The imminent launch of space telescopes designed to probe the atmospheres of exoplanets has prompted new efforts to prioritise the thousands of transiting planet candidates for follow-up characterisation. We report the detection and confirmation of TOI-1842b, a warm Saturn identified by TESS and confirmed with ground-based observations from Minerva-Australis, NRES, and the Las Cumbres Observatory Global Telescope. This planet has a radius of 1.04−0.05+0.06RJup, a mass of 0.214−0.038+0.040MJup, an orbital period of 9.5739−0.0001+0.0002 days, and an extremely low density (ρ=0.252±0.091 g cm−3). TOI-1842b has among the best known combinations of large atmospheric scale height (893 km) and host-star brightness (J=8.747 mag), making it an attractive target for atmospheric characterisation. As the host star is beginning to evolve off the main sequence, TOI-1842b presents an excellent opportunity to test models of gas giant re-inflation. The primary transit duration of only 4.3 hours also makes TOI-1842b an easily-schedulable target for further ground-based atmospheric characterisation.
@article{arxiv.2112.00198,
title = {TOI-1842b: A Transiting Warm Saturn Undergoing Re-Inflation around an Evolving Subgiant},
author = {Robert A. Wittenmyer and Jake T. Clark and Trifon Trifonov and Brett C. Addison and Duncan J. Wright and Keivan G. Stassun and Jonathan Horner and Nataliea Lowson and John Kielkopf and Stephen R. Kane and Peter Plavchan and Avi Shporer and Hui Zhang and Brendan P. Bowler and Matthew W. Mengel and Jack Okumura and Markus Rabus and Marshall C. Johnson and Daniel Harbeck and Rene Tronsgaard and Lars A. Buchhave and Karen A. Collins and Kevin I. Collins and Tianjun Gan and Eric L. N. Jensen and Steve B. Howell and E. Furlan and Crystal L. Gnilka and Kathryn V. Lester and Rachel A. Matson and Nicholas J. Scott and George R. Ricker and Roland Vanderspek and David W. Latham and S. Seager and Joshua N. Winn and Jon M. Jenkins and Alexander Rudat and Elisa V. Quintana and David R. Rodriguez and Douglas A. Caldwell and Samuel N. Quinn and Zahra Essack and Luke G. Bouma},
journal= {arXiv preprint arXiv:2112.00198},
year = {2022}
}