Specification points
Edexcel GCSE Astronomy 1AS0
258 points in 19 topics, with Edexcel's codes and titles.
Grade boundaries·Edexcel command words
Codes and titles are read by a script from Edexcel's published specification and have not been checked by a person. What each point covers is in the specification itself: Edexcel’s specification.
1 Planet Earth
2 The lunar disc
3 The Earth-Moon-Sun system
4 Time and the Earth-Moon-Sun cycles
- 4.1 Sidereal and synodic days
- 4.2 Apparent Solar Time
- 4.3 Mean Solar Time and Local Mean Time
- 4.4 The Equation of Time
- 4.5 Annual variation of the Equation of Time
- 4.6 Causes of variation in the Equation of Time
- 4.7 Finding local noon with a shadow stick
- 4.8 Sundials
- 4.9 The lunar phase cycle
- 4.10 Sidereal and synodic months
- 4.11 Annual variation in sunrise and sunset times
- 4.12 Equinoxes and solstices
- 4.13 The Sun's apparent motion through the year
- 4.14 Sidereal and synodic time
- 4.15 Local time and longitude
- 4.16 Time zones
- 4.17 Using time zone data
- 4.18 Greenwich Mean Time and Universal Time
- 4.19 Finding longitude with a shadow stick
- 4.20 Astronomical methods for finding longitude
- 4.21 Harrison's marine chronometer and longitude
5 Solar System observation
6 Celestial observation
- 6.1 Naked-eye astronomical phenomena
- 6.2 Constellations and asterisms
- 6.3 Asterisms as pointers
- 6.4 Star names across cultures
- 6.5 Star charts, planispheres and apps
- 6.6 Light pollution
- 6.7 Celestial sphere, poles and equator
- 6.8 Equatorial coordinates
- 6.9 Horizon coordinates
- 6.10 Linking equatorial and horizon coordinates
- 6.11 Local sidereal time and hour angle
- 6.12 Best times and objects to observe
- 6.13 Cardinal points, culmination, meridian, zenith, circumpolarity
- 6.14 Diurnal motion of the sky
- 6.15 Declination and circumpolar stars
- 6.16 Motion of circumpolar stars
- 6.17 Rising and setting times of stars
- 6.18 Finding latitude using Polaris
- 6.19 Dark adaptation and averted vision
- 6.20 Factors affecting visibility
- 6.21 The Milky Way to the naked eye
7 Early models of the Solar System
8 Planetary motion and gravity
- 8.1 Brahe's observations
- 8.2 Copernicus and Kepler's models
- 8.3 Gravity and elliptical orbits
- 8.4 Kepler's laws of planetary motion
- 8.5 Aphelion, perihelion, apogee and perigee
- 8.6 Kepler's third law
- 8.7 Kepler's third law constant and central mass
- 8.8 Newton explaining Kepler's laws
- 8.9 Newton's law of gravitation
9 Exploring the Moon
10 Solar astronomy
- 10.1 Safe telescopic observation of the Sun
- 10.2 Internal divisions of the Sun
- 10.3 Energy production and transfer in the Sun
- 10.4 The proton-proton cycle
- 10.5 Chromosphere and corona
- 10.6 Sunspots
- 10.7 Solar rotation from sunspot data
- 10.8 The solar cycle
- 10.9 The Sun across the electromagnetic spectrum
- 10.10 The solar wind
- 10.11 Effects of the solar wind
- 10.12 The magnetosphere and Van Allen Belts
11 Exploring the Solar System
- 11.1 Bodies in the Solar System
- 11.2 Structure of comets
- 11.3 Short-period comets and the Kuiper Belt
- 11.4 Long-period comets and the Oort Cloud
- 11.5 Kuiper Belt, Oort Cloud and heliosphere
- 11.6 Characteristics of the planets
- 11.7 Formation and position of the gas giants
- 11.8 Size of the Solar System
- 11.9 Astronomical unit, light year and parsec
- 11.10 Meteoroids and meteorites
- 11.11 Orbits close to the ecliptic plane
- 11.12 Transits of Venus and the astronomical unit
- 11.13 Origin of water on Earth
- 11.14 Limits of the human eye
- 11.15 Objective and eyepiece of a telescope
- 11.16 Lenses and mirrors collecting light
- 11.17 Making simple telescopes
- 11.18 Designs of refracting and reflecting telescopes
- 11.19 Light grasp of a telescope
- 11.20 Telescope aperture
- 11.21 Field of view
- 11.22 Resolution of a telescope
- 11.23 Magnification of a telescope
- 11.24 Galileo's telescopic observations
- 11.25 Reflecting versus refracting telescopes
- 11.26 Types of space probe
- 11.27 Examples of space probes
- 11.28 Escape velocity for space probes
- 11.29 Manned missions: advantages and disadvantages
- 11.30 The Apollo programme
12 Formation of planetary systems
- 12.1 Gravitational and tidal effects in the Solar System
