APOD: Sunrise Shadows in the Sky (2024 Sep 21)

[APOD Robot]

Sunrise Shadows in the Sky

Explanation: The defining astronomical moment of this September's equinox is at 12:44 UTC on September 22, when the Sun crosses the celestial equator moving south in its yearly journey through planet Earth's sky. That marks the beginning of fall for our fair planet in the northern hemisphere and spring in the southern hemisphere, when day and night are nearly equal around the globe. Of course, if you celebrate the astronomical change of seasons by watching a sunrise you can also look for crepuscular rays. Outlined by shadows cast by clouds, crepuscular rays can have a dramatic appearance in the twilight sky during any sunrise (or sunset). Due to perspective, the parallel cloud shadows will seem to point back to the rising Sun and a place due east on your horizon on the equinox date. But in this spectacular sunrise skyscape captured in early June, the parallel shadows and crepuscular rays appear to converge toward an eastern horizon's more northerly sunrise. The well-composed photo places the rising Sun just behind the bell tower of a church in the town of Vic, province of Barcelona, Catalonia, Spain.

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[Ann]

Well, nice.

Sunrise Shadows in the Sky. Image Credit & Copyright: Emili Vilamala

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Starry Night by Vincent van Gogh.

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The dramatic sky and the cypresses in the foreground remind me just a little of Vincent van Gogh's Starry Night.

The Sun peeking through the opening in the bell tower of the church is a fun detail.

Seriously, though, there are too few galaxy APODs these days!

NGC 5068. Credit: NASA, ESA, R. Chandar (University of Toledo), and J. Lee
(Space Telescope Science Institute);
Processing: Gladys Kober (NASA/Catholic University of America)

Ann

[guest again]

"Seriously, though, there are too few galaxy APODs these days!"

Ann, maybe we ran out of galaxies?

[VictorBorun]

was the disk of the sun above the skyline?
was the disk of the sun scarlet rather than yellow?
was the window in the tower much narrower than the bright spot we see?

[RDaneelOlivaw]

I always wonder why we start the seasons on the equinoxes and solstices. If you add up the daytime hours and nighttime hours of the seasons, the total northern hemisphere daytime hours are more in the one-fourth of the year that the summer solstice is in the MIDDLE of, not the one-fourth of the year that follows the summer solstice. Another way of saying it, the total daytime hours annually in the northern hemisphere is the most from halfway between the vernal equinox and the summer solstice to halfway between the summer solstice and the autumnal equinox. That's kind of hard to explain, but I think I got it right and that you will understand what I mean. So tomorrow (Sunday) we will be in the MID-POINT of the fall, not at its beginning. – Ron

[VictorBorun]

another attempt to make the low sun redder

1) dim the Green and Blue channels with .5 factor
2) deepen the Red channel with ɣ = .3
3) rise the saturation by .08

[VictorBorun]

another attempt to make the low sun redder

New Red = Old Red + Old Green - Old Blue
New Green = -0.3 Old Red + Old Green + 0.3 Old Blue

[VictorBorun]