Astro Bob: Big sunspot spins into view

A magnetic blotch nearly eight times the size of the planet now faces the Earth.

Sunspot group grows
This big, beautiful sunspot group, called active region 2936, has grown rapidly in the past few days. Recent solar flares from the region could spark auroras in the coming nights. Keep your eyes peeled.
Contributed / NASA, SDO
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Proof that the current sunspot cycle is percolating right along comes with the appearance a large, new sunspot group that's quadrupled in size over the past few days. Active region 2936 is now about 62,000 miles (100,000 km) across or nearly eight times the size of Earth. Both yesterday (Jan. 29) and today I was able to see it through a safe solar filter without any optical aid.

Rapid-growing sunspot group
Here's a full-disk picture of the sun taken through my little 80-mm refracting telescope on Saturday, Jan. 29. The big group is located in the sun's northern hemisphere and one of the largest groups of the current solar cycle.
Contributed / Bob King

Looking closely, I discerned the group's elongated shape and could just made out the two dark cores. Without magnification they appeared fused together like two stars too close to separate. Through a small, filtered telescope the view was glorious, with the sunspot group showing wonderful detail. The two larger spots displayed prominent dark cores called umbrae draped in pale penumbral fringes. Smaller spots dotted the area like sheep on a hillside.

Sun on Sunday, Jan. 30
In this photo, taken Sunday, Jan. 30, active region 2936 has rotated to the right a bit and has changed some in appearance. At lower left, a new sunspot is just rotating into view.
Contributed / Bob King

In fewer than 24 hours it was easily to see changes in the appearance of the group as well as the arrival of a largish, new sunspot along the sun's eastern limb. I always have to remind myself that the sun is a real star just like the ones we look up to at night. What a privilege it is to be able see one up close and feel its heat as well. Speaking of privilege, check out Tim O'Connor's video below. What luck!

If you don't have a pair of safe solar eclipse glasses on hand and you want to see the this monster sight, check with a welding supply store for a #14 welder's glass. That's my go-to. The #14 is safe to use and inexpensive. For telescope-viewing, here's one source for high-quality filters. They also sell something called Baader Solar Safety Film that you can cut and mount in cardboard to fit over your telescope. Remember that all solar filters must cover the front lens or tube end of a telescope or binoculars.

Region 2936 has been steadily producing solar flares, in particular a moderately strong M-class event that happened on Saturday night, Jan. 29 (CST). That blast is heading our way and expected to arrive around Feb. 1-2. It's too early to tell if it will be an aurora-maker or not, but there's always a chance. If so, the moon won't interfere, making its timing perfect.


Sunspots are regions on the sun's surface, called the photosphere, where magnetic fields are some 1,000 times stronger than the average solar magnetic field. They appear dark because they're cooler than their surroundings. Where does all this magnetic energy come to create these massive spots?

Sun sunspot 2936 panel.jpg
This is a close up of sunspot group 2936. Magnetic fields are concentrated in sunspots, with groups often showing poles just like a household magnet. The black-and-white image is called a magnetogram, taken by an instrument that can detect the strength and location of solar magnetic fields. In it, I've marked the group's positive magnetic pole with a "+" and the negative pole with a "-."
Contributed / NASA, SDO

The sun is mostly made of hydrogen, but the tremendous heat the star generates splits the atoms apart into protons and electrons. Each of these carries a charge — positive for protons and negative for electrons. All of this material is in motion, bubbling up from below, cooling and then sinking back into the photosphere.

Any charged particle in motion generates a magnetic field. The sun's rotation concentrates and intensifies those fields to produce sunspots. And inside those sunspots, under the right conditions, some of that magnetic energy is released explosively as solar flares. The particles rush outward across the solar system. If the Earth's in their path, there's always a chance our planet's magnetic field will connect with the one that's bundled with those speeding solar specks to produce an aurora.

So much happens deep down at the particle level that translates into things we find beautiful. The particles dance inside us, too.

Read more from Astro Bob

"Astro" Bob King is a freelance writer for the Duluth News Tribune.

"Astro" Bob King is a freelance writer and retired photographer for the Duluth News Tribune.
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