Cepheids and Standard Candles Quiz

What did Henrietta Swan Leavitt note about cepheid stars in the Magellanic Cloud in 1912?

• They brighten and dim periodically.

• They have irregular periods.

• Their brightness cannot be inferred from their period.

• They are not variable stars.

What is a standard candle in astronomy?

• An object with unknown intrinsic brightness.

• An object whose intrinsic brightness is well-known.

• A tool for measuring traditional distances.

• A method for measuring the speed of light.

How can astronomers calculate the distance of a standard candle?

• By measuring its temperature.

• By comparing its apparent brightness to its intrinsic brightness.

• By observing its color.

• By determining its mass.

What is the cosmic distance ladder?

• A method to measure the speed of light.

• A tool to observe distant galaxies.

• A compilation of data and measurements to understand the scale of the universe.

• A type of telescope used in astronomy.

What are Cepheid Variable Stars?

• Stars that do not change in brightness.

• Stars that pulsate, getting brighter and dimmer over time.

• Stars that explode with a known luminosity.

• Stars that are not useful for measuring distances.

What occurs during a Type Ia supernova?

• A white dwarf star in a binary system explodes.

• A star collapses into a black hole.

• A star loses its luminosity.

• A star becomes a red giant.

What do Type Ia supernovae indicate about the expansion of the universe?

• The expansion is slowing due to gravity.

• The expansion rate is increasing.

• The universe is contracting.

• The expansion rate is constant.

Which property of Cepheid variable stars allows astronomers to determine their distance?

• The relationship between their pulsation period and luminosity.

• Their temperature fluctuations.

• Their color changes over time.

• Their location in the sky.

Why are Type Ia supernovae considered reliable standard candles?

• They have a consistent peak luminosity.

• They always occur in the same galaxy.

• They are the brightest objects in the universe.

• They last for millions of years.

What is the main purpose of using standard candles in astronomy?

• To measure the mass of stars.

• To observe the rotation of galaxies.

• To determine the distances to faraway objects.

• To study the composition of planets.