Sunspot Fires Spectacular Parting Shot : Big Pic

July 20, 2010 -- This spectacular high definition image of the sun was captured by NASA's Solar Dynamics Observatory (SDO) just as sunspot 1087 was rotating out of view. Although it will soon disappear behind the sun, this sunspot region isn't going quietly.

SLIDE SHOW: Seeing the Sun in a New Light : First SDO Photographs

WATCH VIDEO: The SDO's "Coronal rain" explained.

Seen on the limb of the solar disk (to the right of the image), magnetic field lines filled with ionized solar gas (plasma) are very prominent. The field lines originate deep within the sun's body and are forced through the solar surface (or "photosphere") reaching high into the sun's atmosphere, creating the sunspot.

Some of the field lines are "closed," loops of magnetic flux attached to the sun, funneling the highly radiating plasma into space and sending it crashing back down. Other field lines are "open," most likely blasting plasma into space. These open field lines are known to be the source of the solar wind. The magnetic pressures are very high above sunspots, the scene of powerful solar flares and coronal mass ejections (CMEs) that have the potential to wreak havoc if aimed at the Earth.

In addition, another very active region is erupting in the lower left of the image. This complex group of sunspots (designated sunspot 1089) rotated into view on July 19, another potential region for flare and CME activity over the coming days.

Below is another view of the same image, but in a different wavelength. The top image highlights the million-degree corona, whereas the image below highlights plasma at lower temperatures in the chromosphere (the base of the sun's atmosphere), typically of around 60,000 Kelvin (or 100,000 degrees Fahrenheit).

--Ian O'Neill, Discovery News

Source and full-resolution photographs: SDO mission website.

Images courtesy of SDO (NASA) and the AIA consortium.