Astralarium

A small, 99% offline¹ editor for custom star maps and constellations. Made because I couldn't find a suitable tool anywhere. Check it out here (press h to display hotkeys).

¹: An internet connection is needed if you want to load a background image.

Example

Features

• Stars can be placed manually or randomly
• Stars are customizable (size, inner color, border color and name (currently unused))
• Lines can be drawn between stars manually or randomly (via a terribly simple random constellation generator)
• The background can be a blend of a color and an image (custom URL or premade)
• Text can be placed on the Canvas (customizable color and size)
• Export a map to SVG or PNG
• Experimental: Save/Load a map to/from a JSON file
• Experimental: 'Star shadows' (glow)

Tips

• Performance (FPS) might decrease drastically with more stars. Using a smaller number of bigger stars in conjunction with a background image containing small stars is recommended.
• Enabling "precise selection" (h) might help with selecting stars within line boxes.
• For me, performance in Chromium was better than in Firefox.

TODO

• improve performance for > 500 stars

Maybe

• better UI scaling?
• file-select for local background image
• prevent accidental reload / page leaving
• constellation: counting/tracking
• star: display names
• random: choose star as starting point for constellation
• canvas: pan/zoom, react to resize events
• text tool: fonts

References

• CSS: pico.css
• Canvas Library: fabric.js
• Icons: remixicon

Premade Backgrounds

• Background 1: "Cluster of Stars" by Kai Pilger from Pexels
• Background 2: Photo by Andy Holmes on unsplash
• Background 3: Photo by Jeremy Perkins on unsplash
• Background 4: Photo by Graham Holtshausen on unsplash