GROUND-BASED MULTISITE OBSERVATIONS OF TWO TRANSITS OF HD 80606b

Abstract

We present ground-based optical observations of the September 2009 and January 2010 transits of HD 80606b. Based on 3 partial light curves of the September 2009 event, we derive a midtransit time of T c [HJD] = 2455099.196 ± 0.026, which is about 1σ away from the previously predicted time. We observed the January 2010 event from 9 different locations, with most phases of the transit being observed by at least 3 different teams. We determine a midtransit time of T c [HJD] = 2455210.6502 ± 0.0064, which is within 1.3σ of the time derived from a Spitzer observation of the same event.

MOSTSPACE TELESCOPE PHOTOMETRY OF THE 2010 JANUARY TRANSIT OF EXTRASOLAR PLANET HD80606b

“…In addition, Hébrard et al (2010) found their R p /R * value differed by 3σ compared to the results obtained by both Pont et al (2009) and Winn et al (2009). Shporer et al (2010) launched a multiple-site ground-based observation of the same transit in an attempt to confirm the Hébrard et al (2010) timing discrepancy. Their midtransit time was 12 minutes earlier than predicted and within 1.3σ of Hébrard et al (2010).…”

“…Hébrard et al (2010) discovered their mid-transit time to be approximately 24 minutes earlier than the value predicted by Winn et al (2009). In addition, Hébrard et al (2010) found their R p /R * value differed by 3σ compared to the results obtained by both Pont et al (2009) and Winn et al (2009). Shporer et al (2010) launched a multiple-site ground-based observation of the same transit in an attempt to confirm the Hébrard et al (2010) timing discrepancy.…”

“…Since the 12 hour duration of HD80606b's transit presents a difficulty for accurate ground-based observations, Hébrard et al (2010) employed the combination of Spitzer photometry and SOP HIE spectroscopy to continuously observe the full January 2010 transit. Hébrard et al (2010) discovered their mid-transit time to be approximately 24 minutes earlier than the value predicted by Winn et al (2009).…”

“…Shporer et al (2010) launched a multiple-site ground-based observation of the same transit in an attempt to confirm the Hébrard et al (2010) timing discrepancy. Their midtransit time was 12 minutes earlier than predicted and within 1.3σ of Hébrard et al (2010).…”

The LCOGT Network

“…LCOGT also participates in follow-up studies of known transiting exoplanets. For example, Hidas et al (2010) and Shporer et al (2010a) describe two follow-up campaigns led by LCOGT researchers where a complete coverage of HD 80606b 12 hour transits was obtained.…”