THESEUS (satellite)


Transient High-Energy Sky and Early Universe Surveyor is a space telescope mission proposal by the European Space Agency that would study gamma-ray bursts and X-rays for investigating the early universe. If developed, the mission would investigate star formation rates and metallicity evolution, as well as studying the sources and physics of reionization.

Overview

THESEUS is a mission concept that would monitor transient events in the high-energy Universe across the whole sky and over the entirety of cosmic history. In particular, it expects to make a complete census of gamma-ray bursts from the Universe's first billion years, to help understand the life cycle of the first stars. THESEUS would provide real-time triggers and accurate locations of the sources, which could also be followed up by other space- or ground-based telescopes operating at complementary wavelengths.
The concept was selected in May 2018 as a finalist to become the fifth Medium-class mission of the Cosmic Vision programme by the European Space Agency. The other two finalists are SPICA, an infrared space telescope, and EnVision, a Venus orbiter. The winner will be selected in 2021 and it would launch in 2032.
The space observatory would study gamma-ray bursts and X-rays and their association with the explosive death of massive stars, supernova shock break-outs, black hole tidal disruption events, and magnetar flares. This can provide fundamental information on the cosmic star formation rate, the number density and properties of low-mass galaxies, the neutral hydrogen fraction, and the escape fraction of ultraviolet photons from galaxies.

Science payload

The conceptual payload of THESEUS includes: