The “body” of a sunspot exploded Monday (April 11) and triggered a mass ejection of solar material heading in the Earth’s direction.
The explosion comes courtesy of a dead sunspot called AR2987, according to SpaceWeather.com (opens in new tab). The sunspot explosion released lots of energy in the form of radiation, which also led to a coronal mass emission (CME) – explosive spheres of solar material – both of which could spur more intensely northern Light in the earth‘s upper atmosphere. The material in that CME is likely to affect Earth on April 14, according to SpaceWeather.
Sunspots are dark areas on the surface of the sun. They are caused by intense magnetic flux from the inside of the sun, according to Center for forecasting space weather (opens in new tab). These spots are temporary and can last anywhere from hours to months. The idea of a “dead” sunspot is more poetic than scientific, said Philip Judge, a solar physicist at the High Altitude Observatory at the National Center for Atmospheric Research (NCAR), but the sun’s convection breaks these spots apart and leaves in their waking magnetically disturbed chunks of quiet sun surface.
“Occasionally,” Judge Live Science wrote in an email, “sunspots can ‘restart’ and more magnetism occurs later (days, weeks) in the same area, as if a weakness had been made in the convection zone, or as if there is an unstable area below the surface that is particularly good at generating magnetic fields below. ”
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Regardless of the future of AR2987, the sunspot triggered a C-class solar flare at. 5:21 universal time Monday (April 11). Such eruptions occur when the plasma and magnetic fields above the sunspot give way under stress; they accelerate outward, Judge said, because they would run into dense material if they went downward toward the interior of the sun.
C-class flare is quite common and rarely causes any direct impacts on Earth. Sometimes, as with today’s eruptions, solar eruptions can trigger coronal mass emissions, which are huge eruptions of plasma and magnetic fields from the sun that travel into space at millions of miles per hour. C-class solar flares rarely trigger CMEs, according to SpaceWeatherLive (opens in new tab)and when they do, the CMEs are usually slow and weak.
When CMEs hit the magnetic field that surrounds the Earth, the charged particles in the exhaust can move down the magnetic field lines emanating from the North and South Poles and interact with the gases in the atmosphere and release energy in the form of photons and create the changing, dazzling curtains known as the aurora – northern and southern lights.
In quiet times on the surface of the sun, a stream of particles known as the solar wind is enough to trigger the northern lights in the polar regions. During a large CME, the greater disturbance of the planet’s magnetic field means that northern lights can occur over a much wider area. A so-called cannibal CME ran towards Earth at the end of March and triggered the Northern Lights in Canada, the northern United States and New Zealand, It reported Space.com.
CME, released Monday, could provide a minor (G1) geomagnetic storm on April 14, meaning there could be minor impacts on satellite operations and slight fluctuations in the power grid, according to SpaceWeather. The aurora can become visible at lower latitudes than normal, as far south as northern Michigan and Maine.
All of this activity is roughly on par with the course of the sun, according to the Solar Influences Data Analysis Center, part of the Royal Observatory of Belgium. It is a time of increased activity for our nearest star, which goes through periods of quiet and activity known as solar cycles. The sun is currently in solar cycle 25, the 25th since the formal observations began in 1755. The number of sunspots in this cycle is rising and is expected to peak in 2025which means more opportunities for solar storms – and northern lights.
Strong geomagnetic storms were also observed Sunday (April 10). However, according to the Solar Influences Data Analysis Center, no other terrestrial CMEs have been observed in the last 24 hours than the one spit out of the remains of AR2987.
Originally published on Live Science.