MOST Spacebased Photometry of HD 189733: Precise Timing Measurements for Transits Across an Active Star

Autor(en)

Eliza Miller-Ricci, Jason F. Rowe, Rainer Kuschnig, Werner Wolfgang Weiss

Abstrakt

We have measured transit times for HD 189733 passing in front of its bright (V = 7.67) chromospherically active and spotted parent star. Nearly continuous broadband photometry of this system was obtained with the MOST (Microvariability & Oscillations of STars) space telesope during 21 days in August 2006, monitoring 10 consecutive transits. We have used these data to search for deviations from a constant orbital period which can indicate the presence of additional planets in the system that are as yet undetected by Doppler searches. We find no variations above the level of ±45 s, ruling out planets in the Earth-to-Neptune mass range in a number of resonant orbits. We find that a number of complications can arise in measuring transit times for a planet transiting an active star with large star spots. However, such transiting systems are also useful in that they can help to constrain and test spot models. This has implications for the large number of transiting systems expected to be discovered by the CoRoT and Kepler missions.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Harvard University, University of British Columbia (UBC)

Journal

Proceedings of the International Astronomical Union

Band

253

Seiten

459-461

Anzahl der Seiten

3

ISSN

1743-9213

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/98561d7d-4530-4866-affc-48b0fa4e6ac1