Activity And Telluric Contamination In HARPS Observations Of Alpha Centauri B


Alpha Centauri B

The Alpha Centauri system is the primary target for planet search as it is the closest star system composed of a solar twin Alpha Centauri A, a K-dwarf Alpha Centauri B and an M-dwarf Proxima Centauri, which has a confirmed planet in the temperate zone.

Alpha Centauri A & B were monitored intensively with the HARPS spectrograph for over 10 years, providing high-precision radial velocity 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 radial velocity measurements. Our suggested procedures lead to discarding about 5% of HARPS data, providing a dataset 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.

Maksym Lisogorskyi, Hugh Jones, Fabo Feng
(Submitted on 27 Feb 2019)

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:1902.10711 [astro-ph.SR] (or arXiv:1902.10711v1 [astro-ph.SR] for this version)
Submission history
From: Maksym Lisogorskyi
[v1] Wed, 27 Feb 2019 19:00:00 UTC (1,488 KB)

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