The Sun is currently going through a solar minimum, a period in its 11-year cycle when it has less activity and fewer sunspots. But quiet doesn’t mean completely uneventful and our star can still treat us to some pretty impressive "fireworks".
Just last week, a region on the Sun’s surface was home to not one but two consecutive bursts of plasma over the course of 18 hours. In the images collected by NASA’s Solar Dynamics Observatory, we were treated to a beautiful display of bright coils stretching from the Sun’s photosphere into space. These swirling ribbons are produced by the intense magnetic fields created in the interior of the star.
The arches are magnetic field lines, which behave in a similar way to the example illustrated in many schools using a magnet, a piece of paper, and iron filing. But instead of iron filings, you have the hot plasma that makes up the Sun and stretches for thousands of kilometers.
The images and video have a picture of the Earth for scale and to really put things in perspective. The explosion is huge – and yet by the Sun’s standard, it's not that impressive. The bursts are actually on the small side. And that's not a bad thing.
“It’s exciting to see these kind of solar eruptions, even while the Sun is heading toward a minimum of activity,” solar physicist Dr Miho Janvier, from Université Paris-Sud, told IFLScience.
"There is nothing out of the ordinary, but ordinary is actually what we need: Studying eruptions during maximum prevents us from being able to separate the different processes happening at the same time because of the complexity/numbers of erupting regions during this period. During quiet activity periods, eruptions from simpler regions provide us with the possibility of investigating what are the fundamental mechanisms at heart.”
The Solar Dynamics Observatory collected the series of images using its Extreme Ultraviolet Variability Experiment. The images were then stitched together into a video that shows both bursts. There is about a second in the video where the screen goes black due to our planet photobombing the observation. The spacecraft, which is in a geosynchronous orbit, was moving behind Earth at the time.