Stellar radii

Need to know

What you need to know

• Luminosity (L) is the total power a star emits (W).
• Radiant Flux (F) is the power received per unit area (W m⁻²).
• The inverse square law, F = L / (4πd²), links these quantities with distance (d).
• Standard candles are objects of known luminosity used to measure cosmic distances.

Explanation

Stellar radii

1. Luminosity (L) is the total power a star emits (W).
2. Radiant Flux (F) is the power received per unit area (W m⁻²).
3. The inverse square law, F = L / (4πd²), links these quantities with distance (d).
4. Standard candles are objects of known luminosity used to measure cosmic distances.