Alpha2 Capricorni
star in the constellation Capricornus
Alpha2 Capricorni is a triple star system in the southern constellation of Capricornus. It has the proper name Algedi, pronounced ; Alpha2 Capricorni is its Bayer designation. This system is visible to the naked eye as a point of light with an apparent visual magnitude of +3.57. It is separated from the fainter α¹ Capricorni by 0.11° of the sky, a gap just resolvable with the naked eye, similar to Mizar and Alcor. Based on parallax measurements, the star is approximately 101 light-years (31 pc) away from the Sun.
Properties
The primary, component A, is an evolved G-type star with a stellar classification of G8.5III-IV, indicating that the spectrum displays mixed traits of a giant and subgiant star. At the age of 1.3 billion years, is currently on the red giant branch and is generating energy through hydrogen fusion along a shell surrounding an inert helium core. The star has around double the mass of the Sun and has expanded to more than eight times the Sun's radius. It is radiating 40 times the solar luminosity from its photosphere at an effective temperature of 5,030 K.
The secondary components B and C form a binary system that orbit each other with a period of about 244 years. Both stars have masses about half that of the Sun.
“Alpha2 Capricorni” enters the record as star in the constellation Capricornus. Crown Archives preserves that source wording while asking what Alpha2, Capricorni and star can confirm, complicate or overturn.
Why this record matters
“Alpha2 Capricorni” is worth following because a concise public description often conceals a longer documentary argument. Here, Alpha2, Capricorni and star provides the most credible route into that argument.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Mar 17, 2026. The linked authority identifier is Q77155. 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
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Alpha2 Capricorni”, its source revision and the description used here.
- Expand the search: follow Alpha2 Capricorni primary sources, Alpha2 Capricorni archive and Alpha2 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
- Which source most directly establishes the central claim about “Alpha2 Capricorni”?
- What terminology or title could unlock a more precise catalogue search?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Alpha2 Capricorni” 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.