Solar Dynamics Observatory magnetic (top) and visible light (bottom) observations from the spacecraft’s Helioseismic and Magnetic Imager of an emerging active region on the Sun. Credit: Stephane Regnier
NASA’s Solar Dynamics Observatory has been used to monitor the birth of a sunspot over a period of eight hours.
Researchers at the University of Central Lancashire made use of the Solar Dynamics Observatory (SDO) to observe the growth of the sunspot.
How sunspots are born, evolve and die is still a concern for solar physicists, noted Stephane Regnier of the Jeremiah Horrocks Institute at the UK’s University of Central Lancashire. He presented his research at the Royal Astronomical Society’s National Astronomy Meeting being held this week in Llandudno, Wales.
The emerging sunspot was first detectable in SDO magnetograms, which map the magnetic intensity of the solar disc. Some five hours after the first signs of the eruption, a “pore” had formed that was observable in visible wavelength images, followed by the appearance of sunspots.
The photosphere is the visible surface of the Sun. Convection cells of hot, bright gas rising up to the surface are surrounded by sinking, cool, darker material, giving the photosphere a granular appearance.
These granules are grouped into supergranules, which can be more than 20,000 kilometers across.
“The peculiarity of what we are seeing is that the pore emerges at the edge of a supergranular cell. Models have predicted that we would see this at the cell center where the upflows are more significant,” Regnier explained.
The NASA SDO spacecraft allows scientists to study temperature measurements ranging from 50,000 to 10 million degrees Celsius on an almost second by second basis.
The Solar Dynamics Observatory was launched into space in February 2010.
By Leonard David