Aurora’s Out Right Now – Sunday Morning June 17

The wall of auroral rays that covered much of the northern sky early this morning around 12:15 p.m. CDT. Photo: Bob King

Aurora predictions were dead on. As soon as our lengthy twilight ended Saturday night, the glow of northern lights gave the sky a whitewashed appearance in the north. A green arc simmered very low, but above it, there was little more than a featureless glow.

Subtle to the eye, the camera recorded colors according to which atmospheric gas was giving off light. The arc glows green from oxygen and the rays blue from nitrogen. Photo: Bob King

Around 11:30 p.m. that all changed. Soft, faint rays with hints of blue suddenly stood up across the northern sky as high as the North Star. They ebbed and flowed, fading and flowering, slowly intensifying into what I called the “wall of light”. More distinct rays lit up the northwest beneath the Big Dipper. The display was impressive and literally threw enough light to see your way in the darkness.

Are the stripes at left connected to this morning’s aurora or were they airglow, the nighttime glow of air molecules that release energy after being charged by sunshine during the day?  At right you can see the regular aurora. Photo: Bob King

Odd pale stripes crossed the sky much further south, reaching from beneath Arcturus all the way east to Pegasus. Time exposure photos revealed them as pale green in color. I’ve seen these curious faint bands of aurora in the southern half of the sky before and still can’t quite figure them out.

One bright ray stood out from the crowd for a brief minute. Clouds moved through the scene at the same time. Photo: Bob King

It was a pretty show for the dark-adapted eye with lots of slow, pulsing rays, but thanks to the extra sensitivity of the camera, the display proved spectacularly colorful. Pinks and greens from oxygen and delicate blues from nitrogen molecules painted the upper atmosphere. Fireflies added their own flashes of pale green to nightscape.

One of the most enjoyable aspects of aurora watching is getting into their rhythm. Like a work of classical music, a display can unfold in slow and grand style taking hours to reach a crescendo. This storm had that feel. Others hit all the highs and lows in the space of an hour like a Beethoven symphony.

Auroras will likely continue through the remainder of tonight; there’s also a chance of more activity Sunday night. If you haven’t been out yet for a look, the northern sky’s still aglow as of 2:30 CDT.

15 Responses

  1. Pallavi

    I feel terrible, i missed it..drove from the twin cities and was planning on driving to duluth when the kp index dropped to 4, waited for a while at forest lake to see if it would go up..thought i saw a faint greenish blue tinge but then decided it was “wishful thinking”.since the kp index was still at 4 returned to the twin cities at 1.00 am- whats the probabilty of seeing it in duluth when its 4?so that next time ill just drive north if its 4. Your picures of the auroras are gorgeous..!

    1. astrobob

      Darn! That is frustrating. This was an interesting aurora – not much color to the eye except for the green arc. From a dark sky site, the very slow crescendo of rays and expansive unfolding were very enjoyable to watch. Much of it happened as the Kp dropped from 6 to 4. The peak was around 12:30-1 a.m. but the glow – with a ray here and there – was out all night. Some nights, Kp=4 means just a low arc and maybe a very faint ray or two. Other nights like this one had a lot more to show for a modest storm.

  2. Chris Garner

    Bob

    I captured some of the same images at the same time you did last night. Very cool show last night. I’m still learning, hard to focus at night and I need a better lens. Could I email you a pic or two?

    Chris

  3. Mike Thiele

    Good morning Bob! Great aurora! Great photos!

    So much nicer to observe these when it is in the 60’s instead of the -20’s!

    The folks in Alaska and Norway missed out as the sun is too far north!

    Can you share the technical of the photos? Lens, exp, aperture, ISO, etc. Thanks Bob! Take care.

    Mike

    1. astrobob

      Hi Mike,
      Yes, the weather was perfect here. Temp. of 53 degrees and a nice breeze. Pics were taken at between 16mm and 35 mm focal length, ISO 800, f/2.8 and 30 seconds.

  4. Chris

    Bob-

    I tried sending pics to the address you gave me but they all came back “failed”. I just tried sending them a different way, so hopefully you received them.

    Thanks,
    Chris

    1. astrobob

      Hi Chris,
      Got your photos – you got some great shots! And the fireflies weren’t too bad either. Two of the pix were focused close to infinity, the other a little off. Focusing at night with a digital camera takes practice. You can keep working trial and error with the stars or wait until the moon is back, which can be a little easier to focus on. Once you get just one perfectly focused, sharp image, make a note of exactly what the lens setting is. You can mark the barrel with tape or marker or simply memorize the focused (infinity) position, so you can return to it in a moment the next clear night.

  5. kevin scanlon

    on sunday june 17 2012 I kept seeing random flashes of soft light throughout the sky although the sky was clear. could this be from solar activity

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