Multiple Choice
The hydrogen lines in spectral type A stars
A) are most narrow for supergiants.
B) are most narrow for main-sequence stars.
C) can not be used to estimate the luminosity of the star.
D) are very weak and difficult to see.
E) are useful in determining the apparent magnitude of the star.
Correct Answer:
Verified
Correct Answer:
Verified
Q116: White dwarfs are dense, cool, and dim.
Q117: What measurements are needed to determine the
Q118: Of the three units of astronomical distances,
Q119: When we see a binary system producing
Q120: Which one of the methods below enables
Q122: How do astronomers know that the newly
Q123: The absolute magnitude of a star is
Q124: <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB5757/.jpg" alt=" As shown in the
Q125: <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB5757/.jpg" alt=" -By how much
Q126: Binary (double) stars can be detected by<br>A)being