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...
Gespeichert in:
Veröffentlicht in: | Publications of the Astronomical Society of Japan 2008-12, Vol.60 (6), p.1317-1326 |
---|---|
Hauptverfasser: | , , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
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 |