Stanley Park stargazing spot shoots for official status
Astronomers shooting for an official stargazing designation at Stanley Park's Beaver Lake
On a clear, moonless night, maybe a couple of dozen stars might be visible in the night sky from a downtown location such as Davie and Granville streets.
But if you go up the Fraser Valley far away from the lights of the big city, you would be able to see many more. From a single vantage point on Earth, astronomers estimate that somewhere around 2,000 stars can be seen by the naked eye without a telescope.
There's an initiative underway to bridge the gap between city and country to help connect Vancouver with the cosmos. Beaver Lake in Stanley Park could be one of the city's locations recognized by the Royal Astronomical Society of Canada (RASC) for the importance of its night sky.
The association's Dark- Sky Program not only identifies key locations to gaze at the stars, it helps to educate the public about how poor outdoor lighting contributes to obscuring the stars in the night sky, said Bob King, national chairman of the RASC'S Light Pollution Abatement Committee.
“We want to have an area that is accessible to those who want to enjoy the sky or nocturnal environment and appreciate the value and necessity of darkness,” he said from Calgary. “Having those sites in place, we ask that they be protected from on-site lighting and intrusion from offsite lighting.”
Official steps to protect the night sky started in 1999 when Torrance Barrens, about two hours north of Toronto, was designated as the first Dark- Sky Preserve in the country. Far away from any urban centre, the site on the Canadian shield has what's described as a spectacular 360-degree view of the night sky.
Another step in building a national program came several years later with the creation of the Cypress Hills Dark- Sky Preserve in the interprovincial park in Alberta and Saskatchewan in 2004. Now there are 22 Dark-sky Preserves across Canada, including one in B.C. at Mcdonald Park, east of Abbotsford.
The challenge with Dark- Sky Preserves is that they tend to be a long way from major urban centres where most Canadians live and work. The RASC started to think about establishing locations closer to cities. There was also a growing awareness that the names of the constellations and the stories about them came from a Western European tradition. How could the public be educated about the different Indigenous stories of the night sky?
“We came up with the idea of a Nocturnal Preserve: areas which may not be perfect or accessible for observing the sky, but the purpose is to protect nocturnal environment for flora and fauna,” he said.
Another designation is Urban Star Parks, which are found closer to a city so amateur astronomers can set up telescopes for looking at the stars or cameras on tripods to practise astrophotography. There is already one Urban Star Park in B.C. at Cattle Point in Oak Bay on Vancouver Island.
The challenge for Beaver Lake is that it's next to Vancouver's skyglow, which refers to the illumination in the night sky created by all the light from a city that seeps into space.
In Vancouver, there are an estimated 50,000 city lights on streets, sidewalks, paths and plazas. Numerous private sources of outdoor light include annual decorative lighting during Christmas and other festivals. Most outdoor lights are high-pressure sodium (HPS), which have an amber glow. They're being replaced with light-emitting diodes (LED), which are far more efficient and reliable.
Installing LED street lights at 125 signalized intersections, for example, has led to a 21 per cent drop in collisions and a 65 per cent decrease in traffic-related fatalities and injuries involving pedestrians, a 2019 City of Vancouver report says. While whiter LED lights provide greater visibility, they're not as warm or inviting as amber-coloured HPS lights. Studies show that lighting above a certain colour temperature with more blue can negatively affect human health.
“Unshielded fixtures that direct light upwards into the sky or into areas where light is unwanted should be avoided to the greatest extent possible,” according to the city's public-realm lighting design guidelines. “Shielding should be considered where lighting may impact residents and sensitive ecological areas.”
One of the city's dark locations is Beaver Lake. In mid-july, Peter Kan, senior lighting consultant at Quantum Lighting in Coquitlam, was part of a team that included Paul Darlington, Quantum's vice-president, who conducted an inventory of the light around the site near the centre of Stanley Park. They mapped out nearby street lights along Pipeline Road and in the Vancouver park board works yard. What stood out were the flood lights in the mounted police parking lot.
“They're not dark-sky friendly,” Kan said.
Floodlights often indiscriminately illuminate a wide area — usually far wider than is necessary for safety and security. It's that additional illumination that causes the kind of light pollution that contributes to reducing the visibility of stars in the night sky.
As dusk deepened into night, the trees in Stanley Park became a shield that created an oasis of darkness around the lake. To measure the darkness of the night sky, Kan and Darlington used a sky quality meter (SQM), a hand-held device that measures light photons. As Kan said, the meter's readings are counterintuitive: the higher the number, the darker the sky.
SQM measures luminance, the light that can be seen with the eye. Technically, it measures magnitudes-per-square-arcsecond on a logarithmic scale. A bright night sky would have a reading of 16; a dark sky, 22.
By 11 p.m., the bright red numbers on the screen recorded the darkest sky at 19.32. Kan also took photos of the sky as it changed from dusk to darkness for the RASC application.
“(The RASC) want to see the skyline and the sky with stars,” he said. “It's not just a number that you give them. You also have to establish boundaries which probably will be the trail that goes around Beaver Lake.”
Heading out late at night on a summer evening to measure the night sky isn't a usual part of what Kan does as a senior lighting consultant.
“This is very interesting for me,” he said. “I love it because it's so close to home. I hope this goes forward and we could say we're part of this.”
At the H.R. Macmillan Space Centre in Vanier Park, Michael Unger is the program co-ordinator. He said most Canadians who live in cities don't even realize they're living under an urban skyglow.
“We casually look up on a clear night and you can barely see any stars,” he said. “For the majority of people who live in cities, the stars aren't relevant anymore.”
Unger said he was recently introduced to the idea of scotobiology, the study of the biology of darkness and its importance to the health of humans, animals and insects. “If Beaver Lake gets this designation, I can certainly see us doing some events out there,” he said.