University of Hertfordshire

From the same journal

From the same journal

By the same authors

The impact of unresolved magnetic spots on high precision radial velocity measurements

Research output: Contribution to journalArticlepeer-review


  • 2007.12193v1

    Accepted author manuscript, 3.71 MB, PDF document

  • Maksym Lisogorskyi
  • Susdeshna Boro Saikia
  • Sandra V. Jeffers
  • Hugh R. A. Jones
  • Julien Morin
  • Matthew Mengel
  • Ansgar Reiners
  • Aline A. Vidotto
  • Pascal Petit
View graph of relations
Original languageEnglish
Article numberstaa2184
JournalMonthly Notices of the Royal Astronomical Society
Early online date23 Jul 2020
Publication statusE-pub ahead of print - 23 Jul 2020


The Doppler method of exoplanet detection has been extremely successful, but suffers from contaminating noise from stellar activity. In this work a model of a rotating star with a magnetic field based on the geometry of the K2 star Epsilon Eridani is presented and used to estimate its effect on simulated radial velocity measurements. A number of different distributions of unresolved magnetic spots were simulated on top of the observed large-scale magnetic maps obtained from eight years of spectropolarimetric observations. The radial velocity signals due to the magnetic spots have amplitudes of up to 10 m s$^{-1}$, high enough to prevent the detection of planets under 20 Earth masses in temperate zones of solar type stars. We show that the radial velocity depends heavily on spot distribution. Our results emphasize that understanding stellar magnetic activity and spot distribution is crucial for detection of Earth analogues.


This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.


ID: 22397967