Huge Sunspot Aimed At Earth -- Eruption Imminent?
Ever wondered what the view would be like when looking down the barrel of a stellar gun? Look no further, this is it.
(Active Region 11476 appears just above the center of the disk in this white light image. Credit: NASA/SDO)
“As captured in breathtaking high-definition by NASA’s Solar Dynamics Observatory (SDO), an erupting active region has rotated into view and is currently facing us, dead-on. The active region in question, called AR11476, is huge. In fact, as cheerfully pointed out by the SDO’s little yellow chicken mascot Camilla, the sunspot complex underlying the active region is about the size of Jupiter! In the image shown above, we are looking at light generated by plasma (heated to approximately 6,000 Celsius/Kelvin) in the sun’s photosphere. The sunspots appear dark as the sun’s intense magnetic field is thrusting through the photosphere from the interior, pushing the hotter surface layers aside, exposing the cooler plasma below.”
“To make this active region even more dramatic, it has been crackling with intense magnetic activity, triggering a powerful M-class flare early on Thursday… And now, according to Spaceweather.com, NOAA space weather forecasters estimate a 75 percent chance of AR1476 producing more M-class flares and a 20 percent chance that it will erupt with a more powerful X-class flare in the next 24 hours. Should a coronal mass ejection (CME) also be launched in our direction, we could be in for a rough ride.”
(AR 11476 is one of the largest sunspot groups I can remember in my lifetime. It’s evidently easily viewed with the unaided eye, but if you look , make sure you use a proper solar filter! Viewing the Sun unfiltered, through a telescope or otherwise, is extremely dangerous and can lead to loss of eyesight. Be careful! -JCB)
Web-Based Tools For Tracking Solar Activity
As we head into the peak of solar Cycle 24 this summer, I thought it would be a good idea to list some websites that are useful for keeping an eye on what the Sun is up to.
Why care about this? Solar activity is rapidly ramping up and significantly affects the geophysical environment of our planet. Bursts of high-energy particles emitted from solar flares can damage Earth-orbiting satellites, disrupt terrestrial radio communications, interfere with GPS navigation, and even threaten the integrity of electrical power grids.
Here are a summary of some sites and what they have to offer:
☀ NASA space mission websites: Solar Dynamics Observatory (SDO), Solar And Heliospheric Observatory (SOHO), Solar TErrestrial RElations Observatory (STEREO)
☀ Space Weather Prediction Center (space weather forecasting by the National Oceanic and Atmospheric Administration; in particular, see “Today’s Space Weather”)
☀ Current Solar Data (convenient, one-page summary of plots from NOAA)
☀ Spaceweather (the go-to website for information about current solar activity and space weather forecast information)
☀ SolarSoft ”Latest Events” (a single page, graphical, ‘at-a-glance’ summary of recent solar imagery and activity levels)
☀ SolarHam (lots of graphical information about solar activity mainly pertinent to terrestrial, long-wave radio propagation; of interest to amateur radio operators and others)
☀ Solar Terrestrial Activity Report (oodles of information about current solar activity levels and events in the geomagnetic environment compiled by Jan Alvestad)
☀ Planetary K-Index (a numerical representation of the current level of solar-geomagnetic activity near the Earth; when K ≥ 7, auroral activity at mid-latitudes is likely)
☀ Helioviewer (an interactive tool for visualizing solar activity data, mostly spacecraft imagery)
☀ POES Auroral Oval (a realtime depiction of the “auroral oval” around the Earth’s poles from orbiting satellites; useful for predicting where aurora may be seen on the ground)
☀ The Watchers Solar Activities Archive (blog consisting of short news-style updates about solar goings-on)
This list is by no means exhaustive, but should serve as a good jumping-off point for those interested in tracking the activity of our dynamic Sun.
(Image credit: NASA/Steele Hill)
Giant sunspot could hurl strong solar flares toward Earth
A “monster sunspot” more than 60,000 miles wide could send some powerful solar flares toward Earth on Wednesday, NASA says.
(Image of Active Region 11476. CREDIT: NASA/SDO)
“The sunspot — actually a group of four spots, each larger than Earth, and smaller spots — emerged over the weekend and was spotted by the orbiting Solar Dynamics Observatory and amateur astronomers,Spaceweather.com reported (via Space.com). It tossed off a moderately strong M-class flare today, and is expected to follow up with even stronger flares, possibly even X class.”
(Observers at mid to high latitudes, above about 40º, should be on the lookout for aurorae later this week, if AR 11476 pops off an X-class flare. -JCB)
Solar storm headed toward Earth
The biggest solar storm in five years is expected to bombard the Earth on Thursday, potentially upsetting airplane flights, GPS systems and electric power grids.
(An ultraviolet wavelength image provided by NASA shows a solar flare.)
The first effects of the storm will come at about 7 a.m. ET, says Joe Kunches of the Space Weather Prediction Center in Boulder, Colo. Kunches says the storm should last about a day.
On the “G1 to G5” scale of geomagnetic storm intensity, with G5 being the worst, Kunches says this storm is expected to be a G3, considered to be a “strong” one.
The storm has the potential to trip electrical power grids, although Kunches said power companies around the world have been alerted for possible outages.
Solar storms can also disrupt GPS systems or make them less accurate. The storm can lead to communication problems and added radiation around the North and South poles, which will probably force airlines to reroute flights.
