If You Wanted to Discover the Youngest Stars You Could
If you wanted to discover the youngest stars you could find in some grouping of stars in the Galaxy, which type of star group would be the best to search?
A) globular clusters
B) open clusters
C) the type of clusters that form a halo around the disk of the Milky Way
D) stellar associations
E) all types of star groups have an equal number of young stars in them
Section 22.3 Checking Out the Theory
As a cluster of stars begins to age, which type of star in the cluster will move off the main sequence of the H-R diagram first?
A) all the stars in a cluster are born at the same time; so they will all move off the main sequence at the same time, as they evolve
B) G type stars, like our Sun
C) M type stars, which are the coolest
D) the lowest mass stars, which have the least amount of fuel for fusion
E) the O and B type stars
An astronomy student, for her PhD, really needs to estimate the age of a cluster of stars. Which of the following would be part of the process she would follow?
A) measure the Doppler shift of a number of the stars in the cluster
B) search for x-rays coming from the center of the cluster
C) plot an H-R diagram for the stars in the cluster
D) count the number of M type stars in the cluster
E) search for planets like Jupiter around the stars in the center of the cluster
On an H-R diagram of a cluster of stars, which characteristic of the diagram do astronomers use as a good indicator of the cluster's age?
A) the number of M stars on the main sequence
B) the lowest luminosity star that is visible in the cluster
C) the point on the main sequence where stars begin to "turn off" -- to move toward the red giant region
D) how high up on the main sequence M type stars are found
E) the coolest surface temperature for a star that they can measure