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Posts Tagged ‘Totality’

08/10/2017 – Ephemeris – The brief wonderland of Totality, my second total eclipse

August 10, 2017 1 comment

Ephemeris for Thursday, August 3rd. The Sun rises at 6:31. It’ll be up for 14 hours and 33 minutes, setting at 9:04. The Moon, half way from first quarter to full, will set at 3:43 tomorrow morning.

The brief world of solar eclipse totality is one everyone should experience at least once in their lifetime.  For this eclipse Totality will last from 2 minutes, and 5 seconds on the Oregon coast to 2 minutes 40 seconds in Kentucky, down to 2 minutes 35 seconds on the South Carolina coast. And this is for the center of the path of totality.  The duration of totality is so brief that one cannot really absorb it all. As the Moon covers the last of the Sun’s bright photosphere there is a chill as the Sun’s heat is extinguished. Darkness of a deep twilight descends. Street lights come on, cocks will crow, as animals take the darkness as the approach of night. The approaching shadow of the Moon can be seen. During totality the Sun’s corona can be seen as a silvery apparition around the black spot of the Moon that’s covering the Sun’s disk. Bright planets and some stars will appear in a surreal image in the darkened sky, but the horizon is bright. Then suddenly the diamond ring appears and it’s over.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Somehow this is a repeat of last Thursday’s program.  I’ve added a sentence or two in the text above and I’ve added different content below.

This the story of my second total eclipse, March 7, 1970.

Waycross motel

Setting up the day before the eclipse at a motel in Waycross Georgia. My automated equipment is on the right with the controller on the near table.  My photo.

For this eclipse the path of totality ran parallel to the east coast of the US from Florida to Virginia.  Perry, Florida proclaimed itself “Eclipse Capital of the World”, and attracted lots of folks down there.  Waycross was lower key.  This is what they ran on their weather channel:

The local baseball park hosted a menagerie of chickens and other animals for folks could watch their eclipse antics.  Also there was an ABC television crew, whose normal job was to televise golf tournaments.  The big TV camera, they were big in those days, was placed on a fork lift to tilt it back far enough to reach the Sun.  Scattered on the ground were lots of 2×2 inch black squares with holes in them.  It turns out they were neutral density filters that they were inserting in the camera, near the focal plane.  Of course the concentrated sunlight near the focal plane would burn through the filter in nothing flat.  Some of the younger members in our group had created exposed x-ray film for filters, and showed the TV crew how to fasten the filters in front of the camera lens.  It worked, but the guys in the TV van outside the stadium complained that something was wrong with the filters, because there were black spots on the Sun.  They were of course sunspots.

All day that day, the sky was slowly clouding up, with high cirrus.  There was a storm front moving up the eclipse path,

Plotting the escape to Blabenboro

The maps came out to plot a move up the eclipse path. My photo.

The plan was to leave at midnight and drive to Florence, South Carolina and meet up for breakfast and pick a final location.  We all met at a restaurant in Florence, and decided on Bladenboro NC as the spot view the eclipse from.  Up to this point I drove.  I turned the wheel over to my wife Judy and slipped into the back seat to recompute the eclipse timing, since I set my photographic program to start one minute before totality.

We finally ended up in a corn field, filled with corn stubble just outside the town.

Bladenboro

Everyone Else’s setup in the corn field. My equipment is off to the right out of sight. My photo.

We had students from the University of Michigan, Grand Valley State University, the Detroit Observational and Astrophotographic Association, and the Grand Rapids Amateur Astronomical Association, of which I was a member at that time.  The farmer, whose land we were on, was quite drunk and was spending his time harassing the red-headed member of our group Dave DeBruyn while he was trying to set up his equipment.

It turned out that we didn’t quite escape the clouds.

partial phase

The Sun a few minutes before Totality taken through clouds and no filter. My photo.

It did eventually clear enough to see the eclipse, helped by all of us shouting at the clouds.  Moving to the corn field meant no electricity.  I did have an inverter, however I didn’t really test it, thinking we’d have power at our motel location.  However the inverter couldn’t hold up its voltage under load and a relay meant to act as a safety for a problem I had at my first eclipse, dropped and made the camera inoperative.  However I came prepared.  I built what I called a contingency camera, with which I took the above photo, and got some good photos as seen below.

