Bibcode
Perger, M.; Ribas, I.; Damasso, M.; Morales, J. C.; Affer, L.; Suárez Mascareño, A.; Micela, G.; Maldonado, J.; González Hernández, J. I.; Rebolo, R.; Scandariato, G.; Leto, G.; Zanmar Sanchez, R.; Benatti, S.; Bignamini, A.; Borsa, F.; Carbognani, A.; Claudi, R.; Desidera, S.; Esposito, M.; Lafarga, M.; Martinez Fiorenzano, A. F.; Herrero, E.; Molinari, E.; Nascimbeni, V.; Pagano, I.; Pedani, M.; Poretti, E.; Rainer, M.; Rosich, A.; Sozzetti, A.; Toledo-Padrón, B.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 608, id.A63, 15 pp.
Fecha de publicación:
12
2017
Revista
Número de citas
17
Número de citas referidas
16
Descripción
Context. Short- to mid-term magnetic phenomena on the stellar surface of
M-type stars can resemble the effects of planets in radial velocity
data, and may also hide them. Aims: We analyze 145 spectroscopic
HARPS-N observations of GJ 3942 taken over the past five years and
additional photometry in order to disentangle stellar activity effects
from genuine Doppler signals as a result of the orbital motion of the
star around the common barycenter with its planet. Methods: To
achieve this, we use the common methods of pre-whitening, and treat the
correlated red noise by a first-order moving average term and by
Gaussian-process regression following an MCMC analysis. Results:
We identify the rotational period of the star at 16.3 days and discover
a new super-Earth, GJ 3942 b, with an orbital period of 6.9 days and a
minimum mass of 7.1 M⊕. An additional signal in the
periodogram of the residuals is present, but at this point we cannot
claim with sufficient significance that it is related to a second
planet. If confirmed, this planet candidate would have a minimum mass of
6.3 M⊕ and a period of 10.4 days, which might indicate
a 3:2 mean-motion resonance with the inner planet.
Based on observations made with the Italian Telescopio Nazionale Galileo
(TNG), operated on the island of La Palma by the INAF - Fundación
Galileo Galilei at the Roque de los Muchachos Observatory of the
Instituto de Astrofísica de Canarias (IAC); photometric
observations from the APACHE array located at the Astronomical
Observatory of the Aosta Valley; photometric observations made with the
robotic APT2 (within the EXORAP program) located at Serra La Nave on Mt.
Etna.Table 9 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A63