WASP-78b and WASP-79b: Two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus

Smalley, B.; R. Anderson, D.; Collier-Cameron, A.; P. Doyle, A.; Fumel, A.; Gillon, M.; Hellier, C.; Jehin, E.; Lendl, M.; F. L. Maxted, P.; Pepe, F.; Pollacco, D.; Queloz, D.; Segransan, D.; M. S. Smith, A.; Southworth, J.; H. M. J. Triaud, A.; Udry, S.; G. West, R.

Abstract

We report the discovery of WASP-78b and WASP-79b, two highly-bloated Jupiter-mass exoplanets orbiting F-type host stars. WASP-78b orbits its V=12.0 host star (TYC 5889-271-1) every 2.175 days and WASP-79b orbits its V=10.1 host star (CD-30 1812) every 3.662 days. Planetary parameters have been determined using a simultaneous fit to WASP and TRAPPIST transit photometry and CORALIE radial-velocity measurements. For WASP-78b a planetary mass of 0.89 +/- 0.08 M_Jup and a radius of 1.70 +/- 0.11 R_Jup is found. The planetary equilibrium temperature of T_P = 2350 +/- 80 K for WASP-78b makes it one of the hottest of the currently known exoplanets. WASP-79b its found to have a planetary mass of 0.90 +/- 0.08 M_Jup, but with a somewhat uncertain radius due to lack of sufficient TRAPPIST photometry. The planetary radius is at least 1.70 +/- 0.11 R_Jup, but could be as large as 2.09 +/- 0.14 R_Jup, which would make WASP-79b the largest known exoplanet.

• Journal Article Type: Article
• Acceptance Date: Sep 28, 2012
• Online Publication Date: Oct 29, 2012
• Publication Date: 2012-11
• Deposit Date: Jul 6, 2023
• Publicly Available Date: Jul 6, 2023
• Journal: Astronomy & Astrophysics
• Print ISSN: 2329-1273
• Electronic ISSN: 1432-0746
• Publisher: Hans Publishers
• Peer Reviewed: Peer Reviewed
• Volume: 547
• Article Number: A61
• DOI: https://doi.org/10.1051/0004-6361/201219731
• Keywords: Earth and Planetary Astrophysics