Tag Archives: solar activity

Large Sunspot Forming

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BIG SUNSPOT, CHANCE OF FLARES: Yesterday, sunspot AR2339 unleashed an intense X2-class solar flare. It might not be finished. The active region has doubled in size since yesterday, and it has a ‘beta-gamma’ magnetic field that harbors energy for more eruptions. Amateur astronomer Philippe Tosi sends this picture of the behemoth sunspot from his backyard in Nîmes, France:

As the blue-circular insert shows, several of the sunspot’s dark cores are larger than Earth itself. From end to end, the sunspot group sprawls more than 100,000 km. These dimensions make it an easy target for backyard solar telescopes. If you have one, take a look. You might catch some action. NOAA forecasters estimate a 55% chance of M-class flares and a 10% chance of X-flares on May 7th.

from:    spaceweather.com

Solar X-Flare 5/05

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X-FLARE: The sun is no longer quiet. Emerging sunspot AR2339 unleashed an intense X2-class solar flare on May 5th at 22:11 UT. NASA’s Solar Dynamics Observatory captured the extreme ultraviolet flash:

A pulse of UV radiation and X-rays from the flare caused a strong radio blackout over the Pacific side of Earth. This map shows the extent of the blackout, which affected frequencies below 20 MHz. Mariners, aviators, and ham radio operators are the type of people who might have noticed the disturbance.

The explosion also hurled a CME into space: movie. Traveling faster than 1100 km/s (2.5 million mph), the expanding cloud does not appear to be heading for Earth.

In addition to causing a radio blackout, the flare also caused a radio burst. Immediately after the flare, a roar of static bellowed from the loudspeakers of shortwave receivers on Pacific isles and western parts of North America. Amateur radio astronomer Thomas Ashcraft of New Mexico recorded the outburst:

“The sound file is in stereo with one channel at 22 MHz and the other at 23 MHz,” says Ashcraft. “It is very intricate if listened to with headphones.”

What caused this burst of “solar static”? The same magnetic explosion that caused the flare also produced beams of electrons. As the electrons sliced through the sun’s atmosphere, they generated a ripple of radio-loud plasma waves. Astronomers classify solar radio bursts into five types; this one was a mixture of Type III and Type V.

from:    spaceweather.com

New CME

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CME, POSSIBLY EARTH-DIRECTED: A magnetic filament snaking around the sun’s southern hemisphere erupted on May 3rd. The blast did not create a pulse of electromagnetic radiation (i.e., a solar flare), but it did hurl a CME into space. The Solar and Heliospheric Observatory recorded the expanding cloud:

Although the CME is not moving directly along the sun-Earth line, it might still be geoeffective. A glancing blow is possible on May 5th or 6th. NOAA analysts are evaluating this possibility as they receive additional coronagraph data. Stay tuned for updates in the hours ahead.

fr/spaceweather.com

SOlar FLares

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OLAR FLARE AND RADIO BLACKOUT: Sunspot AR2257 erupted on Jan. 13th, producing an M5-class solar flare at 04:24 UT. A pulse of extreme UV radiation from the flare ionized Earth’s upper atmosphere over Australia and the Indian Ocean. Mariners and ham radio operators may have noticed a brief communications blackout at frequencies below about 10 MHz. This map from NOAA shows the affected region:

We do not yet know if the flare also produced a coronal mass ejection (CME). If so, the plasma cloud will probably miss Earth because of the sunspot’s off-center location on the solar disk.

More flares could be in the offing. AR2257 has an unstable ‘beta-gamma-delta’ magnetic field that seems poised to explode again. NOAA forecasters estimate a 40% chance of M-class flares and a 10% chance of X-flares on Jan. 13th.

fr/spaceweather.com

Large Coronal Hole

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HOLE IN THE SUN’S ATMOSPHERE: A vast hole has opened in the atmosphere over the sun’s south pole, and it is spewing solar wind into space. The gaseous gap, a.k.a. a ‘coronal hole,’ is colored dark-purple in this extreme ultraviolet image from NASA’s Solar Dynamics Observatory:


Curved lines trace the sun’s magnetic field in this EUV image from SDO

Coronal holes are places where the sun’s magnetic field opens up and allows solar wind to escape. A stream of solar wind flowing from this particular hole is expected to reach Earth’s orbit on Jan. 4-5. The bulk of the stream will flow south of our planet. However, not all of it will miss. NOAA forecasters estimate a 40% chance of polar geomagnetic storms when the solar wind arrives in the next 48 hours.

