2025-10-23 カリフォルニア大学アーバイン校(UCI)
Web要約 の発言：
An artist’s conception of GJ 251 c, showing the planet (left), its host star (right), and a previously discovered planet that orbits closer to the star (middle). Michael Marcheschi / m2design
＜関連情報＞
- https://news.uci.edu/2025/10/23/uc-irvine-astronomers-discover-nearby-exoplanet-in-habitable-zone/
- https://iopscience.iop.org/article/10.3847/1538-3881/ae0e20
直接撮影可能なハビタブルゾーン近傍のスーパーアース候補の発見 Discovery of a Nearby Habitable Zone Super-Earth Candidate Amenable to Direct Imaging
Corey Beard, Paul Robertson, Jack Lubin, Eric B. Ford, Suvrath Mahadevan, Gudmundur Stefansson, Jason T. Wright, Eric Wolf, Vincent Kofman, Vidya Venkatesan,…
The Astronomical Journal Published: 2025 October
DOI:10.3847/1538-3881/ae0e20
Abstract
We present the discovery of GJ 251 c, a candidate super-Earth orbiting in the habitable zone (HZ) of its M dwarf host star. Using high-precision Habitable-zone Planet Finder and NEID RVs, in conjunction with archival RVs from the Keck I High Resolution Echelle Spectrometer, the Calar Alto High-resolution Search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrograph, and the Spectropolarimétre Infrarouge, we improve the measured parameters of the known planet, GJ 251 b (Pb = 14.2370 days;m sin(i) = 3.85+0.35-0.33 M⊕), and we significantly constrain the minimum mass of GJ 251 c, placing it in a plausibly terrestrial regime (Pc = 53.647 ± 0.044 days;m sin ic = 3.84 ± 0.75 M⊕). Using activity mitigation techniques that leverage chromatic information content, we perform a color-dependent analysis of the system and a detailed comparison of more than 50 models that describe the nature of the planets and stellar activity in the system. Due to GJ 251’s proximity to Earth (5.5 pc), next generation, 30 meter class telescopes will likely be able to image terrestrial planets in GJ 251’s HZ. In fact, GJ 251 c is currently the best candidate for terrestrial, HZ planet imaging in the northern sky.
