TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with the Habitable-Zone Planet Finder
Abstract
We present the validation of two planets orbiting M dwarfs, TOI-1696b and TOI-2136b. Both planets are mini-Neptunes orbiting nearby stars, making them promising prospects for atmospheric characterization with the James Webb Space Telescope (JWST). We validated the planetary nature of both candidates using high-contrast imaging, ground-based photometry, and near-infrared radial velocities. Adaptive optics images were taken using the ShARCS camera on the 3 m Shane Telescope. Speckle images were taken using the NN-Explore Exoplanet Stellar Speckle Imager on the WIYN 3.5 m telescope. Radii and orbital ephemerides were refined using a combination of the Transiting Exoplanet Survey Satellite, the diffuser-assisted Astrophysical Research Consortium (ARC) Telescope Imaging Camera (ARCTIC) imager on the 3.5 m ARC telescope at Apache Point Observatory, and the 0.6 m telescope at Red Buttes Observatory. We obtained radial velocities using the Habitable-Zone Planet Finder on the 10 m Hobby-Eberly Telescope, which enabled us to place upper limits on the masses of both transiting planets. TOI-1696b (P = 2.5 days; R p = 3.24 R ⊕; M p < 56.6 M ⊕) falls into a sparsely populated region of parameter space considering its host star's temperature (T eff = 3168 K, M4.5), as planets of its size are quite rare around mid- to late-M dwarfs. On the other hand, TOI-2136b (P = 7.85 days; R p = 2.09 R ⊕; M p < 15.0 M ⊕) is an excellent candidate for atmospheric follow-up with the JWST.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 2022
- DOI:
- 10.3847/1538-3881/ac69ec
- arXiv:
- arXiv:2204.09063
- Bibcode:
- 2022AJ....163..286B
- Keywords:
-
- Gaussian Processes regression;
- Mini Neptunes;
- Radial velocity;
- Transit photometry;
- Exoplanets;
- 1930;
- 1063;
- 1332;
- 1709;
- 498;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted for Publication in the Astronomical Journal