What type of star is represented by NGC 6888?

NGC 6888, also known as the Crescent Nebula, is associated with a particular type of star known as a Wolf-Rayet star. Wolf-Rayet stars are massive stars that have exhausted the hydrogen fuel in their cores and are characterized by strong stellar winds and the presence of heavy elements in their spectra. These stars are often hot and luminous, exhibiting temperatures that can exceed 30,000 Kelvin.

In the case of NGC 6888, it is specifically related to a Wolf-Rayet star named WR 136. This star is in a late stage of its evolution and sheds a significant amount of material through intense stellar winds, which contribute to the nebula we observe. The stellar wind interacts with the surrounding medium, forming the intricate structure of the nebula.

The properties of Wolf-Rayet stars make them significant in the context of stellar evolution and nucleosynthesis, as they are precursors to supernovae and play a crucial role in enriching the interstellar medium with heavy elements. Thus, NGC 6888 is primarily recognized and classified as a nebula formed by the activities of a Wolf-Rayet star.