| Haro 2 | |
|---|---|
 Haro 2 bySloan Digital Sky Survey | |
| Observation data (J2000epoch) | |
| Constellation | Ursa Major |
| Right ascension | 10h 32m 32.0s[1] |
| Declination | 54° 24′ 02″[1] |
| Redshift | 0.004796 ± 0.000007[1] |
| Heliocentric radial velocity | 1438 ± 2km/s[1] |
| Distance | 124 ± 58Mly (38 ± 18Mpc)[1] |
| Apparent magnitude (V) | 13.1 |
| Characteristics | |
| Type | Im pec[1] |
| Apparent size (V) | 1.12′ × 0.80′[1] |
| Notable features | Blue compact dwarf |
| Other designations | |
| UGC 5720,Arp 233,MRK 33,MCG +09-17-070,PGC 31141[1] | |
Haro 2 is ablue compact galaxy in the constellationUrsa Major. The galaxy lies about 120 millionlight years away from Earth based on redshift independent measurements, which means, given its apparent dimensions, that Haro 2 is approximately 45,000 light years across, while redshift indicates a distance of 70 million light years.[1]
Guillermo Haro first described H2 in a study published in 1956 listing 44 galaxies that were blue.[2] Blue compact galaxies have been found to host large numbers of young massive stars due to aburst of star formation. The galaxy spectrum features emission fromWolf-Rayet stars.[3] The age of the current starburst activity is calculated to be 5.8 ± 1.0 million years.[4]
An outflow of ionised gas around the centralHII region forming a shell could begalactic wind created by the starburst activity in the centre of the galaxy. The galaxy has been found to emitLyman-alpha both from the central HII region and the shell.[5] The expanding shell has also been observed in X-rays withROSAT, indicating it forms asuperbubble.[4] Imaging of CO(2–1) indicates that the shell has entrained molecular gas.[6] The kinematics of the shell suggest that it has an age of 5 to 6 million years.[7]
