From July 2 to July 5, the Sun shot off a whopping eighteen M-class solar flares. Most originated from Active Region 1515 and ranged from M1.1 to M6.1. On July 4th alone, there were seven M-class solar flares. According to SpaceWeather.com, big sunspot AR1515 appears to be on the verge of producing an X-class explosion. NOAA forecasters estimate an 80% chance of M-flares and a 10% chance of X-flares during the next 24 hours.
Continue reading “Fireworks from the Sun”
New Warning System Designed to Keep Astronauts Safe from Solar Storms
A new solar storm prediction system based in Antarctica could provide astronauts in space warning time of over two hours for them to take cover after massive flares or Coronal Mass Ejections erupt from the Sun. The South Pole Neutron Monitor is able to forecast the radiation intensity of solar protons using two different types of neutron detectors installed at the geographic South Pole, which measures gigaelectron volt neutrons that are produced during a solar storm.
The designers of the device have been testing it and say it could provide a warning times of up to 166 minutes, depending on the protons’ energy. Additionally, the team says, it is a practical system for forecasting peak intensity of solar energetic protons in the tens to hundreds of megaelectron volt energy range.
With activity on the Sun increasing as the Solar Maxiumum approaches, there will likely be heightened rates of flares and CMEs, putting at risk the human presence in space, which will likely be ever-increasing, with the advent of commercial space flights and NASA’s plans to send astronauts into deep space, along with crews of six that are usually on board the International Space Station. Even people in airplanes at high altitudes near the poles can be exposed to this increased radiation. Exposure can potentially cause radiation sickness, with symptoms such as fever and vomiting.
During a solar flare or CME, particles from the Sun can be accelerated to very high energies—in some cases traveling near the speed of light. Protons with energies surpassing 100 megaelectron volts essentially sandblast everything in their path.
S.Y. Oh from Chungnam National University in South Korea and an international team of researchers have created and installed the warning system at the Amundsen-Scott South Pole Station. Using one detector located indoors and another outside, they can measure the intensity of the much faster gigaelectron volt neutrons also produced during a solar storm when protons interact with Earth’s atmosphere. By combining the observations of the two detectors, they can then extrapolate this spectrum to estimate the peak intensity and event-averaged flux (fluence) of the later-arriving megaelectron volt protons.
The team compared their predictions for 12 solar events against observations made by geosynchronous satellites, such as some of the GOES satellites, and found their measurements were similar for intensity and fluence predictions for protons with energies higher than 40 and 80 megaelectron volts, respectively.
The researchers say the system could be useful for forecasting radiation hazard, because peak intensity and fluence are closely related to the known medical thresholds of radiation doses.
The lead times would allow for astronauts to take shelter in a shielded area of their spacecraft, or polar-flying airplanes ample time to reduce their altitude to be protected by Earth’s magnetic field.
Read the team’s paper: South Pole neutron monitor forecasting of solar proton radiation intensity
Lead image caption: The South Pole neutron monitor. Credit: University of Delaware.
Source: AGU
How Big Are Sunspots?
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The short answer? Really big. The long answer? Really, really big.
The image above shows sunspot regions in comparison with the sizes of Earth and Jupiter, demonstrating the sheer enormity of these solar features.
Sunspots are regions where the Sun’s internal magnetic fields rise up through its surface layers, preventing convection from taking place and creating cooler, optically darker areas. They often occur in pairs or clusters, with individual spots corresponding to the opposite polar ends of magnetic lines.
(Read “What Are Sunspots?”)
The image on the left was acquired by NASA’s Solar Dynamics Observatory on May 11, 2012, showing Active Region 11476. The one on the right comes courtesy of the Carnegie Institution of Washington, and shows the largest sunspot ever captured on film, AR 14886. It was nearly the diameter of Jupiter — 88,846 miles (142,984 km)!
“The largest sunspots tend to occur after solar maximum and the larger sunspots tend to last longer as well,” writes SDO project scientist Dean Pesnell on the SDO is GO blog. “As we move through solar maximum in the northern hemisphere and look to the south to pick up the slack there should be plenty of sunspots to watch rotate by SDO.”
Sunspots are associated with solar flares and CMEs, which can send solar storms our way and negatively affect satellite operation and impact communications and sensitive electronics here on Earth. As we approach the peak of the current solar maximum cycle, it’s important to keep an eye — or a Solar Dynamics Observatory! — on the increasing activity of our home star.
