Observing Exoplanets with the Spitzer Space Telescope

Abstract

At its launch in 2003, Spitzer did not have exoplanet science among its primary goals. Yet in the second half of its lifetime, Spitzer’s exoplanet observations came to be among its most important scientific contributions, including the detection of seven planets – three of them Earth analogs in the habitable zone – transiting the late M-dwarf star TRAPPIST-1. We discuss how Spitzer became the first telescope to detect light from a mature exoplanet, to probe the vertical and horizontal structure of exoplanet atmospheres, to validate and improve our knowledge of transiting exoplanet candidates, and to characterize planets detected via microlensing. In related research topics, Spitzer observed the debris left over from the formation of planetary systems and studied Y dwarfs, the cold, free-floating analogs of Jovian mass objects. We also discuss how Spitzer observations and post-processing techniques were optimized to make these challenging exoplanet observations possible.