CORONAL HOLE: NASA’s Solar Dynamics Observatory is monitoring a hole in the sun’s atmosphere–a “coronal hole.” It is the dark region circled in this extreme ultraviolet image taken during the early hours of April 28th:
Above: A composite 171-193-211 Angstrom EUV image from SDO. April 28 @ 06:28 UT
Coronal holes are places where the sun’s magnetic field opens up and allows the solar wind to escape. A stream of solar wind flowing from this coronal hole is expected to reach Earth on April 30th-May 1st. NOAA forecasters estimate a 35% chance of geomagnetic activity at that time
SOLAR FLARES: Emerging sunspot complex 1195-1196 is crackling with M-and C-class solar flares. John Stetson and students in South Portland, Maine, caught one of them in this snapshot taken April 21st at 1500 UT:
“Big sunspot 1193 was an attractive target,” says Stetson, “but the real action was taking place around the sun’s southeastern limb.” Indeed, that is where readers with solar telescopes should point their optics. AR1195-1196 is growing in complexity and more flares could be in the offing.
STRANGE BEAUTY: It’s been almost a year since NASA’s Solar Dynamics Observatory began taking pictures of the sun. As the first anniversary of First Light approaches on April 21st, researchers are taking stock of the observatory’s many accomplishments. One of the most profound results turns out to be aesthetic: the sun is more beautiful than anyone imagined. Consider the following extreme ultraviolet image, taken just hours ago, of the magnetic canopy of sunspot complex 1191-1193:
This stunning snapshot is actually routine material for SDO. The observatory produces a daily torrent of beauty that, even now, mission scientists haven’t grown used to. Normally unflappable researchers are frequently caught staring slack-jawed at SDO movies. And when they’re done, they don’t have the vocabulary to describe what they have seen. Many of the phenomena SDO catches have no textbook names. SDO’s starscapes may turn out to be as prized to poets, artists, and writers as they are to no-nonsense solar physicists.
Just How Active is our Sun Now Compared to Two Years Ago?
by NANCY ATKINSON on APRIL 5, 2011
This video provided by the Solar Dynamics Observatory provides a side-by-side comparison of the Sun from precisely two years ago (left, from SOHO in 2009) to the present (right, from Solar Dynamics Observatory, showing March 27-28, 2011) which dramatically illustrates just how active the Sun has become. The comparisons shown in two similar wavelengths of extreme ultraviolet light, reveal how the Sun now sports numerous active regions that appear as lighter areas that are capable of producing solar storms. Two years ago the Sun was in an extremely quiet solar minimum. The Sun’s maximum period of activity is predicted to be around 2013, so activity will likely continue to ramp up.
PRIL AURORAS: According to the space weather forecast, geomagnetic storms were unlikely on April 1st. It would’ve been foolish to go out looking for Northern Lights. Warren Gammel of Fairbanks, Alaska, decided to check the skies anyway, and this is what he saw:
“I didn’t expect to see too much when I went out at 2 a.m. on April 1st, but the auroras were fairly strong,” he says. “I took these pictures using a Canon T1i with a Pelang 8mm fisheye lens.”
The display was caused by a minor but effective solar wind stream that arrived during the early hours of April 1st. The impact sparked bright lights across the Arctic realm of North America.
ICONIC ERUPTION: A huge filament of magnetism and hot plasma blasted off the sun’s southwestern limb on March 19th around 1200 UT. NASA’s Solar Dynamics Observatory recorded the action:
The eruption was not Earth-directed, but it did attract plenty of attention on our planet. Many amateur astronomers in Europe witnessed the blast and said it was the biggest one they’d ever seen. This event continues the recent trend of increasing solar activity, and shows anew that Solar Cycle 24 is gaining steam after a long period of relative quiet.
MAGNETIC FILAMENT: A long and sinuous filament of magnetism is snaking over the sun’s western limb. NASA’s Solar Dynamics Observatory captured the 200,000 km-long structure in mid-twist on the morning of March 18th:
Long filaments like this one are often unstable. If this one erupts, it could hurl pieces of itself toward Earth. More likely, the filament will continue to wind over the western limb, active but intact. Either way it’s a good show.
China had two suns recently and there seems to be no valid explanation for the odd phenomenon. The appearance of the two suns comes just weeks after a rumor sent the web into a frenzy by saying that a star would soon blow up causing two suns to appear in the sky. Was this the star showing up or is there some other explanation for the odd event?
Even though the story was debunked, it seems that it happened anyway. The suns appeared next to each other in the sky, creating a dual sunset. One of the sun’s was fuzzy and orange, while the other sun appeared to be more yellow.
According to Jim Kaler from the University of Illinois, the two suns can be explained scientifically, but it’s not something that even science completely understands. Though this is an extremely rare event, the double sun in the sky is actually just an effect of optical refraction, Kaler said.
“I doubt it’s been computer modeled,” Kaler said. “There must have been some blob of atmosphere somewhere that caused this truly spectacular phenomenon, which in a sense is a mirage.”
Other scientists and astronomers agree with Kaler.
“This is not a common optical phenomenon that we’re seeing here,” said Grant Perry, who is an atmospheric scientist at the University of Wisconsin Cooperative Institute for Satellite and Meteorological Studies. “I’m asking myself if this is an artifact of the lens, but if that were the case — if it’s reflections of the lens elements — then the images would move in relation to each other as the camera moves…But that doesn’t happen.”
What do you think of the two suns? It definitely looks like some sort of optical illusion, but at the same time, it’s amazing to think that it is actually a natural phenomenon. Those who witnessed it first hand are very lucky!
Spotless Days Current Stretch: 0 days
2011 total: 1 day (1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 820 days
Typical Solar Min: 486 days
Updated 11 Mar 2011
fr/spaceweather.com
X-FLARE: March 9th ended with a powerful solar flare. Earth-orbiting satellites detected an X1.5-class explosion from behemoth sunspot 1166 around 2323 UT. A movie from NASA’s Solar Dynamics Observatory shows a bright flash of UV radiation plus some material being hurled away from the blast site:
A first look at coronagraph images from NASA’s STEREO-B spacecraft suggests that the explosion did propel a coronal mass ejection (CME) toward Earth. This conclusion is preliminary, however, so check back later for updates.
After four years without any X-flares, the sun has produced two of the powerful blasts in less than one month: Feb. 15th and March 9th. This continues the recent trend of increasing solar activity, and shows that Solar Cycle 24 is heating up. NOAA forecasters estimate a 5% chance of more X-flares during the next 24 hours.
