| NGC 633 | |
| Constellation Name: | Sculptor |
| Ra: | 01h 36m 23s |
| Dec: | -37° 19’ 18” |
| Epoch: | J2000 |
| Appmag B: | 13.5 |
| Sbrightness: | 22.37 mag/arcsec^2 |
| Type: | SBb |
NGC 633 is a large barred spiral galaxy located in the constellation Sculptor. Its speed relative to the cosmic microwave background is 4,979 ± 18 km/s, which corresponds to a Hubble distance of 73.4 ± 5.2 Mpc (∼239 million ly).[1] NGC 633 was discovered by British astronomer John Herschel in 1834.
The luminosity class of NGC 633 is II and it has a broad HI line. It also contains regions of ionized hydrogen.
The smaller galaxy to the south of NGC 633 is PGC 5959 or ESO 297-012, and these two galaxies form a galactic pair.[2] The Hubble distance of ESO 297-012 is 73.51 ± 5.15,[3] which is almost identical to that of NGC 633, confirming that both galaxies are in gravitational interaction.[4] A contrast-enhanced image shows a bridge of matter between these two galaxies.