University of Hertfordshire

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From the same journal

By the same authors

Activity and telluric contamination in HARPS observations of Alpha Centauri B

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Original languageEnglish
Pages (from-to)4804–4816
Number of pages13
JournalMonthly Notices of the Royal Astronomical Society
Early online date27 Mar 2019
Publication statusPublished - 1 Jun 2019


The Alpha Centauri system is the primary target for planet search as it is the closest star system composed of a solar twin α CenA, a K-dwarf α Cen B, and an M-dwarf Proxima Centauri, which has a confirmed planet in the temperate zone. α CenA and B weremonitored intensively with the HARPS spectrograph for over 10 yr, providing high-precision radial velocity (RV) measurements. In this work, we study the available data to better understand the stellar activity and other contaminating signals.We highlight the importance of telluric contamination and its impact on the RV measurements. Our suggested procedures lead to discarding about 5 per cent of HARPS data, providing a data set with an rms improved by a factor of 2. We compile and quantify the behaviour of 345 spectral lines with a wide range of line shapes and sensitivity to activity.


© 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.

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