Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-08-20
Astrophysical Journal 725 (2010) 721-733
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
38 pages, 7 figures, 4 tables, accepted for publication in ApJ
Scientific paper
10.1088/0004-637X/725/1/721
This work presents a homogeneous derivation of atmospheric parameters and iron abundances for a sample of giant and subgiant stars which host giant planets, as well as a control sample of subgiant stars not known to host giant planets. The analysis is done using the same technique as for our previous analysis of a large sample of planet-hosting and control sample dwarf stars. A comparison between the distributions of [Fe/H] in planet-hosting main-sequence stars, subgiants, and giants within these samples finds that the main-sequence stars and subgiants have the same mean metallicity of <[Fe/H]> \simeq +0.11 dex, while the giant sample is typically more metal poor, having an average metallicity of <[Fe/H]> = -0.06 dex. The fact that the subgiants have the same average metallicities as the dwarfs indicates that significant accretion of solid metal-rich material onto the planet-hosting stars has not taken place, as such material would be diluted in the evolution from dwarf to subgiant. The lower metallicity found for the planet-hosting giant stars in comparison with the planet-hosting dwarfs and subgiants is interpreted as being related to the underlying stellar mass, with giants having larger masses and thus, on average larger-mass protoplanetary disks. In core accretion models of planet formation, larger disk masses can contain the critical amount of metals necessary to form giant planets even at lower metallicities.
Cunha Katia
Ghezzi Luan
Schuler Simon C.
Smith Verne V.
No associations
LandOfFree
Metallicities of Planet Hosting Stars: A Sample of Giants and Subgiants 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 Metallicities of Planet Hosting Stars: A Sample of Giants and Subgiants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metallicities of Planet Hosting Stars: A Sample of Giants and Subgiants will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-81266