The well-aligned orbit of Wasp-84b : evidence for disk migration of a hot Jupiter
MetadataShow full item record
We report the sky-projected orbital obliquity (spin–orbit angle) of WASP-84 b, a 0.69 planet in an 8.52 day orbit around a G9V/K0V star, to be λ = −0.3 ± 1.7°. We obtain a true obliquity of ψ = 17.3 ± 7.7° from a measurement of the inclination of the stellar spin axis with respect to the sky plane. Due to the young age and the weak tidal forcing of the system, we suggest that the orbit of WASP-84b is unlikely to have both realigned and circularized from the misaligned and/or eccentric orbit likely to have arisen from high-eccentricity migration. Therefore we conclude that the planet probably migrated via interaction with the protoplanetary disk. This would make it the first "hot Jupiter" () to have been shown to have migrated via this pathway. Further, we argue that the distribution of obliquities for planets orbiting cool stars (Teff < 6250 K) suggests that high-eccentricity migration is an important pathway for the formation of short-orbit, giant planets.
Anderson , D R , Triaud , A H M J , Turner , O D , Brown , D J A , Clark , B J M , Smalley , B , Cameron , A C , Doyle , A P , Gillon , M , Hellier , C , Lovis , C , Maxted , P F L , Pollacco , D , Queloz , D & Smith , A M S 2015 , ' The well-aligned orbit of Wasp-84b : evidence for disk migration of a hot Jupiter ' Astrophysical Journal Letters , vol 800 , no. 1 , L9 . DOI: 10.1088/2041-8205/800/1/L9
Astrophysical Journal Letters
© 2015. The American Astronomical Society. All rights reserved. Reproduced in accordance with the AAS copyright policy. The final version can be found at: http://dx.doi.org/10.1088/2041-8205/800/1/L9
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Showing items related by title, author, creator and subject.
Three newly discovered sub-Jupiter-mass planets : WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary Anderson, D. R.; Cameron, A. Collier; Delrez, L.; Doyle, A. P.; Faedi, F.; Fumel, A.; Gillon, M.; Chew, Y. Gomez Maqueo; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Segransan, D.; Skillen, I.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.; West, R. G. (2014-12-01) - Journal articleWe report the discovery of the transiting exoplanets WASP-69b, WASP-70Ab and WASP-84b, each of which orbits a bright star (V ∼ 10). WASP-69b is a bloated Saturn-mass planet (0.26 MJup, 1.06 RJup) in a 3.868-d period around ...
Domagal-Goldman, S.D.; Segura, A.; Claire, M.W.; Robinson, T.D.; Meadows, V.S. (2014-09-10) - Journal articleThe search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely detectable potential biosignature is considered to be the detection of ...
Biller, Beth A.; Males, Jared; Rodigas, Timothy; Morzinski, Katie; Close, Laird M.; Juhász, Attila; Follette, Katherine B.; Lacour, Sylvestre; Benisty, Myriam; Sicilia-Aguilar, Aurora; Hinz, Philip M.; Weinberger, Alycia; Henning, Thomas; Pott, Jörg-Uwe; Bonnefoy, Mickaël; Köhler, Rainer (2014-08-20) - Journal articleWe report the detection of a faint pointlike feature possibly related to ongoing planet-formation in the disk of the transition disk star HD 169142. The pointlike feature has a Delta-mag(L) ∼ 6.4, at a separation of ∼ 0" ...