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 is known as a mapped, or false color, image and was acquired using narrowband filters. It was assembled using the standard Hubble Palette with SII mapped to Red, Ha mapped to Green and OIII mapped to Blue. The stars were overlaid with data from a Bi-Color (Ha - OIII - OIII) image to give them a more natural appearance. A near true color (Ha,OIII,OIII) image of Sh2-284 may be viewed here.
1https://www.jpl.nasa.gov/news/news.php?feature=2920