NGC 739
galaxy
NGC 739 is a spiral galaxy approximately 193 million light-years away from Earth in the constellation of Triangulum.
Observational history
NGC 739 was discovered by English astronomer Ralph Copeland on January 9, 1874. He was using the 72" telescope at Birr Castle in an observation of Arp 166, which is composed of two interacting galaxies NGC 750 and NGC 751. Copeland reported the wrong direction of the newly observed galaxy, but gave the correct orientation as PA 292° (WNW) and separation 524" (8.7'). Because of his error the derived position was in error and this was copied into the NGC Catalogue.
In 1913 American astronomer Heber Curtis noted there was nothing at that position and suggested MCG +05-05-030 was in fact NGC 739, based on Edward Crossley's photographs taken at Lick Observatory.
Begin with the source’s own compact description: “NGC 739” is galaxy. The dossier treats that line as a proposition to test through galaxy, not as a finished interpretation.
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The phrase “galaxy” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 21, 2026. The linked authority identifier is Q1038699. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1874 and 1913.
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This entry incorporates text from “NGC 739” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.