STEVE Puts on a Show


Steve Auroral Arc over House #2 (May 6, 2018)

The strange aurora named Steve put on a show on Sunday, May 6. 

The past weekend was a good one for Northern Lights here in Alberta and across western Canada.

Aurora and Milky Way over Red Deer River

A decent display lit the northern sky on Saturday, May 5, on a warm spring evening. I took in that show from a favorite spot along the Red Deer River.

The next night, Sunday, May 6, we were hoping for a better show, but the main aurora never amounted to much across the north.

Instead, we got a fine showing of Steve, an unusual isolated arc of light across the sky, that was widely observed across western Canada and the northern U.S.  I caught his performance from my backyard.

Popularized by the Alberta Aurora Chasers Facebook group, Steve is the fanciful name applied to what still remains a partly unexplained phenomenon. It might not even be a true aurora (and it is NOT a “proton arc!”) from electrons streaming down, but a stream of hot gas flowing east to west and always well south of the main aurora.

Thus Steve is “backronymed” as Strong Thermal Emission Velocity Enhancement.

To the eye he appears as a grey arc, not doing much, but fading in, slowly shifting, then fading away after 30 to 60 minutes. He doesn’t stick around long.

The camera reveals his true colours.

Steve Auroral Arc over House #1 (May 6, 2018)

This is Steve to the west, displaying his characteristic pink and white tints.

Fish-Eye Steve #1 (May 6, 2018)

But overhead, in a fish-eye lens view, he displayed ever so briefly another of his talents – slowly moving fingers of green, called a picket fence aurora.

It was appropriate for Steve to appear on cue, as NASA scientists and local researchers who are working on Steve research were gathered in Calgary to discuss future aurora space missions. Some of the researchers had not yet seen Steve in person, but all got a good look Sunday night as they, too, chased Steve!

I shot a time-lapse and real-time videos of Steve, the latter using the new Sony a7III camera which can shoot 4K videos of night sky scenes very well.

The final video is here on Vimeo.

Steve Aurora – May 6, 2018 (4K) from Alan Dyer on Vimeo.

It is in 4K, if you choose to stream it at full resolution.

With summer approaching, the nights are getting shorter and brighter, but we here in western Canada can still see auroras, while aurora destinations farther north are too bright and lack any night skies.

Plus our latitude south of the main auroral oval makes western Canada Steve country!

— Alan, May 9, 2018 / © 2018 / AmazingSky.com

 

The Aurora Starring Steve


"Steve," the Strange Auroral Arc (Spherical Fish-Eye Projection)

I’ve assembled a music video of time-lapse clips and still images of the fine aurora of September 27, with Steve making a cameo appearance.

The indicators this night didn’t point to a particularly great display, but the sky really performed.

The Northern Lights started low across the north, in a very active classic arc. The display then quietened.

But as it did so, and as is his wont, the isolated arc that has become known as Steve appeared across the south in a sweeping arc. The Steve arc always defines the most southerly extent of the aurora.

Steve faded, but then the main display kicked up again and began to fill the sky with a post-sub-storm display of pulsing rays and curtains shooting up to the zenith. Only real-time video can really capture the scene as the eye sees it, but the fast time-lapses I shot do a decent job of recording the effect of whole patches of sky turning on and off.

The display ended with odd pulsing arcs in the south.

Here’s the video, available in 4K resolution.

Alberta Aurora (Sept. 27, 2017) from Alan Dyer on Vimeo.

Expand to fill the screen for the best view.

Thanks for looking!

— Alan, October 7, 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 

Auroras from Alberta


Aurora Self-Portrait (March 2 2017)

The solar winds blew some fine auroras our way this past week. 

Oh, that I had been in the North last week, where the sky erupted with jaw-dropping displays. I could only watch those vicariously via webcams, such as the Explore.org Northern Lights Cam at the Churchill Northern Studies Centre.

But here in southern Alberta we were still treated to some fine displays across our northern sky. The image below is from March 1, from my rural backyard.

Fish-Eye Aurora (March 1, 2017)
A full-frame fish-eye lens image of the aurora on March 1 with curtains reaching up into the Big Dipper.

The Sun wasn’t particularly active and there were no coronal mass ejections per se. But a hole in the corona let a wind of solar particles through to buffet our magnetosphere, stirring up geomagnetic storms of Level 4 to 5 scale. That’s good enough to light our skies in western Canada.

Aurora over Frozen Pond
A 160° panorama of the main auroral oval to the north on March 2 about 11:40 pm MST.

Above is the display from March 2, taken over a frozen pond near home. I like how the Lights reflect in the ice.

This night, for about 30 minutes, an odd auroral form appeared that we see from time to time at our latitudes. A wider panorama shows this isolated arc well south of the main auroral oval and forming a thin arc stretching across the sky from west to east.

Aurora Panorama with Isolated Arc
A 220° panorama of the isolated arc to the west (left) and east (right) and the main auroral oval to the north.

The panorama above shows just the western and eastern portion of the arc. Overhead (image below) it looked like this briefly.

Isolated Auroral Arc Overhead
The overhead portion of the isolated arc at its peak.

Visually, it appeared colourless. But the camera picks up this isolated arc’s usual pink color, with a fringe of white and sometimes (here very briefly) a “picket-fence” effect of green rays.

Isolated Auroral Arc West
The western portion of the isolated auroral arc at its peak.

This is the view of the isolated arc to the west. Erroneously called “proton arcs,” these are not caused by incoming protons. Those produce a very diffuse, usually sub-visual glow. But the exact nature of these isolated arcs remains a mystery.

As we head into solar minimum in the nest few years, displays of Northern Lights at lower latitudes will become less frequent. But even without major solar activity, last week’s displays demonstrated  we can still get good shows.

— Alan, March 4, 2017 / © 2017 Alan Dyer / AmazingSky.com