TOI-1696: A Nearby M4 Dwarf with a 3 R ⊕ Planet in the Neptunian Desert
Name
Mori_2022_AJ_163_298.pdf
Description
Published version
Size
2.78 MB
Format
Adobe PDF
Checksum (MD5)
c0930e7c8d4c0ea115fe50060cbbeac9
Author(s)
Seager, Sara
Date Issued
2022
Journal
Astronomical Journal
Publisher
American Astronomical Society
Citation
Seager, Sara. 2022. "TOI-1696: A Nearby M4 Dwarf with a 3 R ⊕ Planet in the Neptunian Desert." Astronomical Journal, 163 (6).
Version
Final published version
Abstract
We present the discovery and validation of a temperate sub-Neptune around the nearby mid-M dwarf TIC 470381900 (TOI-1696), with a radius of 3.09 ± 0.11 R⊕ and an orbital period of 2.5 days, using a combination of Transiting Exoplanets Survey Satellite (TESS) and follow-up observations using ground-based telescopes. Joint analysis of multiband photometry from TESS, Multicolor Simultaneous Camera for studying Atmospheres of Transiting exoplanets (MuSCAT), MuSCAT3, Sinistro, and KeplerCam confirmed the transit signal to be achromatic as well as refined the orbital ephemeris. High-resolution imaging with Gemini/'Alopeke and high-resolution spectroscopy with the Subaru InfraRed Doppler (IRD) confirmed that there are no stellar companions or background sources to the star. The spectroscopic observations with IRD and Infrared Telescope Facility SpeX were used to determine the stellar parameters, and it was found that the host star is an M4 dwarf with an effective temperature of Teff = 3185 ± 76 K and a metallicity of [Fe/H] = 0.336 ± 0.060 dex. The radial velocities measured from IRD set a 2σ upper limit on the planetary mass to be 48.8 M⊕. The large radius ratio (Rp/R⋆ ∼ 0.1) and the relatively bright near-infrared magnitude (J = 12.2 mag) make this planet an attractive target for further follow-up observations. TOI-1696 b is one of the planets belonging to the Neptunian desert with the highest transmission spectroscopy metric discovered to date, making it an interesting candidate for atmospheric characterizations with JWST.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.3847/1538-3881/AC6BF8
