Small Sunspot, Big Flare – Things are Hotting Up

Small Sunspot, Big Flare – Things are Hotting Up

Solar Image
Solar Image

One of the brightest solar flares of the current cycle erupted this weekend from a relatively small sunspot group.

This weekend a major solar flare erupted on the northeast limb of the Sun at 1928 UT on February 5. According to data from the NOAA Space Environment Center, it was one of the largest and brightest optical flares of the current solar cycle.

The eruption was bright across the electromagnetic spectrum. It registered the maximum rating of “B” (for brilliant) on the 3-level of optical intensity for solar flares. At X-ray wavelengths the Earth-orbiting GOES 8 satellite also detected a bright surge that put the flare in the most powerful X-class Large flares like this one can emit up to 1032 ergs of energy. This energy is ten million times greater than the energy released from a volcanic explosion. On the other hand, it is less than one-tenth of the total energy emitted by the Sun every second.

The intense radiation from a solar flare travels to Earth in eight minutes. As a result:

  • The Earth’s upper atmosphere becomes more ionized and expands.
  • Long-distance radio signals can be disrupted by the resulting change in the Earth’s ionosphere.
  • A satellite’s orbit around the Earth can be disturbed by the enhanced drag on the satellite from the expanded atmosphere.
  • Satellites’ electronic components can be damaged.
Flare Animation

Solar flares become more common during sunspot maximum. The current sunspot cycle is slated to peak in mid-2000, and remain high for at least a year.