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

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

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37 Citations (Scopus)


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 plusmn 0.08 M$_Jup$ and a radius of 1.70 plusmn 0.11 R$_Jup$ is found. The planetary equilibrium temperature of T$_P$ = 2350 plusmn 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 plusmn 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 plusmn 0.11 R$_Jup$, but could be as large as 2.09 plusmn 0.14 R$_Jup$, which would make WASP-79b the largest known exoplanet. Photometric data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/547/A61Table 1 is available in electronic form at http://www.aanda.org
Original languageEnglish
Pages (from-to)A61
JournalAstronomy and Astrophysics
Publication statusPublished - 1 Nov 2012


  • planets and satellites: general, stars: individual: WASP-78, stars: individual: WASP-79, techniques: spectroscopic, techniques: radial velocities, techniques: photometric


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