2025年8月18日
NGC 1309: A Useful Spiral Galaxy
Image Credit: NASA, ESA, Hubble; Processing: L. Galbany, S. Jha, K. Noll, A. Riess
Explanation: This galaxy is not only pretty — it’s useful. A gorgeous spiral some 100 million light-years distant, NGC 1309 lies on the banks of the constellation of the River (Eridanus). NGC 1309 spans about 30,000 light-years, making it about one third the size of our larger Milky Way galaxy. Bluish clusters of young stars and dust lanes are seen to trace out NGC 1309’s spiral arms as they wind around an older yellowish star population at its core. Not just another pretty face-on spiral galaxy, observations of NGC 1309’s two recent supernovas and multiple Cepheid variable stars contribute to the calibration of the expansion of the Universe. Still, after you get over this beautiful galaxy’s grand design, check out the array of more distant background galaxies also recorded in this sharp image from the Hubble Space Telescope.
Tomorrow’s picture: open space
NGC 1309: 有用的螺旋星系
影像提供: NASA, ESA, Hubble; 影像处理: L. Galbany, S. Jha, K. Noll, A. Riess
说明: 这个星系不仅美丽，还具有科学价值。位在波江座边缘的壮丽螺旋星系NGC 1309，距离我们约有1亿光年远。NGC 1309的跨幅约有30,000光年，约莫是我们银河系大小的3分之1。泛蓝年轻恒星组成的星团和尘埃带勾勒出NGC 1309的螺旋臂，而螺旋臂则蜿蜒环绕着由较年老泛黄恒星所聚成的星系核。NGC 1309不仅只是另一个美丽的正向螺旋星系，观测最近出现在它内部的2个超新星与多个造父变星，让我们得以校准宇宙膨胀的速率。不论如何，在你观赏这个宏伟的美丽星系之后，不妨也看看这幅清晰的哈勃太空望远镜影像，所记录的诸多更遥远的背景星系。
明日的图片: open space
