What does this number measure?
A very large spiral galaxy whose extended disc provides a reference larger than the Milky Way. Its extent of about 463 000 light-years is a frequently cited estimate of the disc's large envelope; it depends on the adopted distance and the detection threshold for the outer regions. It is not strictly comparable with every optical galaxy diameter and should be checked against the source before scientific use.
Compare the stated dimensions
The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.
Source and limitations
Proposed catalogue value, an order of magnitude not audited online in this session; an HTTPS source is provided for checking.
An interpretative illustration of the extended disc of the spiral galaxy UGC 2885; the arms, dust and colours are illustrative, not a photograph or an exact map. The adopted large extent depends on the brightness threshold and boundaries chosen.