Four Sub-Earth Planets Orbiting Barnard’s Star From MAROON-X And ESPRESSO
Barnard’s Star is an old, single M dwarf star that comprises the second-closest extrasolar system. It has a long history of claimed planet detections from both radial velocities and astrometry.
However, none of these claimed detections have so far withstood further scrutiny. Continuing this story, extreme precision radial velocity (EPRV) measurements from the ESPRESSO instrument have recently been used to identify four new sub-Earth-mass planet candidates around Barnard’s Star.
We present here 112 radial velocities of Barnard’s Star from the MAROON-X instrument that were obtained independently to search for planets around this compelling object. The data have a typical precision of 30 cm s−1 and are contemporaneous with the published ESPRESSO measurements (2021 – 2023).
The MAROONX data on their own confirm planet b (P = 3.154 d) and planet candidates c and d (P = 4.124 d and 2.340 d, respectively). Furthermore, adding the MAROON-X data to the ESPRESSO data strengthens the evidence for planet candidate e (P = 6.739 d), thus leading to its confirmation.
The signals from all four planets are <50 cm s−1 , the minimum masses of the planets range from 0.19 to 0.34 M⊕, and the system is among the most compact known among late M dwarfs hosting low-mass planets. The current data rule out planets with masses > 0.57 M⊕ (with a 99% detection probability) in Barnard Star’s habitable zone (P = 10 – 42 d).
Ritvik Basant, Rafael Luque, Jacob L. Bean, Andreas Seifahrt, Madison Brady, Lily L. Zhao, Nina Brown, Tanya Das, Julian Stürmer, David Kasper, Rohan Gupta, Guðmundur Stefánsson
Comments: Accepted in ApJL
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2503.08095 [astro-ph.EP] (or arXiv:2503.08095v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2503.08095
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Submission history
From: Ritvik Basant
[v1] Tue, 11 Mar 2025 06:56:16 UTC (3,298 KB)
https://arxiv.org/abs/2503.08095
Astrobiology,
