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Star A is a Type 1 Cepheid with a period of 2 days, and has a known distance of 650 lightyears. Star B is a Type 2 Cepheid with a period of 100 days.

The luminosity of star A is: and The luminosity of star B is:

0.001 times the luminosity of the Sun
the same luminosity as the Sun
100 times the luminosity of the Sun
1,000 times the luminosity of the Sun
10,000 times the luminosity of the Sun

Star A and B appear to have the same apparent magnitude, that is, we receive the same amount of light from both. What is the approximate distance to star B?

O. 250 lightyears
O 650 lightyears
O 2,000 lightyears
O 6,500 lightyears
O 8,000 lightyears
O 65,000 lightyears

1 Answer

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Final answer:

To calculate the distance to Star B without additional data, we must use the inverse square law of light, and the period-luminosity relationship for Cepheid stars. Given Star A's known parameters, these tools can help estimate Star B's distance, understanding that typical Cepheid luminosities range from 1000 to 10,000 times the Sun's.

Step-by-step explanation:

The question relates to the concept of luminosity, apparent magnitude, and distance in astronomy. Given the scenario where Star A is a Type 1 Cepheid with a known distance and luminosity, and Star B is a Type 2 Cepheid with the same apparent magnitude as Star A, we are to determine the approximate distance to Star B.

Using the inverse square law of light, which states that the apparent brightness of a star is inversely proportional to the square of its distance from the observer, we can estimate the distance to Star B. Because both stars have the same apparent magnitude, but different periods and thus different luminosities, we can use the period-luminosity relationship for Cepheid stars to deduce comparative luminosities. Most Cepheid variables have luminosities in the range of 1000 to 10,000 times that of the Sun, so for a Type 1 Cepheid with a period of 2 days like Star A, it might typically be around 1000 times the Sun's luminosity.

Given that Star B is a Type 2 Cepheid with a longer period, it would typically have a higher luminosity, but the exact value would need to be determined from the period-luminosity relationship specific to Type 2 Cepheids. Once we know the luminosity of Star B, we could apply the inverse square law taking into account the known properties of Star A to find the distance to Star B. Without additional mathematical data or the specific period-luminosity relationships for Type 1 and Type 2 Cepheids, we cannot provide an exact distance to Star B.

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