Paper: astro-ph/0512198
Date: Wed, 7 Dec 2005 18:08:34 GMT (931kb)

Title: Planets in Stellar Clusters Extensive Search. IV. A detection of a
possible transiting planet candidate in the open cluster NGC 2158

Authors: B. J. Mochejska, K. Z. Stanek, D. D. Sasselov, A. H. Szentgyorgyi, E.
Adams, R. L. Cooper, J. B. Foster, J. D. Hartman, R. C. Hickox, K. Lai, M.
Westover & J. N. Winn

Comments: 21 pages LaTeX, including 14 figures and 7 tables. To be published in
the February 2006 Astronomical Journal. Paper with better resolution figures
available at

ftp://cfa-ftp.harvard.edu/pub/bmochejs/PISCES/papers/4_N2158/ms.ps.gz
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We have undertaken a long-term project, Planets in Stellar Clusters Extensive
Search (PISCES), to search for transiting planets in open clusters. In this
paper we present the results for NGC 2158, an intermediate age, populous
cluster. We have monitored the cluster for over 260 hours, spread over 59
nights. We have detected one candidate transiting low luminosity object, with
eclipse depth of 3.7% in the R-band. If the host star is a member of the
cluster, the eclipse depth is consistent with a 1.7 R_J object. Cluster
membership of the host is supported by its location on the cluster main
sequence (MS) and its close proximity to the cluster center (2'). We have
discovered two other stars exhibiting low-amplitude (4-5%) transits, V64 and
V70, but they are most likely blends or field stars. Given the photometric
precision and temporal coverage of our observations, and current best estimates
for the frequency and radii of short-period planets, the expected number of
detectable transiting planets in our sample is 0.13. We have observed four
outbursts for the candidate cataclysmic variable V57. We have discovered 40 new
variable stars in the cluster, bringing the total number of identified
variables to 97, and present for them high precision light curves, spanning 13
months.

\\ ( http://arXiv.org/abs/astro-ph/0512198 , 931kb)