The NASA/ESA Hubble Space Telescope image features the spiral galaxy NGC 3285B, a member of the Hydra I cluster of galaxies.
ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)
The swirling spiral galaxy in this NASA/ESA Hubble Space Telescope image is NGC 3285B, which resides 137 million light-years away in the constellation Hydra (the Water Snake). Hydra has the largest area of the 88 constellations that cover the entire sky in a celestial patchwork. It’s also the longest constellation, stretching 100 degrees across the sky. It would take nearly 200 full moons, placed side by side, to reach from one side of the constellation to the other.
NGC 3285B is a member of the Hydra I cluster, one of the largest galaxy clusters in the nearby universe. Galaxy clusters are collections of hundreds to thousands of galaxies bound to one another by gravity. The Hydra I cluster is anchored by two giant elliptical galaxies at its center. Each of these galaxies is about 150,000 light-years across, making them about 50% larger than our home galaxy, the Milky Way.
NGC 3285B sits on the outskirts of its home cluster, far from the massive galaxies at the center. This galaxy drew Hubble’s attention because it hosted a Type Ia supernova in 2023. Type Ia supernovae happen when a type of condensed stellar core called a white dwarf detonates, igniting a sudden burst of nuclear fusion that briefly shines about 5 billion times brighter than the Sun. The supernova, named SN 2023xqm, is visible here as a blueish dot on the left edge of the galaxy’s disk.
Hubble observed NGC 3285B as part of an observing program that targeted 100 Type Ia supernovae. By viewing each of these supernovae in ultraviolet, optical, and near-infrared light, researchers aim to disentangle the effects of distance and dust, both of which can make a supernova appear redder than it actually is. This program will help refine cosmic distance measurements that rely on observations of Type Ia supernovae.
Text credit: ESA/Hubble
这张由NASA/ESA哈勃太空望远镜拍摄的图像展示了螺旋星系NGC 3285B，它是长蛇座星系团（Hydra I）的一员。
图片来源: ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)
这座旋转的螺旋星系NGC 3285B位于长蛇座，距离地球约1.37亿光年。长蛇座是88个全天星座中面积最大的一个，同时也是最长的星座，横跨天空约100度。若将200个月亮首尾相连，才能从该星座的一端延伸到另一端。
NGC 3285B隶属于长蛇座I星系团，这是本地宇宙中最大规模的星系团之一，包含数百至上千个由引力彼此束缚的星系。该星系团的中心由两颗巨大的椭圆星系主导，每颗星系的直径约为15万光年，比我们的银河系大约50%。
NGC 3285B位于其所在星系团的外围，远离中心那两颗庞大的椭圆星系。哈勃之所以将目光投向它，是因为该星系在2023年发生了一次Ia型超新星爆发。Ia型超新星发生在一种被称为白矮星的致密恒星核心发生爆炸时，瞬间引发核聚变，释放出比太阳亮50亿倍的光芒。此次超新星被命名为SN 2023xqm，在图像中可见于星系盘左缘的一颗微微泛蓝的亮点。
哈勃对NGC 3285B的观测是一个针对100颗Ia型超新星的观测项目的一部分。研究人员通过紫外光、可见光和近红外光的观测，试图剖析距离和星际尘埃的影响，因为这两者都会使超新星看起来比实际更红。该项目将有助于优化依赖 Ia 型超新星观测的宇宙距离测量。
文字来源: ESA/Hubble
