Repeated spectral records yield numerical profiles, and five central-row tracks now support a provisional Balmer-reference wavelength scale with unused-line checks.
Five selected central-row profiles support the consecutive Hγ, Hδ, Hε, H8 and H9 interpretation. Other extracted tracks remain in scan-pixel coordinates. The apparent July 1950 date and written numeric settings do not establish a calibrated exposure or brightness sequence; those settings could be focus positions.
The records show repeated transverse features. Five central-row tracks have provisional Balmer-reference coordinates below; all other extracted tracks retain scan-pixel coordinates.
The margin appears to read “OP 966” and “July 25/26 1950”. A morphology-only pass selected some photographic bars as ink. Inspected exclusion regions now preserve those bars while retaining candidate caption numbers and margin writing.
The revised layer uses local contrast in both polarities, expanded inspected writing regions and contextual recovery of short fragments and round digits. Known photographic targets and sampled spectral apertures are protected. It is not OCR and does not reconstruct hidden sky or invent pen strokes.
The selection covers 1.41% of this scan (437,901 pixels). Faint marks, scratches and contacts between ink and photographic images remain ambiguous. The cyan overlay shows the wider exclusion footprint used by the photographic remainder; the stroke mask is supplied separately.
The writing PNG is a white, contrast-rendered stencil of bright and dark observed marks. The observed-pixel PNG preserves their stretched scan appearance. Both use original scan coordinates. The photographic remainder displays excluded pixels as black holes. It is neither a clean-sky reconstruction nor a new photometric product. Keep the mask alongside any measurements. Native original-intensity TIFF/FITS products, where generated, remain in the analysis workspace and are not duplicated in this handoff.
This revision recovers short letter fragments, round digits and inspected dark marks, with broader writing regions. The stroke selection grows from 175,037 to 437,901 pixels (2.50×). The photographic remainder uses a separate 3-pixel exclusion margin, covering 2.32% of the scan.
The wider selection deliberately favors removing writing. Nearby stars, scratches and ambiguous fragments can also be excluded. Explicit photographic protection regions retain known target images and sampled spectra; this does not establish perfect separation elsewhere.
This is not treated as a directly solvable star field. The streak grid has no confirmed celestial catalog correspondence and no WCS is supplied.
The photographic streaks contain transverse band structure. These are recoverable spectral records rather than featureless bars: the extraction measures selected tracks across the graded grid, including both bright and faint examples. Their exposure interpretation remains open; a selected subset has provisional Balmer-reference scales below.
38 selected tracks are plotted below. Final measurements use original 16-bit TIFF values, one sample per native Y pixel, with linear interpolation across each traced aperture. The average of two adjacent sidebands estimates local background. Final profiles are not smoothed.
The ordinate is scanner response after background subtraction. It is not calibrated flux or optical density, and the abscissa is original scan Y, not wavelength. Normalized comparisons cannot establish sensitivity, line strength or exposure linearity without the scanner/emulsion response and wavelength references.
Identify known lines or a comparison source, fit wavelength as a function of scan position, test that fit on unused lines, and establish which tracks share the same instrumental setting. Then assess photographic density, saturation, scattered light and scanner response before interpreting line ratios. The present CSVs preserve the measured scanner values for that next analysis.
Five selected central-row profiles support the consecutive Hγ, Hδ, Hε, H8 and H9 interpretation. Other extracted tracks remain in scan-pixel coordinates. The apparent July 1950 date and written numeric settings do not establish a calibrated exposure or brightness sequence; those settings could be focus positions.
Across these scans, repeated photographic images need not imply the same mechanism. Shutter timing, guiding offsets, objective optics and different pointings can leave related patterns. Establish consistent component membership before fitting a smooth warp. No result here isolates glass deformation from telescope optics, emulsion, scanner geometry and centroid bias.
The selected spectra show five converging features consistent with consecutive Balmer lines: Hγ 4340.462 Å, Hδ 4101.740 Å, Hε 3970.072 Å, H8 3889.049 Å and H9 3835.384 Å (NIST air references). They span violet and near ultraviolet; telescope UV capability alone does not identify a plate’s bandpass.
We use Y = A + B(4000/λ)². Hγ and Hδ determine the two anchor parameters; the other three features are unused checks. Alternative consecutive Balmer assignments starting at upper levels n=3…8 were tested, and n=5 gives the best check residuals for all ten selected OP tracks. The supplied final scale refits all five features after those checks.
| Track | Unused-line RMS / native px | Plot | Data |
|---|---|---|---|
| S14 | 0.427 | Open plot ↗ | CSV ↓ |
| S15 | 0.767 | Open plot ↗ | CSV ↓ |
| S16 | 1.315 | Open plot ↗ | CSV ↓ |
| S17 | 0.742 | Open plot ↗ | CSV ↓ |
| S18 | 0.506 | Open plot ↗ | CSV ↓ |
A common Doppler shift is absorbed by the fitted coefficient B when stellar Balmer lines themselves define the wavelength ruler. These are Balmer-referenced rest-line coordinates, not independently calibrated observed wavelengths. No redshift or radial velocity is measured. A stationary comparison reference or an independently established instrumental dispersion scale is required to break that degeneracy.
The checked interval is 3835.384–4340.462 Å. Outside it, the model is extrapolation. Scanner response, saturation, photographic density, blending and line widths remain uncalibrated. Reported widths combine instrumental, stellar and photographic effects; they are not a pure resolving-power measurement. No calibration is assigned to the remaining raw tracks merely by proximity.
Five selected tracks support the consecutive Balmer assignment Hγ through H9. Hγ and Hδ anchor a two-parameter inverse-square dispersion model; the other three lines test it. Across both OP plates, unused-line RMS spans 0.25–1.32 native pixels. The delivered reference scale is then refitted to all five lines.
This is a provisional Balmer-referenced air-wavelength coordinate over 3835–4340 Å, not an independently determined observed-frame wavelength or flux scale. Fitting stellar lines to rest references absorbs a common Doppler shift into the dispersion coefficient: redshift and radial velocity remain unmeasured.
Select a numbered pin or a note. Locations are editorial review pointers, not measured confidence contours; plate-wide limitations also apply.
Streak strength and shape are measurable in pixels, but exposure ordering and units are unconfirmed.
Short written labels near streaks remain ambiguous where the signals touch. Inspect the layer overlay before deleting selected pixels.
The written schedule or instrument context is not yet transcribed with confidence.
Obtain an independent comparison-lamp or stationary reference, verify the spectral source and exposure schedule, then test observed wavelengths and photographic response.
Five Balmer-referenced profiles per plate are supplied alongside the original pixel-coordinate extractions. Wavelength interpretation is provisional; flux calibration and redshift are unresolved.
All scientific numbers are snapshots of the saved analysis products. The original 16-bit scans remain the measurement source. JPEG derivatives, contrast stretching and masked previews are inspection tools; do not derive photographic density or absolute response from their appearance.
