A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2020 Dec 10, 15:13 -0800
Have a look at Jupiter and Saturn over the next few days. By Saturday (+/- a day depending on your location on Earth), the angle will fall from 1.2° to 1.0°. Can you measure it with your sextant? Do you have to apply any corrections for dip or refraction or parallax? Of course, the angular distance will continue to fall after Saturday heading for a minimum of just a tenth of a degree, which will happen (by coincidence) on the solstice.
I tried about twenty minutes ago (22:46 UT) with an un-adjusted sextant. My results are in the images attached. One shows the index error, about 0°00.7' and the other is the observation of the angle between Jupiter and Saturn, which ends up being an exercise in reading an off-arc angle. Enjoy!
Oh, by the way, the sextant has a side offset of about 5 minutes of arc. Nothing to worry about, but I thought I would mention it.