What is the diameter of the largest star, and what is its name?
No one can say for sure what the largest star is. With 100 billion galaxies in the universe, and billions of stars per galaxy, there are just too many stars to measure.
However, perhaps the largest star yet measured is Mu Cephei in the constellation Cepheus. It is about 1.4 billion miles (2.25 billion km) in diameter. For comparison, our Sun has a diameter of approximately 864,000 miles. The diameter of Betelgeuse, a star in Orion, is about 600 million miles (one billion km).
The size of a star depends on its mass and its stage in the stellar life cycle. Both Betelgeuse and Mu Cephei are red supergiants. They are much more massive than the Sun, and are relatively late in their lives, so they have “puffed up” like over-inflated beachballs. The Sun will puff up at the end of its life, too, swelling to around 30 times its present diameter.
» FAQs about StarDate Online
Astronomers and Observatories Links
History of Astronomy
International Astronomical Union
SEDS Large Telescopes Page
Keck Observatory
NAIC Arecibo Observatory
Hobby-Eberly Telescope
Space Telescope Science Institute
SCOPE Home Page
The Astrophysical Journal
American Astronomical Society
|
  |
Contact | About | Friends of McDonald | Sign up for Sky Tips
