NEID Reveals that The Young Warm Neptune TOI-2076 b Has a Low Obliquity

分类： 天文学 >> 天文学 提交时间： 2023-02-19

Robert C. Frazier Gudmundur Stefansson Suvrath Mahadevan Samuel W. Yee Caleb I. Canas Josh Winn Jacob Luhn Fei Dai Lauren Doyle Heather Cegla Shubham Kanodia Paul Robertson John Wisniewski Chad Bender Jiayin Dong Arvind F. Gupta Samuel Halverson Suzanne Hawley Leslie Hebb Rae Holcomb

摘要： TOI-2076 b is a sub-Neptune-sized planet ($R= 2.39 \pm 0.10 {R_\oplus}$) that transits a young ($204 \pm 50 {MYr}$) bright ($V = 9.2$) K-dwarf hosting a system of three transiting planets. Using spectroscopic observations with the NEID spectrograph on the WIYN 3.5 m Telescope, we model the Rossiter-McLaughlin effect of TOI-2076 b, and derive a sky-projected obliquity of $\lambda=-3_{-15}^{+16\:\circ}$. Using the size of the star ($R=0.775 \pm0.015 {R_\odot}$), and the stellar rotation period ($P_{\mathrm{rot}}=7.27\pm0.23$ days), we estimate an obliquity of $\psi=18_{-9}^{+10\:\circ}$ ($\psi < 34^\circ$ at 95\% confidence), demonstrating that TOI-2076 b is on a well-aligned orbit. Simultaneous diffuser-assisted photometry from the 3.5 m Telescope at Apache Point Observatory rules out flares during the transit. TOI-2076 b joins a small but growing sample of young planets in compact multi-planet systems with well-aligned orbits, and is the fourth planet with an age $\lesssim 300$ Myr in a multi-transiting system with an obliquity measurement. The low obliquity of TOI-2076 b and the presence of transit timing variations in the system suggest the TOI-2076 system likely formed via convergent disk migration in an initially well-aligned disk.

同行评议状态:待评议

 点击量 15  下载量 12  评论