Posted on by Nancy Atkinson

Activity on the Sun Ramps Up with Monster Prominences; Huge Filament Snaps

A large protuberance on the Sun, from Nov. 13, 2011. Credit: César Cantú, Chilidog Observatory.

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A huge wall of plasma rose from the Sun’s southeast limb over the weekend, with what might be one of the biggest prominences seen in many years. César Cantu from Monterrey, Mexico, took the image above, adding an “Earth” for reference of how big this prominence really is. A solar prominence is a large, bright feature extending outward from the Sun’s surface. Prominences are anchored to the Sun’s surface in the photosphere, and can loop hundreds of thousands of kilometers into space.

Leonard Mercer from Malta sent us the image below, saying “I never encountered such a huge prominence since I started imaging the Sun.”

A mosaic of 4 images taken of the Sun on Nov. 13, 2011. Credit: Leonard Mercer.

As large as this prominence is, there was also another even larger feature on the Sun. A filament (which is a prominence that is viewed against the solar disk) on the upper left snakes across the Sun’s surface, stretching more than a million km or about three times the distance between Earth and the Moon.

The video below from the Solar Dynamics Observatory shows the filament intact at first, and then later, from 13:00 to 16:00 UT on November 14, 2011, the filament shoots up from the Sun’s surface and snaps apart.

The SDO team explains that the red-glowing looped material is plasma, a hot gas comprised of electrically charged hydrogen and helium. The prominence plasma flows along a tangled and twisted structure of magnetic fields generated by the Sun’s internal dynamo. An erupting prominence occurs when such a structure becomes unstable and bursts outward, releasing the plasma.

Despite all this activity, there hasn’t been much as far as solar flares, but Spaceweather.com encourages anyone with solar telescopes to monitor developments.

Posted on by Nancy Atkinson

Portraits of Our Sun on 11/11/11 at 11:11 UTC

The Sun captured by NASA's Solar Dynamics Observatory Spacecraft.
The Sun captured by NASA's Solar Dynamics Observatory Spacecraft.

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The Solar Dynamics Observatory takes images of the Sun about every 10 seconds, so it easily was able to capture the Sun when the clocks and calendars lined up for a mathematically synchronous readout. Below is another image at the same time in different wavelength.

You can check out what the Sun looks like at anytime of the day or year the the SDO website.

The Sun at 11:11 UTC on 11/11/11 in a different wavelength. Credit: NASA

Posted on by Nancy Atkinson

Astronomy Cast Ep. 238: Solar Activity

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The Solar Cycle

The Sun looks like a harmless burning ball of fire in the sky: warm, life-giving and forever unchanging. But we know better, don’t we. It’s really a massive ball of churning hydrogen plasma, encased in twisting magnetic field lines, speckled with sunspots, and constantly disgorging vast plumes of radiation and charged particles. The Sun is very active indeed.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Solar Activity” shownotes on the Astronomy Cast website.

Posted on by Nancy Atkinson

Giant Sunspot Turns to Face the Earth

The full face of the Sun as seen on Nov. 6, 2011, showing AR 1339 and several other sunspots. Credit: Alan Friedman. Click for a stunning larger version.

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What has been billed as the largest sunspot observed in several years has now rotated around to stare straight at Earth. How large is it? Active Region 1339 and the group of sunspots adjacent to it extends more than 100,000 km from end to end and each of the several dark cores is larger than Earth. The now very active Sun has already blasted out several medium- to large-sized solar flares and has the potential to hurl out more.

And the Sun is now dotted with several smaller sunspots as well. Above is an amazing image of all this activity, as captured by astrophotographer Alan Friedman. “This has been a glorious week for solar observers!” Friedman said. “Led by large sunspot region AR1339, the sun’s disk is alive with activity… the most dynamic show in many years.”

Take a look below for an incredible closeup of AR1339 taken by Friedman, as well as a movie from the Solar Dynamics Observatory showing the sunspots rotating into view.

Click on the image for a larger version on Friedman’s website, AvertedImagination.com

From all this activity, there may be a good chance for viewing aurorae. On November 9 at around 1330 UT, a magnetic filament in the vicinity of sunspot complex 1342-1343 erupted, producing a M1-class solar flare and hurling a CME into space, which will probably deliver a glancing blow to Earth’s magnetic field on Nov 11 or 12, according to SpaceWeather.com

A portrait of Active Region 1339 in the wavelength of hydrogen alpha light showing the large sunspot group and the maelstrom of chromosphere that surrounds it. Credit Alan Friedman

And here’s an image from astrophotographer Raymond Gilchrist showing a labeled version of all the current sunspots: 1338, 1339, 1340, 1341, 1342, 1343, 1344.

The 'spotty' Sun on Nov. 10, 2011. Credit: Raymond Gilchrist. Click for version on Flickr.

Raymond used a Baader Solar Continuum Filter and Thousand Oaks Full Solar Filter with a Skywatcher 120mm S/T Refractor,
with a Canon 350D, 1/15th Sec Exp. at ISO400. You can see more of his images at his Flickr page.

