Planetary Companions to Evolved Intermediate-Mass Stars: 14 Andromedae, 81 Ceti, 6 Lyncis, and HD167042

We report on the detection of four extrasolar planets orbiting evolved intermediate-mass stars from a precise Doppler survey of G-K giants at Okayama Astrophysical Observatory. All of the host stars are considered to be formerly early F-type or A-type dwarfs when they were on the main sequence. 14 A...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Publications of the Astronomical Society of Japan 2008-12, Vol.60 (6), p.1317-1326
Hauptverfasser: Sato, Bun'ei, Toyota, Eri, Omiya, Masashi, Izumiura, Hideyuki, Kambe, Eiji, Masuda, Seiji, Takeda, Yoichi, Itoh, Yoichi, Ando, Hiroyasu, Yoshida, Michitoshi, Kokubo, Eiichiro, Ida, Shigeru
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:We report on the detection of four extrasolar planets orbiting evolved intermediate-mass stars from a precise Doppler survey of G-K giants at Okayama Astrophysical Observatory. All of the host stars are considered to be formerly early F-type or A-type dwarfs when they were on the main sequence. 14 And (K0 III) is a clump giant with a mass of 2.2 $M_{\odot}$ and has a planet of minimum mass $m_2$ sin $i$ $=$ 4.8 $M_{\rm J}$ in a nearly circular orbit with a 186d period. This is one of the innermost planets around evolved intermediate-mass stars, and such planets have only been discovered in clump giants. 81 Cet (G5 III) is a clump giant with 2.4 $M_{\odot}$ hosting a planet of $m_2$ sin $i$ $=$ 5.3 $M_{\rm J}$ in a 953d orbit with an eccentricity of $e=$ 0.21. 6 Lyn (K0 IV) is a less-evolved subgiant with 1.7 $M_{\odot}$ , and has a planet of $m_2$ sin $i$ $=$ 2.4 $M_{\rm J}$ in a 899d orbit with $e=$ 0.13. HD167042 (K1 IV) is also a less-evolved star with 1.5 $M_{\odot}$ hosting a planet of $m_2$ sin $i$ $=$ 1.6 $M_{\rm J}$ in a 418d orbit with $e=$ 0.10. This planet was independently announced by Johnson et al. (2008, ApJ, 675, 784). All of the host stars have solar or sub-solar metallicity, which supports the lack of a metal-rich tendency in planet-harboring giants in contrast to the case of dwarfs.
ISSN:0004-6264
2053-051X
DOI:10.1093/pasj/60.6.1317