Astronomy and Astrophysics – Astronomy
Scientific paper
Mar 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008mnras.384.1563f&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Volume 384, Issue 4, pp. 1563-1566.
Astronomy and Astrophysics
Astronomy
6
Stars: Evolution, Stars: Fundamental Parameters, Stars: Individual: Hd 155358, Planetary Systems, Stars: Population Ii
Scientific paper
The nearby subgiant HD 155358 has very recently been announced by Cochran et al. to harbour two Jovian-mass planetary companions and to be the lowest metallicity exoplanet host star yet found. Here, we present a model atmosphere analysis and stellar evolutionary tracks for HD 155358, and demonstrate that it is actually a member of the ancient thick-disc population of the Milky Way (τ >= 12 Gyr). As such, HD 155358 is considerably rich in its α-chain nuclei, and hence only about a factor of 2 below the solar abundance in terms of these species. Yet, as a precursor to the thin disc and residing on the metal-poor end of the thin-disc metal abundance distribution, HD 155358 gives way to the principal possibility that any star of the thin-disc population of the Galaxy can be a potential exoplanet host. As opposed to this, the formation of planets and even planetary systems for HD 155358 and HD 37124 (another previously known thick-disc exoplanet host) is mentionable, as there is strong evidence for a vigorous starburst phase in the early Milky Way, and secondly, the direct census of an unbiased nearby thick-disc sample implies a minimum fraction of no less than 30 per cent multiple star systems (N >= 3) to originate from that epoch.
Bernkopf Jan
Fuhrmann Klaus
No associations
LandOfFree
On the thick-disc exoplanet host subgiant HD 155358 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the thick-disc exoplanet host subgiant HD 155358, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the thick-disc exoplanet host subgiant HD 155358 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-870709