| Name: | Suvrath Mahadevan |
| Affiliation: | Penn State |
| Conference ID : | ASI2024_937 |
| Title : | Discovery of a Close-in Neptune mass Planet around a low mass M dwarf Challenges Planet Formation Models |
| Authors : | Suvrath Mahadevan, Gudmundur Stefansson, Joe Ninan, and the HPF Team |
| Authors Affiliation: | 1. Suvrath Mahadevan, Penn State, USA
2. Gudmundur Stefansson, Princeton University, USA
3. Joe Ninan, Tata Institute of Fundamental Research, India
4. HPF Team, Multiple Institutions |
| Mode of Presentation: | Oral |
| Abstract Category : | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract : | Current theories of planet formation suggest that low-mass stars should rarely host exoplanets with masses exceeding that of Neptune. Using precise near-infrared radial velocities obtained with the highly stabilized Habitable-Zone Planet Finder on the 10 meter Hobby Eberly Telescope equipped with a frequency stabilized laser-comb calibrator, we present the discovery of an unexpected Neptune-mass (minimum mass) exoplanet in a 3.7 day orbit around LHS 3154, a dim late M dwarf significantly less massive than the Sun. The mass of a typical disk expected around such a star cannot form this planet easily, and such high planet-to-star mass ratios are not a natural outcome from core-accretion theory, or with gravitational instability. In the core-accretion scenario such planets can only be produced if the dust mass in the protoplanetary disk is 10x higher than typically observed around such very-low mass stars. We will present the discovery of LHS3154b and discuss its implications on our current understanding of how exoplanets form around the most numerous stars in our Galaxy- the M dwarfs. |
