[en] We present the first ground-based detection of thermal emission from an exoplanet in the H-band. Using HAWK-I on the VLT, we observed an occultation of WASP-19b by its G8V-type host star. WASP-19b is a Jupiter-mass planet with an orbital period of only 19 h, and thus, being highly irradiated, is expected to be hot. We measure an H-band occultation depth of 0.259[SUP]+0.046[/SUP][SUB]-0.044[/SUB]%, which corresponds to an H-band brightness temperature of T[SUB]H[/SUB] = 2580 ± 125 K. A cloud-free model of the planet's atmosphere, with no redistribution of energy from day-side to night-side, under predicts the planet/star flux density ratio by a factor of two. As the stellar parameters, and thus the level of planetary irradiation, are well-constrained by measurement, it is likely that our model of the planet's atmosphere is too simple. Based on data collected with the VLT/HAWKI instrument at ESO Paranal Observatory, Chile (programs 083.C-0377(A)).The photometric time-series used in this work are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/513/L3">http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/513/L3</A>
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Anderson, D. R.; Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Maxted, P. F. L.; Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK
Barman, T. S.; Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA
Collier Cameron, A.; School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife KY16 9SS, UK
Hellier, C.; Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK