View Full Version : Eclipse reminder

05-17-2012, 10:46 AM
The shadow passes just south of Alaska's Aleutian Islands as the central track slowly curves to the southeast. After a 7000 kilometre-long ocean voyage lasting nearly 2 hours, the antumbra finally reaches land again along the rugged coastlines of southern Oregon and northern California (Figure 2) at 01:23 UT (May 20 local time).

Redding, CA lies 30 kilometres south of the central line. Nevertheless, it still experiences an annular phase lasting 4 1/2 minutes beginning at 01:26 UT. It is already late afternoon along this section of the eclipse path. The Sun's altitude is 20 during the annular phase and decreasing as the track heads southeast. Central Nevada, southern Utah, and northern Arizona are all within the annular path.

By the time the antumbra reaches Albuquerque, NM (01:34 UT), the central duration is still 4 1/2 minutes, but the Sun's altitude has dropped to 5. As its leading edge reaches the Texas Panhandle, the shadow is now an elongated ellipse extending all the way to Nevada. Seconds later, the antumbra begins its rise back into space above western Texas as the track and the annular eclipse end.

Use this map to find the exact times for your location. Move the marker to your location and it will pop up all the particulars of time and duration etc.


05-17-2012, 11:21 AM
It's so late for me it will be behind the trees anyhow.:(

Harvey Melvin Richards
05-17-2012, 11:24 AM
I get it for 4 1/2 minutes with a magnitude of .963, whatever that means.

05-17-2012, 12:50 PM
Although it looks rather close on some maps, seeing the eclipse would entail a three-day round trip from Phoenix, with few good options for lodging or campgrounds around the Grand Canyon without advanced reservations. So I will probably give it a miss.

I'm going to the North Rim campground on 10 July, hoping my day will coincide with the summer monsoon thunderstorms.

05-18-2012, 09:45 AM
The magnitude is the percentage of the sun that will be covered by the Moon. At my location we get a .739 (~74%) eclipse which will be the most I have ever seen.

05-20-2012, 10:03 PM
We are having rain today, but I took a timelapse of the event as it played out in my back yard. It got pretty dark here east of Seattle.

14 MB MP4, about 2 hours of still shots.


Edit: Just noticed a funny - at about 5:30:18 one of my cats jumped up onto the stand where the camera/laptop was to get a better look at a robin that was hopping around on the deck and rocked the picture. There was also a humming bird captured.

The camera was making step adjustments to compensate for the lighting change, and the cloud cover was variable. A few lights with ambient light detectors came on and went off along the way.

05-20-2012, 10:52 PM
I was fortunate enough to be able to almost view a full annular eclipse. I used my Jackson variable density electronic welding helmet filter to direct view the event, one I hadn't seen since childhood.

A couple of observations:

1) As the light diminished a small breeze started, once normal daylight returned, the breeze dissapeared.

2) During maximum eclipse it became dark enough the mosquitos emerged for the evening.

3) There were some interesting shadow patterns generated by the sun light. Some folks took some great photos.

4) Monitoring my weather station for solar radiation indicated about 1/5 (in W/m sq.) of normal radiation during maximum eclipse as compared with full sun or roughly the same period.

I wish we had more moons so we could do this more often.:D

05-20-2012, 11:32 PM
I built a pin-hole viewer by knocking a 1/2" hole in a flattened Costco-sized cereal box with a gasket punch, taping a piece of foil over the hole, and then poking a ~1-mm-dia hole with a sewing needle. My son and I projected the image onto a white junk-mail envelope. It worked really well. We live in the SF Bay area, and did not quite experience a full annulus. Very interesting nonetheless. Lots of neighbors were out with various bits of cardboard. It was a good way to meet the neighbors.

05-20-2012, 11:34 PM
Whoops - rookie mistake. I replied to my post rather than editing it.

J Tiers
05-20-2012, 11:39 PM
Lovely rainstorm here, complete with lightning and thunder...... nothing happening for viewing eclipses

05-21-2012, 12:36 AM
The camera was making step adjustments to compensate for the lighting change, and the cloud cover was variable. A few lights with ambient light detectors came on and went off along the way.

That explains it. Next eclipse, will you try using manual exposure?