Secrets and techniques behind sunquakes might lurk beneath the floor of the solar – watts with that?
From NASA
January 4, 2021
A secret behind the effects of sunquakes – seismic activity on the sun during solar flares – might be hidden beneath the sun’s surface.
These earthquake-like events release acoustic energy in the form of waves that, in the minutes after a solar flare, ripple along the sun’s surface like waves on a lake – an outburst of light, energy and material in the sun’s outer atmosphere.
Film of a sunquake – the earthquake-like waves that pull through our star. The left frame shows the active area in visible light (amber) and extreme ultraviolet (red) on July 30, 2011. The right frame shows the ripples on the outer surface of the sun up to 42 minutes after the torch is inserted, which is caused by the label marked “IP” for impulsive flare.Credits: NASA / SDO
Scientists have long suspected that sunquakes are caused by magnetic forces or heating of the outer atmosphere in which the torch occurs. It was believed that these waves descended through the surface of the sun and deep inside. However, new results using data from NASA’s Solar Dynamics Observatory have found otherwise.
In July 2011, SDO observed a sunquake with unusually sharp waves that are based on a moderately strong solar flare. Scientists were able to trace the waves that created these waves back to their source using a technique known as helioseismic holography. This technique, which used SDO’s Helioseismic and Magnetic Imager to measure how the sun’s surface was moving, was previously used to track sound waves from a variety of other sources in the sun.
Instead of the waves traveling into the sun from above, the scientists saw the waves of a sunquake that appeared deep below the sun’s surface immediately after a flare-up. The results, published in the Astrophysical Journal Letters, found the sound source was about 700 miles below the surface of the Sun – not above the surface as previously thought.
Scientists believe that these waves were propelled by a submerged source, which in turn was somehow caused by the solar flare in the atmosphere above. The new findings could help explain a long-standing mystery surrounding sunquakes: Why do some of their properties look remarkably different from the torches they trigger.
Scientists still haven’t figured out exactly what mechanism actually causes sunquakes, although the results suggest that their origin is likely lurking beneath the surface. The scientists plan to continue looking for a mechanism by studying other sunquakes to see if they have similarly submerged sources.
connected::
Solar flares make the sun shake
Learn more about SDO
By Mara Johnson-Groh
NASA’s Goddard Space Flight Center, Greenbelt, Md. Last updated: January 4, 2021 Publisher: Lina Tran
4.5
2
be right
Item rating
Like this:
Loading…
Comments are closed.