What kind of star is Altair?
Altair, catalogued as Alpha Aquilae (α Aql), appears in the official constellation Aquila. Its apparent visual magnitude is 0.76, while its estimated distance is about 16.7 light-years. Astronomers classify the object as A7 Vn. These labels describe temperature, luminosity class or system components; they should not be read as a claim that every naked-eye point is a single isolated star.
The coordinate pair RA 19h 50m 47.00s, Dec +08° 52′ 05.96″ fixes the object’s direction on the celestial sphere for the J2000 reference epoch. Right ascension works like celestial longitude measured in hours, while declination works like latitude north or south of the celestial equator. Proper motion and improved measurements can refine catalogue positions, but these coordinates are sufficiently precise for a finder chart or planetarium search.
The name Altair
From Arabic al-nasr al-ṭāʾir, “the flying eagle.”
Modern professional catalogues retain identifiers such as the Bayer designation alongside a proper name. The International Astronomical Union standardizes which name belongs to which component—an important distinction for systems whose combined light looks like one star from Earth.
How to find Altair
Follow the Milky Way from Cygnus toward Aquila. Altair is the bright middle star in a short three-star line flanked by Tarazed and Alshain; no telescope is needed.
Visible from most inhabited latitudes; prominent on northern summer and autumn evenings. Visibility on a particular night still depends on latitude, season, time, horizon obstructions, weather and local light pollution. Use the interactive atlas below to check the surrounding field before observing.
Interesting facts about Altair
- Altair forms the Summer Triangle with Vega and Deneb.
- It is among the nearest naked-eye first-magnitude stars.
- It completes a rotation in roughly ten hours and spins at more than 200 kilometres per second near its equator.
- Rapid rotation makes Altair measurably wider at the equator than at the poles.
- Its hotter poles and cooler equator make it a textbook example of gravity darkening.
Sources and further reading
Measurements are rounded for readability. Multiple systems, variable stars and distant supergiants can have component-specific or model-dependent values.