How Old Is The Oldest And How Big Is The Biggest Known Stars In The Universe?

Answer 1

Gauging the age of a star can be tricky, particularly for the oldest stars. The only reliable technique is to look at a cluster of stars which were born at the same time; one can determine the age of the cluster, and all the stars will be the same age. The oldest cluster of stars we’ve observed is M4, which clocks in at perhaps 12.7 billion years old. So any one of those stars would qualify as the “oldest known,” even though there might be older stars out there.

As far as what star would qualify as the “biggest,” one could choose either the largest in size or the most massive.

Betelgeuse pretty much takes the prize in the first category, with a diameter some 650 times that of the Sun—if you replaced the Sun with Betelgeuse, it would extend farther than the orbit of Mars! (Theoretically, a star can have a diameter of about 2,000 times that of the Sun, but we haven’t found any that big.)

In terms of mass, the biggest known star is probably the Pistol Star, which “weighs in” at about 150 times the mass of the Sun. Stars that big don’t even form on their own—they probably result from collisions between several massive stars, all of which combine to form a single, enormous star.


Ryan Wyatt
Rose Center for Earth & Space
New York, New York

Answer 2

The oldest known galaxy is currently unnamed.It is 10 billion light years away.Biggest known star is 2000 times the size of the sun.

Answer 3

oldest star is about 14 billion years ago i.e from the beggining of the universe http://news.bbc.co.uk/2/hi/science/nature/2381935.stm

The largest star that is known is a star in the constellation of Auriga, the charioteer. Its name is Epsilon Aurigae. It is thought to be a gigantic star that is about 2,700 times the size of the Sun

http://www.windows.ucar.edu/tour/link=/kids_space/bigstar.html

Answer 4

Betelgeuse from the constellation Orion.