Starshade Rendezvous: Exoplanet Orbit Constraints from Multi-Epoch Direct Imaging
Abstract
The addition of an external starshade to the {\it Nancy Grace Roman Space Telescope} will enable the direct imaging of Earth-radius planets orbiting at 1 AU. Classification of any detected planets as Earth-like requires both spectroscopy to characterize their atmospheres and multi-epoch imaging to trace their orbits. We consider here the ability of the Starshade Rendezvous Probe to constrain the orbits of directly imaged Earth-like planets. The target list for this proposed mission consists of the 16 nearby stars best suited for direct imaging. The field of regard for a starshade mission is constrained by solar exclusion angles, resulting in four observing windows during a two-year mission. We find that for habitable-zone planetary orbits that are detected at least three times during the four viewing opportunities, their semi-major axes are measured with a median precision of 7 mas, or a median fractional precision of 3\%. Habitable-zone planets can be correctly identified as such 96.7\% of the time, with a false positive rate of 2.8\%. If a more conservative criteria is used for habitable-zone classification (95\% probability), the false positive rate drops close to zero, but with only 81\% of the truly Earth-like planets correctly classified as residing in the habitable zone.
Cite
@article{arxiv.2101.01276,
title = {Starshade Rendezvous: Exoplanet Orbit Constraints from Multi-Epoch Direct Imaging},
author = {Andrew Romero-Wolf and Geoffrey Bryden and Greg Agnes and Jonathan W. Arenberg and Samuel Case Bradford and Simone D'Amico and John Debes and Matt Greenhouse and Renyu Hu and Steve Matousek and Jason Rhodes and John Ziemer},
journal= {arXiv preprint arXiv:2101.01276},
year = {2021}
}