Cold Jovian planets play an important role in sculpting the dynamical environment in which inner terrestrial planets form. The core accretion model predicts that giant planets cannot form around low-mass M dwarfs, although this idea has been challenged by recent planet discoveries.
Here, we investigate the occurrence rate of giant planets around low-mass (0.1-0.3M⊙) M dwarfs. We monitor a volume-complete, inactive sample of 200 such stars located within 15 parsecs, collecting four high-resolution spectra of each M dwarf over six years and performing intensive follow-up monitoring of two candidate radial-velocity variables.
We use TRES on the 1.5 m telescope at the Fred Lawrence Whipple Observatory and CHIRON on the Cerro Tololo Inter-American Observatory 1.5 m telescope for our primary campaign, and MAROON-X on Gemini North for high-precision follow-up. We place a 95%-confidence upper limit of 1.5% (68%-confidence limit of 0.57%) on the occurrence of MPsini>1MJ giant planets out to the water snow line and provide additional constraints on the giant planet population as a function of MPsini and period.
Beyond the snow line (100 K <Teq<150 K), we place 95%-confidence upper limits of 1.5%, 1.7%, and 4.4% (68%-confidence limits of 0.58%, 0.66%, and 1.7%) for 3MJ<MPsini<10MJ, 0.8MJ<MPsini<3MJ, and 0.3MJ<MPsini<0.8MJ giant planets; i.e., Jupiter analogs are rare around low-mass M dwarfs. In contrast, surveys of Sun-like stars have found that their giant planets are most common at these Jupiter-like instellations.
Emily K Pass, Jennifer G Winters, David Charbonneau, Jonathan M Irwin, David W Latham, Perry Berlind, Michael L Calkins, Gilbert A Esquerdo, Jessica Mink
Comments: Accepted for publication in AJ; 19 pages, 5 figures, 2 tables Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2305.19357 [astro-ph.EP] (or arXiv:2305.19357v1 [astro-ph.EP] for this version)
Submission history From: Emily Pass [v1] Tue, 30 May 2023 18:57:33 UTC (786 KB)
https://arxiv.org/abs/2305.19357
Astrobiology
