M42, the Great Orion Nebula

M42 is the most prominent diffuse nebula visible to observers in North America. It's a star-forming cloud of hydrogen highlighted by the Trapezium, a tiny cluster of very young stars at its core.

M42 is unusual among deep sky objects in that it has such a huge range of brightnesses. The inner parts are so bright that they show up well in a 30 second exposure. The dimmer parts need eight minutes of exposure or more at f/9. At eight minutes, the inner parts are completely blown out. To make this image, I combined 30 images ranging from eight minutes at ISO 1600 to one minute at ISO 400.
This is probably the best I can do from my current location. The long exposures were pretty swamped by light pollution. Made with my 155mm refractor.

Image copyright by Joe Bergeron.