Four Hours Up, Forty Degrees High

Here is the scene tomorrow evening, Wednesday Nov. 25, looking not west toward where the Sun has set but east to the horizon over which the Full Moon has risen.

Moon Full in the Hyades, 2015 Nov 25-26

The arrow on the celestial equator shows how far everything in the sky moves in one hour.

The Moon is, at this time and place, just about exactly 40 degrees high. I know this because I had included an altitude scale in my diagram, before deleting it to reduce clutter. – Actually I didn’t delete it but sent it to the background, a thing you can do to any object in Adobe Illustrator, in case you should want to look at it again or bring it back to the foreground. Presto!

ho151125evAltScale

The more exact instant of Full Moon, two hours before the time of the picture, was when it passed closest to the “Earth’s shadow,” which is my way of showing the place in the sky opposite to the Sun. I’ve just now improved the representation of this shadow by using my subroutine that I call POOL, which grades colors from the middle to the edge of any shape – well, any ellipse or simple polygon. Earth’s shadow can be reddish toward its edges because of light refracted through the atmosphere.

The shadow isn’t really visible unless it is intercepted by the Moon. That (a Lunar eclipse) does not happen, as it did on April 4 and September 28, because the Moon passes south of the shadow.

The clearance is wider than it looks, because in the picture the sizes of both Moon and shadow are exaggerated by 2.

The Moon is shown displaced by parallax from this northerly location on Earth. As seen from Earth’s center it would be slightly more to the north; it would be, in fact, in line with the arrows showing its travel from day to day, those being plotted without parallax.

The Moon is about to sweep across the middle of the Hyades cluster. At the other corner of the cluster, it will be less than a degree north of Aldebaran at Nov. 26, UT (5 EST), occulting the bloodshot star for the 12th of 13 times this year.

occ15AldebDetail

As shown by this detail from the “Occultations” section of Astronomical Calendar 2015, this event should be observable from much of America in darkness. The star will collide with the dazzling Moon; disappear behind it, for a longer time if you are in Canada than if you are in the northern U.S.

It seems only a couple of days since I saw the Moon through our Moon Window and said “Look, the Moon – eight days old, I think” – it was slightly fatter than a D shape.  Now, growing apace like the giants in fairy stories, it is full grown at fourteen days. That brings to mind one of my jingles about cats:

I knew a cat called Carpetcat,
I knew a cat called Cupboardcat,
I knew a cat called Tabliki
and her auntie called Tipsippili,
I knew a cat called the Bearded Lady,
I knew a cat called Bramblevoice,
I knew a cat called Kouskous and another cat called Pattern,
I knew cats called Sheba, Hooper, Freakout, Puddn, Thudd,
I knew a cat whose name was Twody,
Threedy, Fourdy, Fivedy, Sixdy,
When she was two days, three days, four days,
Five days, six days old.

Yes, there was a child who, asked about her kitten’s name, said it was Toody, “because she’s two days old.” Further, here’s a link that Tilly sent me yesterday, though she tells me it may already be for you old hat.

http://www.theguardian.com/world/2015/nov/22/national-emergency-belgians-respond-with-cats

 

 

One thought on “Four Hours Up, Forty Degrees High”

  1. As with so many other things, if not for your blog I wouldn’t have known about the brave cats of Belgium.

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