Questions where students often pick the tempting wrong answer — make sure you know the right one:
Why do brighter-looking stars not necessarily have higher luminosity?✗ Brighter-looking stars are always intrinsically more luminous.✓ Apparent brightness depends on both luminosity and distance — a closer dim star can look brighter than a distant luminous one.
Why do more massive stars have shorter main-sequence lifetimes than smaller ones?✗ All stars live the same time on the main sequence regardless of mass.✓ They burn through their hydrogen fuel much faster because higher core temperature drives nuclear fusion at a vastly greater rate.
Do all stars end their lives as supernovae?✗ Yes — every star eventually explodes.✓ No — only stars above about 8 solar masses end in core-collapse supernovae; lower-mass stars become white dwarfs, which explode (as Type Ia supernovae) only if they gain matter from a binary companion.
Practise Astrophysics & Cosmology — free games
Test yourself with these quick revision games for this topic:
