Night of the Great Aurora


Great Aurora of May 27, 2017 – Wide-Angle v5

No one predicted this spectacle. But on May 27 the last-minute warnings went out to look for a fabulous show as night fell.

And what a show it was! As darkness fell the sky was lit with green curtains. After midnight the curtains converged at the zenith for that most spectacular of sky sights, a coronal burst.

Aurora over the Rothney Observatory

As the night began I was at the Rothney Observatory helping out with the public stargazing night.

ISS and Aurora - Rising out of the West

We saw the Space Station rise out of the west over the Rockies and pass through the Northern Lights.

ISS and Aurora - In the East over Rothney Observatory

It then headed off east, appearing here as the streak amid the Lights and light pollution of Calgary.

To continue to shoot the display I, too, decided to head east, to home. I should have gone west, to the mountains.

I drove through rain to get home, and missed the peak of the display, judging by images from others in the Rockies, and those to the north.

ISS Through the Aurora (May 27, 2017)

But as I got home clouds began to clear enough for a glimpse of the Space Station, on its next pass, flying overhead, again through the aurora. I wonder what the astronauts might have been seeing looking down.

Great Aurora of May 27, 2017 – Wide-Angle v3

From home, I caught another bright sub-storm outburst to the north, as the curtains suddenly exploded in brightness and rapid motion, with characteristic pink fringes at the bottoms, from nitrogen molecules.

What impressed me about this display was the smell! Yes, you see auroras and some claim to hear them. But this display is one I’ll remember for the springtime scent of lilacs in the night air as the Lights danced. 

The Great Aurora of May 27 from Alan Dyer on Vimeo.

Here is a short music video of several time-lapse sequences I shot, of the sub-storm then post-storm subsidence into the patchy flaming and flickering effect that we often see at the end of a great display. And this was certainly one of them.

We southerners were treated to the class of display you usually have to travel north the Arctic and auroral oval to see.

— Alan, May 31, 2017 / © 2017 Alan Dyer / AmazingSky.com 

 

Rivers of Earth and Sky


Shooting at Orkney Viewpoint

The arch of the Milky Way mirrors the sweep of the Red Deer River on a magical night in the Alberta Badlands.

Images of the Milky Way arching across the sky are now iconic. They are almost always assembled from individual frames stitched together to make a seamless panorama.

From the northern hemisphere, spring is the best season to shoot such a panorama as the Milky Way then remains confined to the eastern sky.

Later in summer, when the Milky Way passes directly overhead, panoramas are still possible, but the Milky Way looks distorted. The process of mapping a round sky onto a rectangular image, as I show here, inevitably stretches out the Milky Way near the zenith.

Last Saturday, in search of the Milky Way during prime panorama season, I set up for the night at Orkney Viewpoint overlooking the Red Deer River in the Alberta Badlands north of Drumheller. There, the river performs a grand curve through the valley below.

Above, the Milky Way, often described as a river of stars, sweeps in mirror-image fashion above the earthly river.

Rivers of Earth and Sky
This is a stitch of 8 segments with the Sigma 20mm Art lens, in portrait mode, and Nikon D750. Each 30 seconds at f/2 and ISO 3200. Stitched with Adobe Camera Raw. Taken on a mild and moonless night, May 20, 2017.

The panorama above contains the reflection of stars – of the constellation of Delphinus in particular – in the smooth water on a windless night.

To the north at left, the Northern Lights put on a subtle show. While never spectacular to the eye, the camera records the aurora’s colour and forms that often elude the naked eye.

Aurora over Red Deer River
This is a stack of 4 x 15-second exposures for the ground to smooth noise, and one 15-second exposure for the sky, all with the 20mm Sigma lens at f/2.8 and Nikon D750 at ISO 3200. They were part of a 250-frame time-lapse.

The display was brightest early in the evening – that’s 11 p.m. now in May at my latitude.

The display then faded in intensity before I shot the two panoramas about 1 a.m., but the last few frames of the time-lapse show a final burst of colour from a lone curtain reflected in the river.

