RT Journal Article
T1 The CARMENES search for exoplanets around M dwarfs Period search in H alpha, Na I D, and Ca II IRT lines
A1 Cortés Contreras, Miriam
A1 Díez Alonso, Enrique
A1 Montes Gutiérrez, David
AB We use spectra from CARMENES, the Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs, to search for periods in chromospheric indices in 16 M0–M2 dwarfs. We measure spectral indices in the Hα, the Ca II infrared triplet (IRT), and the Na I D lines to study which of these indices are best-suited to finding rotation periods in these stars. Moreover, we test a number of different period-search algorithms, namely the string length method, the phase dispersion minimisation, the generalized Lomb–Scargle periodogram, and the Gaussian process regression with quasi-periodic kernel. We find periods in four stars using Hα and in five stars using the Ca II IRT, two of which have not been found before. Our results show that both Hα and the Ca II IRT lines are well suited for period searches, with the Ca II IRT index performing slightly better than Hα. Unfortunately, the Na I D lines are strongly affected by telluric airglow, and we could not find any rotation period using this index. Further, different definitions of the line indices have no major impact on the results. Comparing the different search methods, the string length method and the phase dispersion minimisation perform worst, while Gaussian process models produce the smallest numbers of false positives and non-detections.ǀ
PB EDP Sciencies
SN 1432-0746
YR 2019
FD 2019-02-27
LK https://hdl.handle.net/20.500.14352/13301
UL https://hdl.handle.net/20.500.14352/13301
LA eng
NO © ESO 2019. Artículo firmado por 23 autores. B.F. acknowledges funding by the DFG under Cz 222/1-1. CARMENES is an instrument for the Centro Astronómico Hispano-Alemán de Calar Alto (CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Científicas (CSIC), the European Union through FEDER/ERF FICTS2011-02 funds, and the members of the CARMENES Consortium (Max-PlanckInstitut für Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, the states of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.
NO European Union through FEDER/ERF FICTS2011-02 funds
NO DFG
NO German Max-Planck-Gesellschaft (MPG)
NO Spanish Consejo Superior de Investigaciones Científicas (CSIC)
NO Max-PlanckInstitut für Astronomie
NO Instituto de Astrofísica de Andalucía
NO Landessternwarte Königstuhl
NO Institut de Ciències de l’Espai
NO Institut für Astrophysik Göttingen
NO Universidad Complutense de Madrid
NO Thüringer Landessternwarte Tautenburg
NO Instituto de Astrofísica de Canarias
NO Hamburger Sternwarte
NO Centro de Astrobiología and Centro Astronómico Hispano-Alemán
NO German Science Foundation through the Major Research Instrumentation Programme
NO DFG Research Unit FOR2544 “Blue Planets around Red Stars”
NO Klaus Tschira Stiftung
NO states of Baden-Württemberg and Niedersachsen
NO Junta de Andalucía, Spain
DS Docta Complutense
RD 16 may 2024