A Photometric Study of the Hot Exoplanet WASP-19b
A Photometric Study of the Hot Exoplanet WASP-19b
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DOI：
10.1051/0004-6361/201220924
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发表时间：
2012-12
影响因子：
6.5
通讯作者：
M. Lendl;M. Gillon;D. Queloz;R. Alonso;R. Alonso;A. Fumel;E. Jehin;D. Naef
中科院分区：
文献类型：
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作者：
M. Lendl;M. Gillon;D. Queloz;R. Alonso;R. Alonso;A. Fumel;E. Jehin;D. Naef
上下文已经被详细研究过的热扩散器的样本仍在不断增加。特别是，当行星经过它的宿主星星时，可以测量行星半径和行星质量（用径向速度数据）。对于行星大气的研究，必须获得多波长的凌日和掩星测量。目标。我们的目标是通过从凌日和掩星的专门观测活动中获得准确和精确的行星参数来描述凌日热木星WASP-19 b。方法.我们在Euler-Swiss望远镜和TRAPPIST上用EulerCam获得了r '-古恩、I-耿、z'-古恩和I+z'滤波器中的14条凌日光变曲线和z'-古恩中的10条掩星光变曲线。我们还在VLT上用HAWK-I的窄带滤光片NB 1190测量了1.19米的掩星，得到了一条光变曲线。我们对所有新数据进行了全球MCMC分析，并结合一些存档数据，以改进行星参数并测量z '波段和1.19 m处的掩星深度。结果我们测量了一颗行星的半径为Rp = 1：376 0：046 RJ，行星的质量为Mp = 1：165 0：068 MJ，并且发现了一个非常低的偏心率e = 0：0077 +0：0068 0：0032，与圆形轨道兼容。我们已经检测到的z '带掩星在3个意义，并测量它是焦点; z 0 = 352 116 ppm，比以前公布的小2倍以上。1.19米的掩星仅在Focc处受到轻微限制; NB 1190 = 1711 + 745 ppm。结论.我们表明，在可见光范围内的掩星的检测是触手可及的，即使是1米级的望远镜，如果观察到相当数量的个别事件。我们的研究结果表明，WASP-19 b的大气层以氧气为主，这使得该行星成为一个有趣的富氧行星测试案例，而没有温度反演。
Context. The sample of hot Jupiters that have been studied in great detail is still growing. In particular, when the planet transits its host star, it is possible to measure the planetary radius and the planet mass (with radial velocity data). For the study of planetary atmospheres, it is essential to obtain transit and occultation measurements at multiple wavelengths. Aims. We aim to characterize the transiting hot Jupiter WASP-19b by deriving accurate and precise planetary parameters from a dedicated observing campaign of transits and occultations. Methods. We have obtained a total of 14 transit lightcurves in the r’-Gunn, I-Cousins, z’-Gunn, and I+z’ filters and 10 occultation lightcurves in z’-Gunn using EulerCam on the Euler-Swiss telescope and TRAPPIST. We also obtained one lightcurve through the narrow-band NB1190 filter of HAWK-I on the VLT measuring an occultation at 1.19 m. We performed a global MCMC analysis of all new data, together with some archive data in order to refine the planetary parameters and to measure the occultation depths in z’- band and at 1.19 m. Results. We measure a planetary radius of Rp = 1:376 0:046 RJ, a planetary mass of Mp = 1:165 0:068 MJ, and find a very low eccentricity of e = 0:0077 +0:0068 0:0032 , compatible with a circular orbit. We have detected the z’-band occultation at 3 significance and measure it to be Focc;z0 = 352 116 ppm, more than a factor of 2 smaller than previously published. The occultation at 1.19 m is only marginally constrained at Focc;NB1190 = 1711 +745 ppm. Conclusions. We show that the detection of occultations in the visible range is within reach, even for 1m class telescopes if a considerable number of individual events are observed. Our results suggest an oxygen-dominated atmosphere of WASP-19b, making the planet an interesting test case for oxygen-rich planets without temperature inversion.