M85-HCC1

M59-UCD3
Images of two ultracompact dwarf galaxies. M59-UCD3 is in the inset to the left, while M85-HCC1 is in the inset to the right.
Observation data (J2000 epoch)
ConstellationComa Berenices
Right ascension12h 25m 22.842s
Declination+18° 10 53.67
Heliocentric radial velocity658 ± 4
Apparent magnitude (V)18.80 ± 0.03
Absolute magnitude (V)−12.55 ± 0.07
Characteristics
Mass(1.2±0.1)×107 M
Half-light radius (physical)1.85 ± 0.9 pc
Other designations
2MASS J12252287+1810539, SDSS J122522.84+181053.6

M85-HCC1 is an ultracompact dwarf galaxy with a star density 1,000,000 times that of the solar neighbourhood, lying near the galaxy Messier 85. As of 2015, it is the densest galaxy known.