E3+STELLAR+DISTANCES

Back to IB PHYSICS > IB ASTROPHYSICS OPTION E1-E4 are the sections required for the SL option =STELLAR DISTANCES= [|MEASURING DISTANCE IN SPACE] - Astronomycast podcast episode on this stuff media type="custom" key="12492868"
 * E1 INTRODUCTION TO THE UNIVERSE || E2 STELLAR RADIATION AND STELLAR TYPES || E3 STELLAR DISTANCES || E4 COSMOLOGY || E5 STELLAR PROCESSES AND STELLAR EVOLUTION || E6 GALAXIES AND THE EXPANDING UNIVERSE ||
 * Parallax method **

Define the //parsec//.

Describe the stellar parallax method of determining the distance to a star. [|ANIMATION OF STELLAR PARALLAX]





Explain why the method of stellar parallax is limited to measuring stellar distances less than several hundred parsecs.

Solve problems involving stellar parallax.

Describe the apparent magnitude scale Students should know that apparent magnitude depends on luminosity and the distance to a star. They should also know that a magnitude 1 star is 100 times brighter than a magnitude 6 star.
 * Absolute and apparent magnitudes **

Define //absolute magnitude//. Solve problems involving apparent magnitude, absolute magnitude and distance

Solve problems involving apparent brightness and apparent magnitude.


 * Spectroscopic parallax **

State that the luminosity of a star may be estimated from its spectrum Explain how stellar distance may be determined using apparent brightness and luminosity

State that the method of spectroscopic parallax is limited to measuring stellar distances less than about 10 Mpc.

Solve problems involving stellar distances, ap parent brightness and luminosity

Outline the nature of a Cepheid variable Students should know that a Cepheid variable is a star in which the outer layers undergo a periodic expansion and contraction, which produces a periodic variation in its luminosity.
 * Cepheid variables **

State the relationship between period and absolute magnitude for Cepheid variables.

Explain how Cepheid variables may be used as “standard candles”. It is sufficient for students to know that, if a Cepheid variable is located in a particular galaxy, then the distance to the galaxy may be determined.

Determine the distance to a Cepheid variable using the luminosity–period relationship