TOI-1842b: A Transiting Warm Saturn Undergoing Reinflation around an Evolving Subgiant

February 2022 • 2022AJ....163...82W

Authors • Wittenmyer, Robert A. • Clark, Jake T. • Trifonov, Trifon • Addison, Brett C. • Wright, Duncan J. • Stassun, Keivan G. • Horner, Jonathan • Lowson, Nataliea • Kielkopf, John • Kane, Stephen R. • Plavchan, Peter • Shporer, Avi • Zhang, Hui • Bowler, Brendan P. • Mengel, Matthew W. • Okumura, Jack • Rabus, Markus • Johnson, Marshall C. • Harbeck, Daniel • Tronsgaard, René • Buchhave, Lars A. • Collins, Karen A. • Collins, Kevin I. • Gan, Tianjun • Jensen, Eric L. N. • Howell, Steve B. • Furlan, E. • Gnilka, Crystal L. • Lester, Kathryn V. • Matson, Rachel A. • Scott, Nicholas J. • Ricker, George R. • Vanderspek, Roland • Latham, David W. • Seager, S. • Winn, Joshua N. • Jenkins, Jon M. • Rudat, Alexander • Quintana, Elisa V. • Rodriguez, David R. • Caldwell, Douglas A. • Quinn, Samuel N. • Essack, Zahra • Bouma, Luke G.

Abstract • The imminent launch of space telescopes designed to probe the atmospheres of exoplanets has prompted new efforts to prioritize the thousands of transiting planet candidates for follow-up characterization. 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 ${1.04}_{-0.05}^{+0.06}$ R _J, a mass of ${0.214}_{-0.038}^{+0.040}$ M _J, 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 characterization. As the host star is beginning to evolve off the main sequence, TOI-1842b presents an excellent opportunity to test models of gas giant reinflation. The primary transit duration of only 4.3 hr also makes TOI-1842b an easily-schedulable target for further ground-based atmospheric characterization.

Links

• PREPRINT http://arxiv.org/abs/2112.00198
• ELECTR https://doi.org/10.3847/1538-3881/ac3f39
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2022AJ....163...82W
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/ac3f39/pdf
• DATA http://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/163/82
• DATA https://archive.gemini.edu/searchform/publication=2022AJ....163...82W
• DATA https://irsa.ipac.caltech.edu/bibdata/2022/W/2022AJ....163...82W.html