By OBAKENG MAJE
The spectacular aurora also known as the Southern Lights, caused by a solar storm that impacted the earth on 10 and 11 May 2024, was seen and captured across the southern hemisphere, including in places such as Gansbaai and Namibia in Southern Africa.
A team of researchers from the North West University (NWU), captured this rare and historic event through the university’s solar telescope observatory on the Potchefstroom Campus.
This observatory daily records solar activity, and on the NWU’s Open Day on 4 May, two researchers and a student from the Centre for Space Research at the NWU noticed a particularly active region when they did their observations.
The NWU’s Dr Ruhann Steyn and a Master’s Degree student, Calmay Lee, decided to focus the telescopes on where the activity was as part of a demonstration to prospective students and their parents. Steyn said at that stage, they were unaware that they were recording one of the largest active regions in recent history.
“During the next week, the team focused their attention on the active region (AR 3664, shown in the image), while it produced several large solar flares that caused the aurora.
“Calmay recorded a large solar flare produced by AR 3664 in real time at 09:00 on 11 May – an extraordinary event to capture on the NWU solar telescope. Although AR 3664 has now moved out of sight, it is still producing large solar flares,” he said.
Steyn further said while a repeat of the auroras seen in South Africa is not expected, the team will continue observing active regions in the hope of learning more about the sun. He added that, there is yet little understood processes that generate such beautiful phenomena here on earth.
“This is the largest solar storm in more than two decades. During the evening of 10 May 2024, and the early morning of 11 May 2024, the people in many parts of the world were treated to a sight rarely seen outside the polar regions.
“The aurora is a result of a solar flare transporting solar energetic particles from the sun to earth, along the sun’s magnetic field. Some of the particles interact with the Earth’s magnetic field and are then carried to the South and North Pole,” said Steyn.
He said the particles collide with oxygen and nitrogen atoms in the earth’s atmosphere, emitting light with a particular colour, depending on whether it collided with either an oxygen or a nitrogen atom.
Steyn said the majority of aurora sightings in South Africa were red, which means that these collisions were mostly with oxygen atoms at an altitude between 240 and 450km above the surface of the earth.
“On 10 May 2024, AR 3664 spanned over 200 000km across the solar disk. To give an idea of the magnitude of this region, it is the equivalent of more than 15 times the diameter of the earth,” he said.
Meanwhile, the NWU’s Centre for Space Research, Prof Eugene Engelbrecht said the presence of solar flares is not unusual, as solar activity has increased over the past five years, with the sun approaching the peak of its usual 11-year solar cycle. Engelbrecht said what was different this time was the magnitude of this particular flare, along with the sheer size of the active region it came from.
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