Altair
Where is Altair?
Look south, about 47° up at 20:20 in Aquila. It sinks lower through the evening and sets at 02:43.
- Rises
- 13:06
- Highest
- 19:54
- Sets
- 02:43
- Best after dark
- 20:20 · 47°
Can I see Altair tonight?
From London tonight, Altair is above the horizon after dark. It’s highest soon after dark, around 20:20, in the south at 47°.
At magnitude 0.8 it is one of the brighter points in the sky, easy to see by eye when it’s clear.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does Altair look like?
Altair looks white to the eye. Its spectral type is A7Vn: white main-sequence star (hotter than the Sun).
Eyes
A bright white star flanked by two fainter stars, one on each side.
Binoculars
The line of Altair and its two neighbors, Tarazed and Alshain, is easy to see. Rich Milky Way fields lie nearby.
Telescope
A point of light. The nearby Coathanger cluster and the Dumbbell Nebula are good targets.
About Altair
Altair is the brightest star in Aquila, the Eagle, and one corner of the Summer Triangle with Vega and Deneb. It is a nearby white star, only about 17 light-years away.
Altair spins remarkably fast, once every nine hours or so, compared with nearly a month for the Sun. That rapid rotation flattens it, and astronomers have even made images showing its stretched shape and darker equator.
In East Asian tradition, Altair is the cowherd who is separated from the weaver girl, Vega, by the Milky Way. They are said to meet once a year.
Altair is about 1.8 times the mass of the Sun and around 10 times as luminous. Its fast spin makes its equator about 20% wider than its poles, and its poles are hotter than its equator.
Its two neighbors, Tarazed and Alshain, look like companions but are unrelated stars at different distances.
Altair in Aquila
Questions
Why is Altair flattened?
Which stars make the Summer Triangle?
Sources: SkyMate; Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences