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Partial Solar Eclipse October 23rd at Sunset

(Updated October 28, 2014)


On Wednesday October 23, the sky above Richmond Hill was nearly perfect for the prepared viewer to witness the Moon partially eclipse the setting Sun. And as an added bonus, viewers also got to see a rare naked-eye sunspot that was visible all through last week.

To safely view the Sun when it's NOT TOTALLY eclipsed (i.e.- like during last week's partial solar eclipse or when the Sun is not right at the horizon) requires special glasses or filters. The common types of "sun glasses" are NOT sufficient. You need "eclipse" or "solar" glasses like those that were made available to safely watch the Transit of Venus in 2012. Or you can use a filter designed for use with an arc-welding helmet (shade number 12 or 14, nothing less dark). As a test: if you can see anything else other than just the Sun when you look through your filter, that means it's NOT dark enough!!! And making a filter by using a candle flame to put soot on a piece of glass is EVEN WORSE than using no filter at all, as it will still let through the invisible heat radiation coming from the Sun even if it looks dark in visible light. Your eyes don't have pain receptors in them, so you will be COOKING YOUR EYEBALLS and not even feel this until it's too late and you have PERMINENT EYE DAMAGE.

There is an even simpler safe way to watch a partial solar eclipse. Make a small (~1mm) hole in the centre of a piece of cardboard or dark plastic to let just a small beam of sunlight go though it. DO NOT LOOK THROUGH THE PIN HOLE TO SEE THE SUN! Rather, use the pin hole to project a tiny circle of sunlight onto a white piece of paper or cardboard set up a metre or two behind the card that has the pin hole in it. That cicle of light is an image of the Sun. And if any part of the Sun is being blocked (eclipsed) by the Moon or if there is a big sunspot on the Sun, you will see it in the projected image of the Sun.

If you missed the eclipse last week, the next one visible from Richmond Hill will be on August 21, 2017. It won't be a TOTAL eclipse for us; but a lot more of the Sun will be blocked compared to the Oct.23 eclipse and the Sun will be much higher up in the sky.

--Ian Shelton
DDOD's Vice Chair & Resident Astronomer

The David Dunlap Observatory lies nestled in the heart of Richmond Hill, Ontario, a city of 200,000 just north of Canada's largest city, Toronto. The 190-acre oasis of mature forests, pastures and springs is home to two distinct deer herds and an abundance of other wildlife, including a coyote pack, foxes, voles, rabbits, honey bees, many species of butterflies, and birds including hawks, owls, doves, crows and songbirds. The property represents the last and largest urban open green space in southern Richmond Hill.


Originally deeded to the University of Toronto by the philanthropist Jessie Donalda Dunlap in memory of her husband David, the Dunlap Observatory opened on May 31st, 1935. Its magnificent 74-inch telescope was the second largest in the world at that time and has been used through seven decades to conduct much groundbreaking research, including the discovery of the first known black hole, Cygnus X-1.

In 2007, the University of Toronto wrested control of the land from Jessie Dunlap's heirs through a protracted legal case spanning 4 years. They then broke the public covenant that the land would remain a park and a research and outreach centre in perpetuity by selling the property to a developer intent on replacing most of the greenspace with hundreds of houses.

The DDO Defenders have been working hard to represent the public and inform all levels of government about what will be lost if the developer is allowed to proceed.


On April 12th, 2012, after six long and anxiety-ridden months of Ontario Municipal Board (OMB) mandated mediation following a four year hard-fought and very public battle, an agreement was reached in March between the mediation parties to the David Dunlap Observatory Lands OMB case.

Minutes of Settlement were drawn up for signing by all parties to the mediation -- the landowner, Corsica Development Inc. (a subsidiary of MetrusDevelopments Inc.), the Town of Richmond Hill, the Region of York, the Toronto and Area Conservation Authority (TRCA), and the David Dunlap Observatory Defenders (DDO Defenders) Inc. This historic document was ratified by Richmond Hill Town Council on Thursday, April 12th. All mediation parties had been sworn to absolute secrecy under a strict gag order until Council signed off on the agreement, but now the silence has finally been broken and the details of the settlement agreement can be made public. (read more)

For further information or to offer support, please contact:

The Minutes of Settlement is posted at the Town of Richmond Hill - DDO webpage.


Please support our Community Advocacy

The DDO Defenders are deeply committed to preserving the David Dunlap Observatory, surrounding Lands and the Dunlap Legacy. Our mandate is to ensure that the campus continues to operate as a world-class astronomical and astrophysical research facility and a centre of excellence in public Outreach, Education and Experiential Learning regarding all aspects of the Scientific, Physical and Natural World.

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DDO Defenders
18 Harding Blvd, Unit 902
Richmond Hill, ON
Canada L4C 0T3.

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