Mid year, mid eclipse

The Sun stands still today.

Or, put another way, Earth leans its north pole maximally toward the Sun.

The instant of the solstice or “Sun-stand” is 21:45 Universal Time, which is after sunset in Europe, 5:45 PM in eastern North America, 4:45 in the Central time zone, and so on.  So the Sun at that instant is overhead near Hawaii.  But, because this is the smooth top of a sine curve, the midday altitude of the Sun is not discernibly different for other places around the world.

Modern Druids, who usually gather at Stonehenge to see the solstice Sun rise at its northernmost point on the horizon, had to gather virtually this time, because of a certain modern plague.

At the solstice, the Sun is at longitude 90° on the ecliptic, and therefore is said to enter the traditional sign Cancer.  It did enter Cancer at the summer solstice about two millennia ago.  But now, because of the slow change called precession, the Sun is a little over a whole constellation further back, in Taurus, and will enter Gemini on June 21 at 9 UT.

It also happens that today is the mid point of an eclipse season.  Most eclipse seasons consist of two eclipses, a solar and a lunar (in either order), but this is of the less common kind with three eclipses, because the flanking ones are slight.  So the central eclipse comes almost at the middle of the season: on June 21.  It will sweep across Africa and Asia; it is a solar eclipse of the annular-total kind, that is, almost grazing the surface, with a very narrow track.  Only in the central part of the track will the Moon just cover the Sun; along the early part through Africa and Arabia, and the late part in eastern China, anyone looking up will see the Sun hollowed out to a blazing ring.

The huge gray elliipse is the Moon’s penumbra or partial shadow, and curves mark its outline at earlier and later hours.  The stars in the background from this point of view are those of Sagittarius.

I should have kept for today my quotations of “times when time stood still.”  You might look back at them, and tell me if you know of other instances of this human fantasy.

Or, if today happens to be your wedding anniversary (which it may be, since midsummer is often the chosen time), then you might augment your merriment reading together one of the most amusing of ballads, which starts (you can find it by googling its first line):

John Gilpin was a citizen
Of credit and renown,
A train-band captain eke was he
Of famous London town,
John Gilpin’s spouse said to her dear
“Though wedded we have been
These twice ten tedious years, yet we
No holiday have seen.
Tomorrow is our wedding day,
And we shall then repair
Unto the Bell at Edmonton
All in a chaise and pair…”

__________

ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format.  You may be able to enlarge them on your monitor.  One way: right-click, and choose “View image”, then enlarge.  Or choose “Copy image”, then put it on your desktop, then open it.  On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers).  Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.

Sometimes I make improvements or corrections to a post after positing it.  If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version.

This weblog maintains its right to be about astronomy or anything under the sun.