Large coronal hole near the sun’s north pole

Date:

Share post:

The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun’s north pole on July 18, 2013, at 9:06 a.m. EDT. Coronal holes are dark, low density regions of the sun’s outermost atmosphere, the corona. They contain little solar material, have lower temperatures, and therefore, appear much darker than their surroundings.

Large coronal hole near the sun's north pole
The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun’s north pole on July 18, 2013, at 9:06 a.m. EDT [Credit: ESA & NASA/SOHO]

Coronal holes are a typical feature on the sun, though they appear at different places and with more frequency at different times of the sun’s activity cycle. The activity cycle is currently ramping up toward what is known as solar maximum, currently predicted for late 2013. During this portion of the cycle, the number of coronal holes decreases. During solar max, the magnetic fields on the sun reverse and new coronal holes appear near the poles with the opposite magnetic alignment. The coronal holes then increase in size and number, extending further from the poles as the sun moves toward solar minimum again. At such times, coronal holes have appeared that are even larger than this one.

The holes are important to our understanding of space weather, as they are the source of a high-speed wind of solar particles that streams off the sun some three times faster than the slower wind elsewhere. While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere.

Source: NASA/Goddard Space Flight Center [July 19, 2013]

ADVERTISEMENT

spot_img

Related articles

Fifth century Basilica Church unearthed in South Syria

The foundations of a Church's wall near the southern side of the Roman Temple in the old site...

Examining embryo-like fossils from the Ediacaran Doushantuo formation, South China

The origin and early evolution of animals have been a fascinating topic since Charles Darwin. Definite early animal...

Two 26th Dynasty tombs unearthed near Minya

A Spanish-Egyptian team has uncovered two 26th Dynasty tombs during excavation work at Al-Bahnasa archaeological site in Minya. 26th...

More on Gaul warriors unearthed at 2,300-year-old site

In a muddy field located between a motorway and a meander of the Seine southeast of Paris, French...

Ploughed field find was silver Viking ring

A man who found a dirty piece of metal in a field has discovered he is actually the...

Hubble finds ‘smoking gun’ after gamma-ray burst

NASA's Hubble Space Telescope has provided the strongest evidence yet that short-duration gamma-ray bursts are triggered by the...

Dust pillars of destruction reveal impact of cosmic wind on galaxy evolution

Astronomers have long known that powerful cosmic winds can sometimes blow through galaxies, sweeping out interstellar material and...

Newly unearthed fossils from Libya give clues to our own evolution

Libya hasn't been terribly hospitable for scientific research lately. Since the 2011 toppling of Muammar Gaddafi, fighters tied...