Scientists have found a bizarre star 1,200 light-years from Earth that appears to be shooting giant balls of plasma twice the size of Mars into space. Yes, you read that right.
The discovery was made by scientists using NASA’s Hubble Space Telescope and published in The Astrophysical Journal, led by Raghvendra Sahai of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.
The star in question is V Hydrae, a bloated red giant. Observing the star from 2002 to 2004, and 2011 to 2013, the scientists used spectroscopy to find there were super-hot blobs – described as "cannonballs" by NASA – more than 9,400°C (17,000°F) being fired into space from the star. That’s twice the temperature of the surface of the Sun.
But the red giant itself could not be the source of the blobs. Red giants are dying stars in their latter stages with limited nuclear fuel, having expanded massively in size and shedding their outer layers into space.
Thus, the researchers suggest there is another smaller star orbiting this one, in a highly elliptical orbit. This star swings through the outer layers of the red giant, where it picks up material and forms a disk. As this material builds up, it reaches a tipping point and is eventually fired out into space. And it has been doing this for the last 400 years or so.
Shown is the step by step process of how the blobs are created. NASA/ESA/STScI
The process repeats every 8.5 years, the time it takes the smaller star to orbit the red giant. So intense is the process that the blobs are traveling at about half a million miles per hour, meaning they would cover the distance from Earth to the Moon in just 30 minutes. The furthest blobs that can be seen from the star are 60 billion kilometers (37 billion miles) away from V Hydrae.
"We knew this object had a high-speed outflow from previous data, but this is the first time we are seeing this process in action," said Sahai in a statement.
Perhaps most interestingly of all, this process could explain a mysterious cosmic phenomenon called planetary nebulae. When stars die, they can be surrounded by these vast and colorful nebulae in just 200 to 1,000 years, which is a tiny amount of time on a cosmic scale.
(It should be noted the name planetary nebulae is a misnomer. They have nothing to do with planets, but were merely mislabeled when they were first discovered in the 1780s. The name has stuck since, though.)
"We suggest that these gaseous blobs produced during this late phase of a star's life help make the structures seen in planetary nebulae," said Sahai.
The astronomers are now planning to use the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to study blobs from the past few hundred years that are too cool to be seen by Hubble, said NASA.
Above, a famous planetary nebula called the Cat's Eye Nebula. NASA/CXC/SAO/STScI