PCS 181 Chapter 8: PCS181 WEEK 8 TEXTBOOK NOTES.pdf
7 May 2015
School
Department
Course
Professor
Document Summary
The parallax involves the parallax angle: the farther the star, the smaller the angle. Spectroscopic parallax method involves the hr diagram: diagram tells what type of star it is and its intrinsic brightness. Cepheid variable method cepheid variable star is a young star, it oscillates in brightness there is an exactly correlation between how long it takes to go through one cycle & its brightness cepheid variable star. Rst one discovered in constellation cepheus cepheids can be used as farther distance indicators to other galaxies used by hubble & humason detected for faraway galaxies. 5 (all cepheids have a minus sign) we can observe the period of a distant cepheid and nd its average absolute magnitude on the period-luminosity curve (of leavitt) Will be asked on the test no what is the distance (in pc and in ly) to the cepheid/galaxy? d = 10 (m - m+5)
