NGC 7678 is a spiral galaxy in the constellation Pegasus, notable for having one particularly massive and bright spiral arm, which earned it a spot in the Atlas of Peculiar Galaxies as Arp 28 ("spiral galaxies with one heavy arm"). Located about 164 million light-years away, it's similar in size to the Milky Way and features a weak bar, a pseudo inner ring, and numerous HII regions, especially in its prominent southern arm, indicating active star formation.
Type: Intermediate spiral galaxy (SAB(rs)c)
Location: Constellation Pegasus
Distance: Approximately 164 million light-years
Size: About 115,000 light-years in diameter, similar to the Milky Way
Peculiarity: One arm is significantly more massive and brighter than the other, likely due to a higher density of gas and stars, possibly from a past interaction or merger.
Classification: Also cataloged as Arp 28 in Halton Arp's Atlas of Peculiar Galaxies.
Heavy Arm: The southern arm is exceptionally bright and dense with HII regions (areas of active star formation).
Nucleus: It has a bright, compact nucleus that is bluer than the surrounding bulge and bar.
Structure: Shows a weak bar and a pseudo inner ring. Image Credit ESA/Hubble & NASA, A. Riess et al
Comments