HVC 127-41-330

HVC 127-41-330 is a high-velocity cloud in the constellation of Pisces. The three numbers that compose its name indicate, respectively, the galactic longitude and latitude, and velocity towards Earth in km/s. It is 20,000 light years in diameter and is located 2.3 million light years (700 kiloparsecs) from Earth, between M31 and M33.^[2] This cloud of neutral hydrogen (detectable via 21 cm H-I emissions), unlike other HVCs shows a rotational component and dark matter. 80% of the mass of the cloud is dark matter. It is also the first HVC discovered not associated with the Milky Way galaxy or subgroup (subcluster).

HVC 127-41-330

Interstellar cloud
High-velocity cloud
Observation data: J2000.0[1] epoch
Right ascension	01h 05m [1]
Declination	+21.8°[1]
Distance	2,300,000 ly   (700,000[2] pc)
Designations	HVC 127-41-331, HVC 128-41-329, HVC 127-42-352, HVC 127-41-330[1]
See also: Lists of nebulae

Astronomer Josh Simon considers it a candidate for being a dark galaxy.^[2] With its rotation, it may be a very low density dwarf galaxy of unused hydrogen (no stars), a remnant of the formation of the Local Group.

See also

• Dark galaxy
• VIRGOHI21
• LSB galaxy