Determining Distance

Photometric measurements can be used for determining distance and comparing objects

Students learn to:

• define absolute and apparent magnitude
• explain how the concept of magnitude can be used to determine the distance to a celestial object
• outline spectroscopic parallax
• explain how two-colour values (eg colour index, B-V) are obtained and why they are useful
• describe the advantages of photoelectric technologies over photographic methods for photometry

Students:

• solve problems and analyse information using: 
  to calculate the absolute or apparent magnitude of stars using data and a reference star
• perform an investigation to demonstrate the use of filters for photometric measurements
• identify data sources, gather, process and present information to assess the impact of improvements in measurement technologies on our understanding of celestial objects