Disentangling the hemispheres of Teegarden's Star b with LIFE

Abstract

Teegarden's Star is one of the most promising targets for the first observations of LIFE, as a non-transiting rocky planet with similar bulk properties to the Earth, and a relatively quiescent M-dwarf host star. We use LIFEsim, a software developed by the ETH LIFE team, along with thermal emission maps obtained from a suite of three-dimensional global climate model (GCM) simulations, to explore the sensitivity of LIFE to the observation geometry. We find that 3 days of observation in broadband would be enough to disentangle the hemispheres of the planet with a 1σ or 3σ confidence level with a baseline or optimistic scenario respectively. Doing the same for a fast-rotator in the habitable zone of a G-class star would be prohibitively challenging. Given enough observation time, the sensitivity of LIFE may allow some spatial resolution of Teegarden's Star b to be achieved, which may directly link to the presence of water clouds and therefore an active hydrology.