The birth of a sunspot cluster

By Phil Plait | April 19, 2011 7:00 am

Ever wanted to see how sunspots form and change as they grow? The folks working with NASA’s SDO satellite just released this amazing video of the adorable younglings.

Not much happens until about 18 seconds in, and then a lot happens.

That is so freaking cool. Taken over the course of two weeks (half a rotation of the Sun), you can see them pop up, darken, and grow, and even rotate a bit as the Sun’s complex magnetic fields change… and the neatest part to me is the foreshortening they undergo as they approach the east side of the Sun’s disk. Amazing!

Sunspots are actually regions of slightly cooler material at the Sun’s surface. Hot plasma (ionized gas, stripped of one electron or more) rises from the solar interior, reaches the surface, cools off, and sinks back down. This is called convection, and is the same process you see in a pot of boiling water. But at the surface, the tortured and twisted magnetic field of the Sun can suppress convection, preventing the cooler material from sinking. Since the brightness of the plasma depends on the temperature, this cooler stuff is darker. Boom! Sunspot.

Or, in this case, sunspots. You can see five of the suckers here, changing and mutating as the plasma interacts with the magnetic field. I recognize these spots, too: they were responsible for the first X-class flare of the season on March 15th. There’s dramatic footage of that as well which I posted on my blog at the time. They’re busy spots; they blew out a lower energy flare a few days earlier, too.

And here I am calling them cute and little when they’re actually comfortably bigger than the Earth and exploded with the energy equivalent of millions — millions! — of nuclear bombs.

Good thing they’re 150 million kilometers away. That lessens the impact, but doesn’t negate it. The more we learn about the way sunspots behave, the better. SDO, STEREO, and the rest of our sunward-looking fleet are teaching us a lot about our nearest star. And we’ll need that information as we enter the beginning of yet another solar cycle.

Video credit: NASA/SDO

Related posts:

Sunspot 1158 ain’t done yet
kaBLAM! Footage of the X class solar flare
Seriously jaw-dropping picture of the Sun
A computer’s spot in the Sun (must-see gorgeous model of a sunspot)

MORE ABOUT: SDO, solar flare, Sun, sunspots

Comments (19)

  1. That’s exactly what happened on my face every day when I was a teenager …

  2. Jeff

    yes it is cool.

    I’ve showed classes for 30 years a very simple little experiment to show sunspots, and I’ve probably lived through 3 sunspot cycles as a prof. Just use a small telescope or binocs and then PROJECT the solar disk onto a piece of paper, and the sunspots are so very obvious. Measure the diameter of the solar disk image and the size of sunspots on the paper. To get the true size of sunspots, just multiple the ratio of above numbers times real solar diameter 1,500,000 km. I typical get 2 mm for sunspot image and 200 mm for solar disk image and ratio of 2/200 = 0.01 and times 1,500,000 km gives 15,000 km and what is neat is I point out this is bigger than earth’s diameter 12,000 km.

  3. Jeff,

    That is a very cool observational experiment! I think I will do that with my daughter and kids in the neighborhood!

  4. Jeff

    #3: I just did it an hour ago with a class of 17-20 year olds and they comprehended it very well. They really enjoyed it and it was a successful experiment. Right now there is an excellent sunspot group visible.

  5. Well that’s one thing I have never seen… and it looked pretty amazing. I didn’t know that sunspots were so dynamic over such a short period of time. Do all of these result in CMEs or do some just make loops that can settle back into the sun? Does that correspond to the size of the spot?

  6. Cindy

    Perfect timing. I showed this to my Astronomy class right before doing a lab using SDO data to determine the rotation period of the Sun.

    Unfortunately we have too much low altitude water vapor to see the Sun today and show them sunspots (have a solar filter).

  7. panini

    The most amazingest video I’ve seen in a while!

  8. Steve D

    Two other really cool features. First the bright filaments or faculae. These are more numerous when there are sunspots, enough to offset the reduced light from sunspots, so a sunspot-maximum sun is actually brighter by a tiny amount. Second, as the group rotates out of view the sunken nature of the sunspots becomes readily apparent.

  9. Messier Tidy Upper

    Ever wanted to see how sunspots form and change as they grow?

    Not with my unaided eyes! ūüėģ

    But, yes, great video. 8)

  10. Messier Tidy Upper

    @1. Dave Brooks : That’s exactly what happened on my face every day when I was a teenager …

    Your *face* had tangled magnetric fields larger than the Earth and cooled from 6,000 degrees to to just 3,000 degrees?! ūüėČ

  11. csrster

    I have a PhD in sunspots, but I never realised until I saw this video how important vorticity is in their growth and formation. Look at 23s and again at 37s.

  12. tracey

    this is a great video it makes me think about things i have never thought about before! i don’t know a lot about sun spots but i would like to learn more.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


See More

Collapse bottom bar