This question is incomplete. Here is the complete question:
1. Why can certain stars sometimes be identified as eclipsing binary stars?
A. They are brighter than any single star
B. They are all white dwarfs
C. They become dimmer at regular intervals
D. They are cool red stars
Answer:
The correct answer is option C. They become dimmer at regular intervals
.
Explanation:
Eclipsing binary stars are those that we can see as a point of light, but in reality they are two stars that orbit one close to the other.
When one star passes in front of the other, the observer can see how the intensity of the brightness varies. Algol is the best known eclipsing binary star and has an eclipse interval of 173 hours (2.9 days).
These stars orbit an eclipsing binary star system, where one star outshines another.
