학술논문
The TESS-Keck Survey. III. A Stellar Obliquity Measurement of TOI-1726 c
Document Type
article
Author
Dai, Fei; Roy, Arpita; Fulton, Benjamin; Robertson, Paul; Hirsch, Lea; Isaacson, Howard; Albrecht, Simon; Mann, Andrew W; Kristiansen, Martti H; Batalha, Natalie M; Beard, Corey; Behmard, Aida; Chontos, Ashley; Crossfield, Ian JM; Dalba, Paul A; Dressing, Courtney; Giacalone, Steven; Hill, Michelle; Howard, Andrew W; Huber, Daniel; Kane, Stephen R; Kosiarek, Molly; Lubin, Jack; Mayo, Andrew; Mocnik, Teo; Murphy, Joseph M Akana; Petigura, Erik A; Rosenthal, Lee; Rubenzahl, Ryan A; Scarsdale, Nicholas; Weiss, Lauren M; Van Zandt, Judah; Ricker, George R; Vanderspek, Roland; Latham, David W; Seager, Sara; Winn, Joshua N; Jenkins, Jon M; Caldwell, Douglas A; Charbonneau, David; Daylan, Tansu; Günther, Maximilian N; Morgan, Edward; Quinn, Samuel N; Rose, Mark E; Smith, Jeffrey C
Source
The Astronomical Journal. 160(4)
Subject
Language
Abstract
We report the measurement of a spectroscopic transit of TOI-1726c, one of two planets transiting a G-type star with V = 6.9 in the Ursa Major Moving Group (∼400 Myr). With a precise age constraint from cluster membership, TOI-1726 provides a great opportunity to test various obliquity excitation scenarios that operate on different timescales. By modeling the Rossiter-McLaughlin (RM) effect, we derived a sky-projected obliquity of -1-+3235∘. This result rules out a polar/retrograde orbit and is consistent with an aligned orbit for planet c. Considering the previously reported, similarly prograde RM measurement of planet b and the transiting nature of both planets, TOI-1726 tentatively conforms to the overall picture that compact multitransiting planetary systems tend to have coplanar, likely aligned orbits. TOI-1726 is also a great atmospheric target for understanding differential atmospheric loss of sub-Neptune planets (planet b 2.2 R☉ and c 2.7 R☉ both likely underwent photoevaporation). The coplanar geometry points to a dynamically cold history of the system that simplifies any future modeling of atmospheric escape.