The largest identified star in the known universe is VY Canis Majoris, a hypergiant of the constellation Canis Major, calculated to be more than 1,540 times larger than the sun. YV Canis Majoris is situated 5,000 light y... More »

As of 2015, the largest known planet in the universe is TrES-4, a gas giant that is approximately 1.7 times the diameter of Jupiter, but only approximately 92 percent as massive. Located 1,430 light-years from Earth, TrE... More » Science Astronomy Planets

The exact number of stars in the universe is not known, and the total figure might be unknowable from the Earth's position in space. The universe almost certainly contains no fewer than 10^24, or 1 septillion, stars, and... More » Science Astronomy Stellar Astronomy

The brightest star visible from Earth is Sirius, located in the Canis Major constellation. There are many very bright stars in the night sky that are visible from Earth, and as the moon makes its orbit it does pass near ... More »

Stars vary in size from less than 8 percent of the size of the sun to those with diameters of more than 1,800 times that of the sun. In terms of mass, stars must have enough mass to support the nuclear chain reaction tha... More »

Sirius, commonly referred to as the "dog star" is said to be twice as massive as the sun, with a diameter of 1.5 million miles. Its comparatively tiny companion star, called Sirius B, is only 98 percent of the sun's mass... More »

The Big Dipper is an asterism, or pattern of stars, in the constellation Ursa Major. People can see asterisms relatively easily because the stars are close to each other and have similar levels of brightness. More » Science Astronomy Stellar Astronomy