| Type |
Journal Article |
| Names |
Alexei Y. Kniazev, Petri Väisänen, Patricia A. Whitelock, John W. Menzies, Michael W. Feast, Eva K. Grebel, David A. H. Buckley, Yas Hashimoto, Nicola Loaring, Encarni Romero-Colmenero, Ramotholo Sefako, Eric B. Burgh, Kenneth Nordsieck |
| Publication |
Monthly Notices of the Royal Astronomical Society |
| Volume |
395 |
| Issue |
2 |
| Pages |
1121-1126 |
| Date |
May 1, 2009 |
| URL |
http://adsabs.harvard.edu/abs/2009MNRAS.395.1121K |
| Library Catalog |
NASA ADS |
| Abstract |
We report the discovery of the first symbiotic star (V = 21.6,
KS = 15.8mag) in the Local Group dwarf irregular galaxy
NGC6822. This star was identified during a spectral survey of Hα
emission-line objects using the Southern African Large Telescope during
its performance-verification phase. The observed strong emission lines
of HI and HeII suggest a high electron density and T* < 130000K for
the hot companion. The infrared colours allow us to classify this object
as an S-type symbiotic star, comprising a red giant losing mass to a
compact companion. The red giant is an asymptotic giant branch (AGB)
carbon star, and a semiregular variable, pulsating in the first overtone
with a period of 142 d. Its bolometric magnitude is Mbol =
-4.4mag.
We review what is known about the luminosities of extragalactic
symbiotic stars, showing that most, possibly all, contain AGB stars. We
suggest that a much larger fraction of Galactic symbiotic stars may
contain AGB stars than was previously realized.
Based on observations made with the Southern African Large Telescope
(SALT) and the Infrared Survey Facility (IRSF).
E-mail: akniazev@saao.ac.za |
| Tags |
binaries: symbiotic, galaxies: individual: NGC6822, stars: mass-loss |