fr/spaceweather.com

Incoming CME 12/19

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CHANCE OF MAGNETIC STORMS TODAY: A CME is heading in the general direction of Earth, and it could deliver a glancing blow to our planet’s magnetic field later today. Scroll past this SOHO coronagraph movie for storm probabilities:

NOAA forecasters estimate a 50% chance of polar geomagnetic storms. The cloud was hurled into space two days ago by an M9-class explosion in the magnetic canopy of sunspot AR2242. Although the bulk of the CME flew south of the sun-Earth line, a collision is still possible. Computer models suggest a glancing impact on Dec. 19th with magnetic reverberations lasting until the 20th. High-latitude sky watchers should be alert for auroras.

fr/spaceweather.com

Incoming CME

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CME TARGETS EARTH, AFTER ALL: On Nov. 7th, when an X-flare from AR2205 hurled a CME into space, at first it appeared that the cloud would miss Earth. Follow-up computer modeling by NOAA analysts suggests that the CME might deliver a glancing blow to our planet’s magnetic field after all. A complete forecast follows this movie of the eruption recorded by the Solar and Heliospheric Observatory:

The CME left the sun traveling approximately 600 km/s (1.3 million mph) albeit not directly along the sun-Earth line. If the computer models are correct, the outskirts of the cloud should reach Earth mid-day on Nov. 10th (Universal Time). First contact could spark a G2-class geomagnetic storm on Nov. 10th subsiding to G1-class on Nov. 11th. NOAA forecasters are citing storm probabilities as high as 75%.

These storms in the forecast are mild, not extreme, so there is no danger of power outages or communications blackouts. However, the CME impact could spark some beautiful auroras around the Arctic Circle. The lights might even spill across the Canadian border into northern-tier US states such as Maine, Michigan, Minnesota and the Dakotas.

fr/spaceweather.com

Hyper Flare from Sun 11/01

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HYDER FLARE MISSES EARTH: Earth-orbiting satellites detected a solar flare on Nov. 1st. Usually solar flares come from sunspots, but there were no sunspots anywhere near this blast. A movie from the Solar Dynamics Observatory shows what happened:

The C3-category flare was caused by a filament of magnetism, which rose up and erupted between 0400 and 0600 UT. Some of the material in the filament fell back to the sun, causing a flash of X-rays where it hit the stellar surface. That was the flare. The rest of the filament flew out into space, forming the core of a massive CME. A movie from the Solar and Heliospheric Observatory shows the CME billowing away from the sun. NOAA analysts say it will not hit Earth.

Flares like this, which happen without sunspots, are called Hyder Flares. They help keep solar activity high even when sunspot counts are low.

fr/spaceweather.com

Huge Skull-like Sunspot

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SUPER-SUNSPOT PREPARES TO DEPART: The biggest sunspot in nearly 25 years is about to leave the solar disk. This picture from Sergio Castillo of Corona CA shows AR2192 approaching the western limb on Oct. 27th:

“For its final trick, AR2192 is going to treat us by mimicking a Giant Skull,” says Castillo, one of many readers who has noted the resemblance between the sunspot and a skeletal face. “Say Happy Halloween as it gets ready to turn away from us. “

As AR2192 approaches the sun’s horizon, it is no longer facing Earth. However, the odds of an Earth-directed radiation storm are higher than ever. The reason is, the western limb of the sun is well-connected to Earth. Solar magnetic fields springing out of that region spiral back to our planet. If a sunspot passing through the area explodes, those spiralling magnetic fields can funnel energetic particles in our direction.

In only a few days, the behemoth sunspot will begin a 2-week transit of the far side of the sun, carried around by the sun’s 27-day rotation. However, that doesn’t mean we’ve seen the last of this magnificent active region. Big sunspots typically persist for two or three solar rotations before they decay. After it leaves, AR2192 will return in November.

fr/spaceweather.com

Huge Sunspot Emerging

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A BEHEMOTH SUNSPOT EMERGES: A large and active sunspot is rotating over the sun’s southeastern limb on Oct. 17th. J. P. Brahic sends this picture of the behemoth from Uzès, France:

“I inserted a picture of Earth for scale,” says Brahic. The sunspot’s primary dark core could swallow our entire planet with room to spare.

This sunspot could cause a sharp increase in solar activity over the weekend. Earlier this week, while it was still hidden behind the southeastern limb, the active region unleashed several M-class solar flares and hurled a massive CME into space. Considering the fact that the blast site was partially eclipsed by the edge of the sun, those flares were probably much stronger than their nominal classification. Now that the sunspot has revealed itself, X-flares may be in the offing.

fr/spaceweather.com