M 33 · RGB Session 1 · 2026-11-07

Observing conditions

Saved context for this physical observing session. Separate time spans remain visible below.

RGB · 2026-11-07 19:52:31 CET (UTC+0100) → 2026-11-07 22:16:26 CET (UTC+0100)

Moon · calculated

2.3%

Illuminated · Waning

Altitude -53.1° · below the geometric horizon

Reference: 2026-11-07T20:04:28.758 UTC

Observing site

—

Location not recorded, or withheld in this read-only share.

Weather · model context

ECMWF IFS archive · Open-Meteo

Cloud cover: 0.0–0.0 %
Dew point: -3.2–-3.1 °C
Relative humidity: 69.0–74.0 %
Air temperature: 0.9–2.1 °C
Wind at 10 m: 3.8–4.1 m/s

Ranges of hourly model samples. Air temperature is not sensor temperature.

Hourly values and coverage

UTC	Air temperature · °C	Relative humidity · %	Dew point · °C	Wind at 10 m · m/s
2026-11-07T18:00:00+00:00	2.1	69.0	-3.1	3.8
2026-11-07T19:00:00+00:00	1.6	71.0	-3.2	3.8
2026-11-07T20:00:00+00:00	1.2	72.0	-3.2	3.9
2026-11-07T21:00:00+00:00	0.9	74.0	-3.1	4.1

Hourly gridded model context, not measurements at the telescope. Hourly samples bounding this exposure-group interval; no minute interpolation.

Cloud cover: 4/4 samples; Dew point: 4/4 samples; Relative humidity: 4/4 samples; Air temperature: 4/4 samples; Wind at 10 m: 4/4 samples

Retrieved 2026-11-08T23:03:24.490610+00:00

Provider and model documentation

Context provenance and limits

Recorded DATE-OBS time interpretation retained; if TIMESYS is absent it is provisionally UTC.

Saved calculation at this exposure group's midpoint. Geometric altitude assumes sea level, no terrain or refraction. Schematic orientation, not a sky photograph.

Weather does not establish seeing, transparency at the telescope, a Bortle class or a photometric correction. Missing values do not imply clear skies.

Saved context SHA-256: f7f36bf0a1bdfeed083063ed566e6667c0150eac79b87fc6f416f845a716d561

RGB · 180 s · 43 Lights

2 h 09 min · 43 exposures available.

Selected input exposures

Image quality at a glance

Selected inputs against your whole archive · RGB and DNB remain separate.

RGB · all contributing sessions

Star width / FWHM: 2.74 sensor pixels; Current archive average3.00 sensor pixels; Difference -0.26; 43/43 selected · archive 865/865 exposures · 11 sessions · 8 objects
Star shape / eccentricity: 0.48 dimensionless; Current archive average0.45 dimensionless; Difference +0.03; 43/43 selected · archive 865/865 exposures · 11 sessions · 8 objects
Background: 746.51 ADU; Current archive average749.61 ADU; Difference -3.10; 43/43 selected · archive 865/865 exposures · 11 sessions · 8 objects
Background scatter: 34.18 ADU; Current archive average34.26 ADU; Difference -0.07; 43/43 selected · archive 865/865 exposures · 11 sessions · 8 objects
Stellar model SNR: 123.15 dimensionless; Current archive average138.73 dimensionless; Difference -15.59; 43/43 selected · archive 865/865 exposures · 11 sessions · 8 objects; Stellar model estimate · different fields

Star width / FWHM — Selected exposure values · whole-archive RGB mean · physical sessions separated.

Star shape / eccentricity

Background

Background scatter

Stellar model SNR

How this archive average is calculated

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

Matched acquisition settings · original session-weighted comparison

Selected input exposures

Image quality at a glance

Measurements of the selected input exposures, not the finished master.

RGB · 180.0 s · 43 Lights

Acquisition settings & contributing sessions

180.0 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.

RGB Session 1 · 2026-11-07

Execution version was not saved: this comparison is limited to the same observing session.

