Abstract
Early-type stars appear to be a difficult place to look for planets astrometrically. First, they are relatively heavy, and for fixed planetary mass the astrometric signal falls inversely as the stellar mass. Second, they are relatively rare (and so tend to be more distant), and for fixed orbital separation the astrometric signal falls inversely as the distance. Nevertheless, because early-type stars are relatively more luminous, their habitable zones are at larger semimajor axis. Since astrometric signal scales directly as orbital size, this gives early-type stars a strong advantage, which more than compensates for the other two factors. Using the Hipparcos Catalog, we show that F and A stars constitute the majority of viable targets for astrometric searches for planets with semimajor axes currently in the habitable zone. Thus, astrometric surveys are complementary to transit searches, which are primarily sensitive to habitable planets around late-type stars.
| Original language | English (US) |
|---|---|
| Pages (from-to) | L155-L158 |
| Journal | Astrophysical Journal |
| Volume | 591 |
| Issue number | 2 II |
| DOIs | |
| State | Published - Jul 10 2003 |
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All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
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Early-type stars : Most favorable targets for astrometrically detectable planets in the habitable zone. / Gould, Andrew; Ford, Eric B.; Fischer, Debra A.
In: Astrophysical Journal, Vol. 591, No. 2 II, 10.07.2003, p. L155-L158.Research output: Contribution to journal › Article
TY - JOUR
T1 - Early-type stars
T2 - Most favorable targets for astrometrically detectable planets in the habitable zone
AU - Gould, Andrew
AU - Ford, Eric B.
AU - Fischer, Debra A.
PY - 2003/7/10
Y1 - 2003/7/10
N2 - Early-type stars appear to be a difficult place to look for planets astrometrically. First, they are relatively heavy, and for fixed planetary mass the astrometric signal falls inversely as the stellar mass. Second, they are relatively rare (and so tend to be more distant), and for fixed orbital separation the astrometric signal falls inversely as the distance. Nevertheless, because early-type stars are relatively more luminous, their habitable zones are at larger semimajor axis. Since astrometric signal scales directly as orbital size, this gives early-type stars a strong advantage, which more than compensates for the other two factors. Using the Hipparcos Catalog, we show that F and A stars constitute the majority of viable targets for astrometric searches for planets with semimajor axes currently in the habitable zone. Thus, astrometric surveys are complementary to transit searches, which are primarily sensitive to habitable planets around late-type stars.
AB - Early-type stars appear to be a difficult place to look for planets astrometrically. First, they are relatively heavy, and for fixed planetary mass the astrometric signal falls inversely as the stellar mass. Second, they are relatively rare (and so tend to be more distant), and for fixed orbital separation the astrometric signal falls inversely as the distance. Nevertheless, because early-type stars are relatively more luminous, their habitable zones are at larger semimajor axis. Since astrometric signal scales directly as orbital size, this gives early-type stars a strong advantage, which more than compensates for the other two factors. Using the Hipparcos Catalog, we show that F and A stars constitute the majority of viable targets for astrometric searches for planets with semimajor axes currently in the habitable zone. Thus, astrometric surveys are complementary to transit searches, which are primarily sensitive to habitable planets around late-type stars.
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U2 - 10.1086/377147
DO - 10.1086/377147
M3 - Article
AN - SCOPUS:0141725739
VL - 591
SP - L155-L158
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 II
ER -