You See Two Main-Sequence Stars with the Same Spectral Type

question 92

Multiple Choice

You see two main-sequence stars with the same spectral type. Star 1 is dimmer in apparent brightness than Star 2 by a factor of 100. What can you conclude, assuming there is no absorption of either star's light by interstellar gas or dust?

• A) Without first knowing the distances to these stars, you cannot draw any conclusions about how their true luminosities compare to each other.
• B) The luminosity of Star 1 is a factor of 100 less than the luminosity of Star 2.
• C) Star 1 is 100 times more distant than Star 2.
• D) Star 1 is 100 times nearer than Star 2.
• E) Star 1 is 10 times more distant than Star 2.

---

Definitions:

Alternative Hypothesis

A statistical hypothesis that specifies a population parameter's value is different from the value stated in the null hypothesis.

Pooled Estimate

A method used to combine estimates from different groups or studies to obtain a common estimate when the groups are considered homogeneous.

Water Consumption

The amount of water utilized by individuals, households, or groups for drinking, sanitation, cooking, and other purposes.

Confidence Interval

A span of numerical outcomes obtained from statistical analysis of a sample, which probably includes the value of a parameter from the entire population that is not known.