Astro Camera
night · 2026-10-09
2026-10-212026-10-202026-10-192026-10-182026-10-172026-10-142026-10-132026-10-122026-10-112026-10-102026-10-092026-10-082026-10-072026-10-06
The deep sky
astrocam v3 · night of 9 Oct 2026
Every 10 minutes of the night, registered on the stars and averaged with aircraft clipped out: the faintest stars and the Milky Way's dark lanes. The steps below show how it was made. · full-res1How dark the night was
2697 frames of 14.9 s, 19:21 to 06:31 (London time). Darkest sky 4.27 stops above black (18.0 mag/arcsec²), so clear. A deliberate focus-test night: the lens stepped 1.10 to 1.40 and back all night to find the sharpest setting. Star sharpness barely changed across that range (about 1%); the lens is set to 1.25 from 10-10.
2378 / 2697
frames in star trails / captured
4.27
darkest sky, stops above black (59.9 s equiv.)
18.01
darkest sky, mag/arcsec² (Gaia G)
1
bad pixels
astrocam v3 · night of 9 Oct 2026
Sky brightness of every frame (log₂: one stop is twice the light). Dusk and dawn are the slopes at each end; cloud shows as a bump. The star-trail stack uses only frames within 30% of the darkest 10 minutes, so twilight and cloud are left out of it. Left out is not thrown away: those frames still go into the videos.2What the camera saw
astrocam v3 · night of 9 Oct 2026
The raw night: a 10 minute stack sliding on 1 minute per video frame. Dusk, cloud, aircraft and dawn all show here, five seconds for the whole night. · full-res3Sky glow removed
astrocam v3 · night of 9 Oct 2026
The night's smooth glow from streetlights is fitted and subtracted from every frame, and the trees and roof are masked. Star trails wheel round the pole and the Milky Way survives. · full-res4Sky held still
astrocam v3 · night of 9 Oct 2026
Each frame mapped onto the sky through a fitted model of the lens and turned back about the pole, so stars stay points. This shows the brightest of each window's frames once aircraft are clipped out; the average of the same frames is the deep sky above. · full-res5The whole night in one frame
astrocam v3 · night of 9 Oct 2026
The brightest value each pixel reached all night: every star draws its trail across the night.