HD 3240
star in the constellation Cassiopeia
HD 3240 is a single star in the northern constellation of Cassiopeia, positioned near Zeta Cassiopeiae. This object has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.08. The distance to HD 3240 is approximately 480 light years based on parallax. At that range, the visual magnitude of the star is diminished by an extinction of 0.22 due to interstellar dust.
This star has a stellar classification of B9IV, matching a subgiant that has exhausted the supply of hydrogen at its core. Despite the spectral luminosity class, evolutionary models place the star near the end of the main sequence, having gone through 91% of its main sequence lifespan. It is around 201 million years old and is spinning with a projected rotational velocity of 59 km/s, well below its critical velocity of 335 km/s.
This brief starts where responsible research should: with the source description of “HD 3240” as star in the constellation Cassiopeia. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as star in the constellation Cassiopeia. Its deeper value depends on whether names, dates, institutions and citations support that framing.
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 Aug 23, 2026. The linked authority identifier is Q5097529. None of the 0 selected statements returned an explicit reference.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. 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.
- Subject orientation
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Three-step research path
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- Expand the search: follow HD 3240 primary sources, HD 3240 archive and star research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
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This entry incorporates text from “HD 3240” 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.