Planet-Hosting M Dwarfs Have Fewer Close-In Stellar Companions
Abstract
Stellar companions are known to affect multiple facets of exoplanet formation, evolution, detection, and characterization. In particular, recent studies of FGK stars from Kepler, K2, and TESS have shown that stellar companions to planet-hosting stars have a projected separation distribution that peaks at a larger value than what is expected from non-planet-hosting field stars. This is likely the result of close-in companions affecting and perhaps inhibiting the planet formation process. To test if this is true for the lowest-mass stars as well, we have conducted a volume-limited, high-resolution imaging survey of M dwarfs out to 15 pc. The 15-pc POKEMON sample consists of 455 M dwarfs from M0V through M9V, making it one of the most complete surveys across the broad range of M-dwarf masses. We find a stellar multiplicity rate of 24.0±2.0%, and a projected separation distribution that peaks at 6.81 au, which is consistent with previous studies of M-dwarf multiplicity. However, the projected separation distribution of the planet-hosting stars in the sample is shifted significantly – out to 198 au — similar to what has been found for the FGK stars. These results indicate that the presence of a stellar companion impacts the formation and evolution of any planets around our low-mass neighbors.
- Publication:
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AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- April 2024
- Bibcode:
- 2024ESS.....561401C