NASA reports that the current increase in the number of solar storms is part of the sun’s normal 11-year solar cycle, during which activity on the sun ramps up to the solar maximum, which should peak in late 2013.
“We’re in the season for these now,” says Kunches, who adds that similar solar storms will occur every month or two for the next few years.
Skywatchers in the North will get a treat from the aurora borealis, or northern lights, which are caused by the solar storm and should be near peak tonight.
The lights will occur across much of the northern tier of the USA, as far south as Oregon in the West, Illinois in the Midwest, and the Mid-Atlantic states in the East, Kunches says.
Largest Sunspot in Years Observed on the Sun
(The gigantic sunspot in the upper left of this image is about 50,000 miles (80,000 km) long and was observed on the sun by NASA’s Solar Dynamics Observatory on Nov. 3, 2011. CREDIT: SDO )
“One of the largest sunspots in years has appeared on the sun, darkening part of its glowing face.”
“The massive sunspot, called AR1339, is about 50,000 miles (80,000 km) long, and 25,000 miles (40,000 km) wide, reportsSpaceWeather.com. For comparison, Earth itself is only 8,000 miles (12,800 km) wide.”
“The sunspot behemoth isn’t yet facing our planet, but was spotted today (Nov. 3) by NASA’s Solar Dynamics Observatory (SDO) satellite. The spacecraft’s photos of the giant sunspot show the solar region as it comes into view on the northeastern edge, or limb, of the sun.”
The NASA Solar Dynamics Observatory (SDO)’s AIA instrument at 171 Angstrom took some amazing pictures of solar activity.
Solar Flares Aren't What They Seemed
(The SDO observations have revealed a set of flares that have a large second peak for some of the extreme ultraviolet (EUV) emissions. It had previously been known that the EUV emissions have a peak near the time of the flare’s X-ray peak, but this second EUV peak is one to five hours later and without a corresponding X-ray peak. We refer to this delayed, second peak as the EUV Late Phase. CREDIT: NASA/University of Colorado/Tom Woods)
“For roughly the last 50 years, solar flares have been categorized and detected by the x-rays they give off. The current classification of flares goes, in increasing power at their peak, A, B, C, M, X.”
“Last Wednesday, scientists reported that they haven’t been noticing most of the solar flares’ energy. In a NASA Press Conference, held simultaneously with the release of a paper online in The Astrophysical Journal, they reported on new results based on observations with NASA’s Solar Dynamics Observatory.”
“Several analyses have now shown that at least a group of the most powerful flares, which are detected in x-rays by satellites such as the GOES (Geostationary Operational Environmental Satellite) series of the National Oceanic and Atmospheric Administration, give off more energy about 90 minutes later than the x-ray peak than occurred in that first detected peak.”
There may be more to solar flares than meets the eye, not only in the energy output of these events but in their impact on the geomagnetic environment of the Earth. It has long been known that Earth-orbiting satellites are vulnerable to the the streams of charged particles emitted by flares, as are ground-based radio and electrical networks. The extended emission in flares recently discovered may even have an adverse effect on the Global Positioning System, or GPS, constellation of satellites, on which everything from ships at sea to commercial airliners depend for reliable, world-wide navigation. There is also an economic impact involved: costs due to damage of the communications infrastructure caused by solar magnetic activity could run into the hundreds of billions. As we enter the upcoming “solar max”, the problem becomes more acute with each passing day.
Solar Flare May Spark Dazzling Northern Lights Displays Friday
(A powerful M9-class solar flare erupted from the sun at 10:09 p.m. EDT on July 29 (0209 GMT July 30). Image credit: NASA/SDO)
“Those who look to the skies on Friday (Aug. 5) may see exceptional auroras thanks to a strong solar flare that hurled a cloud of plasma toward Earth earlier this week.”
“The solar flare occurred yesterday (Aug. 2) when an intense magnetic event above sunspot 1261 blasted out a flow of charged particles that’s now headed toward Earth, according to SpaceWeather.com, a website that monitors space weather. This could unleash a geomagnetic storm here on our planet that might disrupt satellite and radio communications.” “The plus side, though, is that skywatchers at high latitudes can expect extra-special aurora borealis displays, also known as the Northern Lights, from the interaction of these charged particles with Earth’s magnetic field.”
Is The Sun About To 'Fizz Out'?
(Staring, Blankly: The solar disk with no sunspot activity. Credit: NASA)
“As perplexing as it may sound, solar researchers are predicting the sun is about to fall into the doldrums,again.” “Despite all the incredible solar flare action we’ve seen in recent months as our nearest star ramps up toward solar maximum predicted to occur in 2013, scientists are predicting the next solar cycle (Cycle 25) will be notable in that it might not even happen.” “This finding was announced today at the Solar Physics Division of the American Astronomical Society, being held at New Mexico State University in Las Cruces.” “This is highly unusual and unexpected,” Frank Hill, associate director of the NSO’s Solar Synoptic Network, said in a conference press release. “But the fact that three completely different views of the sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation.”
Astronomy news, recent research results, and pretty pictures from the media along with context, commentary, and explanations for folks who dig this sort of thing. Written by a quasi-professional astronomer affiliated with the University of Texas at Austin.
