IC 1396A - Elephant's Trunk Nebula · DNB Session 1 · 2026-09-14

Observing conditions

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

DNB · 2026-09-15 01:06:27 CEST (UTC+0200) → 2026-09-15 04:03:52 CEST (UTC+0200)

Moon · calculated

16.2%

Illuminated · Waxing

Altitude -58.4° · below the geometric horizon

Reference: 2026-09-15T00:35:09.866 UTC

Observing site

—

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

Weather · model context

ERA5 reanalysis · Open-Meteo

Cloud cover
6.0–51.0 %
Dew point
10.2–11.2 °C
Relative humidity
91.0–95.0 %
Air temperature
10.9–12.6 °C
Wind at 10 m
1.4–1.9 m/s

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

Hourly values and coverage
UTCAir temperature · °CRelative humidity · %Dew point · °CCloud cover · %Wind at 10 m · m/s
2026-09-14T23:00:00+00:0012.691.011.251.01.9
2026-09-15T00:00:00+00:0011.893.010.824.01.8
2026-09-15T01:00:00+00:0011.395.010.410.01.4
2026-09-15T02:00:00+00:0010.995.010.26.01.4

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 2026-10-20T16:42:35.740444+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: a7dae142d8d4bc573caae0e528f39d9f2ca84ba6b526200e26134dfcf4c0a742

DNB · 300 s · 32 Lights

2 h 40 min · 32 exposures available.

Session
Preview image · up to 2560 px

Selected input exposures

Image quality at a glance

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

DNB · all contributing sessions

Star width / FWHM
2.77 sensor pixels
Current archive average2.96 sensor pixels
Difference -0.19
32/32 selected · archive 342/342 exposures · 10 sessions · 6 objects
Star shape / eccentricity
0.56 dimensionless
Current archive average0.49 dimensionless
Difference +0.07
32/32 selected · archive 342/342 exposures · 10 sessions · 6 objects
Background
514.56 ADU
Current archive average574.41 ADU
Difference -59.85
32/32 selected · archive 342/342 exposures · 10 sessions · 6 objects
Background scatter
9.24 ADU
Current archive average17.93 ADU
Difference -8.69
32/32 selected · archive 342/342 exposures · 10 sessions · 6 objects
Stellar model SNR
25.49 dimensionless
Current archive average77.42 dimensionless
Difference -51.92
32/32 selected · archive 342/342 exposures · 10 sessions · 6 objects
Stellar model estimate · different fields
Star width / FWHM
Selected exposure values · whole-archive DNB mean · physical sessions separated.
Star shape / eccentricity
Star shape / eccentricity
Selected exposure values · whole-archive DNB mean · physical sessions separated.
Background
Background
Selected exposure values · whole-archive DNB mean · physical sessions separated.
Background scatter
Background scatter
Selected exposure values · whole-archive DNB mean · physical sessions separated.
Stellar model SNR
Stellar model SNR
Selected exposure values · whole-archive DNB mean · physical sessions separated.
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.

DNB · 300.0 s · 32 Lights

Acquisition settings & contributing sessions

300.0 s · Gain 100.0 · Archive snapshot 2026-11-09T03:24:34.927460+00:00

Recorded focal length: 612.0 mm · separate header/settings cohorts, not additional observing sessions.

DNB Session 1 · 2026-09-14

Star width (FWHM)
2.77 sensor pixels
Current archive average2.94 sensor pixels
Difference -0.17 sensor pixels
32/32 frames · archive: 4 Sessions
Star shape
0.56 dimensionless
Current archive average0.51 dimensionless
Difference +0.05 dimensionless
32/32 frames · archive: 4 Sessions
Eccentricity of stellar model fits
Background
514.56 ADU
Current archive average561.08 ADU
Difference -46.51 ADU
32/32 frames · archive: 4 Sessions
Background scatter
9.24 ADU
Current archive average16.63 ADU
Difference -7.39 ADU
32/32 frames · archive: 4 Sessions
Stellar SNR
25.49 dimensionless
Current archive average73.38 dimensionless
Difference -47.89 dimensionless
32/32 frames · archive: 2 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

  1. Calibrationsuccess
  2. Registrationsuccess
  3. Stackingsuccess
  4. ReportSaved results

32/32 Lights calibrated; {'bias': 47, 'dark': 40, 'flat': 30} calibration frames. Unknown compatibility fields: device_id, filter, optical_configuration, readout_mode.

