This bright, somewhat blob-like object — seen in this image taken by the NASA/ESA Hubble Space Telescope — is a galaxy named NGC 1803. It is about 200 million light-years away, in the southern constellation of Pictor (the Painter’s Easel).
NGC 1803 was discovered in 1834 by astronomer John Herschel. Herschel is a big name in astronomy; John, his father William and his aunt Caroline all made huge contributions to the field, and their legacies remain today. William systematically cataloged many of the objects he viewed in the night sky, named many moons in the solar system, discovered infrared radiation and more. Caroline discovered several comets and nebulas. John took this aforementioned catalog of night-sky objects and reworked and expanded it into his General Catalogue of Nebulae and Clusters of Stars. This was the basis for the cataloging system still used today by astronomers, John Louis Emil Dreyer’s New General Catalogue of Nebulae and Clusters of Stars, or the New General Catalogue for short.
This gives rise to the NGC names assigned to a vast number of galaxies — including NGC 1803. This galaxy is one of a galactic pair. It was described by Dreyer as being “faint, small, [and] round,” and located near to a very bright star to the southeast. This star is in fact the nebulous lenticular galaxy PGC 16720 — not visible in this image.
Text credit: ESA (European Space Agency)
Image credit: ESA/Hubble & NASA, A. Bellini et al.
这产生了分配给包括NGC 1803在内的众多星系的NGC名称。这个星系是一对星系中的一个。德雷尔将它描述为“微弱，小而圆”，位于东南方，靠近一颗非常明亮的恒星。这颗恒星实际上是星云状透镜星系PGC 16720——在这张图片中不可见。
文字来源: ESA (European Space Agency)
影像来源: ESA/Hubble & NASA, A. Bellini et al.