- 12.2 Interactions forming planets and moons
- 12.3 Formation of gas giants in planetary systems
- 12.4 Methods for discovering exoplanets
- 12.5 Requirements for life elsewhere
- 12.6 Goldilocks zones
- 12.7 The Drake equation
- 12.8 The search for extra-terrestrial intelligence
13 Exploring starlight
- 13.1 Apparent magnitude
- 13.2 Absolute magnitude
- 13.3 The distance modulus
- 13.4 Information from stellar spectra
- 13.5 Spectral classification of stars
- 13.6 Colour, spectral type and temperature
- 13.7 Sketching a Hertzsprung-Russell diagram
- 13.8 Stellar life cycles on the H-R diagram
- 13.9 Inverse square law of brightness
- 13.10 Degrees, arcminutes and arcseconds
- 13.11 The parsec
- 13.12 Heliocentric parallax
- 13.13 Distances from the H-R diagram
- 13.14 Light curves of variable stars
- 13.15 Variability of eclipsing binaries
- 13.16 Cepheid variables and distance
- 13.17 Binary stars and clusters
- 13.18 Period of an eclipsing binary
- 13.19 Sidereal day from star trails
- 13.20 Digital sensors in astronomy
- 13.21 Studying spectral lines
- 13.22 Atmospheric blocking of radiation
- 13.23 Optical and radio telescopes at sea level
- 13.24 How a radio telescope works
- 13.25 Large apertures for radio telescopes
- 13.26 Aperture synthesis arrays
- 13.27 Discoveries of radio astronomy
- 13.28 High-altitude infrared telescopes
- 13.29 Discoveries of infrared astronomy
- 13.30 Atmospheric effects on image quality
- 13.31 Telescopes above the atmosphere
- 13.32 Space telescopes: advantages and disadvantages
- 13.33 Gamma ray, x-ray and ultraviolet astronomy
- 13.34 Telescopic appearance of celestial objects
14 Stellar evolution
- 14.1 Messier and NGC catalogues
- 14.2 The Bayer naming system
- 14.3 Radiation pressure and gravity in main sequence stars
- 14.4 Pressure-gravity balance in Sun-like stars
- 14.5 Electron pressure in white dwarfs
- 14.6 Pressure-gravity balance in massive stars
- 14.7 Neutron pressure in neutron stars
- 14.8 The Chandrasekhar Limit
- 14.9 Evolution of Sun-like stars
- 14.10 Evolution of massive stars
- 14.11 Evidence for black holes
15 Our place in the Galaxy
- 15.1 The Milky Way through binoculars or a telescope
- 15.2 Size, shape and structure of our Galaxy
- 15.3 21 cm radio waves and the Galaxy's structure
- 15.4 The Local Group
- 15.5 Composition and scale of the Local Group
- 15.6 Hubble classification of galaxies
- 15.7 Hubble's tuning fork diagram
- 15.8 The Milky Way as a barred spiral
- 15.9 Galaxies emitting beyond visible light
- 15.10 Active galactic nuclei
- 15.11 Types of active galaxy
- 15.12 Observing AGNs across the spectrum
- 15.13 Clusters and superclusters of galaxies
- 15.14 Formation and evolution of galaxies
16 Cosmology
- 16.1 Redshift of distant galaxies
- 16.2 Redshift from receding galaxies
- 16.3 Redshift equation
- 16.4 Evidence for the expanding universe
- 16.5 Hubble's law
- 16.6 Age and size of the Universe
- 16.7 Expansion and theories of the Universe
- 16.8 Evidence for the Big Bang
- 16.9 Fluctuations in the CMB
- 16.10 Dark matter and dark energy
- 16.11 Detecting dark matter and dark energy
- 16.12 Future evolution of the Universe
OBS Observational skills
A Unaided tasks
- A1 Demonstrate the changing appearance of lunar features
- A2 Finding the radiant point of a meteor shower
- A3 Assess the accuracy of stellar magnitude estimates
- A4 Estimate a celestial property using drawings of a suitable event
- A5 Estimating levels of light pollution
- A6 Estimate the solar rotation period using drawings of sunspots
- A7 Estimating the period of a variable star
- A8 Comparing stellar density estimates
- A9 Finding longitude using a shadow stick
- A10 Assess the accuracy of a sundial
B Aided tasks
- B1 Demonstrate the changing appearance of lunar features
- B2 Finding the radiant point of a meteor shower
- B3 Assess the accuracy of stellar magnitude measurements
- B4 Measuring a celestial property from drawings or photographs
- B5 Measuring levels of light pollution
- B6 Determine the solar rotation period using photographs of sunspots
- B7 Measuring the period of a variable star
- B8 Comparing stellar density measurements
- B11 Demonstrate the range of objects in the Messier Catalogue
- B12 Calculation of the length of the sidereal day