New sunspots on the surface of the sun and the largest solar flares since 2017 could be a sign that our star is awakening from a long slumber, according to NASA.
The NASA Solar Dynamics Observatory (SDO) saw the “ strongest eruption since October 2017, ” on May 29, suggesting it may be entering a new solar cycle.
A solar flare is a burst of radiation from sunspots – relatively cool spots on the sun’s surface – and NASA says there is also an increase in sunspot activity.
The flare is not a danger to Earth because it was not aimed at our planet, but NASA says it is a sign that the star is moving into a more active phase of its 11-year cycle.
The flares were too weak to cross the threshold at which the Space Weather Prediction Center would trigger a warning to scientists on Earth, NASA said.
NASA’s Solar Dynamics Observatory (SDO) saw the “ strongest eruption since October 2017, ” on May 29, suggesting it may be entering a new solar cycle
After several months with very little sunspots and little solar activity, scientists and weather forecasters are watching this new cluster to see if they are growing or disappearing quickly.
According to NASA, “the sunspots may well be the harbingers of the sun’s solar cycle that is increasing and becoming more active.”
Whether it is a temporary change or a move to a new, more active phase will not be known in the coming months, NASA said.
“It takes a minimum of six months of solar observations and sunspot counts after a minimum to know when it occurred,” the space agency wrote on its website.
“Because that minimum is determined by the lowest number of sunspots in a cycle, scientists need to see the numbers rise constantly before they can determine when exactly they were at the bottom.”
It means that the solar minimum is only recognizable afterwards – you cannot say ‘we are currently in the solar minimum’ because it takes up to 12 months to confirm – at which point we would be without the solar minimum.
During the Sun’s 11-year cycle activity, up and down also sunspots increase and decrease – these sunspots are followed by NASA and other agencies.
By tracking the sunspots, they can determine and predict the progress of the solar cycle and the solar activity coming to Earth.
“Currently, scientists are paying a lot of attention to the number of sunspots, as this is key to determining the dates of the solar minimum,” NASA wrote.
We are currently in solar cycle 24, but if we go through a solar minimum, we would enter solar cycle 25.
“This new sunspot activity could be a sign that the sun may be moving towards the new cycle and the minimum has passed,” NASA said.
The natural variability of the sun is one reason why we will not know the exact details for at least six months.
If the number of sunspots rises or falls within a month, it doesn’t mean it won’t change the following month.
Therefore, scientists need long-term data to get a picture of the trends the sun is currently going through to decide if it will enter the next cycle.
Usually this means that the number we use to compare a given month is the average number of sunspots six months back and forward.
“This means we can now confidently characterize what October 2019 looks like compared to the months before (there were definitely fewer sunspots!), But not yet what November looks like compared to that,” NASA said.
Solar astronomers count the number of sunspots to track solar activity. The last major solar flare was in 2017 – when these sunspots were seen on the star’s surface
The flares detected on May 29 were classified as M-class flares – from the new sunspots on the sun’s surface.
Solar flares are rated A, B, C, M, or X, depending on how powerful the radiation they emit when they reach Earth.
An M-class eruption is ‘medium in size’ and if it directly hits Earth it can cause brief radio outages across the polar regions and minor radiation storms.
However, these torches were not directed to Earth and do not pose a hazard.
According to SpaceWeatherLive, this is the first M-class eruption of the sun in 925 days, saying it is “ very likely ” to mark the start of the next solar cycle.
The solar cycle is an average of 11 years – but can last nine to 14 years and starts at a solar minimum – the least active point in a star cycle.
The cycles have been measured since 1755 and this would be the 25th in the chain.
At its peak, during the maximum of the sun, the sun produced more electrons and protons and caused more intense solar flares.
“Interesting times and possibly a historic moment like this is indeed the first M-class event of the new solar cycle,” said SpaceWeatherLive.com.
EXPLANED: HOW THE SUN CHANGES IN THE 11 YEAR SOLAR CYCLE
The sun is a huge sphere of electrically charged hot gas that moves and generates a powerful magnetic field.
This magnetic field goes through a cycle called the solar cycle.
Every 11 years – although it can range from nine to 14 years – the sun’s magnetic field completely reverses, meaning the sun’s north and south poles change places.
The solar cycle affects activity on the sun’s surface, such as sunspots caused by the sun’s magnetic fields.
One way to track the solar cycle is to count the number of sunspots
The start of a solar cycle is a solar minimum, or when the sun has the fewest sunspots.
Over time, solar activity – and the number of sunspots – increases.
The center of the solar cycle is the solar maximum, or when the sun has the most sunspots.
When the cycle ends, it fades back to the minimum of the sun and then starts a new cycle.