This NASA/ESA Hubble Space Telescope image features the spiral galaxy NGC 4535, which is situated about 50 million light-years away in the constellation Virgo (the Maiden). Through a small telescope, this galaxy appears extremely faint, giving it the nickname ‘Lost Galaxy’. With a mirror spanning nearly eight feet (2.4 meters) across and its location above Earth’s light-obscuring atmosphere, Hubble can easily observe dim galaxies like NGC 4535 and pick out features like its massive spiral arms and central bar of stars.
This image features NGC 4535’s young star clusters, which dot the galaxy’s spiral arms. Glowing-pink clouds surround many of these bright-blue star groupings. These clouds, called H II (‘H-two’) regions, are a sign that the galaxy is home to especially young, hot, and massive stars that blaze with high-energy radiation. Such massive stars shake up their surroundings by heating their birth clouds with powerful stellar winds, eventually exploding as supernovae.
The image incorporates data from an observing program designed to catalog roughly 50,000 H II regions in nearby star-forming galaxies like NGC 4535. Hubble released a previous image of NGC 4535 in 2021. Both the 2021 image and this new image incorporate observations from the PHANGS observing program, which seeks to understand the connections between young stars and cold gas. Today’s image adds a new dimension to our understanding of NGC 4535 by capturing the brilliant red glow of the nebulae that encircle massive stars in their first few million years of life.
Image credit: ESA/Hubble & NASA, F. Belfiore, J. Lee and the PHANGS-HST Team
这张由NASA/ESA哈勃太空望远镜拍摄的图像展示了旋涡星系NGC4535。它位于室女座，距离地球约5000万光年。通过小型望远镜观察时，这个星系显得极为昏暗，因此获得了“失落的星系”（Lost Galaxy）的昵称。而拥有直径近2.4米主镜、且位于地球大气层之上的哈勃望远镜，则能轻松观测到像NGC4535这样微弱的天体，并分辨出其巨大的旋臂与由恒星组成的中央棒状结构。
图像中可见点缀在旋臂上的年轻星团。这些明亮的蓝色星团周围往往伴随着发光的粉红色云气。这些云气被称为H II区，是星系中存在大量年轻、炽热且大质量恒星的标志。这些巨大恒星释放强烈辐射和恒星风，加热并扰动其诞生云，最终将以超新星爆发的方式结束生命。
此图包含来自一个观测计划的数据，该计划旨在为附近的恒星形成星系（如NGC4535）记录约5万处H II区。哈勃曾在2021年发布过这座星系的另一幅图像。本次的新图像与2021年版本均基于PHANGS观测计划，该计划旨在揭示年轻恒星与冷气体之间的联系。本次图像新增了能捕捉围绕大质量恒星、在其生命最初几百万年间闪耀的红色星云光辉的数据，为我们理解NGC4535提供了更全面的视角。
图片来源: ESA/Hubble & NASA, F. Belfiore, J. Lee and the PHANGS-HST Team
