High-precision transit observations of the exoplanet WASP-13b with the RISE instrument Transit observations of WASP-13b
High-precision transit observations of the exoplanet WASP-13b with the RISE instrument Transit observations of WASP-13b
复制标题
使用 RISE 仪器对系外行星 WASP-13b 进行高精度凌日观测 WASP-13b 凌日观测
DOI：
10.1111/j.1365-2966.2011.19784.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Barros S
中科院分区：
文献类型：
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作者：
Barros S
WASP-13 b是一颗周期为4.35 d的亚木星质量系外行星，围绕一颗G1 V型星星运行。 目前其撞击参数（0 <B< 0.46）的不确定性导致恒星和行星半径定义不清。为了更好地约束撞击参数，我们使用安装在2.0米利物浦望远镜上的快速成像仪搜索系外行星（RISE）仪器获得了高精度的凌日观测。我们提出了四个新的过境，这是适合与马尔可夫链蒙特卡罗例程，以获得准确的系统参数。我们发现轨道倾角为85°.2 ± 0°.3，导致恒星和行星半径分别为1.56 ± 0.04 R⊙和1.39 ± 0.05RJup。 这表明主星星已经脱离主序星，处于氢壳燃烧阶段。我们还讨论了临边暗化对系统参数的影响。WASP-13 b的密度为0.17ρJ，加入了低密度行星的行列，这些行星的半径太大，无法用标准的辐射模型来解释。我们得到了新的星历表，T0= 2455575.5136 ± 0.0016（HJD），P = 4.353011 ± 0.000013d。 行星的平衡温度（Tequ= 1500 K）和明亮的宿主星星（V= 10.4等）使其成为后续大气研究的良好候选者。
WASP-13b is a sub-Jupiter mass exoplanet orbiting a G1V type star with a period of 4.35 d. The current uncertainty in its impact parameter (0 <b< 0.46) results in poorly defined stellar and planetary radii. To better constrain the impact parameter, we have obtained high-precision transit observations with the rapid imager to search for exoplanets (RISE) instrument mounted on 2.0-m Liverpool Telescope. We present four new transits which are fitted with a Markov chain Monte Carlo routine to derive accurate system parameters. We found an orbital inclination of 85°.2 ± 0°.3 resulting in stellar and planetary radii of 1.56 ± 0.04 R⊙and 1.39 ± 0.05RJup, respectively. This suggests that the host star has evolved off the main sequence and is in the hydrogen-shell-burning phase. We also discuss how the limb darkening affects the derived system parameters. With a density of 0.17ρJ, WASP-13b joins the group of low-density planets whose radii are too large to be explained by standard irradiation models. We derive a new ephemeris for the system,T0= 245 5575.5136 ± 0.0016 (HJD) andP= 4.353 011 ± 0.000 013 d. The planet equilibrium temperature (Tequ= 1500 K) and the bright host star (V= 10.4 mag) make it a good candidate for follow-up atmospheric studies.