New type of explosion spotted on sun’s surface
WASHINGTON — Astronomers spotted a magnetic explosion on the surface of the sun unlike anything they’ve ever seen before. Although it was initially theorized about 15 years ago, this was their first direct observation of it thanks to NASA’s Solar Dynamics Observatory.
Findings about the explosion published this week in the Astrophysical Journal.
They witnessed the result of an eruption on the surface of the sun, flinging up a loop of material in the sun’s corona, or upper atmosphere. This erupted material is known as a prominence. The prominence then fell back toward the sun, but collided with lines of magnetic field. This created the unprecedented magnetic explosion.
Lines of magnetic field snap and realign explosively, based on previous observations of behavior called magnetic reconnection. But this is the first time astronomers have seen this reconnection sparked by an eruption.
Understanding this phenomenon could help scientists understand more about the sun’s atmosphere as well as predict space weather.
This new behavior has been dubbed forced reconnection. It’s triggered by an eruption that causes plasma, or energized gas, to be pushed together with magnetic fields and forces them to reconnect.
Previously, scientists have spotted spontaneous reconnection on the sun and Earth. Spontaneous reconnection only happens in situations where plasma weakly conducts electrical current.
The magnetic field lines on the sun are invisible, but they’re also impacted by the super-heated charged particles of plasma nearby. For this observation, the Solar Dynamics Observatory was able to zero in on plasma reached between 1.8 and 3.6 million degrees Fahrenheit.
For years, scientists have attempted to understand why the sun’s corona is actually millions of degrees hotter than the sun itself. NASA’s Parker Solar Probe is investigating that right now as it closely orbits the sun.