Category Archives: solar studies

solar studies, sun, sunspots

Sinuous Solar Ropes

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An Active Solar Region

Sunspot 1087 as imaged by Britta Suhre, a Germany amateur observer who took this image from her backyard in Germany. Credit: Britta Suhre, via Spaceweather.com

No, this isn’t a picture of an animal fur up close and personal — it’s a fantastically detailed image of an active area on the Sun’s surface.  The image is a highly magnified view of sunspot 1087. You can see a filament winding across the surface of the sunspot region, which is many times wider than our own planet.  Observers are monitoring the solar flares emanating from this area.  Click on the image to enlarge it and you’ll be amazed at the detail.  And, this is just one tiny region of the Sun!

You might wonder how people can get such wonderful images of the sun’s active regions. Of course, they don’t do it by looking directly at the Sun — that’s a recipe for disaster if you plan on using your eyes for anything else during your lifetime.  Of course, there are those folks who think it’s okay to look at the Sun for a few seconds — but even a short glance can do damage to your retina. And, forget about looking through a telescope or binoculars — that’s an even bigger risk to your eyesight. But, if you have a special filter for your telescope, or you have eclipse viewer glasses (which allow you to look safely at the Sun), you can do some solar observations.  People like Britta Suhre use specialized filters and cameras attached to telescopes to capture these views — and really, looking at those images is the very safest way you can enjoy the gorgeousity (technical term) of the active solar regions that the Sun is presenting to us as it ramps up to its maximum active state.  Want to see more solar images, there are plenty of places to do it:

Spaceweather.com frequently posts images of the Sun. Also check out the National Solar Observatory, the STEREO Mission site, the Solar and Heliospheric Observatory Homepage, the Wilcox Solar Observatory, the Institute for Solar Physics in Sweden , the Solar Dynamics Observatory and many others that you can find by simply Googling the term “solar observatory”.  Happy hunting!

P.S.  By the way, there’s a chance for people living at high latitudes to see possible aurorae action from solar activity. Check Spaceweather.com for more details.

solar physics, solar studies, sun

Does the Sun Miss its Spots?

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Minima-lly Invasive Technique for Sounding the Sun

Our pesky Sun has been diabolically withholding its sunspots for the past couple of years, causing solar physicists to wonder what’s going on with this most minimum of sunspot minima.  The Sun goes through an eleven-year cycle of magnetic activity related to the appearance of sunspots, solar flares, and disturbances of the interplanetary environment called space weather.  We’re at a low in solar activity right now, and it’s been just a LITTLE too quite on the Sun.

a computer representation of one of nearly ten million modes of sound wave oscillations of the Sun, showing receding regions in red tones and approaching regions in blue. By measuring the frequencies of many such modes and using theoretical models, solar astronomers can infer much about the internal structure and dynamics of the Sun. Courtesy National Solar Observatory. Click to embignify.
A computer representation of one of nearly ten million modes of sound wave oscillations of the Sun, showing receding regions in red tones and approaching regions in blue. By measuring the frequencies of many such modes and using theoretical models, solar astronomers can infer much about the internal structure and dynamics of the Sun. Courtesy National Solar Observatory. Click to embignify.

All this lack of activity has scientists wondering just what’s going on inside our star that has kept its normally sunny complexion clear. They can’t exactly go out to the Sun and stick some instruments into the solar surface to diagnose the problem. But, they can do the next best thing — study it remotely with the Global Oscillation Network Group facility. GONG and the orbiting SOHO/MDI instrument measure sound waves on the surface of the Sun. Those sound waves are a very good probe of what’s going on inside the Sun — similar to the way a sonogram tells a doctor what’s happening inside your body. GONG and SOHO/MDI are vanguard instruments in the science of helioseismology.

What they are showing scientists is a clear “sonogram” of a jet stream of material that flows from east to west just beneath the Sun’s visible surface.  It’s called a “torsional oscillation” and a new one gets generated near the solar poles every 11 years. Over a period of 17 years,  the stream migrates slowly to the solar equator.  The most telling point abou these streams is that they are associated with the production of sunspots once they reach a critical latitude of 22 degrees.

Two scientists, Rachel Howe and Frank Hill of the National Solar Observatory, have found that the stream associated with the new solar cycle has been moving rather lazily — taking three years to cover a 10 degree range in latitude compared to two years for the last solar cycle. Since the current minimum is now one year longer than usual, Howe and Hill conclude that the extended solar minimum phase may have resulted from the slower migration of the flow.

Now that the stream has finally reached the critical 22 degree latitude, we should be seeing some more solar activity ramping up as time goes by.  It’s not clear why this torsional oscillation slowed down, but the good news is that the Sun’s magnetic dynamo continues to operate, and we’re probably seeing the beginnings of a new solar cycle.