Where are the Cepheid and RR Lyrae variable stars located on the HR Diagram?

Cepheids can be seen in distant galaxies and so can help determine the distance to those galaxies.

Cepheid variable type stars, found on the instability strip of the HR diagram, are unstable because they have used up all their fuel and they are cooling and fading.

Cepheid variables can be used to determine distances because their can be determined from their , which is observable.

Match the phrases to form complete sentences that hold scientifically true about Cepheid variable stars. Intrinsically bright cepheid variable stars

Match the phrases to form complete sentences that hold scientifically true about Cepheid variable stars. Intrinsically dim cepheid variable stars

Towards which end of the HR diagram's instability strip are Cepheid variable stars located?           

Cepheid variable stars are unique in that their fuel combustion status is what leads to their variable luminosity. What are the combustion fuels in Cepheid variables and where are they burned?

A Type Ia supernova is observed to have an apparent magnitude of 12.2. How far from us is it?

Stars in a cluster form at the same time, but evolve at different rates. Which type of stars evolve the most quickly?

The shortest possible distance that two stars in a binary system can be from one another while staying individual, isolated stars is called the

We can determine the age of a star cluster by looking at the of main sequence on that star cluster's HR diagram.

Novae events are rare, and typically only a few can be seen in our galaxy every

Which of these astronomical phenomena is the most luminous?

To determine the age of a star cluster, first plot those stars (and only those stars) of that cluster on an HR diagram and then look for

According to Einstein, photons leaving a gravitational well

According to Einstein's theory of special relativity, the Apollo astronauts that travelled to the Moon in a rocket experienced time

Einstein explained that gravitational attraction is a result of the

Twin sisters Marissa and Melody want to conduct an experiment to test Einstein's theory of special relativity. Marissa lives on Earth and Melody on the Moon (assuming one day this is possible). They simultaneously click "start" on the stopwatches they're using for this experiment. When Marissa's stopwatch reads 00:11:19 (11 minutes, 19 seconds), which of the following will likely show on Melody's stopwatch on the Moon?

According to Einstein's theory of special relativity, the faster a body moves,