A Sunrise Annular Solar Eclipse

The dance goes on. Two weeks after May's total lunar eclipse, the Sun, Moon and Earth align again on Thursday, June 10th. This time, the Moon glides between the Earth and the Sun to grace the morning sky with an annular eclipse. The eclipse is central but not total because the Moon is near apogee, its most distant point from Earth. Its apparent diameter of 29.5′ will be two arcminutes shy of completely covering the Sun, leaving an arcminute-wide "ring of fire" at maximum eclipse.

The Moon's shadow strikes the Earth at an oblique angle during the upcoming eclipse, cutting a broad path that starts along the north shore of Lake Superior in Ontario and passes over Hudson Bay and northwestern Greenland before moving on to Russia. It even includes the North Pole, where 2 minutes 36 seconds of annularity will interrupt more than 2 ½ months of continuous daylight. Anyone living within this expansive strip — and there aren't many! — will see a ring or annulus of sunlight at maximum eclipse.

COVID-19 Hurdles

Eclipse enthusiasts who hoped to drive north for the event won't be able to cross into Canada due to COVID-19 restrictions in place until at least June 21st. One way around this is to fly into the eclipse path. To that end Sky & Telescope has chartered a flight into southern Ontario on the big day. There are still a few seats left as of this writing. Click here for more information.

Meanwhile, a large swath of the eastern U.S. and Canada along with observers across much of Europe and Asia will witness the eclipse's partial phases. For millions of Americans the Sun will rise steeped in a deep partial eclipse. It goes without saying you'll need an unobstructed northeastern horizon to see it best. If possible, try to watch the eclipse from a lake where the blazing crescent and its glitter path should be nothing short of spectacular. Check out this video made on May 10, 2013, to see just how amazing a sunrise annular eclipse can be.

Many of us will be tempted to look at the rising Sun at the horizon where haze often attenuates its light. Be careful. A momentary glance might be OK, but never stare at the Sun even for a second. Infrared light can cook your retinas and permanently damage your vision. Keep eclipse glasses at the ready. If you purchased a pair for the 2017 total eclipse, inspect them for wear and tear. As long as they're not scratched up or full of pinholes you can reuse them for this eclipse. If you need a fresh pair, try one of these or go to Amazon, which has a similar selection. Make sure they are ISO / CE certified. Another good option is an inexpensive #14 welder's glass from a welding supplier in your city or region.

Do-it-yourself eclipse predictions

The table (below) lists eclipse circumstances for 20 cities, but you can easily get all the details of your local circumstances at Xavier Jubier's Interactive Solar Eclipse Map. Zoom in to the map and click on where you plan to watch the eclipse. A box will pop up that includes the time of sunrise and the percent of the Sun's disk obscured by the Moon. Note that times are in Universal Time (UT). To convert to EDT, subtract 4 hours; 5 hours for CDT; 6 for MDT; and 7 for PDT. For a full explanation of each line in the pop-up box, click the blue Help link.

I'm especially interested in this eclipse because I live in the negative path of annularity, where the Sun will be in annular eclipse shortly before sunrise. I'm envisioning a bizarre twilight that begins normally but then stalls as annularity approaches before resuming its normal (though perhaps muted) progression just before sunrise. The quality of the light during this time should be fascinating to watch as well as any effects the solar annulus might have on clouds along the eastern horizon.

From many central U.S. and southern Canada locations the maximum obscuration occurs before sunrise, so the best views will be just as the Sun comes up with the Moon's egress underway. Locations farther east will see maximum eclipse after sunrise. The diagrams show the percentage obscuration, which is the fraction of the Sun's area covered by the Moon. Charleston, South Carolina, is the largest and southernmost U.S. city to see a partial eclipse, with the Sun just 4.6% covered when it fully clears the horizon. If more than half the Sun is covered from your location be alert for changes in the quality of the light, falling temperatures and unusual animal and insect behavior.

Circumstances around the planet

For now, I'm aware of two livestreams (below) for watching the eclipse online. If you hear of others, please let me know, and I'll add them. Check here for solar eclipse photo tips, and remember to share the event with family and friends. It feels good to finally come out of our COVID-19 shells into the sunshine.

Livestreaming options:

Timeanddate.com YouTube starts June 10th, 3 a.m. CDT (8:00 UT)
CosmoSapiens YouTube, starts June 10th, 2 a.m. CDT (7:00 UT)
Virtual Telescope with Gianluca Masi, starts June 10th, 4:30 a.m. CDT (9:30 UT)

If you're interested in reading more about this and other celestial events this month click here to purchase a copy of the June 2021 issue of Sky & Telescope.