Star-Trails
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Airglow over Misty Canisbay Lake
A one-hour star trails session taken over Canisbay Lake, Algonquin Park got an extra shot of vibrance from airglow. While the airglow wasn’t visible to the eyes, it readily registered on the camera. Even the fog on the lake picked up the colour.
Airglow is a type of chemiluminescence – the emission of light from chemical interactions between oxygen and nitrogen atoms, and other free radicals created from solar energy in the upper atmosphere. While airglow may look somewhat similar to aurora, the energy producing aurora comes from solar wind particles directed towards Earth’s atmosphere through interacting with Earth’s magnetic field.
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Killarney Star Rise
“Killarney Star Rise” captures the experience of watching stars rising behind the picturesque Killarney Lighthouse, as evening twilight turns into darkness. A total of 135 separate exposures were used to compress this 80-minute experience into a single image. All individual exposures were taken with the same camera position and focal length to reflect the true trajectory of the rising stars in relation to the landscape.
What else do you see in this image? There are stars of different colours. The mass of each star, and the phase of stellar evolution it is at, determines the surface temperature of the star, and hence its colour (red is cool, blue is hot). Diphda, the brightest star on the right of the image, changes from dim red to bright yellow as it rises from the horizon. How does that happen? This is the exact same phenomenon we observe during sunrise – near the horizon, starlight and sunlight have to travel through a lot more atmosphere to reach us. The atmosphere dims the light and scatters the blue end of the spectrum, leaving predominantly red light through. And why do the stars rise at about 46 degrees off the vertical? That’s due to the latitude of Killarney at 46 degrees north. If we are at the equator looking east, stars will rise straight up from the horizon.
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Southampton at Night
“Southampton at Night” – Star Trails photographed at the iconic Southampton Lighthouse.
This image can also be titled “Watching the World Goes Around”. Due to the Earth’s rotation, at night looking north, all stars revolve around the celestial north pole, the point in the sky that the Earth’s rotational axis goes through. Polaris, or the North Star, is the star closest to this point. The celestial north pole is just off the top edge of this image..
This image combined 11 exposures of 15 minutes each for a total exposure time of 2 hours 45 minutes. The last exposure extended into the morning twilight, providing the blue colour in the sky.
