A1 Refereed original research article in a scientific journal
Surfing the photon noise: New techniques to find low-mass planets around M dwarfs
Authors: G Anglada-Escudé, R P Butler, A Reiners, H R A Jones, M Tuomi, J S Jenkins, J R Barnes, S S Vogt, M Zechmeister
Publisher: WILEY-V C H VERLAG GMBH
Publishing place: WEINHEIM; BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY
Publication year: 2013
Journal: Astronomical Notes / Astronomische Nachrichten
Journal name in source: Astronomische Nachrichten
Journal acronym: Astro.Nachr.
Number in series: 1-2
Volume: 334
Issue: 1-2
First page : 184
Last page: 187
Number of pages: 4
ISSN: 0004-6337
DOI: https://doi.org/10.1002/asna.201211775
Abstract
The current precision radial velocities techniques to detect low mass planets in M dwarf are quickly reviewed. This includes high resolution spectroscopic observations made both in the optical and in the near infrared. We discuss that, given the current instrumental performance, optical RVs are still far ahead over other approaches. However, this situation might change soon with the advent of new spectrographs with red/nIR capabilities. We review a newly developed method to obtain precision RV measurements on stabilized spectrographs and how it is implemented to archival HARPS observations. In addition to get much closer to the photon noise, this approach allows us to identify and filter out wavelength dependent noise sources achieving unprecedented accuracy on G, K and specially M dwarfs. We show how including red/infrared observations is of paramount importance to efficiently and unambiguously detect very low mass planets around cool spectral types. As examples, we show new measurements on Barnard's star indicating that the star is stable down to 0.9 cm s(-1) over a time-span of 4 years and how RV signals correlated with activity indices disappear when using the reddest half of the HARPS wavelength range. To conclude, we present new results, detections and describe the implications in terms of planet/multi-planet abundances around cool stars. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
The current precision radial velocities techniques to detect low mass planets in M dwarf are quickly reviewed. This includes high resolution spectroscopic observations made both in the optical and in the near infrared. We discuss that, given the current instrumental performance, optical RVs are still far ahead over other approaches. However, this situation might change soon with the advent of new spectrographs with red/nIR capabilities. We review a newly developed method to obtain precision RV measurements on stabilized spectrographs and how it is implemented to archival HARPS observations. In addition to get much closer to the photon noise, this approach allows us to identify and filter out wavelength dependent noise sources achieving unprecedented accuracy on G, K and specially M dwarfs. We show how including red/infrared observations is of paramount importance to efficiently and unambiguously detect very low mass planets around cool spectral types. As examples, we show new measurements on Barnard's star indicating that the star is stable down to 0.9 cm s(-1) over a time-span of 4 years and how RV signals correlated with activity indices disappear when using the reddest half of the HARPS wavelength range. To conclude, we present new results, detections and describe the implications in terms of planet/multi-planet abundances around cool stars. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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