Exoplanets

Cards (19)

  • What is an exoplanet?
    A planet outside our Solar System
  • Why are exoplanets difficult to detect directly?
    Host star light is much brighter than planet light
  • What angles do exoplanets subtend compared to telescopes?
    Extremely small angles
  • What techniques do astronomers use to observe exoplanets?
    Indirect detection techniques
  • What are the two indirect detection techniques for exoplanets?
    • Transit method
    • Radial velocity method
  • What happens during the Transit Method?
    A planet obscures light from its star
  • What is measured to obtain a light curve in the Transit Method?
    The apparent magnitude of the star's light
  • What can the Transit Method tell us about an exoplanet?
    Size and orbital period of the exoplanet
  • How is the size of the exoplanet determined using the Transit Method?
    By measuring the dip in brightness
  • How is the orbital period of the exoplanet determined using the Transit Method?
    By measuring the duration of the dip
  • What is a limitation of the Transit Method?
    Alignment of Earth, planet, and star is crucial
  • What type of planets can be detected using the Transit Method?
    Only planets with a short orbital period
  • What occurs as a planet orbits its host star in the Radial Velocity Method?
    Both orbit around a common center of mass
  • What happens to the star's line spectrum as it moves towards Earth?
    It shows blueshift
  • What happens to the star's line spectrum as it moves away from Earth?
    It shows redshift
  • How are periodic shifts in the star's light wavelength measured?
    Using the Doppler shift
  • What is the relationship between the orbital period of the planet and the Doppler shift?
    They are equal in time period
  • What is a limitation of the Radial Velocity Method?
    Low-mass planets cause less 'wobble'
  • What type of planets do not cause much 'wobble' in the Radial Velocity Method?
    Low-mass or Earth-like planets