On May 5, 2012, while everyone else was waiting for the “Super Moon” astrophotographer Alan Friedman was out capturing this super image of a super Sun from his back yard in Buffalo, NY!
Taken with a specialized telescope that can image the Sun in hydrogen alpha light, Alan’s photo shows the intricate detail of our home star’s chromosphere — the layer just above its “surface”, or photosphere.
Prominences can be seen rising up from the Sun’s limb in several places, and long filaments — magnetically-suspended lines of plasma — arch across its face. The “fuzzy” texture is caused by smaller features called spicules and fibrils, which are short-lived spikes of magnetic fields that rapidly rise up from the surface of the Sun.
On the left side it appears that a prominence may have had just detached from the Sun’s limb, as there’s a faint cloud of material suspended there.
Alan masterfully captures the Sun’s finer details in his images on a fairly regular basis… see more of his solar (and lunar, and… vintage headwear) photography on his blog site here.
Solar flares pose a major hazard to electronics and infrastructure in Low Earth Orbit, but they may have played a role in kick-starting life on Earth. Credit: NASA/SDO/J. Major
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.
A cluster of coronal cells seen by SDO on June 17, 2011. (NASA/SDO AIA instrument)
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There’s something new under the Sun… well, just above the Sun, actually. Scientists at the Naval Research Laboratory have spotted structures in the Sun’s super-hot corona that may shed some light on the way its magnetic fields evolve — especially near the edges of vast, wind-spewing coronal holes.
Coronal holes are regions where the Sun’s magnetic field doesn’t loop back down but rather streams outward into space. Appearing dark in images captured in ultraviolet wavelengths, these holes in the corona allow solar material to flow directly out into the solar system, in many cases doubling the normal rate of the solar wind.
Recently witnessed by NRL researchers using NASA’s SDO and STEREO solar-observing spacecraft, features called coronal cells exist at the boundaries of coronal holes and may be closely associated with their formation and behavior.
The coronal cells are plumes of magnetic activity that stream upward from the Sun, occurring in clusters. Likened to “candles on a birthday cake”, the incredibly hot (1 million K) plumes extend outwards, punching though the lower corona.
Seen near the center of the Sun’s disk, the cells appear structurally similar to granules — short-lived areas of rising and falling solar material on the Sun’s photosphere — but seen from an angle via STEREO, the cells were witnessed to be much larger, elongated and extending higher into the Sun’s atmosphere. For comparison, granules are typically about 1,000 km in diameter while the coronal cells have been measured at 30,000 km across.
“We think the coronal cells look like flames shooting up, like candles on a birthday cake,” said Neil Sheeley, a solar scientist at the Naval Research Laboratory in Washington, D.C. “When you see them from the side, they look like flames. When you look at them straight down they look like cells. And we had a great way of checking this out, because we could look at them from the top and from the side at the same time using observations from SDO, STEREO-A, and STEREO-B.”
Watch a video below of cells made from images acquired by STEREO-B… note how their elongated structure becomes evident as the cells rotate closer to the Sun’s limb.
NRL researchers also noted that the coronal cells appeared when adjacent coronal holes closed and disappeared when the holes opened, suggesting that the holes and cells share the same magnetic structure. In addition, the coronal cells were seen to disappear when a solar filament would erupt nearby, being “extinguished” as the cooler strand of solar material moved across them. Once the filament passed, the cells reformed — again, indicating a direct magnetic association.
The coronal cells were also identified in earlier images from ESA and NASA’s SOHO and Japan’s Hinode spacecraft.
It’s hoped that further study of these candle-like structures will lead to more knowledge of our star’s complex magnetic field and the effects it has on space weather and geomagnetic activity experienced here on Earth.
Read the press release from the Naval Research Laboratory here, and on NASA’s STEREO site here.
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!
SDO AIA 211 image showing a large triangular hole in the Sun's corona on March 13
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An enormous triangular hole in the Sun’s corona was captured earlier today by NASA’s Solar Dynamics Observatory, seen above from the AIA 211 imaging assembly. This gap in the Sun’s atmosphere is allowing more charged solar particles to stream out into the Solar System… and toward Earth as well.
Normally, loops of magnetic energy keep much of the Sun’s outward flow of gas contained. Coronal holes are regions — sometimes very large regions, such as the one witnessed today — where the magnetic fields don’t loop back onto the Sun but instead stream outwards, creating channels for solar material to escape.
The material constantly flowing outward is called the solar wind, which typically “blows” at around 250 miles (400 km) per second. When a coronal hole is present, though, the wind speed can double to nearly 500 miles (800 km) per second.
Increased geomagnetic activity and even geomagnetic storms may occur once the gustier solar wind reaches Earth, possibly within two to three days.
The holes appear dark in SDO images because they are cooler than the rest of the corona, which is extremely hot — around 1,000,000 C (1,800,000 F)!
Here’s another image, this one in another AIA channel (193):
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.
M6.3-class flare from AR1429. (NASA/SDO/AIA team)
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.”
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.
AR1429 (NASA/SDO/HMI Intensitygram)
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.)
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!
A filament partially blocks SDO's view of erupting plasma on Dec. 9. (NASA/SDO)
A video posted today by the team at NASA’s Solar Dynamics Observatory shows two recent events on the Sun: a twisting prominence and the “eclipse” of a plasma eruption by the structure of a darker, cooler filament. Most impressive!
From the SDO team:
Over the past 24 hours we have seen some beautiful solar events. None of them have a direct impact on Earth, but they are astonishing to watch. It just shows how an active star our Sun really is… far from boring!
