Question

Why can the age of a star cluster be determined?

a) The lifetime of a star can be determined because it is directly related to its mass.

b) All of the stars of the cluster formed at the same time.

c) The cluster's HR diagram will show a turnoff point where stars of a given mass have left the main sequence.

d) All of the above.

For any given star, the distance modulus:

a) is the distance in light-years from that star to Earth.

b) is the difference between the absolute magnitude and the apparent magnitude of that star.

c) Varies significantly over the course of a year.

d) All of the above.

If the stars of a cluster are plotted according to their measured apparent magnitudes and surface temperatures, the cluster's _________ could be determined.

a) distance to Earth

b) age

c) age and distance to Earth

d) None of the above; an HR diagram requires the absolute magnitude, not apparent magnitude.

Answer 1

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