NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: DSLR Venus Lunar
From: Peter Hakel
Date: 2010 Sep 16, 11:39 -0700
From: George Huxtable <george@hux.me.uk>
To: NavList@fer3.com
Sent: Thu, September 16, 2010 2:28:49 AM
Subject: [NavList] Re: DSLR Venus Lunar
Meeus was writing for astronomers, who presumably have the sort of
telescope that can clearly identify those two radii; and not for the likes
of us, who in a sextant scope can only view such planets as a displaced
blob-of-light.
[rest deleted by PH]
From: Peter Hakel
Date: 2010 Sep 16, 11:39 -0700
I have a Davis Mark 15 with its one telescope and indeed Jupiter was just a blob of light, when I looked recently. It has been my impression, however, (from reading about lunars, not shooting them much as of now...) that they are best observed with the maximum-magnification telescope available. From that I concluded (perhaps incorrectly) that there are sextant telescopes available that can sufficiently resolve planetary semidiameters so you can go limb-to-limb with the Moon. After all, in lunar calculations we do account for the augmentation effect on Moon's semidiameter, which is of the same order of magnitude (~0.1') as the planetary semidiameters. Now for Venus this would be a bit tricky since both illuminated limbs would face toward the Sun (i.e. in the same direction with Sun
below the horizon), but for an outer planet like Jupiter I'd think it would work.
Can anyone confirm or correct my understanding of this detail? I am pretty sure that in the past Frank and others already commented on this rather extensively...
Peter Hakel
Can anyone confirm or correct my understanding of this detail? I am pretty sure that in the past Frank and others already commented on this rather extensively...
Peter Hakel
From: George Huxtable <george@hux.me.uk>
To: NavList@fer3.com
Sent: Thu, September 16, 2010 2:28:49 AM
Subject: [NavList] Re: DSLR Venus Lunar
Meeus was writing for astronomers, who presumably have the sort of
telescope that can clearly identify those two radii; and not for the likes
of us, who in a sextant scope can only view such planets as a displaced
blob-of-light.
[rest deleted by PH]