The Iris Nebula (also known as NGC 7023 and Caldwell 4) is a bright reflection nebula in the constellation Cepheus. The designation NGC 7023 refers to the open cluster within the larger reflection nebula designated LBN 487. The nebula, which shines at magnitude +6.8, is illuminated by a magnitude +7.4 star designated HD 200775. [1]

鸢尾花星云（ngc 7023），是位于仙王座的一个明亮反射星云和科德韦尔天体。 鸢尾花星云其壮丽、对称的外形结构跨越了约6光年的天区，该星云特有的蓝色色泽是遍布四处的尘埃颗粒反射附近一颗炽热蓝色恒星的星光所致。

Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers. Still, this deep telescopic image shows off the Iris Nebula's range of colors and symmetries, embedded in surrounding fields of interstellar dust.

2024年7月25日 · Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers. Still, this deep telescopic image shows off the Iris Nebula’s range of colors and symmetries embedded in surrounding fields of interstellar dust.

The Iris is a reflection nebula, which means that its light comes from a bright star that reflects nearby dust. This type of deep-sky object does not need a modified astro-camera to record NGC 7023 in detail. Also, narrowband filters that isolate specific wavelengths of light have no benefit on a reflection nebula.

2024年11月1日 · The Iris Nebula (NGC 7023) is a reflection nebula located 1,300 light-years from Earth. A massive star illuminates the interstellar cloud, creating a glow resembling an eye’s iris. NGC 7023 spans 6 light-years across and contains a density of gas and dust contributing to star formation processes.

2014年8月2日 · NGC 7023: The Iris Nebula Image Credit & Copyright: Jimmy Walker. 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, NGC 7023 is not the only nebula in the sky to evoke the imagery of flowers, though.

2 天之前 · The Iris Nebula, officially designated as NGC 7023 and also known as Caldwell 4, is a prime example of a reflection nebula. Unlike emission nebulae that emit their own light due to ionized gases, reflection nebulae like the Iris Nebula shine by reflecting the light of nearby stars. This particular nebula was discovered by the renowned ...

2021年9月3日 · Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers. Still, this deep telescopic image shows off the Iris Nebula’s range of colors and symmetries, embedded in surrounding fields of interstellar dust.

2024年10月20日 · The designation ‘NGC 7023’ refers not to the nebula, but to the open cluster concentrated in the dark area to the right of the nebula’s central star. The Iris Nebula is catalogued as LBN 487. It is primarily a reflection nebula, with the the blue hues coming from light reflected off soot/dust around the bright star.