FULL HALO CME, STORM WARNING: A coronal mass ejection (CME) is heading directly for Earth. It left the sun during the early hours of June 21st, and is expected to sweep up one or two lesser CMEs already en route, before it reaches Earth sometime on June 22nd. Click to view a movie of the “full-halo” CME, then scroll down for more discussion:
NOAA forecasters estimate a 90% chance of polar geomagnetic storms when the CME arrives. This doesn’t mean that a major space weather event is in the offing. The storm could be mild. It all depends on how the magnetic field of the CME connects to the magnetic field of Earth at the time of impact. According to NOAA, there’s only a 10% chance of nothing happening, so stay tuned.
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.
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.
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.
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.
SOLAR ACTIVITY PICKS UP: A new sunspot emerging over the sun’s NE limb is bringing an uptick in solar activity. AR2149 announced itself on August 21st with an impulsive M3-class solar flare. NASA’s Solar Dynamics Observatory recorded the explosion’s extreme ultraviolet flash:
UV radiation from the flare partially ionized the upper layers of Earth’s atmosphere. This “Sudden Ionospheric Disturbance” altered the normal propagation of VLF (very low frequency) radio transmissions over the northern hemisphere, shown here in a recording from the Polarlightcenter in Lofoten, Norway. The disturbance has since subsided.
Because AR2149 is near the sun’s eastern horizon, our view of the region is foreshortened. Evaluating the structure of its magnetic field is therefore tricky. As the sunspot turns toward Earth in the days ahead, we will get a better idea of its flare-producing potential. For now, NOAA forecasters are estimating a 25% chance of M-flares in the next 24 hours.
ERUPTING FILAMENT CREATES ‘CANYON OF FIRE’, CME: A magnetic filament snaking down the middle of the solar disk erupted during the late hours of Aug. 15th. The eruption split the sun’s atmosphere, hurling a CME toward Earth and creating a “canyon of fire,” shown here in a movie recorded by the Solar Dynamics Observatory:
The glowing walls of the canyon trace the original channel where the filament was suspended by magnetic forces above the stellar surface. From end to end, the structure stretches more than 250,000 km–a real Grand Canyon.
Of greater interest to us on Earth is the coronal mass ejection (CME) which billowed away from the blast site: movie. Coronagraph images from the Solar and Heliospheric Observatory show that it is a ‘halo CME.’ In other words, it is heading straight for Earth. Minor geomagnetic storms are possible when the cloud arrives during the late hours of August 18th. High-latitude sky watchers should be alert for auroras.
OLD SUNSPOT RETURNS, SOLAR ACTIVTITY INCREASES: Crackling with solar flares, a large sunspot is emerging over the sun’s southeactive limb. It appears to be AR1944, returning after a two-week trip around the farside of the sun. Earlier today, astronomer Karzaman Ahmad photographed the active region from the Langkawi National Observatory in Malasia:
According to tradition, sunspots that circle around the farside of the sun are re-numbered when they return. The new designation of AR1944 is AR1967. “Sunspot AR1967 is as big as Earth!” notes Ahmad.
Earlier this month, AR1944/AR1967 produced an X1-class solar flare and one of the strongest radiation storms of the current solar cycle. Is round 2 about to begin? Solar activity is definitely increasing as AR1967 comes around he bend. Earth orbiting satellites have detected at least five M-class solar flares since yesterday, including this one recorded on Jan. 28th (07:30 UT) by NASA’s Solar Dynamics Observatory:
More flares are in the offing. NOAA forecasters estimate a 5% chance of X-flares and a 50% chance of M-flares during the next 24 hours
CME, POSSIBLY INCOMING: A coronal mass ejection (CME) might be heading for Earth. The cloud blasted away from the sun during the late hours of Jan 4th following a long-duration M4-class solar flare from big sunspot AR1944. SOHO (the Solar and Heliospheric Observatory) recorded the explosion:
The assymetric CME could deliver a glancing blow to Earth’s magnetic field on January 7th, possibly sparking G1-class geomagnetic storms. NOAA analysts are still processing the CME imagery for a more precise forecast.
Watch the movie again. There might be two CMEs in there. After the first cloud from sunspot AR1944 emerged, a second cloud was propelled off the sun’s western limb by departing sunspot AR1936. The mixture of CMEs complicates analysis of this event.
SUNSPOTS OF INTEREST: Two large sunspot groups, AR1875 and AR1877,have emerged over the sun’s eastern limb and they are turning toward Earth. NASA’s Solar Dynamics Observatory captured this three-day movie of their approach:
AR1877 is large, and AR1875 is rapidly growing to match it. Both sunspot groups have ‘beta-gamma’ magnetic fields that harbor energy for M-class solar flares. So far, however, neither one is actively flaring. Perhaps this is the calm before the storm. NOAA forecasters estimate a 25% chance of M-flares in the next 24 hours.