The IRT Telescope on board the THESEUS mission
Abstract
We present the Infra-Red Telescope (IRT), which is part of the payload of the THESEUS mission, one on the three phase A candidate missions for the M7 slot of ESA (launch date 2037). The IRT is a 0.7 m class telescope with an off-axis Korsch optical design, with imaging capabilities in the 0.7-1.8 microns range over a 15 x 15 arc min field of view. The IRT also provides slit-less low resolution spectroscopy (R~400) over a limited field of view of 2 x 2 arc min, in the 0.8-1.6 microns range. The goal of the IRT is to identify the near infrared counterparts to the Gamma-Ray Bursts (GRBs) detected by the two other telescopes on board THESEUS (the XGIS and the SXI), and to measure on board its photometric redshift in near real-time. The position and the redshift will be transmitted immediately to ground to allow for deeper follow-up by the large telescopes (ELT, VLT, ...). If the source is bright enough, spectroscopy will be performed to characterize the GRB environment.
Keywords
Cite
@article{arxiv.2607.17681,
title = {The IRT Telescope on board the THESEUS mission},
author = {Diego Gotz and Aline Meuris and Eric Doumayrou and Dehbia Lattab and Frederic Pinsard and Samuel Ronayette and Thierry Tourrette and Herni Triou and Bortolino Saggin and Marco Giovanni Corti and Stefano Covino and Fabrizio Fornasiero and Luca Oggioni and Luca Terenzi and Stephane Basa and Enrico Bozzo and Ludovic Genolet and Lauro Conti and Mariachiara Celato and Paul Hedderman and Shaymaa Hussein and Christoph Tenzer and Karine Mercier and Lander Ruiz de Ocenda and Jean-Michel Le Duigou and Adrien Fort and Florent Robinet and Andras Peter Joo and Rebeka Kiss and Bendeguz Koncz and L. Viktor Toth},
journal= {arXiv preprint arXiv:2607.17681},
year = {2026}
}
Comments
20 pages, 14 figures, Proceedings of SPIE Astronomical Telescopes and Instrumentation, July 4-10 2026 , Copenhagen, Manuscript number 14146-33