SPITZER OBSERVATIONS OF THE THERMAL EMISSION FROM WASP-43b
SPITZER OBSERVATIONS OF THE THERMAL EMISSION FROM WASP-43b
复制标题
DOI：
10.1088/0004-637x/781/2/116
复制
发表时间：
2013-02
期刊：
影响因子：
--
通讯作者：
J. Blecic;J. Harrington;N. Madhusudhan;K. Stevenson;R. A. Hardy;P. Cubillos;Matthew R. Hardin;Oliver Bowman;Sarah Nymeyer;D. Anderson;C. Hellier;Alexis M. S. Smith;A. Cameron
中科院分区：
文献类型：
--
作者：
J. Blecic;J. Harrington;N. Madhusudhan;K. Stevenson;R. A. Hardy;P. Cubillos;Matthew R. Hardin;Oliver Bowman;Sarah Nymeyer;D. Anderson;C. Hellier;Alexis M. S. Smith;A. Cameron
WASP-43 b是轨道最近的热彗星之一，半长轴为a = 0.01526 ± 0.00018 Au，周期仅为0.81天。然而，它的轨道是最冷的恒星之一，有一颗热木星（T* = 4520 ± 120 K），使这颗行星的平衡温度为Teq = 1440 ± 40 K，假设邦德轨道为零，行星能量均匀分布。在3.6 μm和4.5 μm处，食深和亮温分别为0.347% ± 0.013%和1670 ± 23 K，0.382% ± 0.015%和1514 ± 25 K。日食的时间将轨道周期P的估计值提高了3倍（P = 0.81347436 ± 1.4 × 10−7天），并为偏心率设定了上限（）。我们使用我们的斯皮策日食深度沿着与四个先前报道的地面测光观测在近红外线约束大气特性的WASP-43 b。这些数据排除了WASP-43 b向阳面大气中强烈的逆温现象。没有热反转和基准富氧成分的模型大气能够解释所有可用的数据。然而，广泛的金属丰度和C/O比可以解释这些数据。这些数据表明，地球上的昼夜能量重新分配较低，与以前的研究一致，在白天入射的能量中，重新分配到黑夜的能量比例的名义上限约为35%。
WASP-43b is one of the closest-orbiting hot Jupiters, with a semimajor axis of a = 0.01526 ± 0.00018 AU and a period of only 0.81 days. However, it orbits one of the coolest stars with a hot Jupiter (T* = 4520 ± 120 K), giving the planet a modest equilibrium temperature of Teq = 1440 ± 40 K, assuming zero Bond albedo and uniform planetary energy redistribution. The eclipse depths and brightness temperatures from our jointly fit model are 0.347% ± 0.013% and 1670 ± 23 K at 3.6 μm and 0.382% ± 0.015% and 1514 ± 25 K at 4.5 μm. The eclipse timings improved the estimate of the orbital period, P, by a factor of three (P = 0.81347436 ± 1.4 × 10−7 days) and put an upper limit on the eccentricity (). We use our Spitzer eclipse depths along with four previously reported ground-based photometric observations in the near-infrared to constrain the atmospheric properties of WASP-43b. The data rule out a strong thermal inversion in the dayside atmosphere of WASP-43b. Model atmospheres with no thermal inversions and fiducial oxygen-rich compositions are able to explain all the available data. However, a wide range of metallicities and C/O ratios can explain the data. The data suggest low day–night energy redistribution in the planet, consistent with previous studies, with a nominal upper limit of about 35% for the fraction of energy incident on the dayside that is redistributed to the nightside.