Smaller than expected bright-spot offsets in Spitzer phase curves of the hot Jupiter Qatar-1b

I will present Spitzer phase curve observations of the hot Jupiter Qatar-1b, taken with the Infrared Red Array Camera instrument onboard the Spitzer space telescope. Qatar-1b is a planet with the same equilibrium temperature — and intermediate surface gravity and orbital period — as the well-studied planets HD 209458b and WASP-43b. General circulation models for HD 209458b and WASP-43b predict that their bright-spots should be shifted east of the substellar point by tens of degrees, and these predictions were previously confirmed with Spitzer full-orbit phase curve observations. The phase curves of Qatar-1b are likewise expected to exhibit eastward offsets. Instead, its phase curves are consistent with no offset. The discrepancy in circulation patterns between these three otherwise similar planets points to the importance of secondary parameters like rotation rate and surface gravity, and the presence or absence of clouds, in determining atmospheric conditions on hot Jupiters.