HD 183579b: a warm sub-Neptune transiting a solar twin detected by TESS
Torres, Guillermo; Barclay, Thomas; Hellier, Coel; Latham, David W.; Foreman-Mackey, Daniel; Kane, Stephen R.; Bedell, Megan; Stassun, Keivan G.; Wittenmyer, Robert A.; Howell, Steve B.; Crossfield, Ian J. M.; Horner, Jonathan; Kreidberg, Laura; Ziegler, Carl; Collins, Karen A.; Ricker, George R.; Vanderspek, Roland; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Shporer, Avi; Mann, Andrew W.; Jensen, Eric L. N.; Meléndez, Jorge; Bowler, Brendan P.; Twicken, Joseph D.; Bean, Jacob L.; Gan, Tianjun; Osborn, Hugh P.; Plavchan, Peter; Spina, Lorenzo; Mao, Shude; Schwarz, Richard P.; Paegert, Martin; Tinney, C. G.; Kielkopf, John; Okumura, Jack; Wang, Sharon Xuesong; Wright, Duncan J.; Zhang, Hui; Law, Nicholas; Smith, Jeffrey C.; Vezie, Michael; Briceño, César; Shiao, Bernie; Addison, Brett C.; Mengel, Matthew W.; Wang, Gavin; Morgan, Edward H.; Ballard, Sarah; Dittman, Jason
China, United States, Brazil, Australia, United Kingdom, Chile, Germany, Switzerland, Italy
Abstract
We report the discovery and characterization of a transiting warm sub-Neptune planet around the nearby bright (V = 8.75 mag, K = 7.15 mag) solar twin HD 183579, delivered by the Transiting Exoplanet Survey Satellite (TESS). The host star is located 56.8 ± 0.1 pc away with a radius of R* = 0.97 ± 0.02 R⊙ and a mass of M* = 1.03 ± 0.05 M⊙. We confirm the planetary nature by combining space and ground-based photometry, spectroscopy, and imaging. We find that HD 183579b (TOI-1055b) has a radius of Rp = 3.53 ± 0.13 R⊕ on a 17.47 d orbit with a mass of Mp = 11.2 ± 5.4 M⊕ (3σ mass upper limit of 27.4 M⊕). HD 183579b is the fifth brightest known sub-Neptune planet system in the sky, making it an excellent target for future studies of the interior structure and atmospheric properties. By performing a line-by-line differential analysis using the high-resolution and signal-to-noise ratio HARPS spectra, we find that HD 183579 joins the typical solar twin sample, without a statistically significant refractory element depletion.