the-head-of-hydra-open-cluster-ngc-1981-and-reflection-nebula-ngc-1999https://www.astronomy.com/observing/deep-sky-objects/page/42/Deep-Sky Objects | Page 42 of 47 | Astronomy.comDeep-sky objects are celestial objects that exist outside our solar system. Three major types of deep-sky objects are nebulae, star clusters, and galaxies.https://www.astronomy.com/wp-content/uploads/sites/2/2021/09/stardome330.gif?fit=330%2C113InStockUSD1.001.00deep-sky-objectsobservingarticleASY2023-05-182013-03-0741602
Deep-sky objects are celestial objects that exist outside our solar system. Three major types of deep-sky objects are nebulae, star clusters, and galaxies.