NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Santa Barbara 2016: Venus sight
From: Peter Hakel
Date: 2016 Dec 20, 00:48 +0000
From: Stan K <NoReply_StanK@fer3.com>
To: pmh099@yahoo.com
Sent: Monday, December 19, 2016 10:38 AM
Subject: [NavList] Re: Santa Barbara 2016: Venus sight
From: Peter Hakel
Date: 2016 Dec 20, 00:48 +0000
Stan,
On this issue I have no comment, since for “Astron” I am just a messenger for “an anonymous benevolent user” who created this spreadsheet; my original spreadsheets do not calculate twilight info.
Peter Hakel
On this issue I have no comment, since for “Astron” I am just a messenger for “an anonymous benevolent user” who created this spreadsheet; my original spreadsheets do not calculate twilight info.
Peter Hakel
From: Stan K <NoReply_StanK@fer3.com>
To: pmh099@yahoo.com
Sent: Monday, December 19, 2016 10:38 AM
Subject: [NavList] Re: Santa Barbara 2016: Venus sight
Peter,
I've been trying to send this privately, both on and off NavList, but the messages keep getting returned. I thought you might have changed you address because of the Yahoo hack, but your messages seem to be coming from the same old address.
Anyway, I have a question about the way Astron defines twilights. All the definitions of twilight, whether civil or nautical (or astronomical) that I can find involve the sun, rise or set. Morning twilight starts at the start of AM nautical/civil twilight and ends at sunrise. Evening twilight starts at sunset and ends at the end of civil/nautical twilight. Astron seems to define AM twilight as starting from the start of AM nautical twilight and ending at the start of AM civil twilight; PM twilight starts at the end of PM civil twilight and ends at the end of PM nautical twilight.
If there is a reference that defines twilights this way, please let me know what it is.
Stan