Calibration and processing evidence
{
  "calibrated": 32,
  "calibration_state": "success",
  "crop": {
    "area_fraction": 0.9847135757771989
  },
  "integration_s": 9600.0,
  "planned": 32,
  "ready": 32,
  "registered": 32,
  "registration_state": "success",
  "selected_calibrations": {
    "bias": 47,
    "dark": 40,
    "flat": 30
  },
  "stacked": 32,
  "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.",
    "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

Verified image · DNB · 2026-09-14

576 verified identities; 14 spatially distributed highlights. Query: G < 16, at most 5000 sources; fainter neighbours may be absent.

Farb-Helligkeits-Diagramm · Gaia G / BP−RP

Scheinbare Kataloghelligkeit, kein HR-Diagramm; Staub und Distance wirken mit.

G (mag)BP−RP (mag)
Identity, data and limitations

Holdout residual: median 0.5461947040680258 px; 95 % 1.4724661083527801 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 geometry

Science & measurements

Experimental photometry · no confirmed transit. 1 unresolved technical review items.

Histograms, light curves & event evidence

Intensity histograms

DNB · 32/32 original exposures measured.

DNB · Raw pixel values

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

-0.56.554e+041.891e+08BG1G2R

All saved bins, including negative values.

Exact counts and measured valuesWerte und Darstellungsbins · Complete unchanged bins (NPZ)

Current display image

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

-0.5255.51.647e+06BGR

All saved bins, including negative values.

Exact counts and measured valuesWerte und Darstellungsbins · Complete unchanged bins (NPZ)

Events · technical review

Searched · technical review pending

1 unresolved technical review items · 15 Gaia IDs searched · 840 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 evidenceTest windows, supporting exposures and limitations

Gaia 2178585194128110080 · 23.78 % relative depth · 15 min · cause unresolved.

Photometry precision and sampling · experimental

Photometry & transit readiness

Individual native exposures, independent of the final display/HDR image. Conditional measurement errors include the comparison ensemble; shared systematics remain outside that model.

Elephant Trunk Nebula · DNB · 300 s · 32 frames

measured diagnostics · 32 timed frames; 0 timing exclusions.

Separate segment c94925ef: 2.96 h span · 303.5 s median cadence · 90.2% exposure duty · 1 large gap(s); 0 overlapping recorded intervals (bins unavailable when present).

2.4725.4298.38611.344Robust scatter (%)10.712.2Gaia G magnitude (catalogue)

Brightness comparison is observational: sources share sky and calibration; points are not independent trials.

Gaia 2178320486702371328 · G 10.71

32/32 valid epochs · robust scatter 4.94% · median conditional error 5.05%. single-event diagnostics only.

0.8230.9481.0721.196Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 4.61% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 4.67% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 4.31% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178322720084600832 · G 10.77

32/32 valid epochs · robust scatter 4.90% · median conditional error 5.65%. single-event diagnostics only.

0.8520.9811.1091.238Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 5.30% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 1.40% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 2.14% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178396799684453376 · G 10.98

32/32 valid epochs · robust scatter 8.25% · median conditional error 5.60%. single-event diagnostics only.

0.7260.8871.0481.209Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 6.91% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 2.37% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 3.51% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178405595778133888 · G 11.04

32/32 valid epochs · robust scatter 4.68% · median conditional error 4.00%. single-event diagnostics only.

0.8350.9421.0491.155Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 3.49% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 3.35% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 3.97% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178512626359162240 · G 11.57

0/32 valid epochs · robust scatter — · median conditional error —. measured, not suitable for search.

