NGC 7822 is a very large nebula and stellar nursery located in the constellation Cepheus approximately 2900 light-years distant. A wide field image showing the full nebula may be viewed here. Many new stars have formed, and are in the process of forming, in this massive collection of gas and dust. Numerous Bok Globules, columns, and pillars abound throughout the nebula and are stellar nurseries where infant stars are formed. The impressive columns in the nebula are very similar in appearance and structure to the famous Hubble image of the "Pillars of Creation" in the Eagle Nebula. The image above spans a small section of the NGC 7822 nebula and highlights two prominent nebular pillars.
NGC 7822 shines in visible light due to intense radiation emanating from a young cluster of very hot stars designated Berkeley 59. This cluster is located in the upper center of the above image. An enlarged image of the cluster, along with its location in the nebula, may be viewed here. Berkeley 59 contains an extremely hot and luminance stellar member designated BD+66 1673. It is an eclipsing binary containing an O5V star with a surface temperature of approximately 45,000 K and a luminosity about 100,000 times that of our Sun. This star is thought to be the primary illuminator of this most impressive nebular complex.
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 color data from a separate RGB image.
2Berkeley59 - Neelam Panwarm et al: https://iopscience.iop.org/article/10.3847/1538-3881/aa9f1b