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"Lighthouses of the sky" are the Cepheid Variables. These are stars that periodically change in brightness, somewhat the way a rotating beam from a lighthouse would as it fell on an observer. The brightness of a Cepheid is proportional to the period of its variance. So if we know the period (how long it takes the beam to come around), we know how bright the star should be. Comparing that to the observed brightness tells us how far away it is (if it's one-quarter as bright as it would be at a standard distance - 32.6 light years - then it's twice as distant (65.2 light years).)
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What is the type of star used by Hubble to measure the distance to other galaxies?
what is the type of star used by the Hubble to measure the distance to other galaxies.
If a star's parallax angle is too small to measure what can you conclude about the star's distance from earth?
It means that the distance is greater than a certain amount - depending on how precisely you can measure the parallax.
Which measure is not considered when measuring absolute magnitude?
Distance. Absolute magnitude is a measure of the intrinsic brightness of a star, independent of its distance from Earth.
If a star's parallax angle is too small to measure what can you conclude about the star's distance from the earth?
It means that the distance is greater than a certain amount - depending on how precisely you can measure the parallax.
How is the distance to a star determined using the measure of parallax?
The distance to a star can be determined using the measure of parallax by observing the star from two different points in Earth's orbit around the Sun. By measuring the apparent shift in the star's position against more distant background stars, astronomers can calculate the star's distance based on the angle of the parallax.
What is the apparent movement of a star used to measure its distance from earth?
The apparent movement of a star used to measure its distance from Earth is called parallax. Astronomers observe how a star's position changes relative to more distant stars as Earth orbits the Sun, allowing them to calculate the star's distance based on the angle of this shift.
The most basic way to measure the distance to a star is?
The most basic way to measure the distance to a star is through parallax. This involves observing the shift in the star's position as seen from different points in Earth's orbit, allowing astronomers to calculate the star's distance based on its apparent movement.
What is a name for the apparent movement of a star used to measure its distance from earth?
parallax
Is a star's absolute magnitude dependent on its distance from the observer?
No, a star's absolute magnitude is a measure of its intrinsic brightness regardless of its distance from the observer. It is a standardized measure that allows for comparison of the brightness of stars at a set distance.
How do astronomers measure the distance to nearby stars?
Astronomers use a method called parallax to measure the distance to nearby stars. By observing how a star's position changes when viewed from different points in Earth's orbit around the Sun, astronomers can calculate the star's distance based on the angle of this apparent shift.
Is a unit used to indicate the distance of star?
Most of the time we use light years, but their are other units to measure distance such as parsecs and arcminutes.
Why can parallax only be used to measure distance to star that are relatively close to earth?
At farther distances, the parallax becomes too small to measure accurately. At a distance of 1 parsec, a star would have a parallax of 1 second (1/3600 of a degree). (The closest star, Toliman, is a little farther than that.) At a distance of 100 parsecs, the parallax is only 1/100 of a second.
