Abbreviated Journal Title
infrared: planetary systems; planets and satellites: atmospheres; planets and satellites: composition; planets and satellites: individual; (WASP-18b); INFRARED-EMISSION SPECTRUM; IRRADIATED GIANT PLANETS; TRANSIT; LIGHT-CURVE; HOT JUPITERS; HD 209458B; TEMPERATURE INVERSION; EXTRASOLAR; PLANET; THERMAL EMISSION; EXOPLANET WASP-12B; GJ 436B; Astronomy & Astrophysics
The transiting exoplanet WASP-18b was discovered in 2008 by the Wide Angle Search for Planets project. The Spitzer Exoplanet Target of Opportunity Program observed secondary eclipses of WASP-18b using Spitzer's Infrared Array Camera in the 3.6 mu m and 5.8 mu m bands on 2008 December 20, and in the 4.5 mu m and 8.0 mu m bands on 2008 December 24. We report eclipse depths of 0.30% +/- 0.02%, 0.39% +/- 0.02%, 0.37% +/- 0.03%, 0.41% +/- 0.02%, and brightness temperatures of 3100 +/- 90, 3310 +/- 130, 3080 +/- 140, and 3120 +/- 110 K in order of increasing wavelength. WASP-18b is one of the hottest planets yet discovered-as hot as an M-class star. The planet's pressure-temperature profile most likely features a thermal inversion. The observations also require WASP-18b to have near-zero albedo and almost no redistribution of energy from the day side to the night side of the planet.
Nymeyer, Sarah; Harrington, Joseph; Hardy, Ryan A.; Stevenson, Kevin B.; Campo, Christopher J.; Madhusudhan, Nikku; Collier-Cameron, Andrew; Loredo, Thomas J.; Blecic, Jasmina; Bowman, William C.; Britt, Christopher B. T.; Cubillos, Patricio; Hellier, Coel; Gillon, Michael; Maxted, Pierre F. L.; Hebb, Leslie; Wheatley, Peter J.; Pollaccoo, Don; and Anderson, David R., "Spitzer Secondary Eclipses of Wasp-18b" (2011). Faculty Bibliography 2010s. 1723.