Arp 29: The fireworks galaxy
An image of Arp 29, the "fireworks galaxy," shows a peculiar galaxy with bright star formation, HII regions, a star cluster, and ten observed supernovae. Its light is partially blocked by dust, and its distance is uncertain at roughly 10-30 million light-years.
Background
The Atlas of Peculiar Galaxies ("Arp") is a 1960s catalog of 338 odd-shaped galaxies compiled by Halton Arp, who controversially argued that galaxy redshifts might not reliably measure distance — a view rejected by mainstream astronomy. Amateurs often re-image Arp objects as a tribute. NGC 6946 (the Fireworks Galaxy) is a nearby spiral famous for ten observed supernovae and intense star formation. The image was taken with a Celestron C9.25, a popular Schmidt-Cassegrain telescope among hobbyists. The author notes the galaxy sits close to the Milky Way's plane, so dust blocks much of its light and dense foreground stars clutter the field, making distance measurements unreliable — a genuine challenge also faced by professional astronomers.