Reference
How big a Messier object is on the sky and which way it lies, and its outline
import { … } from "@johnmorrisdotca/hoshi-stars/deep-sky/shape";2.2 kB minified and gzipped, with everything it imports (measured with esbuild)
Exports
| Name | Kind | What it is |
|---|---|---|
deepSkyOutline | function | The outline of an object on the sky: a closed ring of points (the first repeated as the last) round an ellipse of the shape's major and minor axes at its angle. |
deepSkyShape | function | The size, axis ratio and angle of a Messier object on the sky. |
DeepSkyShape | type | How big a deep-sky object is on the sky and which way it lies. |
DeepSkyShapeSource | type | The place a size came from, as deepSkyShape names it: RC3 (the Third Reference Catalogue of Bright Galaxies, for a galaxy's major axis, axis ratio and angle), NED (NASA/IPAC NED's diameters table, for a galaxy RC3 does not give), or Catalogue row (the one diameter that the object's own row in the deep-sky table carries: Wikidata's, and for a Messier object what the table held already). |
measuredParts | function | Which parts of an object's drawn shape are measured: the size, the axis ratio and the angle. |
offsetOnSky | function | The sky position east and north arc-minutes from a centre, on the tangent plane there (the gnomonic projection, the one that sky photographs and the standard picture header use). |