Near-resonance in a System of Sub-Neptunes from TESS

November 2019 • 2019AJ....158..177Q

Authors • Quinn, Samuel N. • Becker, Juliette C. • Rodriguez, Joseph E. • Hadden, Sam • Huang, Chelsea X. • Morton, Timothy D. • Adams, Fred C. • Armstrong, David • Eastman, Jason D. • Horner, Jonathan • Kane, Stephen R. • Lissauer, Jack J. • Twicken, Joseph D. • Vanderburg, Andrew • Wittenmyer, Rob • Ricker, George R. • Vanderspek, Roland K. • Latham, David W. • Seager, Sara • Winn, Joshua N. • Jenkins, Jon M. • Agol, Eric • Barkaoui, Khalid • Beichman, Charles A. • Bouchy, François • Bouma, L. G. • Burdanov, Artem • Campbell, Jennifer • Carlino, Roberto • Cartwright, Scott M. • Charbonneau, David • Christiansen, Jessie L. • Ciardi, David • Collins, Karen A. • Collins, Kevin I. • Conti, Dennis M. • Crossfield, Ian J. M. • Daylan, Tansu • Dittmann, Jason • Doty, John • Dragomir, Diana • Ducrot, Elsa • Gillon, Michael • Glidden, Ana • Goeke, Robert F. • Gonzales, Erica J. • Hełminiak, Krzysztof G. • Horch, Elliott P. • Howell, Steve B. • Jehin, Emmanuel • Jensen, Eric L. N. • Kielkopf, John F. • Kristiansen, Martti H. • Law, Nicholas • Mann, Andrew W. • Marmier, Maxime • Matson, Rachel A. • Matthews, Elisabeth • Mazeh, Tsevi • Mori, Mayuko • Murgas, Felipe • Murray, Catriona • Narita, Norio • Nielsen, Louise D. • Ottoni, Gaël • Palle, Enric • Pawłaszek, Rafał • Pepe, Francesco • Pitogo de Leon, Jerome • Pozuelos, Francisco J. • Relles, Howard M. • Schlieder, Joshua E. • Sebastian, Daniel • Ségransan, Damien • Shporer, Avi • Stassun, Keivan G. • Tamura, Motohide • Udry, Stéphane • Waite, Ian • Winters, Jennifer G. • Ziegler, Carl

Abstract • We report the Transiting Exoplanet Survey Satellite detection of a multi-planet system orbiting the V = 10.9 K0 dwarf TOI-125. We find evidence for up to five planets, with varying confidence. Three transit signals with high signal-to-noise ratio correspond to sub-Neptune-sized planets (2.76, 2.79, and 2.94 R _⊕), and we statistically validate the planetary nature of the two inner planets (P _b = 4.65 days, P _c = 9.15 days). With only two transits observed, we report the outer object (P _.03 = 19.98 days) as a planet candidate with high signal-to-noise ratio. We also detect a candidate transiting super-Earth (1.4 R _⊕) with an orbital period of only 12.7 hr and a candidate Neptune-sized planet (4.2 R _⊕) with a period of 13.28 days, both at low signal-to-noise ratio. This system is amenable to mass determination via radial velocities and transit-timing variations, and provides an opportunity to study planets of similar size while controlling for age and environment. The ratio of orbital periods between TOI-125 b and c (P _c /P _b = 1.97) is slightly lower than an exact 2:1 commensurability and is atypical of multiple planet systems from Kepler, which show a preference for period ratios just wide of first-order period ratios. A dynamical analysis refines the allowed parameter space through stability arguments and suggests that despite the nearly commensurate periods, the system is unlikely to be in resonance.

Links

• PREPRINT http://arxiv.org/abs/1901.09092
• ELECTR https://doi.org/10.3847%2F1538-3881%2Fab3f2b
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2019AJ....158..177Q
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/ab3f2b/pdf
• PDF https://stacks.iop.org/1538-3881/158/177/pdf
• DATA http://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/158/177
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2019AJ....158..177Q
• DATA https://archive.gemini.edu/searchform/publication=2019AJ....158..177Q
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2019AJ....158..177Q