Astronomy 1021 Lecture 31: Astronomy February Exam Review

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

I(cid:374) astro(cid:374)o(cid:373)y, we measure (cid:862)doppler hifts(cid:863) i(cid:374) the wavele(cid:374)gths of. Thermal radiation has 2 important properties: hotter objects emit more light per unit area at all frequencies (stefan- Boltzmann law: hotter objects emit photons with a higher average energy (wie(cid:374)(cid:859)s. There are 3 basic types of spectra: continuous, emission, and absorption. Apparent brightness depends on where you measure it. Co(cid:374)sider (cid:374)ested spheres arou(cid:374)d a light sour(cid:272)e : energy passing through each sphere is the same, area of each sphere: 4 (cid:894)radius(cid:895)2, divide luminosity by area to get brightness b= l/4 r 2. Few (if any) moons and no rings and hydrogen compounds. Farther from the sun (and farther together, with warmer surfaces apart) with cool temperatures at cloud tops. Four features of the solar system: patterns of motion among large bodies. Sun, planets and moons orbit and rotate in organized way: two major types of planets. Terrestrial & jovian: asteroids and comets.