Hubble Space Telescope confirms that the red giant V Hydrae is the wrong type of star to shed gigantic "cannonballs" of energetic plasma. But it is actually doing this once in every 8.5 years during the past 400 years. On closer examination it has appeared that the one responsible is its invisible companion.
The giant balls of burning plasma being fired out of a distant star system has been detected by The Hubble space telescope. The giant balls of super-heated gas are twice the size of Mars and appear to be coming from a nearby star in its twilight years. What is puzzling astronomers is that the dying star, a red giant, likely doesn’t have enough material of its own left to produce the regular stellar ‘cannon fire’.
V Hydrae is an unremarkable star or may be the stellar oddity was captured in a star system 1,200 light years away. Hubble’s images show the plasma blobs are speeding away from their mystery source at great speeds, equivalent to making the journey from Earth to the moon in just half an hour.
The team says that these plasma balls were most likely due to a superdense companion star, like a white dwarf or neutron star. Too small to be seen, the star circles V Hydrae in a highly elliptical orbit with a period of 8.5 years. As it comes to the closest point in its orbit, it plunges into the vacuous outer atmosphere of V Hydrae and starts to rapidly absorb gases.
Instead, Nasa scientists believe the plasma originates from a nearby companion star, hidden from view. As the star orbits in an elliptical path, it edges close to the red giant once every 8.5 years. Once it strays close enough, material is sucked away and settles into a disc around the companion star.
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 Raghvendra Sahai of NASA's Jet Propulsion Laboratory in California, who led the study.
‘We suggest that these gaseous blobs produced during this late phase of a star's life help make the structures seen in planetary nebulae.'By combining the data from multiple telescopes over a number of years, they are building up a picture of knotty clumps of plasma which expand, cool and spread out, showing the evolutionary process of a star from a red giant to a into a whispy planetary nebulae.
‘The observations show the blobs moving over time,’ added Sahai. ‘The [data] show blobs that have just been ejected, blobs that have moved a little farther away, and blobs that are even farther away.’