Spacecraft Witness 'Puffing' Sun Causing a Reluctant Eruption
Astronomers have spotted an unusual series of eruptions form the sun, thanks to a suite of spacecraft. They've witnessed a fast succession of "puffs" forcing the slow ejection of a massive burst of plasma from the sun's corona taking place over a period of three days.
The outermost layer of the sun is called the corona. This magnetized plasma has a temperature of millions of degrees and extends millions of miles into space. In this case, the spacecraft spotted puffs emanating from the base of the corona and rapidly exploding outward into interplanetary space. The puffs themselves occurred about once every three hours and after about 12 hours, a much larger eruption of material began.
"Looking at the corona in the Extreme UltraViolet light we see the source of the puffs is a series of energetic jets and related flares," said Nathalia Alzate, one of the researchers, in a news release. "The jets are localized, catastrophic releases of energy that spew material out from the sun into space. These rapid changes in the magnetic field cause flares, which release a huge amount of energy in a very short time in the form of super-heated plasma, high-energy radiation and radio bursts. The big, slow structure is reluctant to erupt, and does not begin to smoothly propagate outwards until several jets have occurred."
The researchers didn't just get to view the event from one angle, though. Because multiple spacecraft witnessed the "puffing" and subsequent eruption, the scientists managed to create a 3D configuration of the eruptions. This allowed them to estimate the forces acting on the slow eruption and even discuss the possible mechanisms for the interaction between the slow and fast phenomena.
Currently, the scientists plan to further investigate this event in order to find out whether there are shock waves, formed by the jets, passing through and driving the slow eruption, or whether magnetic reconfiguration is driving the jets, allowing the structure to slowly erupt. The findings could tell scientists a bit more about the sun and the forces that drive it.
The findings were presented at the National Astronomy Meeting 2014.