Posted on by Nancy Atkinson

Largest Sunspot in Years Now on the Sun

The Sun as of 20:00 UT on Nov. 3, 2011. AR 1339 is on the northwest limb. Credit SDO/GSFC

One of the largest sunspots in years is now visible, rotating around into view on the Sun’s limb on November 3, 2011. And it’s a feisty one, too. The Solar Dynamics Observatory team called Active Region 1339 a “Bad Boy,” as at 20:27 UTC, a solar flare peaked at X1.9. X-class flares are massive, and can be major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. This region is not facing Earth — yet. But we’ll be keeping on eye on it as it turns toward an Earth-facing direction.

See a full-Sun image from SDO below.

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This sunspot is huge, measuring some 40,000 km wide and at over 80,000 in length. Spaceweather.com said two or three of the sunspot’s dark cores are wider than Earth itself.

Posted on by Nancy Atkinson

Spooky, Giant Prominence Haunts the Sun

This prominence from the Sun is approximately 158,000 km high. Credit: Monty Leventhal, OAM

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Just in time for Halloween, the Sun has been putting on some spectacular shows recently, including this ghostly-looking prominence captured by amateur astronomer Monty Leventhal from Australia. He estimates this giant pillar shot up over 158,000 km (98,000 miles) from the Sun’s surface! Monty took the image on October 26, 2011 using a Meade SC 10 inch telescope, with a Hydrogen Alpha filter and a Canon 300D camera.


Monty Leventhal is a noted amateur astronomer in Australia and his work has been recognized with several awards including a medal in the General Division of the Order of Australia, “For service to science through volunteer roles at the Sydney Observatory,” and also the Steavensen Award from the British Astronomical Association for his careful and conscientious observations of the Sun for almost two decades. Congratulations to Monty and we thank him for sharing his observations with Universe Today.

Posted on by Nancy Atkinson

Earth Vs. Stuff from the Sun

Compare the size of Eath to a prominence on the Sun on October 10, 2011. Credit: Ron Cottrell

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The Sun is big. And comparatively, Earth is a tiny Lilliputian. We’ve all seen images comparing the size of Earth to the Sun, but here are two images from October 10, 2011 that really bring home the size-scale of features on the Sun when compared to the size of Earth. Amateur astronomer Ron Cottrell from Oro Valley, Arizona took these images of two different features on the the Sun yesterday, overlaying the size of the Earth for reference. Both are viewed in Hydrogen- Alpha light, and the first is a fiery-looking huge prominence from the northwest limb of the Sun. Yikes!

Below, see a comparison of Earth to a current sunspot:

The Earth compared to Sunspot 1312 on 10-10-11. Credit: Ron Cottrell.

This is sunspot 1312 which has a classic sunspot shape with a core a that’s larger than the Earth.

Ron used a 40mm Coronado telescope and a webcam to capture the images. He explains the colors of the Sun in Hydrogen-Alpha, and in particular why the prominence appears fiery red:

“The red color of the prominence is very close to the color collected in the image. The yellow disk is enhanced. I actually capture the disk image in black and white and add the color. I can choose any color. The final image is a composite of two separate images. Prominences are, in general, much fainter than the bright disk. Therefore, the prominence image is captured at a slower shutter speed, e.g. 1/25 sec, compared to the disk image captured at 1/100 sec. The two images are combined in PhotoShop.”

You can see more of Ron’s handiwork on his Flickr page.

And speaking of the Sun, activity on our closest star has been ramping up and last week a series of active regions were lined up one after the other across the upper half of the Sun. Interestingly, the Solar Dynamics Observatory was able to capture how these regions twisted and interacted with each other. The video shows activity from Sept. 28 – Oct. 2, 2011, as seen in extreme UV light. The magnetically intense active regions sported coils of arcing loops and numerous times these magnetic field lines above them can be seen connecting with the active region next door. Towards the end of the clip, a leading active region blasted out a coronal mass ejection, quickly succeeded by a blast from another active region. The disruption of the magnetic field from one likely triggered the second, a phenomenon that has been observed before by SDO.

Posted on by Nancy Atkinson

Did a Comet Hit Cause an Explosion on the Sun?

This amazing video from the SOHO mission (Solar and Heliospheric Observatory) shows a sun-diving comet hitting the solar surface on October 1, 2011 and unexpectedly a huge explosion occurs shortly after. Are the two events related? Probably not, but solar scientists don’t know for sure. The region where the CME originated was on the opposite side of the Sun from the comet hit, so that is very great distance. Scientists say there is no known mechanism for comets to trigger a CME.

SpaceWeather.com reports that before 2011 most solar physicists would have discounted these two events as being related, but earlier this year, the Solar Dynamics Observatory (SDO) watched another sungrazer comet disintegrate in the Sun’s atmosphere, and it appeared to interact with plasma and magnetic fields in its surroundings as it fell apart. Could a puny comet cause a magnetic instability that might propagate and blossom into a impressive CME? Most likely this is just a coincidence, but this is definitely an event in which solar scientists are taking a closer look. The comet, named SOHO-2143, was just discovered on Sept. 30 by an amateur astronomer.

See below for SDO’s look at two solar flares which also occurred on October 1, showing how events on the Sun can be related.
Continue reading “Did a Comet Hit Cause an Explosion on the Sun?”