A star’s tilt angle relative to a planetary system not only gives insight into the system’s formation and evolution, but also hints at the presence of additional bodies within the system.
However, M-type dwarfs, the most promising targets for atmospheric tracking, are underestimated in terms of tilt characterization investigations due to challenges associated with accurate measurements.
In this paper, we measure the tilt angle of the late M dwarf TRAPPIST-1 using the ultra-precision radial velocity spectrograph MAROON-X. The Rossiter-McLaughlin effect gives a system tilt of -2+17−19 degrees and a stellar rotation rate of 2.1 ± 0.3 km s−1. Although we were unable to detect differential rotation of the stellar surface, we found that the current data support a model in which all planets share the same tilt angle.
No planetary features could be detected using Doppler tomography. This may be a result of both the slow rotation of the star and the low SNR of the data. Overall, TRAPPIST-1 appears to have a low tilt angle. This could mean that the system has a low primordial tilt angle. It also appears to be a slow rotor, consistent with past characterizations of the system and estimates of the stellar rotation period.
The MAROON-X data enable accurate measurements of stellar tilts due to the Rossiter-McLaughlin effect, highlighting the capabilities of MAROON-X and its ability to make high-precision RV measurements around late faint stars. increase.
Madison Brady, Jacob Biehn, Andreas Seifert, David Kaspar, Rafael Luque, Ansgar Reiners, Björn Beneke, Gudmundur Stefansson, Julian Sturmer
Comment: 18 pages, 6 figures, submitted to AJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Star Astrophysics (astro-ph.SR)
Quoted as: arXiv:2211.11841 [astro-ph.EP] (or arXiv:2211.11841v1 [astro-ph.EP] for this version)
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From: Madison Brady
[v1] Mon, Nov 21, 2022 20:27:03 UTC (4,508 KB)