M76 is one of the fainter objects on the Messier list and is also known by the popular name of the “Little Dumbbell Nebula”. Like its brighter namesake M27 (the Dumbbell Nebula), M76 is recognized as a planetary nebula – a gaseous remnant of a dying Sun-like star. The nebula itself is thought to be shaped more like a donut, while the box-like appearance of its brighter central region is due to our nearly edge-on view. Gas expanding more rapidly away from the donut hole produces the fainter loops of far flung material. The fainter material is emphasized in this composite image, highlighted by showing emission from hydrogen atoms in orange and oxygen atoms in complementary blue hues. The nebula’s dying star can be picked out in the false-color image as the blue-tinted star near the center of the box-like shape. Distance estimates place M76 about 3 to 5 thousand light-years away, making the nebula over a light-year in diameter.
I was expecting a better image for this object, and had to do a lot of processing to get it somewhat right. Oh well….
This image was using narrowband for colors (primarily Hydrogen – Green, Oxygen – Blue & Sulphur – Red, but using some combination of these) and adding Luminance as a base. Total exposure 15.5 hours (Luminance – 9 images of 30 minutes each, Sulphur – 10 images of 20 min, Hydrogen 13 images of 20 min, Oxygen 10 images of 20 min.)