SkyNew
Spiral galaxy
A spiral galaxy across the sky: a glowing bulge, a disc with arms, star-forming knots and dust lanes, at any size and tilt.
- Version
- 1.0.0
- Added
- 23 October 2026
- Films
- Not used in a film yet
Parameters
| Name | Type | Default | Range | What it does |
|---|---|---|---|---|
| az | number | 180 | 0 to 360 deg | compass direction of the galaxy's centre |
| alt | number | 45 | 0 to 90 deg | height of the galaxy's centre above the horizon |
| size (Can change over time) | number | 3 | 0.05 to 120 deg | angular diameter of the disc, to where its light fades (Andromeda is about 3, the Milky Way would be 100)Can change over time |
| surfaceBrightness (Can change over time) | number | 21.7 | 0 to 30 mag/arcsec2 | surface brightness of the disc's middle: 21.7 is a typical spiral; lower is brighter, 5 magnitudes is 100 timesCan change over time |
| inclination | number | 60 | 0 to 85 deg | how far the disc is tilted from facing us: 0 face-on, 85 almost edge-on |
| positionAngle | number | 35 | 0 to 180 deg | how the long axis lies on the sky: 0 upright, 90 level |
| arms | integer | 2 | 2 to 4 | number of spiral arms |
| tightness | number | 20 | 8 to 40 deg | pitch angle of the arms: low winds them tight, high opens them wide |
| bulge | number | 0.25 | 0 to 0.85 | the bulge's share of the galaxy's light: 0 a pure disc, 0.5 a lenticular |
| dust | number | 0.6 | 0 to 1 | how dark the dust lanes are |
| clumps | number | 0.5 | 0 to 1 | how many bright blue star-forming knots dot the arms |
| bulgeColour | color | #ffd9a3 | – | colour of the old stars of the bulge |
| armColour | color | #a6c6ff | – | colour of the young stars of the arms |
| seed | integer | 2 | 0 to 999 | changes the knots and the wobble of the arms |
Use it in a film
film.js
elements: { 'galaxy-disc': { az: 180, alt: 45 } }Use it from your agent
Ask your agent to put it in a film. It finds the element by name.