Sh2-284 is a HII star forming region of gas and dust located in the constellation Monoceros approximately 15 thousand light years from the Earth. This remarkable nebula resembles the more familiar Rosette Nebula (Caldwell 49). Along the edges of Sh2-284 are several "elephant trunk" formations. These are monstrous pillars of gas and dust that stretch into the central void of the nebula. Perhaps the most prominent of the pillars is located to the right center of the nebula. It resembles the forefinger of a hand pointing to the stars in the center of the nebula. These pillars are formed by intense radiation and stellar winds radiating from the very hot stars of the central open cluster designated
Dolidze 25. The radiation and wind from the cluster is responsible for clearing the central void in the surrounding nebula. Dolidze 25 is a very young cluster with an estimated age of approximately 3 to 4 million years.
The image above was assembled from two narrowband filtered images. These consisted of Ha mapped to red and OIII mapped to green and blue. This bi-color image approximates the true colors of the nebula. A full Hubble Palette version (SII-Ha-OIII) may be viewed here.
1https://www.jpl.nasa.gov/news/news.php?feature=2920