OUTCOME
By the end of the lesson you will recognise that our understanding of how light diminishes with distance will enable us to determine the distance of stars. Recognise the difference between absolute and apparent magnitude and be able to read the magnitude scale.
A stars brightness enables us to determine its distance. The magnitude scale is a way of identifying the brightness of stars
LEARNING TASKS
Explain
Watch the video and answer the following
1. How many stars brightnesses were used in the ancient Greek method
2. how many times brighter is the dimmest to the brightest star in this system
3. How do we have negative magnitudes?
4. What is the magnitude of the moon or the sun?
5. What is the difference between apparent magnitude and absolute magnitude
Evaluate
Try the following questions
Qs 1 – 7, 39 & 40