| NGC 2805 | |
| Constellation Name: | Ursa Major |
| Epoch: | J2000 |
| Type: | SAB(rs)d[1] |
| Dist Ly: | NaNMpc |
| Z: | 0.005779 |
| H Radial V: | 1733 ± 1 km/s |
| Appmag V: | 11.0 |
| Size V: | 6.3' x 4.8' |
| Size: | ~27.84kpc (estimated) |
NGC 2805 is a intermediate spiral galaxy in the constellation of Ursa Major. Its velocity with respect to the cosmic microwave background is 1834 ± 7 km/s, which corresponds to a Hubble distance of 27.05 ± 1.90 Mpc (∼88.2 million light-years). However, 11 non redshift measurements give a distance of 12.76 ± 11.89 Mpc (41.6 million light-years).[2] (Note: this sample of measurements is inconsistent: seven values between 3.03 Mpc and 5.13 Mpc are reported in publications from 1984 to 1985, then four values between 26.8 Mpc and 28.8 Mpc.) The galaxy was discovered by German-British astronomer William Herschel on 2 April 1791.[3]
One supernova has been observed in NGC 2805: SN 2019hsw (type II, mag. 15.4).[4]
NGC 2805 is the namesake of the NGC 2805 group (also known as LGG 173), which includes at least 4 other galaxies: NGC 2814, NGC 2820, NGC 2880, and IC 2458.[5] This group, minus NGC 2880, are also collectively called Holmberg 124.[6]