肉眼几乎可见的猎户座

2019 August 21

The Orion You Can Almost See
Image Credit & Copyright: John Gleason & Rogelio Bernal Andreo

Explanation: Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, this is a more full Orion than you can see — an Orion only revealed with long exposure digital camera imaging and post-processing. Here the cool red giant Betelgeuse takes on a strong orange tint as the brightest star at the lower left. Orion’s hot blue stars are numerous, with supergiant Rigel balancing Betelgeuse on the upper right, and Bellatrix at the upper left. Lined up in Orion’s belt are three stars all about 1,500 light-years away, born from the constellation’s well-studied interstellar clouds. To the right of Orion’s belt is a bright but fuzzy patch that might also look familiar — the stellar nursery known as Orion’s Nebula. Finally, just barely visible to the unaided eye but quite striking here is Barnard’s Loop — a huge gaseous emission nebula surrounding Orion’s Belt and Nebula discovered over 100 years ago by the pioneering Orion photographer E. E. Barnard.

肉眼几乎可见的猎户座
影像提供与版权: John Gleason & Rogelio Bernal Andreo

说明: 你认得这个星座吗？纵然它是地球天空中，最容易辨识的星群之一，但这幅使用数位相机进行长曝光成像及后续影像处理的影像，呈现的猎户座超出人类肉眼所能见。在影像中，低温的红巨星参宿四，是左下角带着鲜明橙色的最明亮恒星。猎户座里有难以数计的炽热泛蓝恒星，其中有位在右上角和参宿四斜角对峙的超巨星参宿七，以及左上角的参宿五。而构成猎户腰带的腰带三星，距离都在1,500光年上下，全都诞生于这个星座被研究得很透澈的星际云里。猎户腰带右方的泛红弥漫光斑，或许看来有些眼熟，因为它就是猎户大星云。最后，肉眼勉强可见，但在这幅影像里却是无比醒目的巴纳德圈，是个环拱猎户腰带和猎户大星云的庞大发射云弧，由首先为猎户座造像的摄影师巴纳德，发现于100多年前。