PCS 181 Study Guide - Midterm Guide: Giant Star, Apparent Magnitude, Carbon-Burning Process

• School: Ryerson University
• Department: Physics
• Course: PCS 181
• Professor: Margaret Buckby

Document Summary

Dust and gas fill the space between the stars. Stars form out of the dust/gas in space. Dust is ~1% of the total visible mass in space. Elongated, tiny grains of dirty ice (shaped like needles), Light from a star passes through the dust. Gas: there is ~100 times more gas mass than dust mass in the universe. H1 regions: these are clouds of neutral (=not ionized) hydrogen, contain ~1 mo to 100 ~mo, the cold hydrogen gas is in its ground state (n = 1 orbit, the hydrogen atom has two possible ground state configurations: This wavelength is used to map the milky way galaxy, and to search for messages from extra- terrestrials. K (takes millions of years to get to this temperature: hydrogen-based nuclear reactions begin in the core and a star is born. A star which has a hydrogen based (h-based) nuclear reactions in the core is a main sequence.