Explore stellar spectra, the Hertzsprung–Russell diagram, parallax, telescope resolution, redshift and Hubble's law in one connected A Level Physics observatory.
Learning guide and suggested activities
What this tool shows
How temperature changes a star's colour, black-body curve and peak wavelength
How stars are classified on the Hertzsprung–Russell diagram
How parallax is used to determine stellar distance
How aperture and wavelength determine telescope resolution
How redshift, recession speed and distance are linked by Hubble's law
OCR A relevance
OCR A H556 Module 5.5: astrophysics and cosmology
Stellar evolution, H–R diagrams and spectral lines
Wien's law, Stefan's law, parallax, redshift and Hubble's law
AQA relevance
AQA 7408 section 3.9: astrophysics option
Telescopes, stellar classification and black-body radiation
Distances, redshift, quasars and cosmology
Try these tasks
Double a star's temperature and predict the change in peak wavelength and luminosity.
Compare Sirius A and Sirius B on the H–R diagram and explain their different luminosities.
Find the aperture needed to resolve a one-arcsecond double star at 550 nm.
Change the Hubble constant and explain what happens to graph gradient, redshift and Hubble time.