/Film on MSN: Why doesn't Star Trek ever leave the Milky Way galaxy?
Throughout the many adventures of Star Trek, it's extremely rare that the Enterprise (or any other ship) leaves the Milky Way galaxy. But why is that?
Its total mass mainly determines its evolution and eventual fate. A star shines for most of its active life due to the thermonuclear fusion of hydrogen into helium in its core. This process releases energy that traverses the star's interior and radiates into outer space.
Star, any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. This article describes the properties and evolution of individual stars.
A star’s gas provides its fuel, and its mass determines how rapidly it runs through its supply, with lower-mass stars burning longer, dimmer, and cooler than very massive stars.
A star that consumes hydrogen to form helium is called a "main-sequence" star for all the time it is a hydrogen-fusing object. When it uses up all its fuel, the core contracts because the outward radiation pressure is no longer enough to balance the gravitational force.
A star’s mass determines its temperature and luminosity, and how it will live and die. The more massive a star is, the hotter it burns, the faster it uses up its fuel, and the shorter its life is.
It's easy enough to say what a star is: one of those bright pointy things that twinkle in the night sky. But the actual definition of a star is as rich and colorful as the stars themselves.
The brightest star in our night sky is called Sirius and is also the brightest star in the constellation of Canis Major, the Big Dog. It lies 8.3 light-years away from us.