What type of astronomical object is the Elephant Trunk Nebula?

The Elephant Trunk Nebula is classified as an ionized gas region or nebula, specifically within the larger framework of an emission nebula. These regions are characterized by their bright colors and are composed of ionized gas that emits light as a result of high-energy radiation from nearby hot stars. The "trunks" in the Elephant Trunk Nebula are dense columns of gas and dust that are illuminated by the radiation from nearby young stars, which makes them visually striking.

In these nebulae, the intense ultraviolet radiation causes the surrounding hydrogen gas to ionize, resulting in the distinctive glowing appearance. This process is associated with star formation, as these dense regions can collapse under their own gravity, leading to the birth of new stars. In contrast, supernova remnants, star clusters, and galaxies represent different types of astronomical structures and phenomena, which do not describe the conditions or characteristics present in the Elephant Trunk Nebula.