Lone Curtain of Aurora over Red Deer River
This is a stack of 84 x 15-second exposures for the ground to smooth noise, and one 15-second exposure for the sky, all with the 20mm Sigma lens at f/2.8 and Nikon D750 at ISO 3200. They were part of a 250-frame time-lapse.

This was a magical night indeed. And a rare one this spring with clouds more often the norm at night.

The next dark of the Moon coincides with summer solstice. So while the moonlight won’t interfere, critical for shooting the Milky Way, the glow of perpetual twilight at my latitude will. The Milky Way will be set in a deep blue sky.

By July’s dark of the Moon the Milky Way will be high overhead, making panorama arches tough to assemble. It looks like this might have been my one best night to capture such a scene this year. But it was a good one.

— Alan, May 24, 2017 / © 2017 Alan Dyer / amazingsky.com 

Meet Steve, the Odd Auroral Arc


Red Auroral Arc #1 (May 10, 2015)

Stargazers in western Canada will have seen him – Steve, the odd auroral arc. 

There’s been a lot of publicity lately about an unusual form of aurora that appears as a stationary arc across the sky, isolated from the main aurora to the north. It usually just sits there – motionless, featureless, and colourless to the eye, though the camera can pick up magenta and green tints.

We often see these strange auroral arcs from western Canada.

Red Auroral Arc #3 (May 10, 2015)

In lieu of a better name, and lacking a good explanation as to their cause, these isolated arcs have become labelled simply as “Steve” by the aurora chasing community (the Alberta Aurora Chasers Facebook group) here in Alberta.

In a gathering of aurora chasers at Calgary’s Kilkenny Pub, aurora photographer extraordinaire and AAC Facebook group administrator Chris Ratzlaff suggested the name. It comes from the children’s movie Over the Hedge, where a character calls anything he doesn’t understand “Steve.” The name has stuck!

Aurora Panorama with Isolated Arc

The 270° panorama from March 2, 2017 shows Steve to the west (right) and east (left) here, and well isolated from the main aurora to the north.

Isolated Auroral Arc Overhead

This is the view of that same March 2, 2017 arc looking straight up, showing Steve’s characteristic gradient from pink at top though white, then to subtle “picket-fence” fingers of green that are usually very short-lived.

Isolated Auroral Arc #3 (Sept 2, 2016)

The view above is Steve from exactly 6 months earlier, on September 2, 2016. Same features. I get the impression we’re looking up along a very tall but thin curtain.

Isolated Auroral Arc #5 (Sept 2, 2016)

Another view of the September 2, 2016 Steve shows his classic thin curtain and gradation of colours, here looking southeast.

Isolated Auroral Arc #4 (Sept 2, 2016)

Looking southwest on September 2, 2016, Steve takes on more rippled forms. But these are very transient. Indeed, Steve rarely lasts more than 30 minutes to an hour, and might get bright for only a few minutes. But even at his brightest, he usually looks white or grey to the eye, and moves very slowly.

Auroral Arc East

Here’s a classic Steve, from October 1, 2006 – a white featureless arc even to the camera in this case.

So what is Steve?

He is often erroneously called a “proton arc,” but he isn’t. True auroral proton arcs are invisible to the eye and camera, emitting in wavelengths the eye cannot see. Proton auroras are also diffuse, not tightly confined like Steve.

Auroral Arc Overhead

Above is Steve from August 5, 2005, when he crashed the Saskatchewan Summer Star Party, appearing as a ghostly white band across the sky. But, again, the camera revealed his true colours.

Steve Auroras in 2015 from Alan Dyer on Vimeo.

Here are a couple of time-lapses from 2015 of the phenomenon, appearing as an isolated arc overhead in the sky far from the main auroral activity to the north. I shot these from my backyard in southern Alberta. In both clips the camera faces north, but takes in most of the sky with a fish-eye lens.

