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Research dossier · General Reference

NGC 684

galaxy

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionSep 3, 2026
Entity authorityQ1038276 ↗
Source-derived summary

NGC 684 is a spiral galaxy approximately 135 million light-years away from Earth in the constellation of Triangulum. It was discovered by William Herschel on October 26, 1786. Edward Swift, Lewis's son, found this galaxy again on 18 Jan 1890 while "searching for Swift's Comet." and it was reported as a new object in list IX-6.

NGC 684 Group

NGC 684 is the largest member of a group of galaxies named after it (also known as LGG 32), which includes the galaxies NGC 670 and IC 1731.

Supernovae

Two supernovae have been observed in NGC 684:

SN 2021ass (Type II, mag. 18.1122) was discovered by the Zwicky Transient Facility on 18 January 2021.

SN 2025aml (Type II, mag. 18.1168) was discovered by the Zwicky Transient Facility on 31 January 2025.

Editorial summary

The public source identifies “NGC 684” as galaxy. This brief keeps that definition visible, then builds a research path around galaxy.

Editorial reviewA concise reference frame for defining the subject, testing terminology and identifying the institution closest to the evidence. The current lead gives the account dated anchors—1786, 1890, 1731, 1122—that can be checked directly. The selected authority fields contribute no independent date. Its value is orientation rather than verdict, with galaxy providing the first useful test.
Editorial analysis

Why this record matters

A short description can identify a subject without explaining its stakes. For “NGC 684”, the useful work is to connect “galaxy” to the records capable of establishing context and consequence.

Evidence profile

Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 3, 2026. The linked authority identifier is Q1038276. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1786, 1890, 1731 and 1122.

Critical limits

The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
Verify next

The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “NGC 684”, its source revision and the description used here.
  2. Expand the search: follow NGC 684 primary sources, NGC 684 archive and galaxy research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “NGC 684”?
  2. What terminology or title could unlock a more precise catalogue search?
  3. Which institution is responsible for the underlying evidence?
Subject index

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Source & attribution

This entry incorporates text from “NGC 684” 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.