Star width (FWHM): 2.74 sensor pixels; Current archive average2.74 sensor pixels; Difference 0.00 sensor pixels; 43/43 frames · archive: 1 Sessions
Star shape: 0.48 dimensionless; Current archive average0.48 dimensionless; Difference 0.00 dimensionless; 43/43 frames · archive: 1 Sessions; Eccentricity of stellar model fits
Background: 746.51 ADU; Current archive average746.51 ADU; Difference 0.00 ADU; 43/43 frames · archive: 1 Sessions
Background scatter: 34.18 ADU; Current archive average34.18 ADU; Difference 0.00 ADU; 43/43 frames · archive: 1 Sessions
Stellar SNR: 123.15 dimensionless; Current archive average123.15 dimensionless; Difference 0.00 dimensionless; 43/43 frames · archive: 1 Sessions; Model estimate · same target field

Star width (FWHM) over time — Star width (FWHM) · saved per-exposure values and current archive average. Sessions are separate; gaps are not joined.

Star shape · Trend

Star shape over time — Star shape · saved per-exposure values and current archive average. Sessions are separate; gaps are not joined.

Background · Trend

Background over time — Background · saved per-exposure values and current archive average. Sessions are separate; gaps are not joined.

Background scatter · Trend

Background scatter over time — Background scatter · saved per-exposure values and current archive average. Sessions are separate; gaps are not joined.

Stellar SNR · Trend

Stellar SNR over time — Stellar SNR · saved per-exposure values and current archive average. Sessions are separate; gaps are not joined.

Provisional star fits · stellar SNR is a model estimate, not master SNR.

Reading these values

Provisional stellar models: undersampled stars can bias the measurements. Differences are not quality grades. Stellar SNR is not nebular or master-image SNR.

Processing and calibration record

Processing for this session

Calibrationsuccess
Registrationsuccess
Stackingsuccess
ReportSaved results

43/43 Lights calibrated; {'bias': 100, 'dark': 58, 'flat': 40} calibration frames. Unknown compatibility fields: device_id, filter, optical_configuration, readout_mode.

Calibration and processing evidence

{
  "calibrated": 43,
  "calibration_state": "success",
  "crop": {
    "area_fraction": 0.9679719732536634
  },
  "integration_s": 7740.0,
  "planned": 43,
  "ready": 43,
  "registered": 43,
  "registration_state": "success",
  "selected_calibrations": {
    "bias": 100,
    "dark": 58,
    "flat": 40
  },
  "stacked": 43,
  "stacking_state": "success",
  "unknown_fields": [
    "device_id",
    "filter",
    "optical_configuration",
    "readout_mode"
  ],
  "warnings": [
    "Bias is used for flat correction only; exposure/linearity suitability remains unvalidated",
    "Flat exposure is not matched to light exposure; flat dark current, illumination and physical optical-state continuity remain unvalidated",
    "Raw ROTATOR/angle semantics are unverified; differences are not evidence of physical rotation.",
    "Short-Flat/Light temperature tolerance: +/-2 C; Dark and Bias tolerances unchanged. Flat diagnostics and optical-history approval remain required.",
    "device_id: compatibility unknown; permitted only by explicit warning policy",
    "filter: compatibility unknown; permitted only by explicit warning policy",
    "optical_configuration: compatibility unknown; permitted only by explicit warning policy",
    "readout_mode: compatibility unknown; permitted only by explicit warning policy"
  ]
}

Explore stars in the image

Image geometry is not sufficiently verified, or the exact catalogue is not yet saved.

Science & measurements

Experimental photometry · no confirmed transit. 0 unresolved technical review items.

Histograms, light curves & event evidence

Intensity histograms

RGB · 43/43 original exposures measured.

RGB · Raw pixel values

ADU · decoded digital value · Pixel count per bin; not a wavelength spectrum.

Channel Range Pixel count

All saved bins, including negative values.

Exact counts and measured values

Werte und Darstellungsbins · Complete unchanged bins (NPZ)

Current display image

8-bit display values · nonlinear · Pixel count per bin; not a wavelength spectrum.

