Author Question: You observe a star cluster with a main-sequence turn-off point at spectral type G2 (the same ... (Read 30 times)

mwit1967 · **on:** Jul 27, 2018

You observe a star cluster with a main-sequence turn-off point at spectral type G2 (the same spectral type as the Sun). What is the age of this star cluster?

A) 4.6 billion years
B) 10 billion years
C) 10,000 years
D) 100 billion years
E) You also need to know the luminosity class of the turn-off point to determine the age.

Question 2

The point along a planet's orbit where it is closest to the Sun is called the orbit's

A) period.
B) perihelion.
C) eccentricity.
D) semi-major axis.
E) aphelion.