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Avior

Epsilon Carinae

Proper NamesAvior
Bayer DesignationEpsilon Carinae
Flamsteed NumberNone
HR (BSC)3307
HD71129
ConstellationCarina
Right Ascension8h 22m 56s
Declination-59° 34' 37"
Distance605 light years
186 parsecs
MagnitudeApparent: +2.0
Absolute: -4.4
Spectral ClassK3III Orange Giant
Optimum VisibilityFebruary (Usually visible from southern latitudes)
NotesAvior is thought to be an eclipsing binary in which two stars, an orange giant and a blue dwarf, orbit a common centre of gravity. The two stars are probably no more than 4 AU apart, and thus pursue a rapid mutual orbit with a period of a little over two years. When the stars eclipse one another, the system's overall brightness briefly falls by more than a tenth of a magnitude.

A bright orange star in the central parts of Carina, a little to the east of brilliant Canopus. Avior is among the brightest stars in the sky (brighter, for example, than Polaris, and closely comparable with Alkaid, the 'handle' of the Plough).

Its location in the southern constellation of Carina meant that it was not historically visible to northern astronomers, and in fact it did not gain a name until the 1930's. It was selected as a navigational star in an almanac for use by the Royal Air Force, who insisted that it be named. The intended meaning of the name is unclear, but given the connection to the RAF it is presumably connected to Latin avis (literally 'bird', but also used in modern times for 'aircraft'). It shares this etymological source with the star Peacock in Pavo, which acquired its name for the same reasons.

Avior lies some 605 light years from the Solar System, and given its brightness in the sky this great distance implies that it is highly luminous. In fact it belongs to a system of at least two stars, with the heart of that system being an orange giant. Within the system orbits a blue dwarf, whose eclipses of its giant companion cause small periodic shifts in its brightness. It is possible that there is a third star in this system, an orange dwarf in orbit around the blue star, though this has yet to be confirmed.

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