A TRANSIT TIMING ANALYSIS OF NINE RISE LIGHT CURVES OF THE EXOPLANET SYSTEM TrES-3

作者：Gibson N P^*; Pollacco D; Simpson E K; Barros S; Joshi Y C; Todd I; Keenan F P; Skillen I; Benn C; Christian D; Hrudkova M; Steele I A

来源：Astrophysical Journal, 2009, 700(2): 1078-1085.

DOI：10.1088/0004-637X/700/2/1078

• methods: data analysis
• planetary systems
• stars: individual (TrES-3)
• techniques: photometric

We present nine newly observed transits of TrES-3, taken as part of a transit timing program using the RISE instrument on the Liverpool Telescope. A Markov-Chain Monte Carlo analysis was used to determine the planet star radius ratio and inclination of the system, which were found to be R(p)/R(star) = 0.1664(-0.0018)(+0.0011) and i = 81.73(-0.04)(+0.13), respectively, consistent with previous results. The central transit times and uncertainties were also calculated, using a residual-permutation algorithm as an independent check on the errors. A re-analysis of eight previously published TrES-3 light curves was conducted to determine the transit times and uncertainties using consistent techniques. Whilst the transit times were not found to be in agreement with a linear ephemeris, giving chi(2) = 35.07 for 15 degrees of freedom, we interpret this to be the result of systematics in the light curves rather than a real transit timing variation. This is because the light curves that show the largest deviation from a constant period either have relatively little out-of-transit coverage or have clear systematics. A new ephemeris was calculated using the transit times and was found to be T(c)(0) = 2454632.62610 +/- 0.00006 HJD and P = 1.3061864 +/- 0.0000005 days. The transit times were then used to place upper mass limits as a function of the period ratio of a potential perturbing planet, showing that our data are sufficiently sensitive to have probed sub-Earth mass planets in both interior and exterior 2:1 resonances, assuming that the additional planet is in an initially circular orbit.

• 出版日期2009-8-1