February 2016 – The Amazing Sky

February 29, 2016

A Panorama of the Spring and Winter Sky

Winter and Spring Sky Panorama

I present a sweeping panorama of the winter and spring stars on a February night.

The lead image is a panorama I shot last Saturday, February 27 that takes in about 200° of sky from northeast to west, and nearly to the zenith. It encompasses most of the northern spring and winter stars and constellations.

I’ve added the labels to help you pick out the celestial highlights. The winter sky, containing Orion as the central constellation, is at right setting into the west. This area of sky contains a rich collection of bright stars and identifiable constellations.

The left side of the sky contains the spring constellations, now coming into view in the east. Note how that area of sky is sparsely populated by bright stars. You can see the Big Dipper, Regulus in Leo, and Arcturus rising at lower left.

The reason for the difference is the Milky Way – you can see it at right arcing up from the southern horizon passing by Orion and through Gemini, Taurus and Auriga. In that direction we are looking into the outlying spirals arms of our galaxy, toward rich areas of star formation.

To the east, at left, we are looking at right angles out of the plane of our spiral galaxy, toward the galactic North Pole, here just left of Leo. In that direction there are very few bright stars between us and the starless depths of intergalactic space. The spring sky is rather blank compared to the rich winter sky.

But you can see Jupiter, the brightest object in view here, and now prominent in the evening sky.

Note one other subtle glow just above Jupiter. That diffuse glow is the Gegenschein, caused by sunlight reflecting off interplanetary dust opposite the Sun in our solar system and in the plane of the ecliptic.

Jupiter is just east (left) of the Gegenschein here, as Jupiter was then just over a week before its date of opposition, March 8. By then the Gegenschein will have moved to superimpose right over Jupiter, as both then lie opposite the Sun.

Winter and Spring Sky Panorama

I shot this scene from home on February 27, 2016, using the new iOptron iPano motorized “gigapan” unit, which I programmed to move and shoot 36 exposures with the Canon 5D MkII and 35mm lens, arranged in 4 rows high with 9 panels wide in each row from east to west. The result is a huge mosaic, 24,000 by 10,000 pixels.

Each exposure was 25 seconds at f/2 and at ISO 3200. The camera was not tracking the sky. I stitched the 36 segments with PTGui using its Spherical Fisheye projection. The image has black margins but I think the circular format is more suggestive of the spherical dome of the sky above and around you. But that’s me, a longtime planetarium show producer.

Next time I will shoot the zenith cap images as well!

February 17, 2016February 18, 2016

The Northern Lights … As They Appeared

Aurora As It Appeared Title

My 10-minute video captures the Northern Lights in real-time video – no time-lapses here!

I hadn’t tried this before but the display of February 12, 2016 from Churchill, Manitoba was so active it was worth trying to shoot it with actual video, not time-lapse still frames.

I used very high ISO speeds resulting in very noisy frames. But I think the motion and colours of the curtains as they ripple and swirl more than overpower the technical limitations. And there’s live commentary!

Select HD and Enter Full Screen for the best quality.

Scenes have been edited for length, and I did not use all the scenes I shot in the final edit. So the scenes you see in the 10-minute video actually took place over about 20 minutes. But each scene is real-time. They show the incredibly rapid motion and fine structure in the auroral curtains, detail blurred in long multi-second exposures.

I used a Nikon D750 camera at ISO speeds from 12,800 to 51,200. While it is certainly very capable of shooting low-light video, the D750 is not optimized for it. A Sony a7s, with its larger pixels and lower noise, would have been a better camera. Next time!

The lens, however, was key. I used the new Sigma 20mm Art lens which, at f/1.4, is the fastest lens in its focal length class. And optical quality, even wide open, is superb.

The temperature was about -30 degrees C, with a windchill factor of about -45 C. It was cold! But no one in the aurora tour group of 22 people I was instructing was complaining. Everyone was outside, bundled up, and enjoying the show.

It was what they had traveled north to see, to fulfill a life-long desire to stand under the Northern Lights. Everyone could well and truly check seeing the aurora off their personal bucket lists this night.

For more information about aurora and other northern eco-tourism tours offered by the Churchill Northern Studies Centre, see churchillscience.ca

— Alan, February 17, 2016 / www.amazingsky.com

February 12, 2016February 12, 2016

Scenes from Under the Auroral Oval

Classic Curtains of the Auroral Oval

From Churchill, Manitoba the Northern Lights dance almost every night over the boreal forest.

This year, as in the last two years, I have traveled to the shores of a frozen Hudson Bay and to the town of Churchill, Manitoba to view and photograph the aurora borealis.

I’m instructing two tour groups at the Churchill Northern Studies Centre, one this week and one last week, in the science and sagas of the aurora and on how to shoot the Lights. The participants in the groups are fabulous, keenly interested and unfazed by the cold and wind.

From Churchill’s latitude of 58° N, we are under the main auroral oval almost every night. Even on nights with low official activity levels, as they were on all the nights I shot these images, we still get sky-filling displays.

Here’s a selection of still images from the last week of shooting, with clear skies on all but a couple of nights. There’s still room in our March sessions!