Hi Dan,
There are numerous examples in the excellent book “The Double Horizontal
Sundial” by John Davis and Michael Lowne, available from the British Sundial
Society on their website. DH dials include a projection of the celestial sphere
between the solstices, show the ecliptic and optionall
On Tue, Jun 7, 2022 at 11:15 AM Dan-George Uza
wrote:
> Hello,
>
> Are there sundials showing the Sun's right ascension? Can you please post
> a photo? Thanks!
>
> Dan Uza
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
> You could sho
Dear Anselmo:
thanks for the approximation. How close is it? And is UT the time at
Greenwich?
Regards, Brad
Yes. UT is Greenwich Mean Time. As regards to the exactness and if I
remember well, it's
reliable in about 4min of time, that is, +/- 1 deg in longitude. I'll
try and check it.
An
Dear Anselmo:
thanks for the approximation. How close is it? And is UT the time at
Greenwich?
Regards, Brad
-Original Message-
From: Anselmo Pérez Serrada [mailto:[EMAIL PROTECTED]
Sent: Friday, January 16, 2004 5:19 PM
To: sundial@rrz.uni-koeln.de
Subject: Re: Right Ascension
Dear
Somewhat off topic, but how do you translate (a) the right ascension of a
star and (b) the current date and time into (c) the apparent longitude of
the star?
-
If by longitude you mean the (western) geographical longitude of the
star, you may also use
the following approximation ( it comes
Designs
N 48.6 W 123.4
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Thibaud
Taudin-Chabot
Sent: January 15, 2004 2:40 PM
To: sundial@rrz.uni-koeln.de
Subject: Re: Right Ascension
At 20:37 14-01-2004, you wrote:
>Somewhat off topic, but how do you tran
lto:[EMAIL PROTECTED] Behalf Of Thibaud
Taudin-Chabot
Sent: January 15, 2004 2:40 PM
To: sundial@rrz.uni-koeln.de
Subject: Re: Right Ascension
At 20:37 14-01-2004, you wrote:
>Somewhat off topic, but how do you translate (a) the right ascension of a
>star and (b) the current date and time into
Somewhat off topic, but how do you translate (a) the right ascension of a
star and (b) the current date and time into (c) the apparent longitude of
the star?
I took my old nautical astronomy book and found:
1. SHA(star) = 360 - right ascencion (SHA=siderial hour angle)
2. LHA(star) = GHA(arie
Patrick's advice is correct but I suspect that it is more than Brad was
looking for. Sidereal time is the hour angle of the Vernal Equinox (Aries),
one of the starting lines for the celestial co-ordinate system, declination
being the other. Right ascension for a star is just the distance from that
