PHYS 183 Lecture Notes - Lecture 15: Annie Jump Cannon, Spectroscopy, Spectroscopic Notation

• School: McGill University
• Department: Physics
• Course: PHYS 183
• Professor: Gilbert Holder

Document Summary

Luminosity l = energy output (j/s = w) Temperature t (k: generally referring to the temperature of the photosphere. Radius r (m, rsun: also of photosphere. Measure the apparent brightness b using a telescope. Measure (cid:272)olours or use wie(cid:374)"s law to deter(cid:373)i(cid:374)e (cid:271)la(cid:272)k(cid:271)ody te(cid:373)perature t. Measure distance d to the star using the parallax technique. With b, d determine the intrinsic luminosity l. From t and l, use the stefan-boltzmann law to determine the stellar radius r: after the midterm. Relates wavelength at which maximum amount of radiation is emitted for a temperature: constant here is for wavelength in meters. Intrinsic luminosity of star determined mainly by temperature, radius. Multiply by 16 because temperature is to the 4 in the law. Because in the law the radius is squared, so the square root of 100 is 10. Clear patterns in line features of spectra. Astronomers in early 1900s studied spectra from millions of stars.