Astro Glossary

African Astronomy and Skylore

Age of the Universe

Airborne Observatories

Aldebaran

The brightest star of the constellation Taurus. It is a red giant star, and is about 67 light-years away.

Alpha Centauri

The closest star system to the Sun, at a distance of more than four light-years, Alpha Centauri consists of three stars. Two of the stars — one of which is similar to the Sun, while the other is a little smaller and cooler — form a tight pairing. The third, known as Proxima Centauri, is about one-tenth of a light-year from the other two, and is a red dwarf star. It is closer to Earth than the other two stars, but it is so faint that it is not visible to the unaided eye.

Altair

The brightest star of the summer constellation Aquila, the eagle. It is a main-sequence star, shining pure white, and is about 17 light-years from Earth. It forms one point of the Summer Triangle. Its name means “the flying eagle.”

American Indian Astronomy and Folklore

Anatomy of Galaxies

Ancient Astronomy

Ancient Observatories and Monuments