A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Stellar activity as noise in exoplanet detection - II. Application to M dwarfs
Tekijät: J. M. Andersen, H. Korhonen
Kustantaja: OXFORD UNIV PRESS
Julkaisuvuosi: 2015
Journal: Monthly Notices of the Royal Astronomical Society
Tietokannassa oleva lehden nimi: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Lehden akronyymi: MON NOT R ASTRON SOC
Vuosikerta: 448
Numero: 4
Aloitussivu: 3053
Lopetussivu: 3069
Sivujen määrä: 17
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stu2731
The ubiquity of M dwarf stars combined with their low masses and luminosities make them prime targets in the search for nearby, habitable exoplanets. We investigate the effects of starspot-induced radial velocity (RV) jitter on detection and characterization of planets orbiting M dwarfs. We create surface spot configurations with both random spot coverage and active regions. Synthetic stellar spectra are calculated from a given spot map, and RV measurements are obtained using cross-correlation technique. We add the RV signal of an orbiting planet to these jitter measurements, and reduce the data to 'measure' the planetary parameters. We investigate the detectability of planets around M dwarfs of different activity levels, and the recovery of input planetary parameters. When studying the recovery of the planetary period we note that while our original orbital radius places the planet inside the habitable zone (HZ) of its star, even at a filling factor of 2 per cent a few of our measurements fall outside the 'conservative HZ'. Higher spot filling factors result in more and higher deviations. Our investigations suggest that caution should be used when characterizing planets discovered with the RV method around stars that are (or are potentially) active.