论文标题
在最小的洁尿污染时
Non-detection of He I in the atmosphere of GJ1214b with Keck/NIRSPEC, at a time of minimal telluric contamination
论文作者
论文摘要
在外球星大气氛中观察氦气可能会揭示出大量气体信封的存在，并表明持续的大气逃逸。 Orell-Miquel等。 （2022）使用卡门氏菌测量了亚新持久性GJ 1214b的氦气检测，其峰值过量吸收在10830埃埃斯特罗姆时的过境深度超过2％。然而，以前已经报道了GJ 1214b的几种非检测氦。差异的一种解释是通过重叠的牙髓吸收和发射线对行星信号的污染。我们使用Keck/NirSpec在10830 Angstroms处观察GJ 1214b的另一个转运，这是在渗透线污染极少的情况下，并且没有观察到行星氦的吸收。考虑到测量中相关的噪声，我们对超过1.22％的多余吸收大小（95％的置信度）设置了上限。我们发现，使用不同的仪器或恒星活动，不太可能引起卡门群和NIRSPEC观察之间的差异。目前尚不清楚差异是由于观测值中的相关噪声而引起的，还是行星大气中的变异性。
Observations of helium in exoplanet atmospheres may reveal the presence of large gaseous envelopes, and indicate ongoing atmospheric escape. Orell-Miquel et al. (2022) used CARMENES to measure a tentative detection of helium for the sub-Neptune GJ 1214b, with a peak excess absorption reaching over 2% in transit depth at 10830 Angstroms. However, several non-detections of helium had previously been reported for GJ 1214b. One explanation for the discrepancy was contamination of the planetary signal by overlapping telluric absorption- and emission lines. We used Keck/NIRSPEC to observe another transit of GJ 1214b at 10830 Angstroms, at a time of minimal contamination by telluric lines, and did not observe planetary helium absorption. Accounting for correlated noise in our measurement, we place an upper limit on the excess absorption size of 1.22% (95% confidence). We find that the discrepancy between the CARMENES and NIRSPEC observations is unlikely to be caused by using different instruments or stellar activity. It is currently unclear whether the difference is due to correlated noise in the observations, or variability in the planetary atmosphere.
