We report the detection of a transiting hot Neptune exoplanet orbiting TOI-824 (SCR J1448-5735), a nearby (d= 64 pc) K4V star, using data from the Transiting Exoplanet Survey Satellite (TESS). The newly discovered planet has a radius, \(R_p= 2.93\pm0.20 R_\oplus\), and an orbital period of 1.393 days. Radial velocity measurements using the Planet Finder Spectrograph (PFS) and the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph confirm the existence of the planet and we estimate its mass to be \(18.47\pm1.84 M_\oplus\). The planet’s mean density is \(\rho= 4.03^{+0.98}_{-0.78}\) g cm\(^{-3}\), making it more than twice as dense as Neptune. TOI-824 b’s high equilibrium temperature makes the planet likely to have a cloud free atmosphere, and thus an excellent candidate for follow up atmospheric studies. The detectability of TOI-824 b’s atmosphere from both ground and space is promising and could lead to the detailed characterization of the most irradiated, small planet at the edge of the hot Neptune desert that has retained its atmosphere to date.
Authors: Jennifer A. Burt, Louise D. Nielsen, Samuel N. Quinn, Eric E. Mamajek, Elisabeth C. Matthews, George Zhou, Julia V. Seidel, Chelsea X. Huang, Eric Lopez, Maritza Soto, Jon Otegi, Keivan G. Stassun, Laura Kreidberg, Karen A. Collins, Jason D. Eastman, Joseph E. Rodriguez, Samuel P. Halverson, Johanna K. Teske, Sharon X. Wang, R. Paul Butler, François Bouchy, Xavier Dumusque, Damien Segransen, Stephen A. Shectman, Jeffrey D. Crane, Fabo Feng, Benjamin T. Montet, Adina D. Feinstein, Yuri Beletski, Erin Flowers, Maximilian N. Günther, Tansu Daylan, Kevin I. Collins, Dennis M. Conti, Tianjun Gan, Eric L. N. Jensen, John F. Kielkopf, Thiam Guan Tan, Ravit Helled, Caroline Dorn, Jonas Haldemann, Jack J. Lissauer, George R. Ricker, Roland Vanderspek, David W. Latham, S. Seager, Joshua N. Winn, Jon M. Jenkins, Joseph D. Twicken, Jeffrey C. Smith, Peter Tenenbaum, Scott Cartwright, Thomas Barclay, Joshua Pepper, Gilbert Esquerdo and William Fong