BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Very precise radial velocities with high-resolution spectrographs 
 - Xavier Dumusque (CfA)
DTSTART:20141112T163000Z
DTEND:20141112T173000Z
UID:TALK55744@talks.cam.ac.uk
CONTACT:Dr B.-O. Demory
DESCRIPTION:I will first discuss a new technique to derive extremely preci
 se radial velocities (RV) from high-resolution spectrographs.\nBy deriving
  the RV of each individual line in a HARPS spectrum\, one can see that som
 e spectral lines are affected by important variations that cannot be assoc
 iated to planetary or stellar signals.\nThese variation are caused by the 
 instrument itself\, and excluding the affected spectral lines when cross c
 orrelating the stellar spectrum with a synthetic template can improve the 
 RV precision.\nIn a second part\, I will present a new model that estimate
 s the effect of stellar activity on RV measurements. This model\, based on
  observations of the Sun\, includes the inhibition of convection which is 
 one of the main cause of the activity-induced RV variation. When comparing
  with observations\, our model reproduces the activity-related variation s
 een in photometry\, RV\, bisector and full width of half maximum. This mod
 el can therefore be used to fit observed data\, which gives us access to i
 nteresting stellar parameters like stellar inclination.
LOCATION:Martin Ryle Seminar Room\, Kavli Institute
END:VEVENT
END:VCALENDAR