학술논문
A Transiting Super-Earth in the Radius Valley and An Outer Planet Candidate Around HD 307842
Document Type
Working Paper
Author
Hua, Xinyan; Wang, Sharon Xuesong; Teske, Johanna K.; Gan, Tianjun; Shporer, Avi; Zhou, George; Stassun, Keivan G.; Rabus, Markus; Howell, Steve B.; Ziegler, Carl; Lissauer, Jack J.; Winn, Joshua N.; Jenkins, Jon M.; Ting, Eric B.; Collins, Karen A.; Mann, Andrew W.; Zhu, Wei; Wang, Su; Butler, R. Paul; Crane, Jeffrey D.; Shectman, Stephen A.; Bouma, Luke G.; Briceno, Cesar; Dragomir, Diana; Fong, William; Law, Nicholas; Medina, Jennifer V.; Quinn, Samuel N.; Ricker, George R.; Schwarz, Richard P.; Seager, Sara; Sefako, Ramotholo; Stockdale, Chris; Vanderspek, Roland; Villasenor, Joel
Source
Subject
Language
Abstract
We report the confirmation of a TESS-discovered transiting super-Earth planet orbiting a mid-G star, HD 307842 (TOI-784). The planet has a period of 2.8 days, and the radial velocity (RV) measurements constrain the mass to be 9.67+0.83/-0.82 [Earth Masses]. We also report the discovery of an additional planet candidate on an outer orbit that is most likely non-transiting. The possible periods of the planet candidate are approximately 20 to 63 days, with the corresponding RV semi-amplitudes expected to range from 3.2 to 5.4 m/s and minimum masses from 12.6 to 31.1 [Earth Masses]. The radius of the transiting planet (planet b) is 1.93+0.11/-0.09 [Earth Radii], which results in a mean density of 7.4+1.4/-1.2 g/cm^3 suggesting that TOI-784b is likely to be a rocky planet though it has a comparable radius to a sub-Neptune. We found TOI-784b is located at the lower edge of the so-called ``radius valley'' in the radius vs. insolation plane, which is consistent with the photoevaporation or core-powered mass loss prediction. The TESS data did not reveal any significant transit signal of the planet candidate, and our analysis shows that the orbital inclinations of planet b and the planet candidate are 88.60+0.84/-0.86 degrees and <= 88.3-89.2 degrees, respectively. More RV observations are needed to determine the period and mass of the second object, and search for additional planets in this system.
Comment: 30 pages, 21 figures, accepted for publication in AJ
Comment: 30 pages, 21 figures, accepted for publication in AJ