This featured photo focuses in on a beautiful galaxy often mistaken for one of our closest neighbors, Triangulum. Instead, the galaxy, which is called NGC 2403, is much more distant, situated approximately 12 million light-years from Earth, toward the Camelopardalis constellation; The two certainly have a lot on common regardless. Both are approximately the same size, and they are both lit up by a remarkable number of HII regions—places that are in the process of forging new stars.
From our vantage point, NGC 2403 is pictured head-on, giving us a great angle to study its inner structure. Indeed, this proved very useful in 2004, when an amature astronomer discovered a supernova near the galaxy’s core. It was so bright, it would take 200 million Suns combined to match its luminosity.
Per NASA, “The arrow at top right points to the stellar blast, called a supernova. The supernova is so bright in this image that it easily could be mistaken for a foreground star in our Milky Way Galaxy. And yet, this supernova, called SN 2004dj, resides far beyond our galaxy. Its home is in the outskirts of NGC 2403, a galaxy located 11 million light-years from Earth. Although the supernova is far from Earth, it is the closest stellar explosion discovered in more than a decade.”
Ultimately, NGC 2403 belongs to the Messier 81 (M81) galaxy group, which hosts around 34 galaxies. A few of which linger nearby, including a galaxy known as NGC 2404. The pair are so close, they are practically conjoined.