photometric and spectroscopic analyses have shown that the Galactic bulge cluster Terzan 5 hosts several populations with different metallicities and ages that manifest as a...

A metallicity, chemical composition, and kinematic survey has been conducted for a sample of 340 candidate field red horizontal-branch (RHB) stars. Spectra with high resolution...

We present a complete spectroscopic survey of 2414 2MASS-selected blue horizontal branch (BHB) candidates selected over 4300{deg}^2^ of the sky. We identify 655 BHB stars in...

We discuss a 175{deg}2 spectroscopic survey for blue horizontal branch (BHB) stars in the Galactic halo. We use the Two Micron All Sky Survey (2MASS, ) and the Sloan Digital Sky...

We isolate samples of 733 bright (g<18) and 437 faint (g>18) high Galactic latitude blue horizontal-branch stars with photometry and spectroscopy in the Sloan Digital Sky...

We discuss a spectroscopic and photometric technique that enables the identification and classification of field horizontal-branch (FHB) and other A-type stars, even from...

A complete sample of blue horizontal branch (BHB) stars in the magnitude range 13.0<V<16.5 is isolated in two Galactic fields that have previously been searched for RR...

We used Legacy Survey photometric data to probe the stellar halo in multiple directions of the sky using a probabilistic methodology to identify Blue Horizontal Branch (BHB)...

Observational evidence has accumulated in recent years, showing that the Galactic bulge includes two populations, a metal-poor one and a metal-rich one, which in addition to...

In this work, we characterize the properties of HB stars in the GCs {omega} Cen and NGC 6752. We use dedicated model atmospheres and synthetic spectra grids computed using a...

Lithium and the carbon isotope ratio ^12^C/^13^C can change during the red giant branch as a result of extra-mixing. This is associated usually with thermohaline mixing acting...

Blue horizontal-branch stars evolve from low-mass stars that have completed their main-sequence lifetimes and undergone a helium flash at the end of their red-giant phase. As...

We recently found the globular cluster (GC) EXT8 in M31 to have an extremely low metallicity of [Fe/H]=-2.91+/-0.04 using high-resolution spectroscopy. Here we present a...

The presence of extreme horizontal branch (EHB) and blue hook stars in some Galactic globular clusters (GGCs) constitutes one of the remaining mysteries of stellar evolution....