The Partial Solar Eclipse of August 21, 2017


Be Safe: never ever look directly at the Sun!

The Solar Eclipse of August 21, 2017: On Monday, August 21, 2017, a much anticipated solar eclipse will be visible for people in North-America. This eclipse is dubbed the Great American Eclipse, since it will be a spectacular total solar eclipse -- but only for people in a narrow path that crosses the USA from Oregon to South Carolina. Here in London, we will get to see a nice partial eclipse that will last for about 3 hours. At the maximum of the eclipse, 75% of the Sun will be covered by the Moon.

The Eclipse @Western: The Department of Physics and Astronomy, the Centre for Planetary Science and Exploration (CPSX), and the London Centre of the Royal Astronomical Society of Canada with support from the London Heritage Council and the City of London will host an event to offer the public a safe, fun and informative opportunity to enjoy this celestial event. Our main observation area for this event will be the hill in front of University College, where we will set up several telescopes along the walkway, demonstrate safe projection methods, and hand out eclipse glasses and information sheets. At the Cronyn Observatory, we will project the Sun's image through our 25.4 cm refractor, and present an exhibit celebrating Canada's astronomical heritage. We will show a live stream from the path of totality from the classroom in the Engineering building right next to the Cronyn Observatory.

Rain Check: In case of rain or overcast skies, we will not be able to see the eclipse and we will not set up telescopes on UC Hill. We will still offer our exhibit at the Cronyn Observatory, and broadcast the live stream from the path of totality.

What to expect: The eclipse starts at 1:07pm, when the Moon will first appear to "take a bite" out of the Sun. The part of the Sun that is covered will gradually grow bigger, until at 2:30pm, about 75% of the Sun has disappeared behind the Moon. From then on, the eclipse happens "in reverse" as more and more of the Sun becomes visible again. The eclipse ends at 3:48pm. The sequence is shown (for a different but similar eclipse) in the image above. This will be a nice partial solar eclipse, and there are more phenomena to observe than just the Sun partially disappearing. However, it is a very different experience than a total solar eclipse!

Be safe: The lens in your eye will focus the bright sunlight onto your retina and burn it in a matter of seconds, causing permanent eye damage. Since there are no pain receptors inside the eye, you wouldn't feel a thing, making it even more dangerous. Update: there's been lots to do in the media about unsafe eclipse glasses. The ones we will hand out on Monday are from one of the most reliable manufacturers in the US, we have their ISO certificate, and we have been using them ourselves in our outreach programs without a problem for well over a year now. We cannot offer these for sale unfortunately, but if you attend our event, you will receive your own pair for as long as the supply lasts.

History: The last time there was a total solar eclipse over London was in 1925 -- read all about it on this 1925 Total Eclipse site compiled by Peter Jedicke of the RASC. For more historical eclipse information or to look at Canada’s rich heritage in astronomy, please visit us at the Cronyn Observatory! Here you can also step back in time to our 1940s-era director's office, and our newly installed control room as it might have looked on Canada Day 1967. (Find the 1940 and 1967 period rooms through the door at the back left of the observatory; go through the main doors and up the stairs for historical displays in the dome).

Event Details:


Monday, Aug. 21, 2017


1:00pm - 4:00pm
(come and go as you please; entrance is free; no registration is necessary) 


Free parking at the Medway Parking lot (click for map).
Then, walk up University drive to arrive at UC Hill.
Exhibit at Cronyn Observatory.
Live feed in Engineering Building (SEB 1200), next to Cronyn.

Social Media

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Safely Observe the Solar Eclipse through eclipse glasses, telescopes and by means of projection. Follow a live stream from the path of totality. Enjoy an exhibit celebrating Canada's astronomical heritage.


Prof. Jan Cami, Director, Cronyn Observatory.
jcami at uwo dot ca
519-661-2111 ext 80978

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