For all their enormous size and furious energies, stars are remarkably simple. Knowing just their mass and the smattering of elements heavier than hydrogen we can predict their lives from cradles to grave. But every now and then, nature throws us something truly bizarre as as reminder that we ain’t seen everything yet.
As reported in Science, just such an oddity has been found in a search of over 30,000 white dwarfs, the end state of stars similar to our sun. This white dwarf appears to be made almost entirely of oxygen. And how it formed is truly a puzzle.
Life Cycle
A star is a fusion bomb, burning light elements like hydrogen and helium through nuclear fusion to form heavier elements like carbon and oxygen. The bigger the star, the brighter it burns and the faster it uses up this fuel.
Stars no more than ten times the mass of our Sun will tend to throw out their nuclear “ash” of heavy elements into space, forming planetary nebulaes, which will eventually condense to form new stars, rocky planets and ultimately maybe even give rise to life like us that breathes the oxygen and eats this carbon. As Carl Sagan noted, we’re made of star-stuff.
What’s left behind in a dying star is a glowing cinder with the mass of our sun crushed to the size of the Earth. This incredible density means that a teaspoon worth of this object would be about the mass of a truck. We call this a white dwarf and it is the fate of our own sun in 5 billion years’ time.
