PDS 70的拱星盘、行星及卫星


图为行星形成恒星系统PDS 70。可以看到会形成行星的拱星盘以及仍在形成卫星的行星。有关更多详细信息,请参阅说明。

PDS 70: Disk, Planets, and Moons
Image Credit:
VLT/MUSE (ESO); M. Benisty et al.

Explanation: It’s not the big disk that’s attracting the most attention. Although the big planet-forming disk around the star PDS 70 is clearly imaged and itself quite interesting. It’s also not the planet on the right, just inside the big disk, that’s being talked about the most. Although the planet PDS 70c is a newly formed and, interestingly, similar in size and mass to Jupiter. It’s the fuzzy patch around the planet PDS 70c that’s causing the commotion. That fuzzy patch is thought to be itself a dusty disk that is now forming into moons — and that has never been seen before. The featured image was taken by the Atacama Large Millimeter Array (ALMA) of 66 radio telescopes in the high Atacama Desert of northern Chile. Based on ALMA data, astronomers infer that the moon-forming exoplanetary disk has a radius similar to our Earth’s orbit, and may one day form three or so Luna-sized moons — not very different from our Jupiter’s four.

Tomorrow’s picture: Earth, Jupiter, or Uranus?

PDS 70的拱星盘、行星及卫星
ALMA (ESO/NAOJ/NRAO); M. Benisty et al.

说明: 影像里最受重视的并非拱星盘。纵然环拱恒星PDS 70、会形成行星的拱星盘,在影像里非常清晰,而且本身也非常有趣。也并非右侧、紧贴在大拱星盘内侧的行星,吸引了最多的讨论声量。虽然这颗编号为PDS 70c的行星,大小和质量都和木星很相近,而且刚形成不久。真正引起骚动的,是行星PDS 70c周围的弥漫斑块。那团弥漫的斑块,咸认是前所未见、正在凝聚成卫星的尘埃碟。这幅主题影像,是由位在北智利.阿塔卡玛高原沙漠,拥有66座电波望远镜天线碟的阿塔卡玛大毫米波阵列(ALMA)所拍摄。从ALMA的数据,天文学家推断这个正在形成卫星的系外行星碟,半径和地球轨道相近,而且未来会形成3颗左右、大小和月球相当的卫星,因此,(这个行星系统的)大卫星数量也和木星的4颗差不多。

明日的图片: Earth, Jupiter, or Uranus?