Next message: Victor Garand: "Re: Lunar calculation (establishing time)"
I wrote earlier:
"So the net refraction (standard plus the weather front) is 4" of arc TOWARDS
the zenith on one side of the zenith and 2" of arc AWAY from the zenith on
the other side.
Make sense?"
Did that resolve the matter for everyone, or no? John B, does that make sense
for you? You asked for a specific example (but that post more or less
coincided in time with the above example so you may have missed the details). The
conclusion is YES, the net refraction CAN place a star's apparent position lower
in the sky than its true position, but rarely and not by much.
By the way, I don't think temperature inversions (plane parallel) make any
overall difference (that is, they can't make the net refraction opposite in sign
from the standard refraction); if the atmospheric density is plane-parallel,
the net refraction always puts the apparent stars above the "true" stars.
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
