Star Facts
Twinkle Twinkle Little Stars....
Stars seem to twinkle because we see them through the layers of the Earth's Atmosphere. As light passes through these layers, it is distorted so that the amount we actually see change constantly. The Stars nearest to the horizon appear to twinkle the most because the light is passing through a greater depth of atmosphere. Starts do not twinkle when viewed from space, which is why telescopes in space, such as the Hubble, give the best possible view of distant stars and galaxies.
Brightest:
Not counting the Sun, the brightest star as seen from Earth is Sirius, known as the Dog Star, in the constellation of Canis Major. It has a diameter of 149,598,020km and is more than 24 times brighter than the Sun. The star Cyrus OB2 No 12, discovered in 1992, is so far away that it cannot be seen from Earth. It may be brightest star in the galaxy – up to six million times as bright as our Sun.
Heaviest:
HDE 269810 is a star on the Large Magellanic Cloud – 170,000 light years from Earth ( a light year is the distance light travels in a year). It has been discovered by the Hopkins Ultraviolet Telescope to be 190 times as heavy as our Sun.
Largest:
The Largest star is the M – class supergiant Betelgeuse, or Alpha Orionis. It is the top left star in the Constellation of Orion, which is 310 light years away. It has a diameter of 700 million km, which is about 500 times greater than that of the Sun.
Nearest:
Proxima Centuari, discovered in 1915, is 4.22 light years (39,953,879,212 km) from Earth. A Spaceship moving at 40,000 km/h – which is faster than any human has yet traveled in space – would take more than 114,000 years to reach it.
Supernovae:
These are vast explosions in which a whole star is blown up. They are extremely bright, rivaling for a few days the combined light output of all the stars in the galaxy. Supernovae are rare – the last one in our galaxy was seen in 1604 by the German Astronomer Johannes Kepler.
Quasars:
Quasars are Extremely distant radio galaxies – galaxies giving out large amounts of radio energy – most distant edge of the observable Universe are easily detected by small radio telescopes. Their radio emission is typically 1,000,000 to 100,000,000 times greater than that of a normal galaxy, and they are as bright as or brighter than the brightest radio galaxies.
Black holes:
A black hole is a star that has collapsed into itself. It has a surface gravity so powerful that nothing can escape from within it.