TY - JOUR
T1 - The CARMENES search for exoplanets around M dwarfs
T2 - A sub-Neptunian mass planet in the habitable zone of HN Lib
AU - González-Álvarez, E.
AU - Kemmer, J.
AU - Chaturvedi, P.
AU - Caballero, J. A.
AU - Quirrenbach, A.
AU - Amado, P. J.
AU - Béjar, V. J.S.
AU - Cifuentes, C.
AU - Herrero, E.
AU - Kossakowski, D.
AU - Reiners, A.
AU - Ribas, I.
AU - Rodríguez, E.
AU - Rodríguez-López, C.
AU - Sanz-Forcada, J.
AU - Shan, Y.
AU - Stock, S.
AU - Tabernero, H. M.
AU - Tal-Or, L.
AU - Osorio, M. R.Zapatero
AU - Hatzes, A. P.
AU - Henning, Th
AU - López-González, M. J.
AU - Montes, D.
AU - Morales, J. C.
AU - Pallé, E.
AU - Pedraz, S.
AU - Perger, M.
AU - Reffert, S.
AU - Sabotta, S.
AU - Schweitzer, A.
AU - Zechmeister, M.
N1 - Publisher Copyright:
© 2023 EDP Sciences. All rights reserved.
PY - 2023/7/1
Y1 - 2023/7/1
N2 - We report the discovery of HN Lib b, a sub-Neptunian mass planet orbiting the nearby (d ≈= 6.25 pc) M4.0 V star HN Lib detected by our CARMENES radial-velocity (RV) survey. We determined a planetary minimum mass of Mb sin i = 5.46 ± 0.75 M and an orbital period of Pb = 36.116 ± 0.029 d, using ∼5 yr of CARMENES data, as well as archival RVs from HARPS and HIRES spanning more than 13 yr. The flux received by the planet equals half the instellation on Earth, which places it in the middle of the conservative habitable zone (HZ) of its host star. The RV data show evidence for another planet candidate with M[c] sin i = 9.7 ± 1.9 M and P[c] = 113.46 ± 0.20 d. The long-term stability of the signal and the fact that the best model for our data is a two-planet model with an independent activity component stand as strong arguments for establishing a planetary origin. However, we cannot rule out stellar activity due to its proximity to the rotation period of HN Lib, which we measured using CARMENES activity indicators and photometric data from a ground-based multi-site campaign as well as archival data. The discovery adds HN Lib b to the shortlist of super-Earth planets in the habitable zone of M dwarfs, but HN Lib [c] probably cannot be inhabited because, if confirmed, it would most likely be an icy giant.
AB - We report the discovery of HN Lib b, a sub-Neptunian mass planet orbiting the nearby (d ≈= 6.25 pc) M4.0 V star HN Lib detected by our CARMENES radial-velocity (RV) survey. We determined a planetary minimum mass of Mb sin i = 5.46 ± 0.75 M and an orbital period of Pb = 36.116 ± 0.029 d, using ∼5 yr of CARMENES data, as well as archival RVs from HARPS and HIRES spanning more than 13 yr. The flux received by the planet equals half the instellation on Earth, which places it in the middle of the conservative habitable zone (HZ) of its host star. The RV data show evidence for another planet candidate with M[c] sin i = 9.7 ± 1.9 M and P[c] = 113.46 ± 0.20 d. The long-term stability of the signal and the fact that the best model for our data is a two-planet model with an independent activity component stand as strong arguments for establishing a planetary origin. However, we cannot rule out stellar activity due to its proximity to the rotation period of HN Lib, which we measured using CARMENES activity indicators and photometric data from a ground-based multi-site campaign as well as archival data. The discovery adds HN Lib b to the shortlist of super-Earth planets in the habitable zone of M dwarfs, but HN Lib [c] probably cannot be inhabited because, if confirmed, it would most likely be an icy giant.
KW - Planetary systems
KW - Stars: individual: HN Lib
KW - Stars: late-type
KW - Techniques: photometric
KW - Techniques: radial velocities
UR - http://www.scopus.com/inward/record.url?scp=85166050883&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202346276
DO - 10.1051/0004-6361/202346276
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:85166050883
SN - 0004-6361
VL - 675
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A141
ER -