2025年11月5日
哈勃望远镜拍摄的螺旋星系NGC 3370
影像提供: ESA/Hubble & NASA, A. Riess, K. Noll
说明: 这就是我们银河系从遥远太空中看到的样子吗？螺旋星系NGC 3370的大小和宏伟结构与我们的银河系相似（尽管没有中央棒状结构），它位于狮子座（Leo）方向，距离我们约1亿光年。哈勃太空望远镜记录下了这颗巨大而美丽的正面螺旋星系，它不仅非常上镜，而且清晰度极高，足以研究被称为造父变星的单个恒星。这幅影像由哈勃太空望远镜以极其精细的细节拍摄，这个美丽的正面螺旋星系不仅极具观赏性，而且其清晰度足以研究被称为造父变星的个别恒星。这些脉动恒星被用来精确测定NGC 3370的距离。之所以选择NGC 3370进行这项研究，是因为这个螺旋星系在1994年曾发生过一次研究较为深入的恒星爆炸——Ia型超新星爆炸。结合基于造父变星测量结果得出的这个标准烛光超新星之已知距离，与更远距离的超新星观测，有助于揭示整个宇宙大小和膨胀速度。
明日的图片: open space
Due to the lapse in federal government funding, NASA is not updating APOD website. We sincerely regret this inconvenience.
由于美国联邦政府资金中断，NASA目前暂停更新APOD网站。对此带来的不便，我们深感抱歉。
英文原文:
Explanation: Is this what our own Milky Way Galaxy looks like from far away? Similar in size and grand design to our home Galaxy (although without the central bar), spiral galaxy NGC 3370 lies about 100 million light-years away toward the constellation of the Lion ( Leo ). Recorded here in exquisite detail by the Hubble Space Telescope, the big, beautiful face-on spiral is not only photogenic, but has proven sharp enough to study individual stars known as Cepheids. These pulsating stars have been used to accurately determine NGC 3370’s distance. NGC 3370 was chosen for this study because in 1994 the spiral galaxy was also home to a well studied stellar explosion — a Type Ia supernova. Combining the known distance to this standard candle supernova, based on the Cepheid measurements, with observations of supernovas at even greater distances, has helped to reveal the size and expansion rate of the entire Universe itself.
