来自地球大小的外行星TRAPPIST-1 b的热辐射使用JWST
Thomas P Greene1, Taylor J Bell2,3, Elsa Ducrot4
1Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA, USA. tom.greene@nasa.gov.
Nature
|March 27, 2023
概括
詹姆斯·韦伯太空望远镜观测到TRAPPIST-1b系外行星,发现它的日边重新辐射恒星的热量. 这表明TRAPPIST-1b可能缺乏大量的大气层来重新分配热量.
科学领域:
- 外行星科学
- 天体物理学
- 星球科学
背景情况:
- 在TRAPPIST-1系统中,有七颗地球大小的行星绕着一颗M矮星运行.
- 哈勃和斯皮策太空望远镜之前的观测没有发现这些行星上的大气特征.
- TRAPPIST-1b收到大量的恒星辐射,使其热辐射成为研究的目标.
研究的目的:
- 测量TRAPPIST-1b系外行星的热辐射.
- 调查TRAPPIST-1b上大气的存在和特征.
- 限制太阳系外行星的热量再分配.
主要方法:
- 对TRAPPIST-1 b的二次日食进行光度观测.
- 使用詹姆斯·韦伯太空望远镜中红外仪器 (MIRI) 的F1500W过器.
- 来自五个独立观测的数据组合,以实现高可靠性检测.
主要成果:
- 检测到TRAPPIST-1b的二次日食,可靠度为8.7σ.
- 测量显示热再辐射主要来自行星的白天半球.
- 没有发现大气中二氧化碳 (CO2) 或其他物种的显著吸收.
结论:
- TRAPPIST-1b几乎没有能够重新分配恒星热量的大气体的证据.
- 太阳系外行星的热辐射与日光照射相一致.
- 这些发现限制了TRAPPIST-1b的进一步大气表征.
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