11:30 〜 11:45
[PEM11-09] Infrared Doppler survey of late-M dwarfs with IRD-SSP: A planet detection and Recent status
キーワード：系外惑星探索、視線速度法、低質量星
We are searching for planets around late-M dwarfs in the framework of the IRD-SSP (InfraRed Doppler - Subaru Strategic Program) with the radial velocity (RV) method at the near-infrared wavelength. In this project, we have conducted a strategic 5-year RV survey of IRD-SSP original sample stars since 2019 and have looking for signs of Earth-like planets in their RV changes.
In 2022, the initial RV survey of the IRD-SSP has been almost completed to investigate the stellar properties of the sample, including stellar parameters and activities. Moreover, we have performed intensive RV monitoring concentrated on samples suitable for low-mass planet detections with low surface activities and surface temperature.
Recently, we reported a discovery of a super-Earth orbiting a M4.5 dwarf, Ross 508, with an orbital period of 10.77 days in IRD-SSP original sample. The planet has a minimum mass of 4.00 Jupiter masses and a semi-major axis of 0.05366 au because the stellar mass of Ross 508 was determined to be 0.1774 solar masses. An orbit-averaged insolation of the planet is estimated to be ~1.4 times the Earth value and the planet locates on near the inner edge of its habitable zone. In addition, the continuous RV survey allows us to discuss detectability of planets in IRD-SSP survey compared with current theoretical models, and to find some candidates of RV variations in IRD-SSP samples.
In 2022, the initial RV survey of the IRD-SSP has been almost completed to investigate the stellar properties of the sample, including stellar parameters and activities. Moreover, we have performed intensive RV monitoring concentrated on samples suitable for low-mass planet detections with low surface activities and surface temperature.
Recently, we reported a discovery of a super-Earth orbiting a M4.5 dwarf, Ross 508, with an orbital period of 10.77 days in IRD-SSP original sample. The planet has a minimum mass of 4.00 Jupiter masses and a semi-major axis of 0.05366 au because the stellar mass of Ross 508 was determined to be 0.1774 solar masses. An orbit-averaged insolation of the planet is estimated to be ~1.4 times the Earth value and the planet locates on near the inner edge of its habitable zone. In addition, the continuous RV survey allows us to discuss detectability of planets in IRD-SSP survey compared with current theoretical models, and to find some candidates of RV variations in IRD-SSP samples.