Terminus: A Versatile Simulator for Space-based Telescopes

TL;DR

Terminus is a versatile, adaptable simulator designed to model space-based telescope observations, accounting for observational gaps and enabling better planning for exoplanet and other celestial object studies.

Contribution

It introduces a comprehensive simulation tool capable of modeling observational gaps and generating light curves and spectra for various space telescopes, especially in low-Earth orbit.

Findings

Successfully models observation gaps due to Earth obscuration.

Can generate realistic light curves and spectra for exoplanet studies.

Applicable to multiple space telescope missions, starting with Twinkle.

Abstract

Space-based telescopes offer unparalleled opportunities for characterising exoplanets, Solar System bodies and stellar objects. However, observatories in low Earth orbits (e.g. Hubble, CHEOPS, Twinkle and an ever increasing number of cubesats) cannot always be continuously pointed at a target due to Earth obscuration. For exoplanet observations consisting of transit, or eclipse, spectroscopy this causes gaps in the light curve, which reduces the information content and can diminish the science return of the observation. Terminus, a time-domain simulator, has been developed to model the occurrence of these gaps to predict the potential impact on future observations. The simulator is capable of radiometrically modelling exoplanet observations as well as producing light curves and spectra. Here, Terminus is baselined on the Twinkle mission but the model can be adapted for any space-based telescope and is especially applicable to those in a low-Earth orbit. Terminus also has the capability to model observations of other targets such as asteroids or brown dwarfs.