Log In
Log In
Led by Henrietta Swan Leavitt
Module 15 of Edexcel GCSE Astronomy. Led by Henrietta Swan Leavitt, the Harvard astronomer whose 1908–1912 Cepheid period–luminosity relation gave Hubble the means to prove that Andromeda was a separate galaxy and that the universe extended far beyond the Milky Way. The student moves from the appearance of the Galaxy through 21 cm radio mapping, the Local Group, the Hubble classification, and active galactic nuclei.
Led by Henrietta Swan Leavitt
The question
What is the structure of the Galaxy we live in, where in it is the Sun, why is most of it invisible to optical telescopes, what other galaxies are gravitationally bound to ours, how do we classify the millions of other galaxies in the universe, and what powers the most luminous of them all? The spec asks the student to describe the Milky Way's appearance and structure, account for 21 cm radio mapping, identify the Local Group and its principal members, apply the Hubble classification scheme, and describe the active galactic nuclei powered by super-massive black holes.
Outcome
the student can describe the appearance and structure of the Milky Way, account for the Sun's location and the distribution of dust, star formation sites, and globular clusters, describe 21 cm radio mapping, identify the Local Group and its principal members, apply the Hubble classification and tuning-fork diagram, classify the Milky Way as SBb, and describe AGN including Seyferts, quasars, and blazars. *(Edexcel 1AS0 Paper 2 — Topic 15, spec points 15.1–15.14)*
Sub-units