论文标题
重新评估外部外部HAT-P-7 B大气中时间变化的证据
Reassessing the Evidence for Time Variability in the Atmosphere of the Exoplanet HAT-P-7 b
论文作者
论文摘要
我们重新评估Armstrong等人报道的热木星HAT-P-7 B大气中声称的可变性。 （2016）。尽管天文学家期望热木星的气氛变化，但可变性很大。我们使用与Armstrong等人相似的方法来寻找Kepler数据中HAT-P-7 B相曲线的时间变化。 （2016年），并确定了与他们发现的显着差异。许多测试表明，对不同的分析策略的变化主要是可靠的。但是，当我们将不变的相位曲线信号注入其他恒星的光曲线并搜索可变性时，我们经常看到与HAT-P-7光曲线相似的变化水平。 HAT-P-7光曲线的傅立叶分析显示，与行星轨道时期相似的时间标准上出现的恒星超级颗粒的背景红噪声。与HAT-P-7的超级晶格相同的噪声测试测试表明，仅此效果就会导致HAT-P-7 b检测到的幅度和相位偏移变异性。因此，HAT-P-7 B大气的明显变化可能是由非星际源引起的，这很可能是由于宿主星上的超颗粒而导致的光度变异性。
We reassess the claimed detection of variability in the atmosphere of the hot Jupiter HAT-P-7 b, reported by Armstrong et al. (2016). Although astronomers expect hot Jupiters to have changing atmospheres, variability is challenging to detect. We looked for time variation in the phase curves of HAT-P-7 b in Kepler data using similar methods to Armstrong et al. (2016), and identified apparently significant variations similar to what they found. Numerous tests show the variations to be mostly robust to different analysis strategies. However, when we injected unchanging phase curve signals into the light curves of other stars and searched for variability, we often saw similar levels of variations as in the HAT-P-7 light curve. Fourier analysis of the HAT-P-7 light curve revealed background red noise from stellar supergranulation on timescales similar to the planet's orbital period. Tests of simulated light curves with the same level of noise as HAT-P-7's supergranulation show that this effect alone can cause the amplitude and phase offset variability we detect for HAT-P-7 b. Therefore, the apparent variations in HAT-P-7 b's atmosphere could instead be caused by non-planetary sources, most likely photometric variability due to supergranulation on the host star.