(Image credit: NASA/SDO and the Carnegie Institution)
How Big Was Monday’s CME?
This big! The M1.7-class flare that erupted from active region 1461 on Monday, April 16 let loose an enormous coronal mass ejection many, many times the size of Earth, making this particular writer very happy that our planet was safely tucked out of aim at the time… and 93 million miles away.
The image above was obtained by NASA’s Solar Dynamics Observatory’s AIA 304 imaging instrument on Monday during the height of the event. I rotated the disk of the Sun 90 degrees to get a landscape look over the eastern limb, cropped it down and then added an Earth image to scale — just to show how fantastically huge our home star really is.
(Read “Watch it Rain on the Sun”)
Some minor editing was done to increase contrast and heighten detail in the eruption.
The CME was not directed our way, but it was aimed at NASA’s STEREO-B spacecraft, which will encounter the ejected material full-on.
Read more about this event in a previous Universe Today post here, and check out hi-def videos of the CME from SDO here.
Image credit: NASA/SDO and the AIA science team. Edited by Jason Major.
Big Blast from the Sun
The CME we reported on earlier today was obviously just a warm up to the latest blast: A beautiful prominence eruption producing a larger CME off the east limb (left side) of the sun on April 16, 2012 at about 17:45 UTC (1:45 pm EDT). The event, which also produced an M1.7-class solar flare, was not Earth-directed, say scientists from the Solar Dynamics Observatory. But SpaceWeather.com says the blast confirms suspicions that a significant active region is rotating onto the Earth-side of the sun.
The Sun Spits Out a Coronal Mass Ejection
Ever squirted water out of your mouth when playing in a swimming pool or lake? This Coronal Mass Ejection (CME) release by the Sun on April 15, 2012 looks reminiscent of such water spouting. But this burst of solar plasma being hurled from the eastern limb of the Sun is more like an explosion, as such CMEs can release up to 100 billion kg (220 billion lb) of material, and the speed of the ejection can reach 1000 km/second (2 million mph) in some flares. Scientists at the Solar Dynamics Observatory say some of the explosions approach the power in one billion hydrogen bombs! In this video, the Sun hurled a cloud of plasma towards the STEREO B spacecraft and SDO captured the event in a couple of different wavelengths.
Coronal Mass Ejections (CMEs) are balloon-shaped bursts of solar wind rising above the solar corona, expanding as they climb. Solar plasma is heated to tens of millions of degrees, and electrons, protons, and heavy nuclei are accelerated to near the speed of light. The super-heated electrons from CMEs move along the magnetic field lines faster than the solar wind can flow. Rearrangement of the magnetic field, and solar flares may result in the formation of a shock that accelerates particles ahead of the CME loop.
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Watch Mercury Get Smacked By CMEs
The bright object in the center of this video sequence is the planet Mercury, seen by NASA’s STEREO-B spacecraft as it was pummeled by wave after wave of solar material ejected from the Sun during the week of March 25 – April 2, 2012.
The video above was released by NASA’s Goddard Space Flight Center earlier today. The Sun is located just off-frame to the left, while Earth would be millions of miles to the right.
Proof that it’s not easy being first rock from the Sun!
Video credit: NASA/GSFC/STEREO
Dark Figures Do An Eerie Dance On The Sun
NASA’s Solar Dynamics Observatory captured this video on March 27 – 28 of two large areas of “dark” plasma on the Sun’s limb, twisting and spiraling in our star’s complex magnetic field. The southern region bears an uncanny resemblance to three figures swaying to some spooky, unheard music… a real “danse macabre” on the Sun!
Continue reading “Dark Figures Do An Eerie Dance On The Sun”
Active Region Is Still Active!
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Even though the CME unleashed by active region 1429 initially hit Earth a bit softer than expected yesterday (read why here), it ended up gaining some extra “oomph” once the magnetic fields lined up right… enough to ignite some amazing displays of aurorae like the one shown above over Iceland, photographed by Jónína Óskarsdóttir!
And that wasn’t the last we’d hear from AR1429 either; at around 10:30 pm EST on March 8, the region lit up again with an M6.3 flare… although smaller than the previous X5.4-class flare, it produced a temporary radio blackout and released another Earth-directed CME, which is expected to arrive in the coming hours.
