Fig. 1 shows a simplified sequence from a computer simulation of a red giant. The outer gas becomes less tightly held as the star expands. Eventually a glow...
Question 1 Report
Fig. 1 shows a simplified sequence from a computer simulation of a red giant. The outer gas becomes less tightly held as the star expands. Eventually a glowing shell is left around the small central remnant. This shell is called a planetary nebula, although it has no connection with a planet. Students use the simulation to identify the path followed by a Sun-like star.
(a) Label the small object at the far right as a white dwarf. [1]
(b) What happens to the outer layers of the red giant? [1]
(c) Describe why the central object remains visible after the gas shell has formed. [2]
A telescope team photographs the remains of a star in a nearby galaxy. Fig. 1 shows a shell of hot gas expanding away from a compact object at its centre. The team detects radiation from the shell and uses the image in a news report. The original star had a much greater mass than the Sun.
(a) What event produced the expanding shell? [1]
(b) Label X by writing the likely compact object for a very massive original star. [1]
(c) Describe what happens to the outer layers during the event in part (a). [2]
(d) Give one reason why this event can briefly be seen from a very large distance. [1]
Answer Details
Planetary nebula sequence
- (a) The small central object at the far right is a white dwarf. [1]
- (b) The red giant's outer layers are expelled and drift away into space. [1]
- (c) The central white dwarf remains visible because it is very hot and emits radiation or light. [2]
Remains of a very massive star
- (a) The expanding shell was produced by a supernova. [1]
- (b) X is most likely a black hole. [1]
- (c) During a supernova, the outer layers are ejected and move outwards at high velocity. [2]
- (d) A supernova releases a very large amount of energy and becomes extremely bright, so it can briefly be seen from a very large distance. [1]
Download The App On Google Playstore
Everything you need to excel in your exams
