Horsehead and Flame Nebulae (IC 434 / Barnard 33, NGC 2024), 59-minute stack, dual-band filter, colour-calibrated, Seestar S30 Pro

Images and files

Record details

Object

Horsehead Nebula (Barnard 33) in IC 434, with Flame Nebula NGC 2024

Object type

Dark nebula and emission nebula

Right ascension (RA)

85.2047 (unit not recorded)

Declination (Dec)

-2.4774°

Reference frame (RADESYS)

ICRS (J2000), image centre from the Siril plate solve against Gaia DR3

Observation date (local)

2026-11-02

Time scale (TIMESYS)

UTC

Time source

Phone network

Telescope and instrument

ZWO Seestar S30 Pro (30 mm f/5.3 apochromat, built-in colour CMOS)

Filter

LP dual-band (H-alpha + OIII)

Exposure time

60 s

Number of combined frames

59

Observing method

ZWO Seestar S30 Pro smart telescope (30 mm aperture, 160 mm focal length, f/5.3; 3840x2160 colour sensor, 2.9 μm pixels), built-in LP dual-band (H-alpha/OIII) filter, gain 200, sensor 24–33 °C. 72 frames of 60 s were captured from 01:47 to 03:58 AEDT. Version 2 (reprocessed 3 Nov 2026) in Siril 1.4: debayered and registered (two-pass), frames outside the best 90% by star sharpness (wFWHM) dropped, and the remaining 59 sigma-clipped (3/3) and stacked with wFWHM weighting (59 min total). The stack was then plate-solved against the Gaia DR3 astrometric catalogue (1,178 image stars matched; 3.664 arcsec/pixel, effective focal length 163.2 mm) and colour-corrected with Siril photometric colour calibration (PCC) using Gaia DR3 star colours (550 stars), with RBF background gradient removal before and after. Then a linked auto-stretch and a mild saturation boost. No colour or detail was painted in, no AI or star removal. No darks or flats were applied. The main image is a crop around the Horsehead and Flame with Rob's semi-transparent "rme" signature; the full frame is attached without it.

Bias frames

0

Dark frames

0

Flat frames

0

Astrometric solution (plate solve)

Solved by contributor

Calibration level

Partially calibrated

Processing level

Stacked

Processing software

Siril 1.4.0-rc2 (plate solve + PCC with Gaia DR3)

Description

The Horsehead Nebula (Barnard 33) in Orion: a dark cloud of dust silhouetted against the glowing hydrogen of the emission nebula IC 434, about 1,400 light-years away. Below it is the Flame Nebula (NGC 2024) beside the bright star Alnitak (zeta Orionis), with sigma Orionis at upper left. Red shows hydrogen-alpha; the blue-green halos round the bright stars come from the dual-band filter. 59 minutes of 60-second frames, restacked from the raw sub-frames. Captured in the early morning of 2 Nov 2026 (night of 1 Nov).

Uncertainty remarks

Colours are calibrated against Gaia DR3 star colours (PCC), but the dual-band filter passes mainly H-alpha and OIII light, so nebula colours are still not true visual colour. Spectrophotometric calibration (SPCC) was not used because it crashes in Siril 1.4.0-rc2. No dark or flat frames, so faint gradients and hot pixels may remain. The plate solve shows the north–south axis runs vertically to within about 1 degree; the image keeps the Seestar's display orientation, so north may be at the bottom. Site position deliberately generalised to the nearest whole degree (about 60 km) to protect a private home.

Data quality statement

59 of 72 frames stacked after star-sharpness filtering. Astrometry and colour from Gaia DR3 via local Siril catalogues (astrometric catalogue for the plate solve; PCC for colour). Version 1 had automatic colour balance only; version 2 replaces it with catalogue-based colour calibration. GPS and camera metadata removed from the published images; the raw FITS (which hold the site position) are kept privately.

Source

Seestar S30 Pro sub-frames Light_IC 434_60.0s_LP_20261102-014857 to _20261102-035942 (72 FITS, original headers kept); Siril log siril-20261103-siril.log; colour reference Gaia DR3 (ESA/Gaia/DPAC) via Siril local catalogue

Original FITS header retained

Yes

Place

Not shown on public record pages

From the Astronomy image profile, version 1.1.0, as signed for this record version. Not shown publicly: place, coordinate and site fields, fields the profile marks sensitive (such as observing times), and the names of observers, collectors and other credited people. In the title, captions and written descriptions, coordinates, street addresses, email addresses and phone numbers are replaced with a marker; other text, including any names or times written in it, is shown as the contributor wrote it.

Cite this record

Rob Evans (2026). Horsehead and Flame Nebulae (IC 434 / Barnard 33, NGC 2024), 59-minute stack, dual-band filter, colour-calibrated, Seestar S30 Pro. Clio Online Museum. https://cliomuseum.org/records/record-60c1c4f4-a402-4c8c-bdc4-9b53873497e5

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https://cliomuseum.org/records/record-60c1c4f4-a402-4c8c-bdc4-9b53873497e5

Published recordVersion 3

Creators

• Rob Evans https://orcid.org/0009-0004-6391-4464 (opens in a new tab) (verified with ORCID)

Version and provenance

Version identifier

version-0ae1e7a7-6d7b-4ff4-a8c0-5dd39f5f6848

Canonical commitment

sha3-384:a5e9ddbe2b3f972b32475fefd813b846f9e917229605ac08d10c94899e79e6780d617b0285fa18a355fdaf9850e663d7

Accepted

2026-11-03

Previous version

version-1e221995-55ef-42f2-9773-2e1e2bdd13a4

Evidence profile and standards

• FITS
• World Coordinate System (WCS)
• IVOA Provenance Data Model