Dr. Alex Young, solar physicist at NASA’s Goddard Space Flight Center, reported this morning on his blog The Sun Today:
The flare produced a temporary radio blackout as well as a possible Earth directed CME. We will have to wait and see. The sunspot group still shows potential for more activity as the region sits near the central meridian of the Sun. Facing directly at Earth this is a prime location to produce more geo-effective solar activity.
Here is a look at the flare captured by the 131 Angstrom wavelength camera on the Solar Dynamics Observatory (SDO). This shows us the super hot 5-10 million degree plasma produced by the solar flare.
Dr. Young also noted that bright aurorae could be visible in lower latitudes as a result of the latest CME, expected to impact Earth at 1:50 am EST:
Aurora watchers at higher latitudes such as the northern US should keep their eyes out in the early morning and maybe even into tonight depending upon how this storm progresses.
Many times the size of Earth, active region 1429 has been the source of at least five significant flares over the past week. As it moves across the face of the Sun, its shape has become more and more complex — a sure sign, notes Dr. Young, that magnetic forces within it are twisting further and further towards a breaking point. And when they snap, there’s a flare.
“It’s interesting, they kind of look like a mole,” Dr. Young said during an interview on March 8. “And when you monitor a mole, they tell you as long as it stays in a nice symmetric shape and it doesn’t become really complicated and complex, it’s okay. It’s the same sort of thing with sunspots… when they become complicated and twisted, then that mean the magnetic fields inside of them have become more twisted, like a rubber band twisting around until little knots pop up in it. And right now we have been monitoring that sunspot and it is getting more complex.”
(See a photo of AR1429 taken from New Mexico!)
As far as the effects we see here on Earth are concerned, that’s all about the resulting CME — the enormous cloud of charged solar particles that gets blown out into the Solar System. If that cloud impacts Earth’s magnetic field, and if the direction of the cloud happens to be opposite the direction that Earth’s magnetic field is pointed, a lot of energy is “pumped into” our magnetosphere, resulting in a geomagnetic storm.
During yesterday’s CME impact the Earth’s magnetic field was pointed north — the same direction as the CME. As a result much of the solar material simply flowed along and over it. But the wake ended up getting caught up in the south-directed part of the field, ramping up the energy index (measured as Kp) as the hours progressed. As yet there’s no way to know for certain how a particular CME will align with Earth’s magnetic field.
According to physicist Dr. Philip Scherrer of Stanford University, “we still need better — or perhaps faster — models” to be able to accurately predict the orientation of incoming CMEs. “We are perhaps a few years of research away from completing the picture.”
Currently the geomagnetic storm level is at G3, which according to the NOAA’s Space Weather Scale could result in voltage problems on power systems, increased drag on satellites and “intermittent satellite navigation and low-frequency radio navigation problems… and aurora has been seen as low as Illinois and Oregon.”
So keep an eye out for northern lights in tonight’s skies, and stay tuned for more updates!
Thanks to Dr. Alex Young for the information! You can follow him on Facebook and Twitter and on his personal blog The Sun Today. Also thanks to Dr. Phil Scherrer at Stanford University and SpaceWeather.com for the heads-up on Jónína’s photo. See more of her aurora photography here. (Used with permission.)
Sun Releases a Powerful X5 Flare
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Active Region 1429 unleashed an X5.4-class solar flare early this morning at 00:28 UT, as seen in this image by NASA’s Solar Dynamics Observatory (AIA 304). The eruption belched out a large coronal mass ejection (CME) into space but it’s not yet known exactly how it will impact Earth — it may just be a glancing blow.
Solar flares are categorized by a scale according to their x-ray brightness. X is the strongest class, followed by M and then C-class. Within each class the numbers 1 through 9 subdivide the flares’ intensity.
A run-in with an X5-class flare is a major geomagnetic event that can cause radio blackouts on Earth and disrupt satellite operations, as well as intensify auroral activity.
The GOES satellite data for the March 7 flare is below:
The CME is expected to impact Earth sometime on the 8th or 9th. Check back here or at Spaceweather.com for updates on the storm (and any subsequent aurora photos!)
Also, check out the video below, assembled by the SDO team. Just after the X5.4-class flare another smaller X1-class flare occurred, sending a visible wave cross the Sun.
Image courtesy NASA, SDO and the AIA science team. And thanks to Camilla Corona SDO for all the updates!