KnowraMessier objectLinked fromLinked fromThe 5 pages that link to Messier object, each with the reason it gives.All 5Broader topic 2Narrower topic 2Compared with 1Equatorial coordinate systemBroader topic: Messier entries are commonly identified by their equatorial coordinates.Messier catalogBroader topic: M-numbers provide a compact naming system used in observation and astronomy literature.