Altair

system

Altair is the brightest star in Aquila and the 12th-brightest in the night sky, 16.7 light-years away. A white A-type star nearly twice the Sun's mass, it spins once every ~9 hours and bulges visibly at the equator — one of the first stars imaged as a flattened disk. It forms the Summer Triangle with Vega and Deneb. No planets are confirmed.

Open in 3D viewSee Altair in the live, interactive 3D map

Key facts

Type

White A-type star

Distance

16.73 light-years

Confirmed planets

Science

Classification

Type: Single A-type star (rapid rotator)
Central star: Altair — A7V (~7550 K, ~1.86 M☉)

Rotation

Spin period: ~8.9 hours (equator ~285 km/s) — visibly oblate

Planets

Confirmed planets: None

Distance

Distance: 16.73 light-years

How we know

Note: No planets are confirmed. Altair's extreme rotation and oblate shape are directly measured by interferometry. Real distance 16.73 light-years.

Discovery & history

Method: Naked-eye star
Name: Its IAU name Altair is from the Arabic 'the flying eagle'; Alpha Aquilae.

Its rapid rotation, inferred from its spectrum, was confirmed in 2007 when interferometers imaged its flattened, gravity-darkened disk.

Images

Where to find it — in Aquila, the Eagle (IAU constellation chart). To the eye it is a single point of light; no telescope has imaged its surface. — IAU / Sky & Telescope, R. Sinnott & R. Fienberg (CC BY 3.0) · Wikimedia Commons

Images from open archives · credit shown per image