NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Star finder tip: subtract one degree
From: Stan K
Date: 2017 Jan 30, 17:42 -0500
From: Stan K
Date: 2017 Jan 30, 17:42 -0500
For learning the night sky, it would also help if the stars were shown from inside the celestial sphere, instead of from outside, so it would match the sky when held overhead.
I tell my students that it also might help if they draw in some other stars that form recognizable asterisms.
Stan
-----Original Message-----
From: Robin Stuart <NoReply_Stuart@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Mon, Jan 30, 2017 5:14 pm
Subject: [NavList] Re: Star finder tip: subtract one degree
From: Robin Stuart <NoReply_Stuart@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Mon, Jan 30, 2017 5:14 pm
Subject: [NavList] Re: Star finder tip: subtract one degree
Frank,
You indicated that the Starfinder was a recent copy but might it be the effect of precession operating between whenever the Rude Starfinder was originally made and the present. For navigation we need Equator of Date and so positions in the star Nautical Almanac will change slowly over time. Precession is a rotation about the poles of the Ecliptic of about 1° every 72 years. It will affect the R.A. and declination of different stars differently but it seems like it's in the ballpark.
The thing that I dislike about the Starfinder is that although it offers a quick fix it probably guarantees that the user will never see or learn the sky as a whole with overall arrangement of the constellations that you can use to hop from one star to the next. If the Starfinder had a additional backing plate that was more like a planisphere that would be helpful.
It might also be worth considering alternative projections used to plot the stars on the backing plate,
Regards,
Robin Stuart
