Abstract: Aims: Previous secondary eclipse observations of the hot Jupiter Qatar-1B in the Ks band suggest that it may have an unusually high day-side temperature, indicative of minimal heat redistribution. There have also been indications that the orbit may be slightly eccentric, possibly forced by another planet in the system. We investigate the day-side temperature and orbital eccentricity using secondary eclipse observations with Spitzer. Methods: We observed the secondary eclipse with Spitzer/IRA…