In the first video clip, note the east-to-west flow of structure, as in classic auroras. In the second clip, Steve is not so well-defined. Indeed, his usual magenta band appears only briefly for a minute or so. So I’m not sure this second clip does show the classic Steve arc.

The origin and nature of Steve are subjects of investigation, aided by “citizen science” contributors of photos and videos.

Local aurora researcher Dr. Eric Donovan from the University of Calgary has satellite data from the ESA Swarm mission to suggest Steve is made of intensely hot thermal currents, and not classic electrons raining down as in normal auroras. He has back-acronymed Steve to mean Strong Thermal Emission Velocity Enhancement.

Learning more about Steve will require a unique combination of professional and amateur astronomers working together.

Now that he has a name, Steve won’t be escaping our attention any longer. We’ll be looking for him!

— Alan Dyer / May 12, 2017 / © 2017 Alan Dyer/AmazingSky.com 

The Amazing Sky of Carina and Centaurus


 

Carina-Centaurus Nebulas Mosaic - Version 1

Deep in the southern Milky Way lies one of the most spectacular regions of sky.

Located about as far south in the Milky Way as it gets you find this wonderful region in Carina and Centaurus.

The Carina Nebula (NGC 3372) at upper right is one of the finest nebulas in the sky for binoculars or any telescope.

At lower left is the Running Chicken Nebula (IC 2948) (aka the Lambda Centauri Nebula). By contrast, this nebula is mostly a photographic target, and is a challenge to see with a small telescope. But can you see the Chicken here?

Carina-Centaurus Nebulas Mosaic (with Labels)

The small red and magenta nebulas at centre are called NGC 3603 and NGC 3576.

The blue Southern Pleiades star cluster (IC 2602) is at bottom right.

The Pearl Cluster (NGC 3766) is above the Running Chicken at left. The cluster IC 2714 is to the right of the Chicken amid dark nebulas.

The Gem Cluster (NGC 3324) is above and right of the Carina Nebula but small and unresolved here.

The Football Cluster (NGC 3532) is top centre, though partly lost amid the rich starfield.

All told, this is one of the best areas in the sky for deep-sky wonders. But you must travel south to see it, to at least 20° North latitude.

This is a mosaic of three segments, taken with the camera in portrait orientation, stitched with Photoshop to make a square framing of the area. Each segment was a stack of 4 x 2-minute exposures at f/2.8 with the 200mm Canon L-series lens and filter-modified Canon 5D MkII at ISO 2500.

I shot this mosaic earlier in April from my observing site at Coonabarabran, Australia.

— Alan, May 4, 2017 / © 2017 Alan Dyer / amazingsky.com 

 

The Amazing Austral Sky


Panorama of the Milky Way Overhead

The latitude of 30° South is the magic latitude on Earth for seeing the Milky Way.

From that region of the world – southern Australia, central South America, southern Africa – the centre of the Galaxy passes overhead, and you see the view at top.

You see the galactic core glowing brightly at the zenith, and the arms of the Milky Way stretching off to the horizon on either side of the core – to Aquila at left, for the northern half of the Galaxy, and to Carina at right, for the southern half of the Galaxy. That area of the Galaxy is always below the horizon for viewers at northern latitudes.

The image below focuses in on just the southern portion of the Milky Way, framing what in Australia is called the “Dark Emu,” a constellation made of the dark lanes along the Milky Way, from his head at right in Crux, to his tail at left in Scutum.

The Dark Emu Overhead

This is the most amazing region of the Milky Way, and is worth the trip south of the equator just to see, by lying back and looking up. You can easily see we live in a vast Galaxy, and not in the centre, but off to one side looking back at the core glowing overhead.

I would say there are three sky sights that top the list for spectacle:

• A bright all-sky aurora

• A total solar eclipse

• and the naked eye view of the Galaxy with its centre overhead and its arms across the sky from horizon to horizon.

I’ve checked off two this year! One more to go in August!

— Alan, May 2, 2017 / © 2017 Alan Dyer / AmazingSky.com