Herschel discovered NGC 508 along with NGC 507 and described the objects as "Two. Both eF, S, but unequal.". His observed position was catalogued and is accurate.[6]John Louis Emil Dreyer, creator of theNew General Catalogue, described the galaxy as "very faint, small, northern of two", with the other object beingNGC 507.[5]
The galaxy has an apparent size of 1.1 × 1.1 arcmins and arecessional velocity of 5525 kilometers per second. It is thought to be a group member with NGC 507, but as there is no evidence ofinteraction between the objects, the two are not necessarily a physical pair. Although NGC 508 is usually treated as part of Arp 229, the description of the Arp-galaxy only applies to the larger NGC 507. Therefore, the term Arp 229 should only be used as an alternative designation for NGC 507.[5]
^abAn object's distance from Earth can be determined usingHubble's law:v=Ho is Hubble's constant (70±5 (km/s)/Mpc). The relative uncertainty Δd/d divided by the distance is equal to the sum of the relative uncertainties of the velocity andv=Ho