Haro 2 is a blue compact galaxy in the constellation Ursa Major.

[1] Guillermo Haro first described H2 in a study published in 1956 listing 44 galaxies that were blue.

[4] An outflow of ionised gas around the central HII region forming a shell could be galactic wind created by the starburst activity in the centre of the galaxy.

The galaxy has been found to emit Lyman-alpha both from the central HII region and the shell.

[5] The expanding shell has also been observed in X-rays with ROSAT, indicating it forms a superbubble.