0.9410.9771.0141.050Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: — · 0 usable bins · 32 native points outside this binned view · insufficient support; 0–0 exposures/bin, 0–0 s integrated, 0–0% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: — · 0 usable bins · 32 native points outside this binned view · insufficient support; 0–0 exposures/bin, 0–0 s integrated, 0–0% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: — · 0 usable bins · 32 native points outside this binned view · insufficient support; 0–0 exposures/bin, 0–0 s integrated, 0–0% coverage. Single-frame bins do not demonstrate averaging.
  • 30 min: — · 0 usable bins · 32 native points outside this binned view · insufficient support; 0–0 exposures/bin, 0–0 s integrated, 0–0% coverage. Single-frame bins do not demonstrate averaging.
Gaia 2178535406865965568 · G 11.67

32/32 valid epochs · robust scatter 10.73% · median conditional error 7.05%. single-event diagnostics only.

0.7980.9631.1291.294Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 7.41% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 9.18% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 2.76% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2202564713791398656 · G 11.67

32/32 valid epochs · robust scatter 3.08% · median conditional error 4.24%. single-event diagnostics only.

0.8250.9301.0341.138Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 4.95% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 2.38% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 2.78% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178585194128110080 · G 11.68

32/32 valid epochs · robust scatter 6.34% · median conditional error 5.15%. single-event diagnostics only.

0.6600.8381.0151.192Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 5.04% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 5.69% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 3.94% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178490052010323840 · G 11.83

32/32 valid epochs · robust scatter 6.34% · median conditional error 4.81%. single-event diagnostics only.

0.7970.9481.0981.249Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 5.74% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 2.73% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 1.72% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2179191437348574336 · G 11.93

32/32 valid epochs · robust scatter 7.20% · median conditional error 6.69%. single-event diagnostics only.

0.7410.9251.1101.295Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 6.13% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 5.65% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 1.88% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178381543960583680 · G 11.99

32/32 valid epochs · robust scatter 9.75% · median conditional error 6.87%. single-event diagnostics only.

0.7230.9011.0781.255Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 9.75% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 7.91% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 1.64% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178578390899342976 · G 12.01

32/32 valid epochs · robust scatter 3.99% · median conditional error 4.98%. single-event diagnostics only.

0.7820.9081.0351.161Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 4.01% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 4.46% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 2.98% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178332065933543424 · G 12.03

32/32 valid epochs · robust scatter 6.53% · median conditional error 5.83%. single-event diagnostics only.

0.7980.9251.0511.177Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 5.46% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 4.30% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 2.86% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2179295409918762496 · G 12.06

32/32 valid epochs · robust scatter 4.23% · median conditional error 5.28%. single-event diagnostics only.

0.8130.9331.0531.173Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 4.84% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 5.73% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 2.23% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178283756140212480 · G 12.16

32/32 valid epochs · robust scatter 8.03% · median conditional error 3.65%. single-event diagnostics only.

0.8310.9621.0941.225Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 6.95% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 6.00% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 5.90% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.
Gaia 2178393879105972224 · G 12.18

32/32 valid epochs · robust scatter 5.65% · median conditional error 5.40%. single-event diagnostics only.

0.7140.8741.0351.195Raw / own medianReference ensembleDifferential2.5174.9Minutes from recorded relative session origin
Precision at common wall-clock intervals

1.4826 × median absolute deviation divided by median. Nonoverlapping bins never split an exposure; boundary crossings remain in the native curve. Sparse bins do not establish a precision improvement.

  • 5 min: 0.00% · 1 usable bins · 31 native points outside this binned view · descriptive only; 1–1 exposures/bin, 300–300 s integrated, 100–100% coverage. Single-frame bins do not demonstrate averaging.
  • 10 min: 4.30% · 16 usable bins · 16 native points outside this binned view · conditional block interval; 1–1 exposures/bin, 300–300 s integrated, 50–50% coverage. Single-frame bins do not demonstrate averaging.
  • 15 min: 7.84% · 11 usable bins · 10 native points outside this binned view · descriptive only; 2–2 exposures/bin, 600–600 s integrated, 67–67% coverage.
  • 30 min: 3.45% · 5 usable bins · 5 native points outside this binned view · descriptive only; 2–5 exposures/bin, 600–1500 s integrated, 33–83% coverage.

