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In my last post § 3.2 , I was not overly confident in my former published results about position change for a 0.1' difference in Lunar Distances "which I trust[ed] as less reliable ..." .

That was sound judgment then. This is why I am hereby publishing the following

1 - Correction to Error Budget :

(1.1) - Starting first from the unchanged [reliable] data hereafter  :

QUOTE

With "BSLD" standing for Brighter Star Limb Distance , and "FSLD" standing for "Fainter Star Limb Distance :

∂BSLD/∂Lat  = -0.036' / 10' Lat            ∂BSLD/∂Lon  = -0.046' / 10' Lon

 ∂FSLD/∂Lat  = +0.145' / 10' Lat            ∂FSLD/∂Lon  = -0.064' / 10' Lon

UNQUOTE

(1.2) - Brightest Star (HIP 29264B) Position change for a 0.1' error in Lunar Distance

With   δBSLD = + 0.1' and δFSLD = 0.0' , then δLat = +7.1' (i.e. 7.1 NM to the North) and δLon = -16.2' (i.e. 13.5 NM to the East). Position change 15.1 NM (vs. 15.8 NM for "updated" Modris Fersters)

(1.3) - Faintest Star (HIP 21482) Position change for a 0.1' error in Lunar Distance

With   δBSLD = 0.0' and δFSLD = + 0.1' , then δLat = +5.1' (i.e. 5.1 NM to the North) and δLon = -4.0' (i.e. 3.4 NM to the East). Position change 6.1 NM (vs. 6 NM for "updated" Modris Fersters)

Full agreement this time between our results on Position changes for a 0.1' error in respective Lunar distances.

(2) - Comparison between resulting positions derived by Modris and Antoine

(2.1) - Modris' updated Position : 30 Apr 2025, 02:58:19 UT / N33°17' / W 111°54'

(2.2) - Antoine's Position : 30 Apr 2025, 02:58:19 UT / 02:59:28.2 TT / N33°21.0' / W 112°07.5'

Both positions differ by only 12 NM.

Assuming that the best we can get from the photo is measuring Lunar Distances to +/- 0.1' and given (1.2) and (1.3) hereabove, not forgetting either that our "Bright stars" are slightly different (probably by 4" to 5"), then this 12 NM difference between our respective positions is hardly significant.

Hence, we will read with interest the position obtained by Frank from the PHOENIX Photographer himself.

Thanks again to both of you, Modris and Frank

Kermit

PS : Modris, as you seem to wish some specific follow-up, do not hesitate to contact me privately here: antoine.m.couette@club-internet.fr