arXiv:2301.02477 (astro-ph)
[Submitted on 6 Jan 2023]
Authors:D. Kossakowski, M. Kürster, T. Trifonov, Th. Henning, J. Kemmer, J. A. Caballero, R. Burn, S. Sabotta, J. S. Crouse, T. J. Fauchez, E. Nagel, A. Kaminski, E. Herrero, E. Rodríguez, E. González-Álvarez, A. Quirrenbach, P. J. Amado, I. Ribas, A. Reiners, J. Aceituno, V. J. S. Béjar, D. Baroch, S. T. Bastelberger, P. Chaturvedi, C. Cifuentes, S. Dreizler, S. V. Jeffers, R. Kopparapu, M. Lafarga, M. J. López-González, S. Martí n-Ruiz, D. Montes, J. C. Morales, E. Pallé, A. Pavlov, S. Pedraz, V. Perdelwitz, M. Pérez-Torres, M. Perger, S. Reffert, C. Rodríguez López, M. Schlecker, P. Schöfer, A. Schweitzer, Y. Shan, A. Shields, S. Stock, E. Wolf, M. R. Zapatero Osorio, M. Zechmeister
Abstract: We present the discovery of an Earth-mass planet ($M_bsin i =
1.36pm0.21M_oplus$) on a 15.6d orbit of a relatively nearby ($dsim$9.6pc)
and low-mass ($0.167pm0.011 M_odot$) M5.0V star, Wolf 1069. Sitting at a
separation of $0.0672pm0.0014$au away from the host star puts Wolf 1069b in
the habitable zone (HZ), receiving an incident flux of
$S=0.652pm0.029S_oplus$. The planetary signal was detected using
telluric-corrected radial-velocity (RV) data from the CARMENES spectrograph,
amounting to a total of 262 spectroscopic observations covering almost four
years. There are additional long-period signals in the RVs, one of which we
attribute to the stellar rotation period. This is possible thanks to our
photometric analysis including new, well-sampled monitoring campaigns undergone
with the OSN and TJO facilities that supplement archival photometry (i.e., from
MEarth and SuperWASP), and this yielded an updated rotational period range of
$P_{rot}=150-170$d, with a likely value at $169.3^{+3.7}_{-3.6}$d. The stellar
activity indicators provided by the CARMENES spectra likewise demonstrate
evidence for the slow rotation period, though not as accurately due to possible
factors such as signal aliasing or spot evolution. Our detectability limits
indicate that additional planets more massive than one Earth mass with orbital
periods of less than 10 days can be ruled out, suggesting that perhaps Wolf
1069 b had a violent formation history. This planet is also the 6th closest
Earth-mass planet situated in the conservative HZ, after Proxima Centauri b, GJ
1061d, Teegarden’s Star c, and GJ 1002 b and c. Despite not transiting
