- by John Hlynialuk
A new type of auroral feature (which is not actually auroral in nature) has been discovered and it goes by the initials "S.T.E.V.E" standing for Strong Thermal Emission Velocity Enhancement. Although a lot of times, astronomers lack imagination, like when they named the largest red stars "Red Giants" or a dark band of dust in a globular cluster, the "Dark Doodad Nebula", they made up for it with STEVE. I think it is a great name.
The story of STEVE starts less than 2 years ago, when a group of aurora photographers, the Alberta Aurora Chasers came to the attention of a University of Calgary auroral scientist, Prof. Eric Donovan. The aurora chasers had been photographing an unusual ray of purplish light that sometimes appeared along with normal aurora and it often showed up with multiple "green fingers" dubbed a "picket fence" nearby. Prof. Donovan had no idea what it was but he was intrigued and gave it the name "Steve" a whimsical label signifying something unknown (that puckish astronomy humour again). Only later was the phenomena give the more elaborate "backronym" STEVE as mentioned above.
Using Earth-orbiting satellites, Prof. Donovan was able to get measurements of the gases in STEVE and detected a large increase in temperature and a westward velocity of the materials (the "T" and the "V" in STEVE's official name). Undoubtedly, STEVE had been observed in the past but scientists did not have networks of all-sky cameras on the ground or satellites in orbit that could take Steve's temperature and other vital signs. Neither had the community of amateur scientists (Citizen Scientists as they are now called) alerted professionals that there was something new up there in the heavens that needed explanation. Equally important were cameras sensitive enough to easily photograph the faintest phenomena in the night sky. A lot of ordinary folks were trying them out taking pictures of star trails, the Milky Way, and, since much of Canada is under the "auroral oval" many images of northern lights. A lot of factors came together, and as a result, STEVE's time had come.
Many readers of this column have described to me occasions when they have observed aurora and now, many are also taking images. It may be that you have seen STEVE so I challenge you to go back through your picture files to see if you have captured this newest auroral phenomena. If you have, please send me an email at [email protected]. My own archive of aurora images has turned up one night (so far) when I think STEVE appeared.
When I heard about STEVE a few months ago, I recognized the "picket fence" as something I had captured on camera on Apr 25, 2012. At the time, I called it a "strange wing-shaped aurora" and it was the second of two displays that appeared two weeks apart. An earlier display on April 12, was a nice violet-coloured curtain above the northern horizon that was accompanied by a few brighter purple rays.
I have now seen "official" images of STEVE, and the strange aurora that I captured on April 25, could be another example! That night, I was just closing up the Fox Observatory and at 11:18 pm I noticed the strange light in the sky. Before the short display had ended around midnight, I had about 5 dozen images. The one included here was taken at 11:38 pm and shows the typical narrow purplish ray as well as the green picket fence, both features characteristic of STEVE.
I have sent a copy of this image to Prof. Donovan for confirmation and am awaiting his reply. Although my images from 6 years ago do not constitute a "scoop" since there are lots of images of STEVE made by the Alberta Aurora Chasers, it is definitely a first for me. Though it felt like I was having an enjoyable night under the stars with an unusual auroral display, it turned out I was doing "citizen science" without realizing it. And now I know I was out there having fun with my new-found "friend" STEVE!
PS: The auroral display two weeks before STEVE appeared, ended up as cover art for a Toronto guitar jazz musician Robert Tardik's CD, "Limitless". I sometimes play it as background music when I observe.
Clear skies!
