The diagram above shows the life track of a 1 MSun protostar from the time it first begins to form until it reaches the main sequence, with four stages labeled. What is happening to the protostar's surface temperature and luminosity during Stage 4, when its life track moves straight down to join the main sequence?
A) Its surface temperature and luminosity increase.
B) Its surface temperature increases, and its luminosity decreases.
C) Its surface temperature and luminosity decrease.
D) Its surface temperature decreases, and its luminosity increases.
E) Its surface temperature and luminosity remain the same.
B) Its surface temperature increases, and its luminosity decreases.
You might also like to view...
Abby throws a ball straight up and times it. She sees that the ball goes by the top of a flagpole after 0.50 s and reaches the level of the top of the pole after a total elapsed time of 4.1 s
What was the speed of the ball at launch? Neglect air resistance. A) 11 m/s B) 23 m/s C) 34 m/s D) 45 m/s E) 48 m/s
When we see a binary system producing eclipses, we know that the orbit is nearly edge-on
a. True b. False Indicate whether the statement is true or false
The Earth's lithosphere
A) is the same as the crust. B) consists of the crust and the asthenosphere. C) is the same as the mantle. D) consists of the crust and the uppermost part of the mantle.
Which of the following is the weakest?
A) a chemical bond B) an ion-dipole attraction C) a dipole-dipole attraction D) a dipole-induced dipole attraction E) an induced dipole-induced dipole attraction