PEPSI Exoplanet Transit Survey
Transmission spectrum of an exoplanet Transmission spectrum of an exoplanet

Transmission spectrum of an exoplanet (artist impression)

Credit: ESO

The PEPSI Exoplanet Transit Survey is a high-resolution spectroscopic survey of exoplanet transits, secondary eclipses, and host-star characterizations of a large number of targets. Its goal is to characterize their planetary atmospheres in exquisite detail. While transit data allow the extraction of the planetary spectrum at the terminator through transmission at high atmospheric altitudes, giving insights on atmospheric chemical species and atmospheric dynamics, the eclipse data allow tracing atmospheric emission from lower altitudes on the dayside of the exoplanet. The strengths and uniqueness of this project are the combination of PEPSI’s spectral resolution and throughput and the light-collecting power of the LBT in binocular mode with a concerted consideration of the applicable science cases. An additional bonus is the possibility of a dual use of high and low resolution instruments like PEPSI and MODS as well as the detailed characterization of the host star from the co-added time-series spectra, allowing, for example, relating Fe/H ratios in planetary atmospheres to those in stellar atmospheres. Some unique targets with starspots or circumplanetary material will also be monitored for science related to stellar activity and star-planet relations as well.


MPIA, INAF, University of Arizona, Ohio State University

Last update: 2. June 2021