TY - JOUR
T1 - WASP-71b: a bloated hot Jupiter in a 2.9-day, prograde orbit around an evolved F8 star
AU - Smith, A.~M.~S.
AU - Anderson, D.~R.
AU - Bouchy, F.
AU - Collier Cameron, A.
AU - Doyle, A.~P.
AU - Fumel, A.
AU - Gillon, M.
AU - Hébrard, G.
AU - Hellier, C.
AU - Jehin, E.
AU - Lendl, M.
AU - Maxted, P.~F.~L.
AU - Moutou, C.
AU - Pepe, F.
AU - Pollacco, D.
AU - Queloz, D.
AU - Santerne, A.
AU - Segransan, D.
AU - Smalley, B.
AU - Southworth, J.
AU - Triaud, A.~H.~M.~J.
AU - Udry, S.
AU - West, R.~G.
PY - 2013/4/1
Y1 - 2013/4/1
N2 - We report the discovery by the WASP transit survey of a highly-irradiated, massive (2.242 plusmn 0.080 M$_Jup$) planet which transits a bright (V = 10.6), evolved F8 star every 2.9 days. The planet, WASP-71b, is larger than Jupiter (1.46 plusmn 0.13 R$_Jup$), but less dense (0.71 plusmn 0.16 $$_Jup$). We also report spectroscopic observations made during transit with the CORALIE spectrograph, which allow us to make a highly-significant detection of the Rossiter-McLaughlin effect. We determine the sky-projected angle between the stellar-spin and planetary-orbit axes to be $ = 20.1 plusmn 9.7 degrees, i.e. the system is ``aligned'', according to the widely-used alignment criteria that systems are regarded as misaligned only when $ is measured to be greater than 10 degrees with 3-$ confidence. WASP-71, with an effective temperature of 6059 plusmn 98 K, therefore fits the previously observed pattern that only stars hotter than 6250 K are host to planets in misaligned orbits. We emphasise, however, that $ is merely the sky-projected obliquity angle; we are unable to determine whether the stellar-spin and planetary-orbit axes are misaligned along the line-of-sight. With a mass of 1.56 plusmn 0.07 M$_⊙$, WASP-71 was previously hotter than 6250 K, and therefore might have been significantly misaligned in the past. If so, the planetary orbit has been realigned, presumably through tidal interactions with the cooling star's growing convective zone. Photometric data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A120
AB - We report the discovery by the WASP transit survey of a highly-irradiated, massive (2.242 plusmn 0.080 M$_Jup$) planet which transits a bright (V = 10.6), evolved F8 star every 2.9 days. The planet, WASP-71b, is larger than Jupiter (1.46 plusmn 0.13 R$_Jup$), but less dense (0.71 plusmn 0.16 $$_Jup$). We also report spectroscopic observations made during transit with the CORALIE spectrograph, which allow us to make a highly-significant detection of the Rossiter-McLaughlin effect. We determine the sky-projected angle between the stellar-spin and planetary-orbit axes to be $ = 20.1 plusmn 9.7 degrees, i.e. the system is ``aligned'', according to the widely-used alignment criteria that systems are regarded as misaligned only when $ is measured to be greater than 10 degrees with 3-$ confidence. WASP-71, with an effective temperature of 6059 plusmn 98 K, therefore fits the previously observed pattern that only stars hotter than 6250 K are host to planets in misaligned orbits. We emphasise, however, that $ is merely the sky-projected obliquity angle; we are unable to determine whether the stellar-spin and planetary-orbit axes are misaligned along the line-of-sight. With a mass of 1.56 plusmn 0.07 M$_⊙$, WASP-71 was previously hotter than 6250 K, and therefore might have been significantly misaligned in the past. If so, the planetary orbit has been realigned, presumably through tidal interactions with the cooling star's growing convective zone. Photometric data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A120
KW - planetary systems, planets and satellites: detection, planets and satellites: fundamental parameters, stars: individual: WASP-71, planets and satellites: individual: WASP-71b
U2 - 10.1051/0004-6361/201220727
DO - 10.1051/0004-6361/201220727
M3 - Article
SN - 0004-6361
VL - 552
SP - A120
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
ER -