Requires very precise measurements of stellar positions, and long baselines

Sana09.02.2017
Hajmi461 b.



Trigonometric Parallax

  • Requires very precise measurements of stellar positions, and long baselines

  • Need telescopes with high resolution, and must observe over several years.

  • Hipparchos satellite measured distances to tens of thousands of stars within 1,500 light-years of the Sun.



2) The Standard Candle

  • Use knowledge of physical and/or empirical properties of an object to determine its Luminosity, which yields distance via the Inverse Square Law of Light.

  • Ex: Cepheid Variables, Supernovae, TRGB, Tully-Fisher

  • Considered to be relative until tied to an absolute calibration.



Cepheid Variable Stars

  • There is a kind of giant star whose surface pulsates in and out with a regular period. That period of pulsation is related to the Luminosity of the star.

  • LMC contains hundreds of known Cepheids all at the same distance. Which allows for robust determination of the Period Luminosity Relationship.




Do'stlaringiz bilan baham:

©2018 Учебные документы
Рады что Вы стали частью нашего образовательного сообщества.
?


rejissorluun-slub-9.html

rejmanta----a-agarodnaya-.html

rejmond-teodor-richi.html

rejshi-ganoderma-lucidum-.html

rejting-2013-azastan-zhoo.html