Selected by you
DNB · 1 observing sessions in the archive
DNB · 6 h 25 min · 77 Lights
Catalogue positions on this exact selected master image.
Open full-resolution field image
Catalogue information from SIMBAD/CDS. Labels are reference positions, not new detections or measured object boundaries.
343 saved star coordinates reproduced. Exact projection reproduction after independently held-out Gaia display registration. Presentation only.. Existing reference residual (95%): 1.44 pixels. This is not a precision estimate for diffuse-object centres.
Catalogue reference centres are not object boundaries or new detections. Diffuse-object positions can be approximate. No physical nebula depth is measured. A display-only affine fit passed held-out controls; this does not validate scientific master registration.
Catalogue retrieved 2026-10-27T08:39:28.725664+00:00. 1f329409782a0ee6877faf92fd9fdb9b83b6267b682860098709c73f2c3413a0
Catalogue landmarks on the selected master.
Verified video for this exact saved image; depth is an illustrative display effect.
Saved per-exposure measurements; no universal quality score.
77 of 77 selected input exposures have cached histograms.
Measured curves in 0 of 1 saved image groups. Measurement availability does not establish a transit or a calibrated detection significance.
Each module is checked separately. An unavailable module does not invalidate the saved master; a complete list is not scientific certification.
Selected input exposures
Selected inputs against your whole archive · RGB and DNB remain separate.
Each unique original exposure contributes once per valid saved metric. Arithmetic mean across all objects; RGB and DNB separate. Missing or invalid values are excluded, never zero. This descriptive reference includes the selected exposures and later nights.
Exposure, camera settings, field brightness, sampling and stellar populations may differ. Background and stellar model SNR are not normalized measures of sky quality, master SNR or detection sensitivity. A difference is not a grade.
Stored per-frame medians of stellar fits are averaged; stars are not pooled. SNR requires a positive recorded effective gain and at least five stellar estimates. Units remain separate. Unknown method versions are recorded, not invented. Small, undersampled stars may bias shape measurements.
Archive version ab3717b4ec376ea87d5261c94fe6dbbd42a97237e09422490b5844921d286006
Selected input exposures
Measurements of the selected input exposures, not the finished master.
300.0 s · Gain 100.0 · Archive snapshot 2026-11-09T03:24:34.927460+00:00
Recorded focal length: 611.0 mm · separate header/settings cohorts, not additional observing sessions.
DNB Session 1 · 2026-10-03
Execution version was not saved: this comparison is limited to the same observing session.
Provisional star fits · stellar SNR is a model estimate, not master SNR.
Provisional stellar models: undersampled stars can bias the measurements. Differences are not quality grades. Stellar SNR is not nebular or master-image SNR.
DNB · 6 h 25 min · 77 Lights
Planning · model estimate
Based on the actual inputs of this selected master. RGB and DNB are modelled separately.
Current relative SNR = 1.00×. This is a reference level, not a measured master SNR. There is no universal “good” SNR target: it depends on the feature, aperture or region, noise definition and intended use.
6 h 25 min · 77 selected Lights. Sub-exposures: 300 s
One more comparable hour: about 7.5% higher SNR relative to now. Each following hour adds less relative benefit; it does not become useless.
| Relative SNR goal | Additional time | Total time |
|---|---|---|
| 1.25× | 3 h 36 min 34 s | 10 h 01 min 34 s |
| 1.50× | 8 h 01 min 15 s | 14 h 26 min 15 s |
| 2.00× | 19 h 15 min | 25 h 40 min |
Detail visibility is not angular resolution. More integration can reveal fainter structures. Seeing, optics, sampling, focus and guiding limit sharpness; this curve does not predict smaller or rounder stars.
Same target region, filter, camera, sub-exposure mix, throughput and sky conditions; independent random noise and comparable stacking weights. Fixed-pattern noise, calibration errors, gradients, correlated noise, changing conditions and rejected data can reduce the realised gain. Total exposure is not an effective per-pixel weight or an HDR-core coverage map.
Relative SNR = √((current time + additional time) / current time). Required extra time = current time × (goal² − 1). No numerical floor or absolute master SNR has been fitted; no per-frame star-SNR median is substituted.
Time means usable integration in the stack, excluding overheads, rejected frames and nights with unsuitable conditions. The curve is a planning scenario, not a measured progress history.
Verified image · DNB · 2026-10-03
572 verified identities; 12 spatially distributed highlights. Query: G < 16, at most 5000 sources; fainter neighbours may be absent.
Scheinbare Kataloghelligkeit, kein HR-Diagramm; Staub und Distance wirken mit.
Holdout residual: median 0.5138871867673964 px; 95 % 1.1267509647617382 px. G<16; fainter neighbours may be absent. Historical solver training set is unknown.
Temperature, mass and radius are catalogue model estimates, not stellar parameters measured from this photograph.
