We present Rossiter-McLaughlin observations of the transiting super-Earth 55 Cnc e collected during six transit events between January 2012 and November 2013 with HARPS and HARPS-N. We detect no radial-velocity signal above 35 cm/s (3-sigma) and confine the stellar v sin i to 0.2 +/- 0.5 km/s. The star appears to be a very slow rotator, producing a very low amplitude Rossiter-McLaughlin effect. Given such a low amplitude, the Rossiter-McLaughlin effect of 55 Cnc e is undetected in our data, and any spin-orbit angle of the system remains possible. We also performed Doppler tomography and reach a similar conclusion. Our results offer a glimpse of the capacity of future instrumentation to study low amplitude Rossiter-McLaughlin effects produced by super-Earths.
Cite
@article{arxiv.1408.2007,
title = {Rossiter-McLaughlin Observations of 55 Cnc e},
author = {Mercedes Lopez-Morales and Amaury H. M. J. Triaud and Florian Rodler and Xavier Dumusque and Lars A. Buchhave and A. Harutyunyan and Sergio Hoyer and Roi Alonso and Michael Gillon and Nathan A. Kaib and David W. Latham and Christophe Lovis and Francesco Pepe and Didier Queloz and Sean N. Raymond and Damien Segransan and Ingo P. Waldmann and Stephane Udry},
journal= {arXiv preprint arXiv:1408.2007},
year = {2015}
}