We report on the discovery of a very prominent mid-infrared (18–25 μm) excess associated with the trans-Neptunian dwarf planet (136472) Makemake. The excess, detected by the Mid-Infrared Instrument of the James Webb Space Telescope, along with previous measurements from the Spitzer and Herschel space telescopes, indicates the occurrence of temperatures of ∼150 K, much higher than what solid surfaces at Makemake’s heliocentric distance could reach by solar irradiation. We identify two potential explanations: a continuously visible, currently active region powered by subsurface upwelling and possibly cryovolcanic activity covering ≤1% of Makemake’s surface or an as-yet-undetected ring containing very small carbonaceous dust grains, which have not been seen before in trans-Neptunian or Centaur rings. Both scenarios point to unprecedented phenomena among trans-Neptunian objects and could greatly impact our understanding of these distant worlds.

中文翻译：

---

JWST/MIRI 发现的矮行星 （136472） Makemake 的显着中红外过剩表明活动正在进行中


我们报告了与跨海王星矮行星 （136472） Makemake 相关的非常突出的中红外 （18-25 μm） 过量的发现。詹姆斯·韦伯太空望远镜的中红外仪器检测到的过量，以及之前从斯皮策和赫歇尔太空望远镜进行的测量，表明温度约为 150 K，远高于 Makemake 日心距离的固体表面通过太阳照射所能达到的温度。我们确定了两种可能的解释：一个持续可见的、当前活跃的区域，由地下上升流和可能的冰火山活动提供动力，覆盖了 Makemake 表面 ≤1%，或者一个尚未检测到的环，其中包含非常小的碳质尘埃颗粒，这在跨海王星或半人马环中以前从未见过。这两种情况都指向跨海王星天体中前所未有的现象，并可能极大地影响我们对这些遥远世界的理解。