M82, also known as the Cigar Galaxy is the home of a large amount of new star formation. It also features a huge plume of hydrogen being ejected from the center of the galaxy. Most of that gas, however, doesn’t show up in a normal color photo. The ionized gas is actually glowing, but it’s so dim that it’s hidden in the brighter glow of the galaxy’s center. The solution is to also take photos using a hydrogen-alpha (Ha) filter that only captures the specific color of light emitted by ionized hydrogen.
This image uses a technique called “continuum subtraction” to bring out more of the hydrogen detail. I recently recorded a video showing how continuum subtraction can be done using Photoshop. If you really want to learn more about my image processing workflow, check out the details for the Southwest Utah Astrophotography Masterclass scheduled for September.