Reference : Activity induced variation in spin-orbit angles as derived from Rossiter-McLaughlin m...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/233287
Activity induced variation in spin-orbit angles as derived from Rossiter-McLaughlin measurements
English
Oshagh, M. mailto [> >]
Triaud, A. H. M. J. [> >]
Burdanov, Artem mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Exotic >]
Figueira, P. [> >]
Reiners, A. [> >]
Santos, N. C. [> >]
Faria, J. [> >]
Boue, G. [> >]
Diaz, R. F. [> >]
Dreizler, S. [> >]
Boldt, S. [> >]
Delrez, L. [> >]
Ducrot, Elsa mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Exotic >]
Gillon, Michaël mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Exotic >]
Guzman Mesa, A. [> >]
Jehin, Emmanuel mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa) >]
Khalafinejad, S. [> >]
Kohl, S. [> >]
Serrano, L. [> >]
Udry, S. [> >]
1-Nov-2018
Astronomy and Astrophysics
EDP Sciences
619
150
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] Astrophysics - Earth and Planetary Astrophysics ; Astrophysics - Solar and Stellar Astrophysics
[en] One of the most powerful methods used to estimate sky-projected spin-orbit angles of exoplanetary systems is through a spectroscopic transit observation known as the Rossiter-McLaughlin (RM) effect. So far mostly single RM observations have been used to estimate the spin-orbit angle, and thus there have been no studies regarding the variation of estimated spin-orbit angle from transit to transit. Stellar activity can alter the shape of photometric transit light curves and in a similar way they can deform the RM signal. In this paper we discuss several RM observations, obtained using the HARPS spectrograph, of known transiting planets that all transit extremely active stars, and by analyzing them individually we assess the variation in the estimated spin-orbit angle. Our results reveal that the estimated spin-orbit angle can vary significantly (up to 42 degrees) from transit to transit, due to variation in the configuration of stellar active regions over different nights. This finding is almost two times larger than the expected variation predicted from simulations. We could not identify any meaningful correlation between the variation of estimated spin-orbit angles and the stellar magnetic activity indicators. We also investigated two possible approaches to mitigate the stellar activity influence on RM observations. The first strategy was based on obtaining several RM observations and folding them to reduce the stellar activity noise. Our results demonstrated that this is a feasible and robust way to overcome this issue. The second approach is based on acquiring simultaneous high-precision short-cadence photometric transit light curves using TRAPPIST/SPECULOOS telescopes, which provide more information about the stellar active region's properties and allow a better RM modeling.
http://hdl.handle.net/2268/233287
10.1051/0004-6361/201833709
http://adsabs.harvard.edu/abs/2018arXiv180901027O
18 pages, 7 figures, 6 tables

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