calculated theta and rho

Doing an experiment, as thunder rolled in the distance. So to simulate the typical experience, wherein I've imaged other stars in the neighbour of my candidate doubles.

Loaded up the ζ UMi shot. Cranked various settings to draw out other stars. Spotted TYC 04563-0528 1 and 04563-0793 1 dimly, in the noise. Mag 11.7 and 11.6 specimens off to the north.

Downloaded the tools from Argyle's book, as referred to by Michaud. Ran RecToPol to convert the RA and Dec values to PA and Sep. Used the apparent RA and Dec from SkyTools.

• zeta to 528: 320.4°, 514.1"
• zeta to 793: 325.8°, 573.3"
• 528 to 793: 3.5°, 78.1"

Too bad it doesn't support copying to the clipboard. Or batch mode. Perhaps I should make a spreadsheet... Ugh. Spherical trig.

Decided to check the numbers in ST3P.

• zeta to 528: 320.7°, 8' 34"
• zeta to 793: 326.1°, 9' 33"
• 528 to 793: 3.5°, 1' 18"

OK.

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In Réduc, I clicked zeta and 528 respectively, and then entered the calibration numbers as per RecToPol. The returned values for Δ and E were: -37.9 and 0.62. And then with ζ and 793: -38.1 and 0.62.

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Was a little put-off by the delta angle. Until I remembered the zeta shots were before turning the camera...