Document Type
Article
Publication Date
10-1-2021
Published In
Monthly Notices Of The Royal Astronomical Society
Abstract
We present the bright (Vmag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 ± 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Satellite (TESS) objects of Interest (TOI)-431 b is a super-Earth with a period of 0.49 d, a radius of 1.28 ± 0.04 R⊕, a mass of 3.07 ± 0.35 M⊕, and a density of 8.0 ± 1.0 g cm⁻³; TOI-431 d is a sub-Neptune with a period of 12.46 d, a radius of 3.29 ± 0.09 R⊕, a mass of 9.90 (+1.53)/(-1.49) M⊕, and a density of 1.36 ± 0.25 g cm⁻³. We find a third planet, TOI-431 c, in the High Accuracy Radial velocity Planet Searcher RV data, but it is not seen to transit in the TESS light curves. It has an Msin i of 2.83 (+0.41)/(-0.34) M⊕, and a period of 4.85 d. TOI-431 d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterization, while the super-Earth TOI-431 b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431 b is a prime TESS discovery for the study of rocky planet phase curves.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
A. Osborn et al.
(2021).
"TOI-431/HIP 26013: A Super-Earth And A Sub-Neptune Transiting A Bright, Early K Dwarf, With A Third RV Planet".
Monthly Notices Of The Royal Astronomical Society.
Volume 507,
Issue 2.
2782-2803.
DOI: 10.1093/mnras/stab2313
https://works.swarthmore.edu/fac-physics/497
Comments
This work is freely available under a Creative Commons license.