Study of Faint Galactic Carbon Stars from the First Byurakan Spectral Sky Survey. IV. GAIA DR2 Data

Autor: G. R. Kostandyan
Rok vydání: 2020
Předmět:
Zdroj: Astrophysics. 63:75-84
ISSN: 1573-8191
0571-7256
DOI: 10.1007/s10511-020-09615-6
Popis: Data from the second Gaia release (Gaia DR2) are used to analyze and evaluate several important parameters for 127 carbon (C) stars of which 56 are AGB stars of class N and 71 are giants of early CH classes detected in low-dispersion spectral plates from the First Byurakan Survey (FBS). For the FBS C-stars Gaia DR2 G broad – band magnitudes are in the range 9m.4 < G < 18m.2. The radial velocities RV are accessible for 75 of the 127 C-stars. For 9 of them RV exceeds 200 km/s. For 18 of the FBS C-stars that have luminosity data in DR2, of which 17 are CH giants, the absolute V magnitudes are estimated to lie in the range -3m .4 ≤ MV ≤+0m.5. For FBS 1918+869 the absolute magnitude MV= – 3m.4 ± 0m.2, which is typical for N type AGB C-stars. A Hertzsprung-Russell diagram (HRD or color-absolute magnitude diagram) was constructed with the estimated distances for the 127 C-stars. All the observed FBS C-stars are giants and AGB stars in the Galactic Halo. They are not far than 14 kpc from the Sun and 8 kpc from the Galactic plane.
Databáze: OpenAIRE