Astronomers therefore use a larger unit to measure stellar distances. This corresponds to a distance of 6 trillion miles. In these terms we would specify the distance to Proxima Centauri as about 4.2 l.y. The stars lie at varying distances away from us. Sirius is for example at a distance of 8.7 l.y., while Procyon is at 11.
Many stars lie vastly much farther away.
Betelguese lies at a distance of 520 l.y. while Rigel is at 900 l.y. The vast distances to the stars tells us something about their nature. The only objects that could be seen at these immense distances would be objects like our sun that pour out vast quantities of light into space. Thus we think that the stars are suns like our own, some larger and brighter, others smaller and dimmer, but all objects similar in character to the sun that we see in our daytime sky. Indeed, at a distance of 4 light years, our sun would appear to be a rather bright star of about zero magnitude.