Day: June 16, 2015

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Solstice Sky at Dinosaur Park


Summer solstice twilight and circumpolar star trails over the badlands of Dinosaur Provincial Park, Alberta. Some bright noctilucent clouds are visible low on the northern horizon. I shot this June 15, 2015 as part of a shoot for a “star trail” video tutorial, as an example image. This is a stack of the first 200 frames of 275 shot for a time-lapse, each 15 seconds at f/2.8 with the Rokinon 14mm lens and Canon 6D at ISO 1600. I stacked them in Advanced Stacker Actions with the ultrastreak mode. The foreground comes from a mean blend of the first 8 frames, to smooth noise, and to provide a brighter foreground from early in the sequence when the sky and ground were brighter.

The stars circle the bright northern sky at solstice time over the Alberta Badlands.

I spent the evening and well into the night on Monday shooting at a favourite spot, Dinosaur Provincial Park in southern Alberta. The result of about an hour of shooting around midnight is the circumpolar star trail composite at top.

It shows the stars spinning about Polaris, while the northern horizon is rimmed with the bright glow of all-night twilight.

Particularly bright in the northwest are noctilucent clouds low on the horizon. These are high-altitude clouds near the edge of space catching the sunlight streaming over the pole at this time of year.

Noctilucent clouds (NLCs) over the silhouette of the badlands of Dinosaur Provincial Park in southern Alberta, on the night of June 15/16, 2015. The clouds remained low on the northern horizon and faded as the Sun angle dropped through the night but then reappeared in the northwest prior to dawn. The bright star at left is Capella, circumpolar at this latitude of 50° N. This is a single exposure for 10 seconds at f/3.2 with the 16-35mm lens and at ISO 800 with the Canon 60Da.

They are a phenomenon unique to the weeks around solstice, and for our latitudes on the Canadian Prairies.

The close-up shot above shows their intricate wave-like formation and pearly colour. They faded though the night as the Sun set for the clouds. But they returned in the pre-dawn light.

If you live at mid-northern latitudes, keep an eye out for these clouds of solstice over the next month. It’s now their peak season.

– Alan, June 16, 2015 / © 2015 Alan Dyer / www.amazingsky.com