Solar eclipse of Monday, Aug 21, 2017

SOLAR ECLIPSE TIME max lasting for about 2min over Vancouver, to 2min 17sec as you go to Eastern BC.

Here are times for cities across BC and Alberta. There are four numbers: the local times for the start, maximum and end, and the maximum fraction of the solar diameter covered: Victoria (09:08, 10:20, 11:37, 91%), Vancouver (09:10, 10:21, 11:37, 88%), Penticton (09:13, 10:25, 11:42, 87%), Cranbrook (10:16, 11:30, 12:48, 85%), Calgary (10:20, 11:33, 12:50, 81%), Edmonton (10:24, 11:35, 12:49, 75%).

Source: https://www.timeanddate.com/eclipse/in/canada

TELESCOPE: if you setup a telescope (with a solar filter and video camera) the Sun should be seen safely on a video display.  We may see sunspots at the centre of the disc, even though the Sun is nearing sunspot minimum.

SPEED OF THE MOON’S SHADOW:  If it’s hazy with forest fire smoke, try going 7000 feet up a mountain to get clearer views.  From a mountain top, I wonder if I’ll be able to see the shadow of the Moon sweeping in from the West?  Over Eastern BC, It’s approaching at around 3,000 km/h; or 0.833 km/s.  That’s 2.5x the speed of sound, so a military jet could keep up with it, but a car can’t.  The totality shadow will be about 109km wide, and take just over 2 minutes to pass.  Source: https://www.space.com/36388-total-solar-eclipse-2017-duration.html

PATH OF TOTALITY: The Map of totality below shows you’ll have to go 500 km South of the US border to Salem, Oregon or to Idaho Falls in Idaho to get the full effect.

Map by Xavier Jubier.  http:\\xjubier.free.fr/en/site_pages/SolarEclipsesGoogleMaps

ECLIPSE GLASSES:  So, where to get adequate eyewear, sunglasses won’t do!  You can send away for cardboard eclipse glasses (mine haven’t arrived yet), but be sure they are very dark, like shade 14.  Try getting some welders replacement lenses; again, shade 14 is safest.   They are rectangular glass plates, about 4” x3” x2”.  They should be available locally at Air Liquide, or Acklands, or other welders supply place (unless they are already all sold out).
EYESIGHT WARNING: When you look at the Sun, the lens in your eyeball acts as a burning glass, and the target is the back of your eye, where imaging happens. You can also damage the protein jelly, or “aqueous humour” that fills your eyeball. The damage can be permanent. Staring at the Sun using a telesc​ope or binoculars that have not been modified for solar observing could likewise lead to permanent damage. A pair of 10×50 binoculars (10 times magnification, 50mm objective lenses), will collect between 50 and 100 times the amount of light and heat that your eye lens will collect. Permanent damage will be near instantaneous. There is specialist hardware that can be used with telescopes and binoculars that make them usable for safe solar observing. However, unless you are completely familiar with these devices and how to use them… DON’T. If you are not an expert then go find one.”  Quote from Ken Tapping, astronomer at Penticton, BC.

SOLAR PROJECTION: (adults only please) using a spotting scope or binoculars (or a magnifying glass).  Set it up on a tripod, and focus the telescope at infinity (a mountain first).  Then hold a white square of cardboard about a foot away from the eyepiece, or against a white wall (some telescopes come with a little arm and clip for this purpose).  The cardboard should be in a shadowed area.  Be careful not to look through the eyepiece of the scope (or the finderscope!)–just look at the shadow of the scope on the ground to point it at the Sun.  Centre the image of the Sun on the white card.  Move the cardboard close for a smaller/brighter image; and further away for a bigger/dimmer image. That way you get enough magnification to see sunspots too. (Galileo pioneered this projection technique back in 1612.  He didn’t go blind until he was 72, and that was from cataracts.)

FIRE AND BLINDING DANGER: Don’t hold the cardboard too close or you’ll burn a hole through it.  Don’t try to look through the eyepiece,  or you’ll burn a hole in your eye’s retina.  Don’t goof-up or you’re permanently blind.  Watch out for kids around you.  Don’t leave unattended.  Don’t burn your finger or start a fire!  (That said, I did this in grade 11 astronomy class and nobody had any trouble.)