The spin axes orbital alignment of both stars within the eclipsing binary system V1143Cyg using the Rossiter-McLaughlin effect

Understand

Context: The Rossiter-McLaughlin (RM) effect, a rotational effect in eclipsing systems, provides unique insight into the relative orientation of stellar spin axes and orbital axes of eclipsing binary systems.

• Aims: Our aim is to develop a robust method to analyze the RM effect in an eclipsing system with two nearly equally bright components.
• This gives access to the orientation of the stellar rotation axes and may shed light on questions of binary formation and evolution.
• Methods: High-resolution spectra have been obtained both out of eclipse and during the primary and secondary eclipses in the V1143Cyg system, using the high-resolution Hamilton Echelle Spectrograph at the Lick Observatory.