A Level 9.2 Life Cycle of a star Quiz

What is the (average) distance from the centre of the Sun to the Earth known as?

• One light year

• One astronomical unit

• One light minute

• One light second

Imagine you're an astronomer trying to determine the distance to a star that's relatively close to Earth. Which method would you use, considering it involves observing the star's apparent shift in position against the backdrop of more distant stars?

• Redshift

• Blueshift

• Parallax

• Luminosity

Approximately how old is the Universe thought to be?

• 10 thousand million years

• 13 billion years

• 100 thousand years

• 1 million years

What is the parallax angle θ defined as in astrophysics?

• The angle subtended by the line between the Sun and the Earth

• The angle subtended to the star by the line between the Sun and the Earth

• The angle between two distant stars as seen from Earth

• The angle between the Earth and the Sun over six months

What is the relationship between the parallax angle θ (in radians) and the distance to a nearby star (d), according to the small angle approximation?

• θ = d / R

• θ = R / d

• d = R / θ

• d = θ / R

How is 1 parsec defined?

• The distance to a star which subtends an angle of 1 degree to the line from the centre of the Earth to the centre of the Sun

• The distance to a star which subtends an angle of 1 arc minute to the line from the centre of the Earth to the centre of the Sun

• The distance to a star which subtends an angle of 1 arc second to the line from the centre of the Earth to the centre of the Sun

• The distance to a star which subtends an angle of 1 radian to the line from the centre of the Earth to the centre of the Sun

What is the value of 1 arc second in degrees?

• 1/3600 degrees

• 1/60 degrees

• 1/180 degrees

• 1 degree

Which of the following statements is true about the parallax method for measuring distances to stars?

• It works well for stars beyond 100 parsecs using ground telescopes.

• Atmospheric refraction does not affect the accuracy of ground telescopes.

• Telescopes on satellites can measure distances to stars beyond 100 parsecs more accurately.

• Parallax angles for distant stars are too large to measure accurately.

On the scientific scale of star magnitudes, what does a star of magnitude 1 signify?

• It is one of the faintest stars in the sky.

• It is one of the brightest stars in the sky.

• It has zero or negative apparent magnitude.

• It cannot be seen with the unaided eye.

What does the term 'absolute magnitude' refer to in the context of star magnitudes?

• The brightness of a star as seen from Earth.

• The brightness of a star as seen from the Sun.

• The brightness of a star as seen from a standard distance.

• The change in brightness of a star over time.