NICMOS OBSERVATIONS OF THE TRANSITING HOT JUPITER XO-1b

作者:Burke Christopher J*; McCullough P R; Bergeron L E; Long Douglas; Gilliland Ronald L; Nelan Edmund P; Johns Krull Christopher M; Valenti Jeff A; Janes Kenneth A
来源:Astrophysical Journal, 2010, 719(2): 1796-1806.
DOI:10.1088/0004-637X/719/2/1796

摘要

We refine the physical parameters of the transiting hot Jupiter planet XO-1b and its stellar host XO-1 using Hubble Space Telescope (HST) NICMOS observations. XO-1b has a radius R-p = 1.21 +/- 0.03 R-J, and XO-1 has a radius R* = 0.94 +/- 0.02 R-circle dot, where the uncertainty in the mass of XO-1 dominates the uncertainty of R-p and R*. There are no significant differences in the XO-1 system properties between these broadband NIR observations and previous determinations based upon ground-based optical observations. We measure two transit timings from these observations with 9 s and 15 s precision. As a residual to a linear ephemeris model, there is a 2.0 sigma timing difference between the two HST visits that are separated by three transit events (11.8 days). These two transit timings and additional timings from the literature are sufficient to rule out the presence of an Earth mass planet orbiting in 2:1 mean motion resonance coplanar with XO-1b. We identify and correct for poorly understood "gain-like" variations present in NICMOS time series data. This correction reduces the effective noise in time series photometry by a factor of 2 for the case of XO-1.

  • 出版日期2010-8-20