SOLAR FLARE AND RADIO BLACKOUT (UPDATED): Giant sunspot AR3354 erupted on June 29th (1415 UT), producing an M3.8-class solar flare (movie) and a shortwave radio blackout over the Atlantic Ocean (map). Newly arriving SOHO coronagraph data suggest that no significant CME will emerge from the blast site. . Solar flare alerts: SMS Text
GIANT SUNSPOT ALERT: When this week began, sunspot AR3354 didn't exist. Now it is 10 times wider than Earth and still growing. The sunspot burst into view on June 27th, breaching the surface of the sun, then blossoming into a giant over the next 48 hours: movie.
AR3354 is so big, amateur astronomers can see details normally reserved for the world's greatest telescopes. Michael Karrer sends this picture of the sunspot's dark heart from his backyard observatory in Austria
"Despite its gigantic size, the sunspot was not as easy to photograph as I expected," says Karrer. "The jetstream brought variable seeing to my observatory. But in a few moments of fair conditions I was able to capture this high-resolution image."
Karrer's photo shows that the sunspot's heart is not completely dark. It is peppered by "umbral dots"--incandescent balls of plasma rising and falling in the sunspot's core. Researchers believe they are turbulent convection cells, which dredge up heat from ~1000 km below. The same kind of motions can be seen in a pan of water boiling on a hot stove. The photo also resolves hundreds of "penumbral filaments," fine magnetic tubes that transport energy out of the sunspot.
While many astronomers are using telescopes to examine the sunspot, telescopes are not required. AR3354 can be seen without any magnification. If you have eclipse glasses, put them on and take a look. Solar flare alerts: SMS Text
more images: from Stuart Green of Preston, Lancashire, UK; from Francisco A. Rodriguez of Vega de San Mateo, Gran Canaria, Canary Islands;
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NATURE'S SOLAR FILTER: Smoke from Canadian wildfires has spread so widely it's now in Europe. This is having an effect on the visibility of the sun. "We can see large sunspot group AR3354 even without a solar filter," reports Jean-Baptiste Feldmann, who sends this picture from Gleizé, France:
Inset into Feldmann's photo of the sunset is a NASA map of black carbon particles—commonly called soot—crossing the Atlantic Ocean. According to the UK Met Office, these particles are contributing to vivid sunrises and sunsets, and very poor air quality.
Sparked mainly by lightning around Quebec, Canada's unusually intense wildfire season has filled skies with smoke since May. Observers in North America have been watching smokey "sunspot sunsets" for weeks. Now Europeans can, too.
Warning: Even when the sun is dimmed by low-hanging smoke, it is still dangerous to look at with unfiltered optics. To avoid eye damage from magnified sunlight, always use your camera's LCD screen for pointing.
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RARE LT. UHURA MUG (COLLECTOR'S ITEM): You can't buy this on Amazon. Only the Earth to Sky Store has the rare Lt. Uhura Coffee Mug. Like the great translator of Star Trek, it has been to space:
On June 20th, this 16 oz. ceramic mug featuring the face of Nichelle Nichols flew to the stratosphere onboard an Earth to Sky Calculus cosmic ray balloon. At the apex of the flight, it floated 92,192 feet above the Sierra Nevada mountains of central California.
You can have it for $170.10 (the serial number of the Enterprise divided by 10). It comes with a greeting card showing the mug in flight and telling the story of its journey to the edge of space and back again.
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MINOR GEOMAGNETIC STORM WATCH: NOAA forecasters say that a CME might graze Earth's magnetic field on July 1st. It was launched into space two days ago by an erupting magnetic filament in the sun's northern hemisphere. The glancing blow, if it occurs, could spark a minor G1-class geomagnetic storm. Aurora alerts: SMS Text
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