학술논문
TESS Reveals a Short-period Sub-Neptune Sibling (HD 86226c) to a Known Long-period Giant Planet
Document Type
Working Paper
Author
Teske, Johanna; Díaz, Matías R.; Luque, Rafael; Močnik, Teo; Seidel, Julia V.; Otegi, Jon Fernández; Feng, Fabo; Jenkins, James S.; Pallè, Enric; Ségransan, Damien; Udry, Stèphane; Collins, Karen A.; Eastman, Jason D.; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Anderson, David. R.; Barclay, Thomas; Bouchy, François; Burt, Jennifer A.; Butler, R. Paul; Caldwell, Douglas A.; Collins, Kevin I.; Crane, Jeffrey D.; Dorn, Caroline; Flowers, Erin; Haldemann, Jonas; Helled, Ravit; Hellier, Coel; Jensen, Eric L. N.; Kane, Stephen R.; Law, Nicholas; Lissauer, Jack J.; Mann, Andrew W.; Marmier, Maxime; Nielsen, Louise Dyregaard; Rose, Mark E.; Shectman, Stephen A.; Shporer, Avi; Torres, Guillermo; Wang, Sharon X.; Wolfgang, Angie; Wong, Ian; Ziegler, Carl
Source
Subject
Language
Abstract
The Transiting Exoplanet Survey Satellite mission was designed to find transiting planets around bright, nearby stars. Here we present the detection and mass measurement of a small, short-period ($\approx\,4$\,days) transiting planet around the bright ($V=7.9$), solar-type star HD 86226 (TOI-652, TIC 22221375), previously known to host a long-period ($\sim$1600 days) giant planet. HD 86226c (TOI-652.01) has a radius of $2.16\pm0.08$ $R_{\oplus}$ and a mass of 7.25$^{+1.19}_{-1.12}$ $M_{\oplus}$ based on archival and new radial velocity data. We also update the parameters of the longer-period, not-known-to-transit planet, and find it to be less eccentric and less massive than previously reported. The density of the transiting planet is $3.97$ g cm$^{-3}$, which is low enough to suggest that the planet has at least a small volatile envelope, but the mass fractions of rock, iron, and water are not well-constrained. Given the host star brightness, planet period, and location of the planet near both the ``radius gap'' and the ``hot Neptune desert'', HD 86226c is an interesting candidate for transmission spectroscopy to further refine its composition.
Comment: Accepted in AJ on 22 June 2020
Comment: Accepted in AJ on 22 June 2020