Star types
Each Spacy solar system is governed by a central star. The star type (its luminosity, its size) determines where the habitable zone lies, how hot orbiting planets get, and indirectly the output of your planets' solar plants and solar satellites (fusion reactors, by contrast, are independent of the star).
The 5 star types
Understanding luminosity
The luminosity index multiplies the heat received by planets in the system, relative to a Yellow star (×1, like our Sun). A Red Dwarf at ×0.04 barely warms anything: its planets stay cold even very close to the star. A Blue Giant at ×30,000 incinerates anything close: only very distant planets are habitable.
Concrete impact on your system
- Habitable zone: the more luminous the star, the farther the temperate zone sits (Red Dwarf: 0.1–0.4 AU / Blue Giant: 5–15 AU)
- Planet temperature: derived from luminosity and orbital radius — see Temperature & habitability
- Solar energy: solar plant and solar satellite output depends on the orbital position relative to the star (fusion reactors are not affected)
- System density: Red Dwarfs produce compact systems, Blue Giants very spread-out ones
Strategic reading
- Red Dwarf (most common): compact systems, cold planets — good for short-distance logistics, but limited solar energy
- Orange / Yellow: balanced Earth-like systems — the reference for newcomers
- White: wider habitable zone, hotter planets, higher energy — risk of hostile worlds
- Blue Giant (rare): vast systems, scorched inner planets — energy is exceptional for those who master it