High-Resolution Spectroscopic Observations of [ITAL]Hipparcos[/ITAL] Red Clump Giants: Metallicity and Mass Determinations

G. Zhao, H. M. Qiu, Shude Mao
2001 Astrophysical Journal  
We obtain high-resolution and high signal-to-noise ratio spectra of 39 red clump giants selected from the Hipparcos Catalogue. We determine their atmospheric parameters, iron abundances, a-element enhancements, and masses. We find that the sample can be divided into a metal-poor group and a metal-rich group. The majority of the stars are metal-rich ( ) with mass around 2 , while the metal-poor group has lower surface gravity and lower mass. The variation of a-element abundances with [Fe/H]
more » ... es with [Fe/H] agrees with that of local G and K disk dwarfs. We also show that the metallicity is weakly correlated with the I-band absolute magnitude and the VϪI color, in agreement with Udalski's recent findings. We make the high-resolution spectra available over the internet for interested readers.
doi:10.1086/319832 fatcat:xcmbb7xs7zemret6cqhmpboace