SIMBAD references

2017MNRAS.470.3557J - Mon. Not. R. Astron. Soc., 470, 3557-3565 (2017/September-3)

GALEX J184559.8-413827: a new extreme helium star identified using SALT.

JEFFERY C.S.

Abstract (from CDS):

A high-resolution spectrum of the helium-rich 'hot subdwarf' GALEX J184559.8-413827 (J1845-4138) obtained with SALT HRS demonstrates it to be the first extreme helium (EHe) star to be discovered in nearly 40 years. A quantitative analysis demonstrates it to have an atmosphere described by Teff = 26 170 ± 750 K, log g/cm s–2 = 4.22 ± 0.10 and a surface chemistry characterized by CNO-processed helium, a 1 per cent contamination of hydrogen (by number) and a metallicity 0.4 dex subsolar. Its distance and position are consistent with membership of the Galactic bulge. Its sharp absorption lines place strong constraints on both the rotation and microturbulent velocities. Spectroscopically, J1845-4138 closely resembles the pulsating EHe star V652 Her, generally considered to be the product of a double helium white dwarf merger evolving to become a helium-rich sdO star.

Abstract Copyright: © 2017 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): stars: abundances - stars: chemically peculiar - stars: fundamental parameters - stars: individual: ((GALEX J184559.8-413827, V652 Her)) - stars: individual: ((GALEX J184559.8-413827, V652 Her))

Simbad objects: 13

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2021.12.03-21:39:21

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