Explain how parallax measurements can be used to determine distances to stars. Why can we not make accurate measurements of parallax beyond a certain distance?
Suppose you have discovered a new cepheid variable star. What steps would you take to determine its distance?
Explain how you would use the spectrum of a star to estimate its distance.
Which method would you use to obtain the distance to each of the following?
- An asteroid crossing Earth’s orbit
- A star astronomers believe to be no more than 50 light-years from the Sun
- A tight group of stars in the Milky Way Galaxy that includes a significant number of variable stars
- A star that is not variable but for which you can obtain a clearly defined spectrum
What are the luminosity class and spectral type of a star with an effective temperature of 5000 K and a luminosity of 100 LSun?