[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#61460: 30.0.50; Calendar shows eclipse for quarter moon
From: |
Ulrich Mueller |
Subject: |
bug#61460: 30.0.50; Calendar shows eclipse for quarter moon |
Date: |
Tue, 14 Feb 2023 08:59:29 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) |
>>>>> On Tue, 14 Feb 2023, Michael Heerdegen wrote:
> I did not find good discussions of the eclipse limits in the English
> Wikipedia version; I found good explanations in German however:
>
> https://de.wikipedia.org/wiki/Finsternis-Limit#Finsternis-Limite_bei_Sonnenfinsternissen
Thanks. I followed the legend of the diagram and was pointed to the
following page, which contains a more comprehensive explanation:
https://www.swetzel.ch/astronomie/finster/finster.html#3
> The limits for an eclipse to happen are not really constant, but taking
> this into account is probably out of scope of the currently available
> code in lunar.el.
I wonder why the angles in above explanation are completely different
from the ones given in eclipse-check:
((< moon-lat 2.42600766e-1)
(concat "** " phase-name " Eclipse **"))
((< moon-lat 0.37)
(concat "** " phase-name " Eclipse possible **"))
These are in radians. The first angle is 13.9° (exactly) and the
second one is 21.2°. They are in argument of latitude, while (IIUC)
the angles in "Finsternis-Limit" are given in ecliptic longitude.
Still, with the moon's orbital inclination being only 5°, one wouldn't
expect much of a difference there. Or am I missing something?
I've also found the book mentioned in lunar.el:
https://books.google.de/books?id=vVBPtkABpUoC&lpg=PA186&vq=eclipse&hl=de&pg=PA177#v=onepage&q&f=false
CCing Nicholas Strauss (who had originally submitted the code in
bug #20414).
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, (continued)
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Mueller, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Mueller, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Eli Zaretskii, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Mueller, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Eli Zaretskii, 2023/02/13
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/14
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon,
Ulrich Mueller <=
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/14
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Müller, 2023/02/14
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/14
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Müller, 2023/02/16
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/17
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Müller, 2023/02/17
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/17
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/18
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Ulrich Mueller, 2023/02/18
- bug#61460: 30.0.50; Calendar shows eclipse for quarter moon, Michael Heerdegen, 2023/02/18