Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system. Issue Volume 8:Issue S299(2013) (6th January 2014)

• Record Type: Journal Article
• Authors: Haywood, R. D.; Cameron, A. C.; Queloz, D.; Barros, S. C. C.; Deleuil, M.; Fares, R.; Gillon, M.; Hatzes, A.; Lanza, A. F.; Lovis, C.; Moutou, C.; Pepe, F.; Pollacco, D.; Santerne, A.; Ségransan, D.; Unruh, Y.
• Is Part Of: Proceedings of the International Astronomical Union. Volume 8:Issue S299(2013)
• Page Start: 237
• Page End: 240
• Publication Date: 2014-01-06
• Subjects: planetary systems, -- stellar activity, -- RV method; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921313008478
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: Since the discovery of the transiting Super-Earth CoRoT-7b, several investigations have been made of the number and precise masses of planets present in the system, but they all yield different results, owing to the star's high level of activity. Radial velocity (RV) variations induced by stellar activity therefore need to be modelled and removed to allow a reliable detection of all planets in the system. We re-observed CoRoT-7 in January 2012 with both HARPS and the CoRoT satellite, so that we now have the benefit of simultaneous RV and photometric data. We fitted the off-transit variations in the CoRoT lightcurve using a harmonic decomposition similar to that implemented in Queloz et al . (2009). This fit was then used to model the stellar RV contribution, according to the methods described by Aigrain et al . (2011). This model was incorporated into a Monte Carlo Markov Chain in order to make a precise determination of the orbits of CoRoT-7b and CoRoT-7c. We also assess the evidence for the presence of one or two additional planetary companions.