On December 8, 2011 a twisting prominence eruption occurred on the lower eastern limb. The view through the AIA 304 angstrom filter shows us this beautiful eruption.
A filament partially blocks SDO's view of erupting plasma on Dec. 9. (NASA/SDO)In the early hours of December 9, 2011 SDO observed a little bit of a different eclipse. An erupting cloud of plasma was eclipsed by a dark magnetic filament. The eruption is still on the far side of the Sun, behind the eastern limb and is slowly moving forward and over the limb sometime next week.
In front you can observe the filament of relatively cool dark material floating across the Sun’s surface in the foreground. That filament partially blocks the view of the hot plasma eruption behind it.
Excellent footage of our constantly-active Sun! It’s easy to forget too that these events and structures are many, many times larger than our entire planet… the sheer power of a star is quite an impressive thing to see. Thanks to SDO we get an unblinking front-row seat to all the action!
Nowhere in the Solar System are conditions more extreme than the Sun. Every second it converts millions of tons of matter into energy to create the intense levels of heat and light we expect of our local star. Study the Sun in different wavelengths and its violent nature can really become apparent. The STEREO satellite has been studying the Sun at a wavelength of 304Å and the results support a controversial solar theory.
Coronal Mass Ejections (or CMEs) are common on the Sun and they have a very real impact to us here on Earth. The solar explosions expel trillions of trillions of tons of super hot hydrogen gas into space, sometimes in the direction of the Earth. Traveling at speeds up to 2,000 kilometers per second it takes just a day for the magnetized gas to reach us and on arrival it can induce strong electric currents in the Earth’s atmosphere leading not only to the beautiful auroral displays but also to telecommunication outages, GPS system failures and even disturbances to power grids.
Solar flares, to use their other name, were first observed back in 1859 and since then, scientists have been studying them to try to understand the mechanism that causes the eruption. It has been known for some time that the magnetically charged gas or plasma is interacting with the magnetic field of the Sun but the detail has been at best, elusive.
In 2006, the international satellite STEREO was launched with the objective of continuously monitoring and studying the CMEs as they head toward the Earth and its data has helped scientists at the Naval Research Laboratory (NRL) in Washington, D.C., start to understand the phenomenon.
Using this new data, scientists at the NRL compared the observed activity with a controversial theory that was first proposed by Dr James Chen (also from the NRL) in 1989. His theory suggested that the erupting clouds of plasma are giant ‘magnetic flux ropes’, effectively a twisted up magnetic field line shaped like a donut. The Sun being a vast sphere of gas suffers from differential rotation where the polar regions of the Sun and the equatorial regions all rotate at different speeds. As a direct result of this, the plasma ‘drags’ the magnetic field lines around and the Sun and it gets more and more twisted up . Eventually, it bursts through the surface, taking some plasma with it giving us one of the most dramatic yet potentially destructive events in the Universe.
Dr Chen and a Valbona Kunkel, a doctorate student at George Mason University, applied Dr. Chen’s model to the new data from STEREO and found that the theory agrees with the measured trajectories of the ejected material. It therefore looks like his theory, whilst controversial may have been right all along.
Its strange to think that our nearest star, the Sun, still has secrets. Yet thanks to the work of Dr. Chen and his team, this one seems to have been unraveled and understanding the strange solar explosions will perhaps help us to minimise impact to Earth based technologies in years to come.
Continuing on its epic journey around the Sun, Ulysses has reached the Sun’s north pole just in the nick of time. In fact, its timing couldn’t be better, just as the Sun begins “Solar Cycle 24”. The probe is in a unique orbit, passing over the solar north and south poles, out of the ecliptic plane of the solar system, giving it an unprecedented view of parts of the Sun we cannot observe on Earth. “Graveyards for sunspots” and mysterious coronal holes lurk in these regions and Ulysses will be perfectly placed, directly above.
The joint NASA and ESA Ulysses mission has been a resounding success in its 18 years of operation since launch on board Space Shuttle Discovery (STS-41) in October 1990. The intrepid spacecraft was helped on it’s way by a gravitational assist by the planet Jupiter which flung it over the poles of the Sun. Quietly travelling in a perpendicular orbit (space missions and the planets usually orbit around the Sun’s equator), Ulysses has been measuring the distribution of solar wind particles emanating from latitudinal locations for one and a half orbits.
As Ulysses passes over the north polar region, the Sun will be observed during a period of minimum activity at this location for the first time. The poles of the Sun are of particular interest to scientists as this is where the fast solar wind originates from open magnetic field lines reaching into space. The dynamics of solar material in this location provides information on how the Sun interacts with interplanetary space and how the solar wind is generated. Observing the solar wind at “solar minimum” will be of massive interest as it may provide some answers as to why the solar wind is accelerated hundreds of kilometers per hour even when activity is at its lowest.
“Just as Earth’s poles are crucial to studies of terrestrial climate change, the sun’s poles may be crucial to studies of the solar cycle.” – Ed Smith, Ulysses project scientist, NASA Jet Propulsion Laboratory.
The dynamics of low altitude magnetic fields in polar regions are also a focus for interest. As 11-year solar cycles progress, sunspot population increase near the solar equator. As the magnetic field is “wound up”, sunspots (and their associated magnetic flux) drift toward the poles where they slowly disappear as the old magnetic field sinks back into the Sun, quite accurately described as sunspot graveyards. Understanding how this cycle works will help to reveal the secrets of the solar cycle and ultimately help us understand the mechanisms behind Space Weather.