Exact catalogue values and geometryExperimental photometry · no confirmed transit. 0 unresolved technical review items.
DNB · 77/77 original exposures measured.
ADU · decoded digital value · Pixel count per bin; not a wavelength spectrum.
All saved bins, including negative values.
8-bit display values · nonlinear · Pixel count per bin; not a wavelength spectrum.
All saved bins, including negative values.
Not measured
0 unresolved technical review items · 0 Gaia IDs searched · 0 tested windows. Windows are not independent events.
No confirmed transit. Short artifact clusters and time-correlated errors can pass this screening. Real periodic search: insufficient coverage; no globally calibrated false-alarm probability is available.
Not measured for this scope. Use the manual Review → Measure action once native exposures, calibration and geometry are qualified.
2026-10-03 22:10:36 CEST (UTC+0200) → 2026-10-04 05:41:48 CEST (UTC+0200)
45.1% Moon illumination · saved calculation
Altitude 24.6°Target separation —Mitte des Aufnahmezeitraums
Time assumption: DATE-OBS interpreted as UTC because TIMESYS is missing. Astronomical context is provisional.
Moon altitude is approximate; local Earth-orientation data may be incomplete.
Geometric Moon altitude, without terrain or refraction; site elevation assumed to be 0 m.
Saved time assumptions are unchanged. Site and weather are shown on the session pages.
Comparison with your current archive: each physical observing session has equal weight. Valid per-exposure values are first averaged within each session, then the session means are averaged. Later sessions and the exposures shown here may be included. This is neither an independent test nor a formal quality grade.
Selected data use the exact input IDs of this product. RGB and DNB, methods, units, sampling and recorded acquisition settings remain separate. Unknown setup metadata do not establish physical compatibility. A few sessions form only a small descriptive reference. Missing values do not count as zero.
FWHM and star shape are saved medians of the stellar fits in each exposure; the display averages these per-exposure values. Stellar SNR is the saved median of model estimates from at least five stars per exposure. Model: source Poisson noise, background variance and uncertainty in the mean local sky. Circular aperture radius 3, sky annulus 5–7 sampling pixels, 3σ clipping. EGAIN in electrons/ADU is required. Different star selections remain a limitation even within the same field.
Background and scatter are raw green-grid ADU under compatible acquisition conditions. Field emission, gradients and stellar populations limit comparison. These are not measurements of pure seeing, nebular SNR or transit sensitivity. The previous grading rule requiring eight other nights has not changed.
DNB · Star shape: 77/77 valid selected exposures; archive 77/77 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.
DNB · Star width (FWHM): 77/77 valid selected exposures; archive 77/77 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.
DNB · Stellar SNR: 77/77 valid selected exposures; archive 77/77 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.
DNB · Background scatter: 77/77 valid selected exposures; archive 77/77 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.
DNB · Background: 77/77 valid selected exposures; archive 77/77 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.
Archive version ab3717b4ec376ea87d5261c94fe6dbbd42a97237e09422490b5844921d286006. This export is a frozen snapshot; it does not update without a new export.
All measurements and frozen archive comparison
1 selected frames worth reviewing · 77/77 inputs have enough same-session support. All frames remain selected exactly as before.
Separate raw measurements, compared with the median of the same session and recorded setup. No overall score, automatic rejection or diagnosis.
| Saved header time / input ID | Measurement | This frame | Session median | Why review? |
|---|---|---|---|---|
| 2026-10-03T23:59:18.057621 29ab7d81f8d5 | Star width (FWHM) | 3.394 sensor pixels | 2.708 | Broader than this session; inspect focus, tracking and sampling. The cause is not identified. |
Review distance = (value − session median) / (1.4826 × MAD). The threshold 3.5 is an advisory rule, not statistical significance. At least 12 valid frames and 75% coverage are required; zero MAD is unavailable. SNR requires the existing gain and star-count checks. Background changes are flagged in either direction.
Shared tracking/focus problems can affect an entire night without producing an outlier. No independent validation labels exist yet. Raw-green sampling and changing star populations limit interpretation. RGB/DNB, exposure, method and recorded orientation remain separate; unknown metadata do not establish compatibility.
DNB · 300.0 s · session acq_3ffd0489: Background level 77/77; Background scatter 77/77; Detected sources 0/77: too few valid session frames; Star eccentricity 77/77; Star width (FWHM) 77/77; Stellar SNR estimate 77/77. Unknown: device_id, filter, optical_configuration, readout_mode, recorded_orientation_deg.
Method session-quality-assistant-1. Saved measurements and existing archive comparisons are unchanged.
Literature context, checked 3 November 2026; not measured from these images. Distances are approximate and depend on the adopted source.
Barnard communicated the discovery directly to Dreyer; the consulted historical account gives no exact observing date. IC 1848 names the cluster as well as the wider Soul Nebula in common usage. The approximate distance follows NASA/WISE; other literature adopts somewhat larger distances.
