Side B5: Astronomy

understand the term luminosity as the total power of radiation emitted by a star

recall and use the inverse square law for radiant flux intensity F in terms of the luminosity L of the source F = L / (4πd 2)

understand that an object of known luminosity is called a standard candle

understand the use of standard candles to determine distances to galaxies

recall and use Wien’s displacement law λmax ∝ 1 / T to estimate the peak surface temperature of a star

use the Stefan–Boltzmann law L = 4πσr 2 T 4

use Wien’s displacement law and the Stefan–Boltzmann law to estimate the radius of a star

understand that the lines in the emission and absorption spectra from distant objects show an increase in wavelength from their known values

use ∆λ / λ . ∆f / f . v / c for the redshift of electromagnetic radiation from a source moving relative to an observer

explain why redshift leads to the idea that the universe is expanding

recall and use Hubble’s law v . H0 d and explain how this leads to the Big Bang theory (candidates will only be required to use SI units) Faculty feedback: ‘Understanding how and why our climate is changing and providing the knowledge and skills to explore the challenges plays a key role in every student’s education.’ Feedback from: Dr Amy Munro-Faure, Head of Education and Student Engagement of Cambridge Zero