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Title: TOI-3785 b: A Low-density Neptune Orbiting an M2-dwarf Star
Abstract Using both ground-based transit photometry and high-precision radial velocity spectroscopy, we confirm the planetary nature of TOI-3785 b. This transiting Neptune orbits an M2-Dwarf star with a period of ∼4.67 days, a planetary radius of 5.14 ± 0.16 R ⊕ , a mass of 14.95 − 3.92 + 4.10 M ⊕ , and a density of ρ = 0.61 − 0.17 + 0.18 g cm −3 . TOI-3785 b belongs to a rare population of Neptunes (4 R ⊕ < R p < 7 R ⊕ ) orbiting cooler, smaller M-dwarf host stars, of which only ∼10 have been confirmed. By increasing the number of confirmed planets, TOI-3785 b offers an opportunity to compare similar planets across varying planetary and stellar parameter spaces. Moreover, with a high-transmission spectroscopy metric of ∼150 combined with a relatively cool equilibrium temperature of T eq = 582 ± 16 K and an inactive host star, TOI-3785 b is one of the more promising low-density M-dwarf Neptune targets for atmospheric follow up. Future investigation into atmospheric mass-loss rates of TOI-3785 b may yield new insights into the atmospheric evolution of these low-mass gas planets around M dwarfs.  more » « less
Award ID(s):
2108493 1910954 2108801 2108512
PAR ID:
10435508
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; « less
Date Published:
Journal Name:
The Astronomical Journal
Volume:
166
Issue:
2
ISSN:
0004-6256
Page Range / eLocation ID:
44
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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