APOD 布满尘埃的虹膜星云

来源：成大APOD

A Dusty Iris Nebula

Credit & Copyright: Alvin Jeng (LightBuckets.com)

Explanation: These clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula and dutifully cataloged as NGC 7023, this is not the only nebula in the sky to evoke the imagery of flowers. Surrounding it, obscuring clouds of dust and cold molecular gas are also present and can suggest other convoluted and fantastic shapes. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the cosmic dust glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula may contain complex carbon molecules known as PAHs. At the estimated distance of the Iris Nebula this remarkable wide field view is over 30 light-years across.

很美很美，暗物质

很神秘

给人一种深奥的感觉，很有立体感！

帮楼主贴个成大的翻译，大家阅读方便。

彩虹星雲的縷縷輕煙
影像提供與 版權: Alvin Jeng (LightBuckets.com)

說明: 這些由星際塵埃及氣體組成的雲氣，如同纖柔嬌貴的宇宙花瓣，遠遠地盛放在1,300光年遠的仙王座恆星豐產區。有時被稱為彩虹星雲，而實實在在被編目為NGC 7023，它可不是天空中唯一會讓人聯想到花的星雲。由塵埃與冷分子雲氣組成的黝黑遮光雲氣，並引領我們的視覺感官去體會各種捲曲與奇異的形狀。星雲物質圍繞在一顆大質量、熾熱，顯然尚處於形成階段的年輕星球，星雲的主要顏色仍是藍色，這是塵埃顆粒反射星光的特徵。然而，洩漏機密的紅色輝光，在恆星明亮的中心區兩側告訴我們，那裡有大量的氫原子被來自於恆星看不見但強烈的紫外光照耀激發。紅外線觀測顯示這個星雲可能包含了複雜的碳分子，即大家所知的PAHs。這張廣視野影像所示的彩虹星雲大約有30光年大小。

美丽而且神秘，

美图…收下…赞美LZ

太牛了，我要上太空拿哈勃狂看