Skip to main content

Research Repository

Advanced Search

Recurring sets of recurring starspots on exoplanet-host Qatar-2

Močnik, T. ; Southworth, J.; Hellier, C.

Recurring sets of recurring starspots on exoplanet-host Qatar-2 Thumbnail


Authors

T. Močnik



Abstract

We announce the detection of recurring sets of recurring starspot occultation events in the short-cadence K2 light curve of Qatar-2, a K dwarf star transited every 1.34 d by a hot Jupiter. In total, we detect 34 individual starspot occultation events, caused by five different starspots, occulted in up to five consecutive transits or after a full stellar rotation. The longest recurring set of recurring starspot occultations spans over three stellar rotations, setting a lower limit for the longest starspot lifetime of 58 d. Starspot analysis provided a robust stellar rotational period measurement of 18.0 ± 0.2 d and indicates that the system is aligned, having a skyprojected obliquity of 0? ± 8?. A pronounced rotational modulation in the light curve has a period of 18.2 ± 1.6 d, in agreement with the rotational period derived from the starspot occultations. We tentatively detect an ellipsoidal modulation in the phase curve, with a semiamplitude of 18 ppm, but cannot exclude the possibility that this is the result of red noise or imperfect removal of the rotational modulation. We detect no transit-timing and transitduration variations with upper limits of 15 s and 1 min, respectively. We also reject any additional transiting planets with transit depths above 280 ppm in the orbital period region 0.5–30 d.

Journal Article Type Article
Acceptance Date Jun 20, 2017
Online Publication Date Jun 22, 2017
Publication Date 2017-10
Publicly Available Date Mar 28, 2024
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Publisher Oxford University Press
Peer Reviewed Peer Reviewed
Volume 471
Issue 1
Pages 394-403
DOI https://doi.org/10.1093/mnras/stx1557
Keywords stars, fundamental parameters, individual, Qatar-2, planetary systems, starspots
Publisher URL http://dx.doi.org/10.1093/mnras/stx1557

Files




You might also like



Downloadable Citations