Channel Range Pixel count

All saved bins, including negative values.

Exact counts and measured values

Werte und Darstellungsbins · Complete unchanged bins (NPZ)

Events · technical review

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.

Saved event evidence

Test windows, supporting exposures and limitations

Photometry precision and sampling · experimental

Photometry & transit readiness

Not measured for this scope. Use the manual Review → Measure action once native exposures, calibration and geometry are qualified.

Comparison-star evidence · experimental

Stack input review · 0 exclusions

Input image review

0 excluded from this imaging stack · 0 flagged for inspection · 43 original exposures retained.

Exclusions affect this image stack only. Raw measurements and calibrated scientific images remain available. A satellite-like line alone does not reject an entire exposure.

Typical reference exposure

Reference raw frame and representative star crops

Method and all inputs

Median/MAD comparisons stay within the same session, exposure, recorded setup and orientation. At least 12 valid frames and 75% coverage are required. Only simultaneous strong width and elongation outliers with at least 20 fitted stars can be excluded automatically. These are engineering thresholds, not a validated defect classifier. Entire-night defects and satellite trails may escape these metrics; pixel rejection remains a separate stack operation.

Exposure	Imaging decision	Reason
Input 079576373b77	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 9d05797d6052	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input dd75da83a1ff	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input b42ab7770e15	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 1044602d77a3	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input a406f98b6c80	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 7f622d9076b8	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 458d27fd9487	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 06b81a6c3ff2	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 56e6c925b77c	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 80ea476ff3cc	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input d8b6f95ff454	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 833561e5df18	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input c36d1cfabc29	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 835f1fadb177	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 208b1fabb7ad	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input c95775266b6b	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input f453a9b23b9c	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input cbcc2bf1f427	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 67b52b047d58	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input e13905911332	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 54ca6afbf91f	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 61d426d994ad	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 08c0c2cfaebc	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 366703f542b2	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 595e402b5ae3	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input bb2a4fb56689	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input fb7fb0ee576b	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 931e55593816	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input f23608239de9	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 840c3fa64642	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 2ae722aa63ac	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input afa973867e75	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 4acb73f02da1	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 94c3b093f4ef	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 47c81091325a	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 12607c403df4	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 6dbfaa107b88	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 55f66f1e9ac5	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input af93b55501cb	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 73ec235166fa	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input bd10694749a2	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier
Input 681964a15a8d	retain · weights R/G/B 1.000 / 1.000 / 1.000	no_supported_outlier

Stack contribution weights

Equal contribution retained after weighting review

Compared with an equal-weight control using the exact same exposures, crop, normalization and pixel rejection. Star width and shape are reviewed separately.

No supported texture improvement without a worse channel

Matched stars: 64 · background-texture ratio R/G/B: 1.000 / 1.000 / 0.993. Ratios compare weighted / equal; they are not a calibrated SNR.

Per-exposure weights and method

Weights are proportional to inverse background variance after Siril additive-scale normalization, independently in R, G and B, normalized to mean one. Displayed native values are reconstructed from rounded saved statistics. A weight is not a universal quality grade.

