TWO ZOMBIE STARS ARE EATING THEIR COMPANIONS

White Dwarf stars aren’t like those happy little munchkins shacked up in the forest with a princess. Sometimes, they’re zombie cannibals, greedily munching away on their nearest neighbors. You don’t want to be around when they belch.

Feeding the zombie dwarf

The star which planet Earth swings around, Sol, is destined to become a white dwarf someday but probably won’t turn cannibal. The ones that do are really interesting to people who follow astronomy, though.

It’s hard to imagine those tiny points of light in the sky can be as fascinating as they are. Humans like to think of stars, planets and galaxies as cosmic tinker toys, whirling around the universe doing strange things, which look awesomely beautiful in photographs.

When our sun runs out of fuel and reaches it’s retirement years, it will first swell up into a red giant, leaving Earth at a distance from the edge like Mercury is now and both Venus and Mercury will be absorbed. From there, it’s expected to collapse back down to a normal, run-of-the-mill variety white dwarf.

Earth and Mars may have a role to play in the drama but the gas giants should be far enough away for safety from a new and improved solar gravity field. Other stars do have close gas giants, even companion stars. Those are the rogue zombie cannibals. Astronomers like to look at two of them for comparison.

The dead core of a white dwarf is still cosmically active. Imagine packing a ball half the size of the sun into a space the size of the earth. A teaspoon of the stuff would weigh about a thousand tons. It’s also hot. Real hot. When one of those cores happens to have an unlucky close companion, especially one made of gas and plasma instead of rock and iron, things get fascinating. Take LAMOST J024048.51+195226.9 for instance.

They like to call it J024048 for short. It blinks like a pinball machine so they call it a “cataclysmic variable.” That’s an astronomer’s first clue that a dwarf star is “drawing off material from a companion.”

Not always stable

The flow of material falling into the gravity well “isn’t always stable, and can slam down onto the white dwarf at extremely high speed, creating tremendous flares of energy.” Like a sealed soda bottle that’s been shaken up with a pin stuck through the side, it can fling hydrogen off with such velocity it rotates the whole star like a child’s pinwheel. The experts clocked the orbit of the companion star at 7.33 hours, which means it’s seriously up close and personal.

According to SyFy, “the system also shows signs of flinging away hydrogen at extremely high speeds, up to 3,000 kilometers per second: that’s ten million kilometers per hour!”

In order for the zombie dwarf to fling hydrogen out like death rays, it has to have one heck of a magnetic field. It gets that by spinning like a gyroscope. The material falling into J0240 has it rotating a “staggering” once every 24.93 seconds.

Twice a minute doesn’t sound like much until you consider the size of the object. That ant from high school math quizzes walking around the equator would be moving “nearly 5 million km/hr.” That’s why the astronomers like to call them “propeller stars.”

Then, there’s white dwarf KPD 0005+5106. It’s right in our neck of the galactic woods, a mere 1,300 light years from Earth. This one’s interesting because “observations from the Chandra X-ray Observatory show it’s shining brightly in X-rays, which means its magnetic field is doing some high-energy shenanigans as well.”

It’s hotter and brighter than J0240. There is also a good chance it’s companion was once a gas giant companion planet. Either that or its a brown or red dwarf. Planet seems real likely though. If Jupiter were sitting where we are now, there’s a good chance it would get old Sol spinning up a deadly X-ray beam generator, too.