TY - JOUR
T1 - The spin-orbit angles of the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b from Rossiter-McLaughlin observations
AU - Simpson, E.K.
AU - Pollacco, Don
AU - Cameron, A.Collier
AU - Hébrard, G.
AU - Anderson, D.R.
AU - Barros, S.C.C.
AU - Boisse, I.
AU - Bouchy, F.
AU - Faedi, F.
AU - Gillon, M.
AU - Hebb, L.
AU - Keenan, F. P.
AU - Miller, G.R.M.
AU - Moutou, C.
AU - Queloz, D.
AU - Skillen, I.
AU - Sorensen, P.
AU - Stempels, H.C.
AU - Triaud, A.
AU - Watson, C.A.
AU - Wilson, P.A.
PY - 2011/7
Y1 - 2011/7
N2 - We present observations of the Rossiter–McLaughlin effect for the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b, and deduce the orientations of the planetary orbits with respect to the host stars’ rotation axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin-orbit angles consistent with zero: λ=−4°.7 ± 4°.0, 15°+33−43 and Graphic, respectively. The host stars have Teff < 6250 K and conform with the trend of cooler stars having low obliquities. WASP-38b is a massive planet on a moderately long period, eccentric orbit so may be expected to have a misaligned orbit given the high obliquities measured in similar systems. However, we find no evidence for a large spin-orbit angle. By contrast, WASP-1b joins the growing number of misaligned systems and has an almost polar orbit, λ=Graphic. It is neither very massive, eccentric nor orbiting a hot host star, and therefore does not share the properties of many other misaligned systems.
AB - We present observations of the Rossiter–McLaughlin effect for the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b, and deduce the orientations of the planetary orbits with respect to the host stars’ rotation axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin-orbit angles consistent with zero: λ=−4°.7 ± 4°.0, 15°+33−43 and Graphic, respectively. The host stars have Teff < 6250 K and conform with the trend of cooler stars having low obliquities. WASP-38b is a massive planet on a moderately long period, eccentric orbit so may be expected to have a misaligned orbit given the high obliquities measured in similar systems. However, we find no evidence for a large spin-orbit angle. By contrast, WASP-1b joins the growing number of misaligned systems and has an almost polar orbit, λ=Graphic. It is neither very massive, eccentric nor orbiting a hot host star, and therefore does not share the properties of many other misaligned systems.
U2 - 10.1111/j.1365-2966.2011.18603.x
DO - 10.1111/j.1365-2966.2011.18603.x
M3 - Article
SN - 0035-8711
VL - 414
SP - 3023
EP - 3035
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
ER -