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.

doi:10.1051/0004-6361/201219731

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.

Authors

Barry Smalley b.smalley@keele.ac.uk

D. R. Anderson

A. Collier-Cameron

A. P. Doyle

A. Fumel

M. Gillon

Coel Hellier c.hellier@keele.ac.uk

E. Jehin

M. Lendl

Pierre Maxted p.maxted@keele.ac.uk

F. Pepe

D. Pollacco

D. Queloz

D. Segransan

A. M. S. Smith

Dr John Taylor j.k.taylor@keele.ac.uk

A. H. M. J. Triaud

S. Udry

R. G. West

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.

Citation

Smalley, B., R. Anderson, D., Collier-Cameron, A., P. Doyle, A., Fumel, A., Gillon, M., …G. West, R. (2012). WASP-78b and WASP-79b: Two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus. Astronomy and Astrophysics, 547, Article A61. https://doi.org/10.1051/0004-6361/201219731

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