Recommended next acquisition: characterize unsaturated stars with matched short-exposure Darks and same-session Flats, then keep one exposure/filter configuration through a dedicated known-host event and its before/after baseline. There is no real 60/120 s improvement demonstrated here.

Timing, uncertainty and applicability
  • Not calibrated standard magnitudes. Native G1+G2 response/Flat/pixel-phase and shared errors remain unbounded.
  • Recorded header start times support relative intervals; TIMESYS and clock accuracy are not established. No BJD_TDB.
  • References exclude each target but share sky/calibration systematics. Conditional errors hold median normalizations fixed.
  • No new search is run here. Existing event evidence and eligibility are retained; review scores are not calibrated false-alarm probabilities.
  • No new aperture is promoted. Mixed exposures, passbands, nights and calibration/angle segments stay separate.
Exact native-photometry diagnosticsConditional errors, rates, source/reference IDs and precision support
Comparison-star evidence · experimental

Comparison-star robustness check

Could a more robust reference ensemble improve these light curves? This controlled experiment reuses the original native fluxes. Your published scientific curves and event results remain unchanged.

DNB · 300.0 s · 0 supported source/segment tests

Insufficient contiguous data or independent references for the blocked comparison.

2 contiguous blocks are too short; no test is forced across the gap.

Scientific baseline retained. No promotion from scatter alone; independent control observations and a calibrated uncertainty model are still required.

Validation design and limits

Four contiguous held-out folds per sufficiently long uninterrupted block, with one purged epoch on each side. Reference medians are learned only from training epochs; each target is excluded from its references. Fixed Huber cutoff 1.5, at least six references. No hyperparameter search or target-based refitting.

  • Blocked epoch checks within existing calibration/orientation segments, not independent new-night validation.
  • Stars share references and are not independent trials; no p-values or discovery probability are inferred.
  • Lower scatter may remove reference contamination but does not prove better physical accuracy.
  • Existing shared-master, flat, centroid, sampling and clock uncertainties remain unresolved.
  • Artificial dimming checks algebraic signal transfer only, not transit detection or recovery efficiency.
  • No re-fitting, smoothing or interpolation of target flux; gaps and unavailable measurements remain gaps.
Reference comparison evidenceHeld-out folds, reference membership, unchanged baseline and signal-transfer checks

Example measured light curve

2026-09-14 · DNB · Gaia 2178283756140212480. First available session and source ID; not selected for apparent variability.

Relative brightness1.1590.89230.04 — 2.92 hours since the first recorded header start · exposure midpoints
Native G1+G2 measurements · separate calibration segments · no connecting lines.
All saved stellar light curves
Appendix · measurement methods & observing conditions
Observing nights and Moon

DNB

2026-09-15 01:06:27 CEST (UTC+0200) → 2026-09-15 04:03:52 CEST (UTC+0200)

16.2% Moon illumination · saved calculation

Altitude -58.4°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.

DNB · Star shape: 32/32 valid selected exposures; archive 139/139 frames, 4 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter.

DNB · Star width (FWHM): 32/32 valid selected exposures; archive 139/139 frames, 4 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter.

DNB · Stellar SNR: 32/32 valid selected exposures; archive 98/98 frames, 2 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter.

DNB · Background scatter: 32/32 valid selected exposures; archive 139/139 frames, 4 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter.

DNB · Background: 32/32 valid selected exposures; archive 139/139 frames, 4 Sessions. Unknown properties: device_id, readout_mode, optical_configuration, filter.

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 · 32/32 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.

DNB · 300.0 s · session acq_e2cac882: Background level 32/32: zero or numerically unresolved MAD; no relative flag; Background scatter 32/32; Detected sources 32/32; Star eccentricity 32/32; Star width (FWHM) 32/32; Stellar SNR estimate 32/32. Unknown: device_id, filter, optical_configuration, readout_mode.

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