Input ID	R / G / B contribution
1044602d77a3	1.0000 / 1.0000 / 1.0000
079576373b77	1.0000 / 1.0000 / 1.0000
458d27fd9487	1.0000 / 1.0000 / 1.0000
a406f98b6c80	1.0000 / 1.0000 / 1.0000
c95775266b6b	1.0000 / 1.0000 / 1.0000
94c3b093f4ef	1.0000 / 1.0000 / 1.0000
d8b6f95ff454	1.0000 / 1.0000 / 1.0000
bd10694749a2	1.0000 / 1.0000 / 1.0000
2ae722aa63ac	1.0000 / 1.0000 / 1.0000
06b81a6c3ff2	1.0000 / 1.0000 / 1.0000
208b1fabb7ad	1.0000 / 1.0000 / 1.0000
b42ab7770e15	1.0000 / 1.0000 / 1.0000
cbcc2bf1f427	1.0000 / 1.0000 / 1.0000
afa973867e75	1.0000 / 1.0000 / 1.0000
73ec235166fa	1.0000 / 1.0000 / 1.0000
f23608239de9	1.0000 / 1.0000 / 1.0000
fb7fb0ee576b	1.0000 / 1.0000 / 1.0000
12607c403df4	1.0000 / 1.0000 / 1.0000
61d426d994ad	1.0000 / 1.0000 / 1.0000
f453a9b23b9c	1.0000 / 1.0000 / 1.0000
af93b55501cb	1.0000 / 1.0000 / 1.0000
08c0c2cfaebc	1.0000 / 1.0000 / 1.0000
9d05797d6052	1.0000 / 1.0000 / 1.0000
595e402b5ae3	1.0000 / 1.0000 / 1.0000
80ea476ff3cc	1.0000 / 1.0000 / 1.0000
7f622d9076b8	1.0000 / 1.0000 / 1.0000
835f1fadb177	1.0000 / 1.0000 / 1.0000
833561e5df18	1.0000 / 1.0000 / 1.0000
840c3fa64642	1.0000 / 1.0000 / 1.0000
56e6c925b77c	1.0000 / 1.0000 / 1.0000
366703f542b2	1.0000 / 1.0000 / 1.0000
c36d1cfabc29	1.0000 / 1.0000 / 1.0000
47c81091325a	1.0000 / 1.0000 / 1.0000
67b52b047d58	1.0000 / 1.0000 / 1.0000
55f66f1e9ac5	1.0000 / 1.0000 / 1.0000
6dbfaa107b88	1.0000 / 1.0000 / 1.0000
54ca6afbf91f	1.0000 / 1.0000 / 1.0000
681964a15a8d	1.0000 / 1.0000 / 1.0000
dd75da83a1ff	1.0000 / 1.0000 / 1.0000
bb2a4fb56689	1.0000 / 1.0000 / 1.0000
e13905911332	1.0000 / 1.0000 / 1.0000
4acb73f02da1	1.0000 / 1.0000 / 1.0000
931e55593816	1.0000 / 1.0000 / 1.0000

Correlated noise, shared calibration errors and local pixel rejection are not represented by these frame-level weights. Individual-exposure photometry is unchanged.

Appendix · measurement methods & observing conditions

Observing nights and Moon

RGB

2026-11-07 19:52:31 CET (UTC+0100) → 2026-11-07 22:16:26 CET (UTC+0100)

2.3% Moon illumination · saved calculation

Altitude -53.1°Target separation —

Mitte des Aufnahmezeitraums

Original saved observation note

Time assumption: DATE-OBS interpreted as UTC because TIMESYS is missing. Astronomical context is provisional.

Original saved observation note

Moon altitude is approximate; local Earth-orientation data may be incomplete.

Original saved observation note

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.

Explain this comparison

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.

RGB · Background: 43/43 valid selected exposures; archive 43/43 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.

RGB · Star shape: 43/43 valid selected exposures; archive 43/43 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.

RGB · Star width (FWHM): 43/43 valid selected exposures; archive 43/43 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.

RGB · Stellar SNR: 43/43 valid selected exposures; archive 43/43 frames, 1 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter, execution_method_version.

RGB · Background scatter: 43/43 valid selected exposures; archive 43/43 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

Individual-frame quality review · advisory

Image-quality assistant

0 selected frames worth reviewing · 43/43 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.

Method, coverage and limitations

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.

RGB · 180.0 s · session acq_a9287c7f: Background level 43/43; Background scatter 43/43; Detected sources 0/43: too few valid session frames; Star eccentricity 43/43; Star width (FWHM) 43/43; Stellar SNR estimate 43/43. Unknown: device_id, filter, optical_configuration, readout_mode, recorded_orientation_deg.

Method session-quality-assistant-1. Saved measurements and existing archive comparisons are unchanged.