Archive for sun magnetic field

Sun: Return of The Big Coronal Hole

Posted in 2016, astronomy, Galaxy with tags , , , , , , , , on November 21, 2016 by MARIE EMMANUELLE QUILICHINI


At the end of October, a hole in the sun’s atmosphere lashed Earth’s magnetic field with solar wind, sparking moderately-strong geomagnetic storms and almost a full week of Arctic auroras.

News flash:  It’s back.  The same “coronal hole” is turning toward Earth again. NASA’s Solar Dynamics Observatory photographed the structure on Nov. 20th.

Coronal holes are regions in the sun’s atmosphere where the magnetic field peels back and allows solar wind to escape.

Since our last encounter with this hole in late October it has been transiting the farside of the sun, carried around by the sun’s 27-day rotation.  Now that it is back we can see that the hole is not quite as large as it was a month ago–but it is still impressive, covering more than 1/4th of the visible solar disk.

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NASA’s Solar Dynamics Observatory (SDO) is monitoring a hole in the sun’s atmosphere–a “coronal hole.”

Posted in 2015, astronomy, Galaxy with tags , , , , , on August 26, 2015 by MARIE EMMANUELLE QUILICHINI


It is colored deep-blue in this extreme UV image of the sun taken by SDO on Aug. 26th


Coronal holes are places where the sun’s magnetic field opens up and allows solar wind to escape. In the image, above, the sun’s magnetic field is traced by pale loops. White arrows show the flow of material out of the hole.

A stream of solar wind flowing from this coronal hole will probably reach Earth on Aug. 28-29. Its impact could spark a geomagnetic storm at the end of this week. If so, bright moonlight will temper the visibility of any auroras. Aurora alerts: text or voice

This visualization shows the position of the sun’s magnetic fields from January 1997 to December 2013

Posted in 2014 with tags , , on January 2, 2014 by MARIE EMMANUELLE QUILICHINI

This visualization shows the position of the sun’s magnetic fields from January 1997 to December 2013. The field lines swarm with activity: The magenta lines show where the sun’s overall field is negative and the green lines show where it is positive. A region with more electrons is negative, the region with less is labeled positive. Additional gray lines represent areas of local magnetic variation.

The entire sun’s magnetic polarity, flips approximately every 11 years — though sometimes it takes quite a bit longer — and defines what’s known as the solar cycle. The visualization shows how in 1997, the sun shows the positive polarity on the top, and the negative polarity on the bottom. Over the next 12 years, each set of lines is seen to creep toward the opposite pole eventually showing a complete flip. By the end of the movie, each set of lines are working their way back to show a positive polarity on the top to complete the full 22 year magnetic solar cycle.

At the height of each magnetic flip, the sun goes through periods of more solar activity, during which there are more sunspots, and more eruptive events such as solar flares and coronal mass ejections, or CMEs. The point in time with the most sunspots is called solar maximum.


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