RC 203 mm + TS 0.67x reducer (f/5.6), IMX571 mono, Baader Sloan filters
Forced aperture photometry (position from WCS) on single 120 s frames; ensemble of Gaia DR3 GSPC comparison stars (synthetic SDSS), linear zero-point plane per frame, fixed check star. Untransformed. Gap 02:55-03:10 UT (meridian flip) on the descending branch; ascending branch only to 04:12 UT. Variable transparency (thin haze) after 23:40 UT. Our own fit (symmetric polynomial, bootstrap): BJD_TDB 2461339.66234, statistical +-0.0005 d, realistic +-0.0017 d. VarAstro prediction (S) was 04:10 UT: O-C about -22 min.

RC 203 mm + TS 0.67x reducer (f/5.6), IMX571 mono, Baader Sloan filters
Forced aperture photometry (position from WCS) on single 120 s frames; ensemble of Gaia DR3 GSPC comparison stars (synthetic SDSS), linear zero-point plane per frame, fixed check star. Untransformed. Gap 02:55-03:10 UT (meridian flip) on the descending branch; ascending branch only to 04:12 UT. Variable transparency (thin haze) after 23:40 UT. Our own fit (symmetric polynomial, bootstrap): BJD_TDB 2461339.66234, statistical +-0.0005 d, realistic +-0.0017 d. VarAstro prediction (S) was 04:10 UT: O-C about -22 min.

GSO NWT 200/1000 + ZWO ASI 178MM
----- EBFit result: -----
Tmin = 2460320.32612
Error (1 sigma): +0.00004/-0.00004 (Bootstrapping), +0.00003/-0.00003 (Prayer bead), +0.00003/-0.00003 (LSM)
Error (95% CI): +0.00009/-0.00008 (Bootstrapping), +0.00006/-0.00005 (Prayer bead)
LSM: chi^2 = 465.8, n_freedom = 156

GSO NWT 200/1000 + ZWO ASI 178MM
B.R.N.O.! (primární)

----- EBFit result: -----
TminGJD = 2460320.32611
Error (1 sigma): +0.00004/-0.00004 (Bootstrapping), +0.00003/-0.00003 (Prayer bead), +0.00003/-0.00003 (LSM)
Error (95% CI): +0.00009/-0.00008 (Bootstrapping), +0.00007/-0.00007 (Prayer bead)
LSM: chi^2 = 430.3, n_freedom = 147

GSO NWT 200/1000 + ZWO ASI 178MM
----- EBFit result: -----
Tmin = 2459246.31975
Error (1 sigma): +0.00007/-0.00007 (Bootstrapping), +0.00003/-0.00003 (Prayer bead), +0.00005/-0.00005 (LSM)
Error (95% CI): +0.00013/-0.00014 (Bootstrapping), +0.00006/-0.00006 (Prayer bead)
LSM: chi^2 = 289.8, n_freedom = 155

GSO NWT 200/1000 + ZWO ASI 178MM
----- EBFit result: -----
TminGJD = 2459246.31974
Error (1 sigma): +0.00006/-0.00007 (Bootstrapping), +0.00003/-0.00003 (Prayer bead), +0.00005/-0.00005 (LSM)
Error (95% CI): +0.00012/-0.00013 (Bootstrapping), +0.00005/-0.00006 (Prayer bead)
LSM: chi^2 = 302.4, n_freedom = 160

Newton 500/2 430, G2-1600
TminHJD = 2455857.43224 +/- 0.00026 primary minimum

Newton 500/2 430, G2-1600
TminHJD = 2455857.43204 +/- 0.00019 primary minimum

Newton 500/2 430, G2-1600
TminHJD = 2455857.42958 +/- 0.00037 primary minimum

Newton 200/1000, G2-1600
TminHJD = 2455599.31561 +/- 0.003

Newton 200/1000, G2-1600
TminHJD = 2455599.31641 +/- 0.003

Newton 200/1000, G2-1600
TminHJD = 2455599.31591 +/- 0.001