Exoplanetary system WASP-3 : measurement of the projected spin-orbit angle and evidence for stellar activity

In this thesis, I present new spectroscopic and photometric observations of WASP-3, a transiting extrasolar planetary system. From spectra obtained during two transits, I use the Rossiter-McLaughlin effect in a simplified physical model to determine the projected spin-orbit angle between the planetary orbital axis and the stellar rotation axis, ... degrees. I use the new photometric data to refine the system parameters. Additionally, I present evidence for stellar activity, as the spectra obtained on UT June 19, 2008 reveal an increase in radial velocity to a peak magnitude of 75 m s-1 larger than the expected orbital velocity. Such an anomaly was not observed during a subsequent transit. I find that a good fit to the radial velocity measurements requires omitting the anomalous data and adding a large stellar jitter of 11 m s-1 to the measurement uncertainties. The resulting planetary mass, Mp = ... MJ differs from previously reported measurements which found Mp = 1.76 ... Together, these observations provide evidence for a region of stellar activity on WASP-3, and the observed anomaly suggests that material in this region exhibited a coherent horizontal motion of approximately 10 km s-' across the stellar surface at the limb.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Tripathi, Anjali

Advisor dc:contributor.advisor

• Joshua N. Winn.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/51586

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/51586