Astronomers studying a newly discovered star collect the spectral intensity data…
PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
Astronomers studying a newly discovered star collect the spectral intensity data shown below. The table lists the measured intensity of emitted radiation at several wavelengths in nanometers. All other observational and instrumental effects can be neglected; treat the star as a perfect thermal emitter.
Wavelength (nm)
350
400
450
500
550
600
Relative Intensity (arb. units)
0.60
0.82
1.00
0.96
0.78
0.55
Use the information in the table to analyze the star’s properties.
(a) Identify the wavelength that most plausibly corresponds to the maximum of the star’s emission spectrum. State any assumptions you make when selecting this value from the discrete data provided.
(b) Using the wavelength you selected in part (a), calculate the star’s surface temperature in kelvin. Show all steps clearly and include appropriate units.
(c) The tabulated wavelengths are spaced by 50 nm. Estimate the fractional uncertainty in the temperature you determined, arising solely from this finite sampling of the spectrum. Explain your reasoning.
(d) Based on your result in part (b), predict the dominant visible color the star would appear to the unaided human eye. Justify your prediction by referring to the relationship between peak wavelength and perceived color.