WASP-22 b: A TRANSITING 'HOT JUPITER' PLANET IN A HIERARCHICAL TRIPLE SYSTEM

Journal Article · Wed Dec 15 00:00:00 EST 2010 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/140/6/2007· OSTI ID:21443153

Maxted, P F. L.; Anderson, D R; Hellier, C; Smalley, B; Wilson, D M; Bentley, S J; Cegla, H ^[1]; Gillon, M; Queloz, D; Mayor, M; Pepe, F ^[2]; West, R G ^[3]; Collier Cameron, A; Enoch, B; Hebb, L; Horne, K; Parley, N ^[4]; Irwin, J ^[5]; Lister, T A ^[6]

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1. Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom)
2. Observatoire de Geneve, Universite de Geneve, 51 Chemin des Maillettes, 1290 Sauverny (Switzerland)
3. Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom)
4. School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS (United Kingdom)
5. Department of Astronomy, Harvard University, 60 Garden Street, MS 10, Cambridge, MA 02138 (United States)
6. Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States)

We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T{sub eff} = 6000 {+-} 100 K, [Fe/H] = -0.05 {+-} 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M{sub p} = 0.56 {+-} 0.02M{sub Jup} and a radius R{sub p} = 1.12 {+-} 0.04R{sub Jup}. In addition, there is a linear trend of 40 m s{sup -1} yr{sup -1} in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet.

• OSTI ID: 21443153
• Journal Information: Astronomical Journal (New York, N.Y. Online), Vol. 140, Issue 6; Other Information: DOI: 10.1088/0004-6256/140/6/2007; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
MAIN SEQUENCE STARS
MASS
ORBITS
PERIODICITY
PHOTOMETRY
PLANETS
RADIAL VELOCITY
SPECTROSCOPY
TELESCOPES
WHITE DWARF STARS
DWARF STARS
STARS
VARIATIONS
VELOCITY