2007
A star at 4000 K
- Round
- Theory
- Points
- 2
- Level
- Bronze
- Taught in
- Section 4.6
Adapted from IOAA 2007 (Chiang Mai), theory problem 1.8. We have restated it in our own words and kept the original data. The solution was last checked on 20 October 2026.
At what wavelength does a star with a surface temperature of 4000 K give out most strongly?
Wien's law links the peak wavelength to the temperature.
- By (4.11),
AnswerThe star gives out most strongly at about 724 nm, at the red edge of visible light.
This problem also appears among the olympiad problems of Section 4.6, Blackbody radiation, which teaches the ideas it uses. Equation and figure numbers refer to the course.