Tag Archives: solar activity

Solar Flare

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SOLSTICE SOLAR FLARE: This morning, June 21st at 03:16 UT, the sun itself marked the solstice with an M2-class solar flare from sunspot AR1777. NASA’s Solar Dynamics Observatory photographed the extreme ultraviolet flash and a plume of material flying out of the blast site:

As sunspots go, AR1777 is neither large nor apparently menacing, yet it has been crackling with flares for days. Before it rotated over the sun’s eastern limb on June 20th, it unleashed a series of farside flares and CMEs. Today’s explosion was not Earth directed, but future explosions could be as the sun’s rotation continues to turn AR1777 toward our planet. NOAA forecasters estimate a 30% chance of M-flares and a 5% chance of X-flares during the next 24 hours.

fr/spaceweather.com

Solar FIlaments

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AN OUTBREAK OF MAGNETIC FILAMENTS: The sunspot number may be low, but the sun is far from blank. Amateur astronomers monitoring the sun report a large number of magnetic filaments snaking across the solar disk. Sergio Castillo captured more than half a dozen in this picture he sends from his backyard observatory in Inglewood, California:

“Filaments are popping up all over the solar surface,” says Castillo. “Each one has a unique shape and length.”

The longest one, in the sun’s southern hemisphere stretches, more than 400,000 km from end to end. “It’s one of the longest filamentary structures I have ever seen,” says veteran observer Bob Runyan of Shelton, Nebraska.

If any of the filaments collapses, it could hit the stellar surface and explode, producing a Hyder flare. Filaments can also become unstable and erupt outward, hurling pieces of themselves into space. Either way, astronomers with solar telescopes are encouraged to monitor developments.

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6/5 Solar Activity

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SOLAR FLARE AND CME: Southern sunspot AR1762 erupted today, June 5th, producing a long-duration M1-class solar flare that peaked around 0900 UT. The explosion hurled a right coronal mass ejection (CME) into space, shown here in a coronagraph image from the Solar and Heliospheric Observatory:

Because the sunspot is approaching the sun’s southwestern limb, the blast was not squarely Earth-directed. In fact, it might miss us altogether. Stay tuned for further analysis of the trajectory of the CME.

Meanwhile, more eruptions could be in the offing. AR1762 has a ‘beta-gamma-delta’ magnetic field that harbors energy for X-flares much stronger than the M1-class event that occured this morning.

fr/spaceweather.com

Geomagnetic Storm

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GEOMAGNETIC STORM: A G1-class (Kp=5) geomagnetic storm is in progress following the arrival of an interplanetary shock wave on May 31st. The source of the shock is not known; it might have been a minor CME that left the sun without drawing attention to itself. The impact sparked auroras across many northern-tier US states. This photo, for instance, comes from Christopher Griffith in Baxter, Minnesota:

“I wasn’t expecting to see any lights, but right before the midnight it broke loose and the sky lit up,” says Griffith. “Sadly the clouds quickly filled in my little window, and the auroras were gone. Just thankful for what I got so see!” Elsewhere in the USA, auroras were sighted as far south as Colorado, Maryland, Iowa, Wisconsin, and Nebraska.

High-latitude sky watchers should remain alert for auroras tonight as Earth’s magnetic field continues to reverberate from the impact. NOAA forecasters estimate a 40% chance of polar geomagnetic storms on June 1st.

from:   spaceweather.com

Solar Coronal Hole

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CORONAL HOLE: A hole in the sun’s atmosphere–a “coronal hole”–has opened up and it is spewing solar wind into space. NASA’s Solar Dynamics Observatory photographed the UV-dark gap during the early hours of May 29th:

Coronal holes are places where the sun’s magnetic field spreads apart and allows solar wind to escape. A windy stream of plasma flowing from this particular hole should reach Earth on June 2-3. The impact could spark geomagnetic storms and auroras around the poles

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New CME 5/22

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M5-CLASS EXPLOSION: The ongoing radiation storm got started on May 22nd when the magnetic canopy of sunspot AR1745 exploded. The blast produced an M5-class solar flare and hurled a magnificent CME over the sun’s western limb:


Credit: the Solar and Heliospheric Observatory (SOHO)

The movie of the CME is very “snowy.” That is caused by high-energy solar protons striking the CCD camera in SOHO’s coronagraph. Each strike produces a brief snow-like speckle in the image. This hailstorm of solar protons is what forecasters mean by “radiation storm.”

Although the explosion was not squarely Earth-directed, the CME will likely be geoeffective. The expanding cloud appears set to deliver a glancing blow to Earth’s magnetic field on May 24th around 1200 UT. According to NOAA forecast models, the impact will more than double the solar wind plasma density around Earth and boost the solar wind speed to ~600 km/s.

from:    spaceweather.com

Incoming CME

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ANOTHER INCOMING CME: As Earth’s magnetic field reverberates from one CME strike, a second more potent CME is on the way. It was propelled in our direction by sunspot AR1748, which unleashed an M3-class solar flare on May 17th (0858 UT). Although this is not the strongest flare we’ve seen from AR1748, it could be the most geoeffective; the sunspot was almost-squarely facing Earth when the blast occurred. NOAA forecasters estimate a 75% chance of polar geomagnetic storms when the cloud arrives.

The Solar and Heliospheric Observatory took this picture of the CME leaving the sun at 1500 km/s (3.4 million mph) on May 17th:

In the video, the CME appears to hit Mercury, but it does not. It is merely passing in front of the innermost planet. The planet in the line of fire is actually Earth.

from:    spaceweather.com

More X-Flares

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X-FLARE THREAT CONTINUES: Sunspot AR1748 has already unleashed four X-class solar flares, but it might not be finished. The active region continues to grow beneath a delta-class magnetic field that harbors energy for powerful eruptions. NOAA puts the odds of another X-flare today at 60%. Solar flare alerts: text, voice.

NASA’s Solar Dynamics Observatory took this picture of AR1748 during the early hours of May 16th:

The sunspot is not particularly large, but it is complex, with many dark cores scattered through its zone of influence. This is a sign of a complicated overlying magnetic field. Magnetic complexity is the source of AR1748’s explosiveness: when tangled lines of magnetic force cross and reconnect–bang! A flare occurs.

All by itself, AR1748 has produced more X-flares than every other sunspot of the past year combined. In summary, AR1748 has given us an X1.7-class flare (0217 UT on May 13), an X2.8-class flare (1609 UT on May 13), an X3.2-class flare (0117 UT on May 14), and an X1-class flare (0152 on May 15). More could be in the offing.

fr/spaceweather.com