A white dwarf surrounded by a cocoon of gas
Click on image for full size
NASA, STScI
White Dwarfs
White Dwarfs are the remnants of stars that were massive enough to stay alive using nuclear fusion in their cores, but not massive enough to blow apart in a Type II supernova. When stars like our own sun die they will become white dwarfs. As a star like our sun is running out of fuel in its core it begins to
bloat into a red giant. When this happens to our sun (don't worry it won't happen for another 5 Billion years) the inner planets, Mercury, Venus, Earth, and Mars will all be consumed by the sun's expanding surface. Then after a few million years the outer layers of the red giant will begin to puff off and form a planetary nebula. Leaving behind only the dead core of the star made of mostly carbon and oxygen. This is the white dwarf.
A typical white dwarf is about the size of the Earth. It is also very dense and hot. The star keeps itself from collapsing under gravity by quantum mechanical electron pressures rather than the thermodynamic pressures that keep most stars from collapse. A spoonful of white dwarf material on Earth would weigh as much as a car. Strange, isn't it?
You might also be interested in:
Neutron Stars are the end point of a massive star's life. When a really massive star runs out of nuclear fuel in its core the core begins to collapse under gravity. When the core collapses the entire star
...more
In the 1960's, the United States launched a series of satellites to look for very high energy photons, called Gamma Rays, that are produced whenever a nuclear bomb explodes. These satellites soon detected
...more
The introduction of telescopes to the study of astronomy opened up the universe, but it took some time for astronomers to realize how vast the universe could be. Telescopes revealed that our night sky
...more
Spiral galaxies may remind you of pinwheels turning slowly as though in some intergalactic breeze. They are rotating disks of gas, dust and stars. Through a telescope or binoculars, the bright nucleus
...more
White Dwarfs are the remnants of stars that were massive enough to stay alive using nuclear fusion in their cores, but not massive enough to blow apart in a Type II supernova. When stars like our own sun
...more
What's in a Name: Arabic for "head of the demon" Claim to Fame: Represents Medusa's eye in Perseus. A special variable star that "winks" every 3 days. Type of Star: Blue-white Main Sequence Star, and
...more
What's in a Name: Nicknamed the "Pup" because it is the companion to Sirius, "the Dog Star" Claim to Fame: Highly compressed white dwarf remnant. Density about 50,000 times that of water. It has approximately
...more
