變星雲 NGC 2261
The Variable Nebula NGC 2261
來源：Tommy Lease｜發表日期：2025-01-31
從這張清晰的望遠鏡快照中可以看到，星際塵埃雲和氣體雲的外觀在短短几周內發生了明顯的變化。這顆明亮的恆星 R Monocerotis 位於扇形星雲的頂端。NGC 2261 的直徑約為 1 光年，距離地球 2500 光年，上世紀初，天文學家埃德溫-哈勃對它進行了研究。那麼，是什麼讓哈勃星雲變化多端呢？NGC 2261 由一個從R Monocerotis 恆星扇形展開的塵埃反射星雲組成。 主要的變異解釋認為，密集的遮擋塵埃結穿過R Mon 附近，在哈勃變星雲其餘部分的塵埃雲上投下移動的陰影。
原文：The interstellar cloud of dust and gas captured in this sharp telescopic snapshot is seen to change its appearance noticeably over periods as short as a few weeks. Discovered over 200 years ago and cataloged as NGC 2261, bright star R Monocerotis lies at the tip of the fan-shaped nebula. About one light-year across and 2500 light-years away, NGC 2261 was studied early last century by astronomer Edwin Hubble and the mysterious cosmic cloud is now more famous as Hubble's Variable Nebula. So what makes Hubble's nebula vary? NGC 2261 is composed of a dusty reflection nebula fanning out from the star R Monocerotis. The leading variability explanation holds that dense knots of obscuring dust pass close to R Mon and cast moving shadows across the dust clouds in the rest of Hubble's Variable Nebula.
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