What is the largest possible mass for a star?

I mean an active, light-emitting star, not a degenerate object like the supermassive black holes at the centers of many galaxies.What is the largest possible mass for a star?I'm not sure that we know what the largest possible mass for a star is. Since astronomers are puzzling over how a star as massive as the Pistol Star (100 solar masses) could have formed, it sounds like they don't believe that a larger star could exist.



The largest known star (in terms of mass and brightness) is called the Pistol Star. It is believed to be 100 times as massive as our Sun, and 10,000,000 times as bright! In 1990, a star named the Pistol Star was known to lie at the center of the Pistol Nebula in the Milky Way Galaxy. In 1995, it was suggested that the Pistol Star was so massive it was throwing off the mass that actually created the Pistol Nebula. Observations from the Hubble Space Telescope in 1997 confirmed the relationship between the star and the nebula. Astronomers are currently unsure how a star this massive could have formed or how it will act in the future.



UPDATE! As of January 2009, we now know about some other really big stars. One is called Eta Carinae. It has a size about 800 times that of our Sun, a mass about 100 times that of our Sun, and is about 4,000,000 times brighter than our Sun. And, yet, we do not think it is the biggest! Recent observations of a star called VY Canus Majoris show that it has a size between 600 and 2100 tims the size of our Sun! However, this star is only about 500,000 times brighter than our Sun and 30 or so times more massive than our Sun. So how can it be so big? It is in a stage of its lifecycle called a red hypergiant, and while it is very big, it is rather cool in temperature compared to our Sun. VY Canis Majoris is located about 5000 light-years away from Earth.What is the largest possible mass for a star?There is hardly no possible limit. The star just becomes more and more unstable. If a star formed with a certain dozens of times the mass of the Sun, the energy would blow away any gases still orbiting it. But if 2 stars 50 times the mass of the Sun each collide, it will form a star and the star will not be so stable. It will 'spew' gas into space forming a nebula, like the Postol Star has. If 2 stars 80 times the Sun's mass each collide, it will form a single star, even less stable. So if an extremely massive star formed by other supermassive stars colliding together and it does happen, it will still form a star, but 'spew' gas faster depending on it's mass and it will lose mass. So it will have time to evolve with over 100 times the mass of the Sun, but all of them lose a large fraction of their mass by the time they come to an end.What is the largest possible mass for a star?The limit is 2.5 times our own sun. If a star goes over this limit scientist say that it will become two. this also is known as the binary-system of stars. scientist also have not found a star to be more than 2.5 times bigger than ours(our star has around 4.3 spetillion tons of mass)What is the largest possible mass for a star?
~150 solar masses