L4

讲座

1. What does the professor mainly discuss?

The discovery of an Earthlike planet orbiting a distant star

A recent study of pulsars that confirms a theory about white dwarfs

The possibility of locating a habitable planet in an unexpected location

New data regarding the life cycles of stars

2. According to the professor, what characteristic do white dwarfs and stars similar to the Sun have in common?

They produce a similar amount of heat and light.

Their habitable zones are equal in size.

They are in long-term states of equilibrium.

They will eventually become pulsars.

3. What is the professor’s opinion of the idea that a habitable planet could orbit a white dwarf star?

The idea cannot be verified because of the difficulty in locating such a planet.

The idea would contradict our current understanding of the universe.

The idea would explain an inconsistency in measurements of the mass of such stars.

The idea is a possibility in spite of certain problematic aspects.

4. What would be the qualities of a planet orbiting a white dwarf?（多选题）

It would not have seasons.

It would have a weak gravitational field.

It would have a very short year.

It would not have a stable orbit.

5. Why does the professor mention pulsars?

To illustrate one step in the life cycle of certain stars

To give an example of a dead star around which planets have been found

To provide a key distinction between the fate of the Sun and that of larger stars

To explain why planets are rarely discovered revolving around white dwarfs

6. Why does the professor mention an eclipse?

To compare the size of Earth’s Moon to that of a white dwarf

To explain why it is difficult to view white dwarfs

To emphasize how far most white dwarfs are from Earth

To suggest how a planet orbiting a white dwarf might be discovered