In 1864, William Huggins showed how these objects could be distinguished from stars on the basis of their spectra.
In 1864, William Huggins showed how these objects could be distinguished from stars on the basis of their spectra. The specific examples known as Herbig-Haro objects are classified as emission types of these objects, while the example Trifid is a combined emission and reflection type. The dark kind includes such examples as the Coalsack and the Horsehead, while other famous types include the Ring, Lagoon, and Crab. FTP, what are these clouds of stellar gas and dust?
In 1864, William Huggins showed how these objects could be distinguished from stars on the basis of their spectra.
nebula(e) or nebulas