Inner corona. My photo.

Inner corona near the center of totality. My photo.

My best photo. Baily’s Beads and chromosphere as totality ends. My photo.

Some of our group decided to stay in Waycross, and were able to see the eclipse.  Perry FL, the Eclipse Capital, had the eclipse rained out.  That’s another proof of Moler’s First Law of Eclipses:  Where the most crowds gather to see an eclipse, so do the clouds.

The story of my first total solar eclipse is here:  https://bobmoler.wordpress.com/2017/07/20/07202017-ephemeris-only-one-month-and-a-day-to-the-great-american-eclipse-and-a-personal-note/

 

08/03/2017 – Ephemeris – The surreal world of totality

August 3, 2017 1 comment

Ephemeris for Thursday, August 3rd. The Sun rises at 6:31. It’ll be up for 14 hours and 33 minutes, setting at 9:04. The Moon, half way from first quarter to full, will set at 3:43 tomorrow morning.

The brief world of solar eclipse totality is one everyone should experience at least once in their lifetime. The duration of totality is so brief that one cannot really absorb it all. As the Moon covers the last of the Sun’s bright photosphere there is a chill as the Sun’s heat is extinguished. Darkness of a deep twilight descends. Street lights come on, cocks will crow, as animals take the darkness as the approach of night. The approaching shadow of the Moon can be seen. During totality the Sun’s corona can be seen as a silvery apparition around the black spot of the Moon that’s covering the Sun’s disk. Bright planets and some stars will appear in a surreal image in the darkened sky, but the horizon is bright. Then suddenly the diamond ring appears and it’s over.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Total eclipse scene

Screen capture from a video of a total solar eclipse of November 2, 2013 at the small village of Mikongo in the equatorial African country of Gabon. This video shows the eclipse expedition of Williams College led by Professor Jay Pasachoff. © 2013 Michael Zeiler. See the video at https://www.greatamericaneclipse.com/splendor/.

Check out the Great American Eclipse web site.

Simulation of the August 21, 2017 totality

An animation of Stellarium’s version of the sky during totality of the August 21, 2017. My personal caveats based on 4 total eclipses are that Venus is always visible, Mercury only sometimes. I’ve never seen a star. Also the Sun’s corona is a whole lot brighter than seen here. See the image above.  Click on this image to enlarge.

Diamond Ring

Diamond ring at the end of totality of the total solar eclipse July 10, 1972. Credit Bob Moler.

Additional notes:

The Sun’s corona is perfectly safe to view without a solar filter.  Actually the Sun will disappear in solar eclipse glasses and projection viewers.  That’s the time to look at the Sun with the naked eye or binoculars.  However, when the corona brightens around the right side of the Moon, and the red chromosphere appears, drop the binoculars for the bright diamond ring will quickly appear.

The corona for the quiet Sun stretches out on either side of the Sun, with little at the poles.  The active Sun, near a sunspot peak, tends to have a roundish corona.  Below is the corona last evening via the Solar and Heliospheric Observatory (SOHO).

SOHO coronagraph

The black disk on the stalk is the occulting disk, hiding the bright photosphere and producing an artificial eclipse.. The white circle is the size of the Sun’s disk. Credit ESA and NASA

Part of the inner corona close to the Sun is covered by the disk.  That is what is easiest to see during a total solar eclipse.

For a couple of minutes just before totality starts and again after it ends strange bands of light and shadow will flit along the smooth surface of the ground.  They’re called shadow bands.  I’ve seen the effect on a large concrete parking lot, an airport tarmac and a softball infield.  The nearest thing I’ve seen to it the shadow ripples on the bottom of a swing pool on a sunny day.  I finally saw them on my fourth total solar eclipse and two subsequent annular eclipses* which were viewed from or near smooth surfaces.  It’s a product of air turbulence and shows up at night in the twinkling of stars.

* An annular eclipse is one in which the Moon is too far, and thus too small to completely cover the face of the Sun.  The central part of this type of eclipse leaves a ring or annulus of the bright Sun surrounding the Moon.