Eta Arae
star in the constellation Ara
Eta Arae is a single star in the southern constellation of Ara. Its name is a Bayer designation that is Latinized from η Arae, and abbreviated Eta Ara or η Ara. This star is visible to the naked eye with an apparent visual magnitude of 3.76. Based on parallax measurements, it is approximately 305 light-years (94 parsecs) distance from Earth. The star is moving away from the Sun with a radial velocity of +9 km/s.
The spectrum of this star matches a stellar classification of K5 III, indicating that, at an estimated age of five billion years, it has reached the giant star stage of its evolution. With 1.12 times the mass of the Sun, it has an outer envelope that has expanded to 40 times the Sun's radius. The star is now spinning so slowly that it takes more than eleven years to complete a single rotation. Eta Arae is radiating energy into space from its photosphere with 575 times the Sun's luminosity at an effective temperature of 4,147 K, giving it the orange-hued glow of a K-type star.
It has a magnitude 13.5 optical companion, located 23.4 arcseconds away along a position angle of 118°, as of 2000.
The public source identifies “Eta Arae” as star in the constellation Ara. This brief keeps that definition visible, then builds a research path around Arae, star and constellation.
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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 12, 2026. The linked authority identifier is Q2444050. The first chronological checks are 2000.
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.
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This entry incorporates text from “Eta Arae” 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.