| Title: |
A candidate super-Earth planet orbiting near the snow line of Barnard’s star |
| Authors: |
Ribas, I; Tuomi, M; Reiners, A; Butler, RP; Morales, JC; Perger, M; Dreizler, S; Rodríguez-López, C; González Hernández, JI; Rosich, A; Feng, F; Trifonov, T; Vogt, SS; Caballero, JA; Hatzes, A; Herrero, E; Jeffers, SV; Lafarga, M; Murgas, F; Nelson, RP; Rodríguez, E; Strachan, JBP; Tal-Or, L; Teske, J; Toledo-Padrón, B; Zechmeister, M; Quirrenbach, A; Amado, PJ; Azzaro, M; Béjar, VJS; Barnes, JR; Berdiñas, ZM; Burt, J; Coleman, G; Cortés-Contreras, M; Crane, J; Engle, SG; Guinan, EF; Haswell, CA; Henning, Th; Holden, B; Jenkins, J; Jones, HRA; Kaminski, A; Kiraga, M; Kürster, M; Lee, MH; López-González, MJ; Montes, D; Morin, J; Ofir, A; Pallé, E; Rebolo, R; Reffert, S; Schweitzer, A; Seifert, W; Shectman, SA; Staab, D; Street, RA; Suárez Mascareño, A; Tsapras, Y; Wang, SX; Anglada-Escudé, G |
| Source: |
Nature, vol 563, iss 7731 |
| Publisher Information: |
eScholarship, University of California |
| Publication Year: |
2018 |
| Collection: |
University of California: eScholarship |
| Subject Terms: |
5109 Space Sciences (for-2020); 5101 Astronomical Sciences (for-2020); 51 Physical Sciences (for-2020); General Science & Technology (science-metrix) |
| Subject Geographic: |
365 - 368 |
| Description: |
Barnard’s star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs1, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard’s star is also among the least magnetically active red dwarfs known2,3 and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging4–6, astrometry7,8 and direct imaging9, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard’s star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard’s star, making it an excellent target for direct imaging and astrometric observations in the future. |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| Relation: |
qt00r9191z; https://escholarship.org/uc/item/00r9191z |
| DOI: |
10.1038/s41586-018-0677-y |
| Availability: |
https://escholarship.org/uc/item/00r9191z; https://doi.org/10.1038/s41586-018-0677-y |
| Rights: |
CC-BY |
| Accession Number: |
edsbas.F02338BA |
| Database: |
BASE |