When is the middle of autumn?

When is the middle of autumn?

90 days in autumn. Adding 45 days to 9/22 gives 11/6. That's one
way.

But when is the middle of fall based on the high noon altitude of the
sun? I believe the days get shorter at an increasing rate near the
solstices (or maybe during the equinoxes).

-
http://mysite.verizon.net/vze8adrh/news.html (profile) --Tim923 My email is valid.

Tim923 writes:

When is the middle of autumn?

90 days in autumn. Adding 45 days to 9/22 gives 11/6. That's one
way.

But when is the middle of fall based on the high noon altitude of the
sun? I believe the days get shorter at an increasing rate near the
solstices (or maybe during the equinoxes).

Well, if you want to consider the middle of summer to coincide with
the solstice (when the Sun is highest in the sky), then the middle
of autumn would coincide with the equinox.

Well, if you want to consider the middle of summer to coincide with
the solstice (when the Sun is highest in the sky), then the middle
of autumn would coincide with the equinox.

From an observer at 28 degrees north latitude, when is the high noon
sun at 50.25 degrees (above the horizon). Is there a chart?

50.25 = (62+38.5)/2

-
http://mysite.verizon.net/vze8adrh/news.html (profile) --Tim923 My email is valid.

Tim923 wrote in message . ..
Well, if you want to consider the middle of summer to coincide with
the solstice (when the Sun is highest in the sky), then the middle
of autumn would coincide with the equinox.

From an observer at 28 degrees north latitude, when is the high noon
sun at 50.25 degrees (above the horizon). Is there a chart?

50.25 = (62+38.5)/2

-
http://mysite.verizon.net/vze8adrh/news.html (profile) --Tim923 My email is valid.

Tim:
I'm replying because this is my second day off work with a cold and am
not sick enough to be in bed and bored stiff. The short answer to
your question is:
on October 23, 2004, at about 21hours 36minutes GMT the center of the
sun would appear 50.25 degrees above the horizon to an observer at
Latitude 28d North IF he was at Longitude 147.94d West. This would
correspond to a computed sun declination of South 11.76 degrees due to
parallax and refraction at the observers position.

However, you appear to want to define the "middle of autumn" by an
astronomical event. Specifically, when the sun's declination is South
11.75 degrees, or halfway between the autumnal equinox and winter
soltice. You should be aware that the sun's declination at winter
soltice in 2004 will be South 23d 26m 19.05s. This is close, but not
exactly 23.5 degrees you seem to be using. Half of 23d 26m 19.05s is
11d 42m 47.25s and the sun will be at this declination on October 23,
2004, at about 20:00 hours GMT regardless of the observers position.

I suggest you download the public domain software ICE (Interactive
Computer Ephemeris) at http://nineplanets.org/ice/ice.html to find out
more than you ever wanted to know about locations of heavenly bodies
(the astronomic variety not the Playboy variety).

Thanks for a fun diversion on a rainly Thursday.

HTH
Jerry Wilkinson