On this day in physics: 31 January 1982 A white dwarf companion to Sirius is discovered by Alvan Graham Clark using an 18.5-inch telescope. [Source] Sirius is the brightest star in the night sky. It is now known as Sirius A, because of this discovery, which saw that a second White Dwarf star, Sirius B, existed and orbits Sirius A.
Word of the Day: White Dwarf- a type of star-leftover which is considered to be the final stage of stars which are not massive enough to become Neutron Stars. These dwarfs were once small to medium mass stars, then entered the red giant phase, which have very large radiuses with relatively low temperature (5000 K or less). Red giants are essentially giant fusion reactors, which fuse helium into carbon, releasing massive amounts of energy. When they run out of energy, what you're left with is a white dwarf. It's the core of the reactor which doesn't have enough energy to react anymore. Imagine the nuclear waste in a nuclear reactor once it's been used up. They are extremely dense, imagine something the size of the sun compressed down to the size of the Earth.
White dwarfs, in this stage, radiate out tons of energy, in the form of white light, and as they have no source of energy, they simply lose energy, dim and fade away. The white will get slightly redder as it ages. They should reach a point of cooling where they will no longer radiate light, and will become the theorized "black dwarf". There are no known black dwarfs to exist. The amount of time that it takes a white dwarf to cool to the black dwarf stage is longer than the current age of the universe. We may see some in the future, but the coolest and oldest White Dwarfs known to exist are still a few thousand Kelvins.
Killer Resource: Drums and Cymbals in Slow Motion. World Record holding drummer, and current Dream Theater drummer Mike Mangini was filmed with high speed cameras to see how drums behave in slow motion.
Keywords: White Dwarf, Star, Black Dwarf, Steller, Universe, Fusion, Reactor
