Discovery Of A Nearby Habitable Zone Super-Earth Candidate Amenable To Direct Imaging
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 (HPF) and NEID RVs, in conjunction with archival RVs from the Keck I High Resolution Echelle Spectrometer (HIRES), the Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrograph (CARMENES), and the SPectropolarimètre InfraROUge (SPIRou), we improve the measured parameters of the known planet, GJ 251 b (Pb = 14.2370 days; msin(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; msinic = 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, thirty 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.
Corey Beard, Paul Robertson, Jack Lubin, Eric B. Ford, Suvrath Mahadevan, Gudmundur Stefansson, Jason T. Wright, Eric Wolf, Vincent Kofman, Vidya Venkatesan, Ravi Kopparapu, Roan Arendtsz, Rae Holcomb, Raquel A. Martinez, Stephanie Sallum, Jacob K. Luhn, Chad F. Bender, Cullen H. Blake, William D. Cochran, Megan Delamer, Scott A. Diddams, Michael Endl, Samuel Halverson, Shubham Kanodia, Daniel M. Krolikowski, Andrea S.J. Lin, Sarah E. Logsdon, Michael W. McElwain, Andrew Monson, Joe P. Ninan, Jayadev Rajagopal, Arpita Roy, Christian Schwab, Ryan C. Terrien
Comments: Accepted for publication
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2510.19956 [astro-ph.EP] (or arXiv:2510.19956v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2510.19956
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Related DOI:
https://doi.org/10.3847/1538-3881/ae0e20
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Submission history
From: Corey Beard
[v1] Wed, 22 Oct 2025 18:29:49 UTC (20,253 KB)
https://arxiv.org/abs/2510.19956
Astrobiology
