DISCOVERY AND ROSSITER-McLAUGHLIN EFFECT OF EXOPLANET KEPLER-8b

Journal Article · Wed Dec 01 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/724/2/1108· OSTI ID:21474483

Jenkins, Jon M; Caldwell, Douglas A ^[1]; Borucki, William J; Koch, David G ^[2]; Marcy, Geoffrey W; Basri, Gibor; Isaacson, Howard ^[3]; Cochran, William D; Endl, Michael ^[4]; Welsh, William F ^[5]; Batalha, Natalie M ^[6]; Buchhave, Lars A; Geary, John C ^[7]; Brown, Timothy M ^[8]; Dunham, Edward W ^[9]; Fischer, Debra A ^[10]; Gautier, Thomas N ^[11]; Gilliland, Ronald L ^[12]; Howell, Steve B ^[13]

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1. SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States)
2. NASA Ames Research Center, Moffett Field, CA 94035 (United States)
3. University of California Berkeley, Berkeley, CA 94720 (United States)
4. University of Texas, Austin, TX 78712 (United States)
5. San Diego State University, San Diego, CA 92182 (United States)
6. San Jose State University, San Jose, CA 95192 (United States)
7. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
8. Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States)
9. Lowell Observatory, Flagstaff, AZ 86001 (United States)
10. Radcliffe Institute, Cambridge, MA (United States)
11. Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109 (United States)
12. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
13. National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)

We report on the discovery and the Rossiter-McLaughlin (R-M) effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius R{sub P} = 1.419 R{sub J} and a mass M{sub P} = 0.60 M{sub J}, yielding a density of 0.26 g cm{sup -3}, one of the lowest planetary densities known. The orbital period is P = 3.523 days and the orbital semimajor axis is 0.0483{sup +0.0006}{sub -0.0012} AU. The star has a large rotational vsin i of 10.5 {+-} 0.7 km s{sup -1} and is relatively faint (V {approx} 13.89 mag); both properties are deleterious to precise Doppler measurements. The velocities are indeed noisy, with scatter of 30 m s{sup -1}, but exhibit a period and phase that are consistent with those implied by transit photometry. We securely detect the R-M effect, confirming the planet's existence and establishing its orbit as prograde. We measure an inclination between the projected planetary orbital axis and the projected stellar rotation axis of {lambda} = -26.{sup 0}4 {+-} 10.{sup 0}1, indicating a significant inclination of the planetary orbit. R-M measurements of a large sample of transiting planets from Kepler will provide a statistically robust measure of the true distribution of spin-orbit orientations for hot Jupiters around F and early G stars.

• OSTI ID: 21474483
• Journal Information: Astrophysical Journal, Vol. 724, Issue 2; Other Information: DOI: 10.1088/0004-637X/724/2/1108; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
INCLINATION
MASS
PHOTOMETRY
RADIAL VELOCITY
STARS
VELOCITY