Table of Contents
- 1 Can variable stars be used to determine the distance to globular clusters?
- 2 How can variable stars be used to measure distance?
- 3 What are variable stars used for?
- 4 What can these pulsating stars help you determine?
- 5 Why are Cepheid variables so important for measuring distances in astronomy?
- 6 Why are pulsating variable stars important to astronomers?
- 7 Why do Cepheid variable stars pulsate?
- 8 Why are pulsating variables important to the study of stars?
- 9 What does it mean when a star is pulsating?
Can variable stars be used to determine the distance to globular clusters?
Type II Cepheids (also termed Population II Cepheids) are population II variable stars which pulsate with periods typically between 1 and 50 days. Type II Cepheids are used to establish the distance to the Galactic Center, globular clusters, and galaxies.
How can variable stars be used to measure distance?
By observing the apparent luminosity, dimmed by the inverse square law of light traveling across the vast reaches of space, and comparing this with the predicted luminosity, astronomers can calculate the distance to that star.
What are variable stars used for?
While stellar parallax can only be used to measure distances to stars within hundreds of parsecs, Cepheid variable stars and supernovae can be used to measure larger distances such as the distances between galaxies.
Why are pulsating variable stars useful for finding distance to globular clusters?
Some stars are very useful for finding distances to clusters and to other galaxies because they have a known luminosity that is large, so they can be seen from great distances away.
How can variable stars be used to determine the distance to globular clusters quizlet?
What kind of stars are in them? Objects used to map spiral arms – for example, O and B associations, open clusters, clouds of ionized hydrogen and some types of variable stars.
What can these pulsating stars help you determine?
Cepheids and RR Lyrae stars are two types of pulsating variable stars. Then, we can calculate their distances by comparing their luminosities with their apparent brightnesses, and this can allow us to measure distances to these stars out to over 60 million light-years.
Why are Cepheid variables so important for measuring distances in astronomy?
33) What is the importance of Cepheid variables in astronomy? Answer: Cepheid variables have a period-luminosity relationship that allows us to determine their luminosity from measuring their periodic variations in brightness. Comparing the luminosity with the apparent brightness then gives us the distance to the star.
Why are pulsating variable stars important to astronomers?
Pulsating variable stars are intrinsic variables as their variation in brightness is due to a physical change within the star. The study of pulsating variables is of great importance to astronomers. Analysis of light curves provides vital information about the interior processes in stars.
Why are Cepheid variables important for measuring distances in astronomy quizlet?
Why are Cepheid variables important? Cepheids are pulsating variable stars, and their pulsation periods are directly related to their true luminosities. Hence, we can use Cepheids as “standard candles” for distance measurements.
Why are Cepheid variable stars good distance indicators?
Why are Cepheid variable stars good distance indicators? Cepheid stars period is related to their luminosity. With that you can find its apparent magnitude and with that you can find distance. They reach the same maximum at explosion, they compare this to the known luminosity to get distance.
Why do Cepheid variable stars pulsate?
Pulsating variable stars are intrinsic variables as their variation in brightness is due to a physical change within the star. In the case of pulsating variables this is due to the periodic expansion and contraction of the surface layers of the stars.
Why are pulsating variables important to the study of stars?
The study of pulsating variables is of great importance to astronomers. Analysis of light curves provides vital information about the interior processes in stars. Perhaps their most valuable property of many types of pulsating variables is a direct relationship between the period of pulsation and their luminosity.
What does it mean when a star is pulsating?
This means the star actually increases and decreases in size periodically. The different types of pulsating variable are distinguished by their periods of pulsation and the shapes of their light curves.
What are the two types of variable stars?
There are two special types of variable stars for which—as we will see—measurements of the light curve give us accurate distances. These are called cepheid and RR Lyrae variables, both of which are pulsating variable stars.
How long does a pulsating variable star last?
Most have a period of between 5 -10 days and an amplitude range of 0.5 – 2.0 magnitudes in visible light. The variations are less pronounced at infrared wavebands. They are 1.5 – 2 magnitudes more luminous than Type II Cepheids.