William Optics RedCat 51 (51 mm aperture, 250 mm focal length); ZWO ASI1600MM Pro, gain 139, offset 10, 1x1 binning, -10 C. Optolong 1.25-inch H-alpha 7 nm, [O III] 6.5 nm and [S II] 6.5 nm filters; ZWO EFW.
NSVS 6869020, 2026-10-18 UTC; 9 retained exposures through [O III]. Optolong 1.25-inch narrowband filter; nominal FWHM 6.5 nm (HASIIOIII-125 set). JD values are UTC exposure midpoints, uncorrected (not HJD/BJD). Relative ensemble magnitudes: this target's Oct 18 median is set to zero separately in each filter. This reference level is not a verified out-of-eclipse maximum; these are not standard magnitudes. Filters must remain separate.
Native-pixel dark/flat calibrated aperture photometry: radius 5 px (~15.8 arcsec), sky annulus 12-18 px; checked at 7/9 px and with an independent ensemble. Clouds/uncertain intervals excluded. Satellite-trail affected comparison measurements masked; target aperture unaffected.
Empirical check-star uncertainty (mag), in file row order: 0.0346, 0.0273, 0.0273, 0.0273, 0.0287, 0.0273, 0.0273, 0.0273, 0.0273.
Finding-chart labels below map local field IDs to Gaia DR3 source IDs. Gaia magnitudes identify stars only, not narrowband calibration. C=comparison ensemble; K=independent checks.
C: 611=182042498078612480, 195=182042193139470720, 698=182091258845865856, 227=182038310490246272, 733=182034011223245312, 1524=183526323383110784, 207=183601953462414848, 187=182087062659275136, 562=182105857436159104, 1327=183532065754594432, 1260=182084176441260032, 322=182085383330710272, 260=183600647793159296, 1111=183551753884620544, 1312=182016075442742656, 434=183604152486555520, 1342=182016556479080064, 249=182773265294445440, 345=182773986847626368, 1293=182060021545192320.
K: 592=183534810238483072, 360=182782336263998720, 341=183563053941908224, 1156=182290369232747904, 467=182806211986555136, 1714=182006008036491392, 1462=183633083385058176, 678=183565012446992000, 246=182805700886058496, 940=183632391892421248, 458=183645933927205504, 1042=181251816077827840, 387=183633804940664832, 331=181998521912286592, 651=183645762128502016, 436=182764984596537216, 690=183627036071109760, 613=183645899567450368, 1333=181253976444979456, 177=182749625793701120.
Known variable; no new period, precise event timing or discovery is claimed. Raw frames, calibrations, rich CSVs and full reduction provenance are retained.

William Optics RedCat 51 (51 mm aperture, 250 mm focal length); ZWO ASI1600MM Pro, gain 139, offset 10, 1x1 binning, -10 C. Optolong 1.25-inch H-alpha 7 nm, [O III] 6.5 nm and [S II] 6.5 nm filters; ZWO EFW.
NSVS 6869020, 2026-10-17 UTC; 14 retained exposures through [O III]. Optolong 1.25-inch narrowband filter; nominal FWHM 6.5 nm (HASIIOIII-125 set). JD values are UTC exposure midpoints, uncorrected (not HJD/BJD). Relative ensemble magnitudes: this target's Oct 18 median is set to zero separately in each filter. This reference level is not a verified out-of-eclipse maximum; these are not standard magnitudes. Filters must remain separate.
Native-pixel dark/flat calibrated aperture photometry: radius 5 px (~15.8 arcsec), sky annulus 12-18 px; checked at 7/9 px and with an independent ensemble. Clouds/uncertain intervals excluded. Satellite-trail affected comparison measurements masked; target aperture unaffected.
Empirical check-star uncertainty (mag), in file row order: 0.0507, 0.0273, 0.0273, 0.0273, 0.0273, 0.0279, 0.0273, 0.0330, 0.0273, 0.0273, 0.0273, 0.0273, 0.0293, 0.0273.
Finding-chart labels below map local field IDs to Gaia DR3 source IDs. Gaia magnitudes identify stars only, not narrowband calibration. C=comparison ensemble; K=independent checks.
C: 611=182042498078612480, 195=182042193139470720, 698=182091258845865856, 227=182038310490246272, 733=182034011223245312, 1524=183526323383110784, 207=183601953462414848, 187=182087062659275136, 562=182105857436159104, 1327=183532065754594432, 1260=182084176441260032, 322=182085383330710272, 260=183600647793159296, 1111=183551753884620544, 1312=182016075442742656, 434=183604152486555520, 1342=182016556479080064, 249=182773265294445440, 345=182773986847626368, 1293=182060021545192320.
K: 592=183534810238483072, 360=182782336263998720, 341=183563053941908224, 1156=182290369232747904, 467=182806211986555136, 1714=182006008036491392, 1462=183633083385058176, 678=183565012446992000, 246=182805700886058496, 940=183632391892421248, 458=183645933927205504, 1042=181251816077827840, 387=183633804940664832, 331=181998521912286592, 651=183645762128502016, 436=182764984596537216, 690=183627036071109760, 613=183645899567450368, 1333=181253976444979456, 177=182749625793701120.
Known variable; no new period, precise event timing or discovery is claimed. Raw frames, calibrations, rich CSVs and full reduction provenance are retained.