Astronomy 120 - Stars and Galaxies » Fall 2022 » Unit 6 Quiz

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Question #1
The of a star is a measure of how bright the star actually is, regardless of how it might appear from Earth.
A.   absolute magnitude
B.   definite magnitude
C.   apparent magnitude
D.   obvious magnitude
Question #2
A star's apparent and absolute magnitudes are given below. m = +0.3 M = +4 Is this star closer than or further than 10 pc from the Earth?
A.   farther
B.   impossible to tell
C.   closer
D.   exactly at 10 pc
Question #3
If a parallax angle of one arcsecond is observed, then the star is at a distance of
A.   106 km
B.   1 AU
C.   1 ly
D.   1 pc
Question #4
Which of the following stars (identical in every possible way except distance) is closest to Earth?
A.   The star with apparent magnitude 0.
B.   The star with apparent magnitude 2.
C.   The star with apparent magnitude 5.
D.   The star with apparent magnitude 3.
Question #5
Measuring the parallax of stars is important to astronomers because it allows for the determination of
A.   mass of the stars.
B.   velocity of the planets orbiting those stars.
C.   distance to those stars.
D.   diameter of the stars.
Question #6
Castor (α Geminorum A), a star in the Gemini constellation, has an apparent magnitude of +1.93. Its absolute magnitude is +0.986. Would it be fair to say that Castor is less than 10pc from the Earth?
A.   Yes, that's right.
B.   that is impossible to tell from the information given
C.   No, that would be incorrect.
D.   Castor is too faint to be seen and therefore its distance cannot be calculated.
Question #7
A parsec is equal to about light years.
A.   360
B.   3.26
C.   0.326
D.   42
Question #8
A red star would have spectral classification of
A.   O or B
B.   A or F
C.   K or M
D.   G or F
Question #9
The apparent magnitude of a star describes its
A.   brightness as seen from Earth.
B.   size and chemical composition.
C.   magnification
D.   distance
Question #10
The Sun's spectral classification is
A.   GII
B.   G2 or G2V
C.   K4III or K4
D.   O0V or O0
Question #11
A parsec is a measure of
A.   distance.
B.   time.
C.   location.
D.   brightness.
Question #12
A star's brightness as it appears from Earth is called its
A.   absolute magnitude.
B.   definitive magnitude.
C.   apparent magnitude.
D.   terrestrial magnitude.
Question #13
The parallax of a nearby star is the result of
A.   The rotation rate of the galaxy.
B.   The star's motion along our line of sight (towards or away from us).
C.   Earth's revolution around the Sun.
D.   Earth's rotation on it axis.
Question #14
Stars that show the Fraunhofer lines of hydrogen most strongly are classified as
A.   O type stars.
B.   G type stars.
C.   A type stars.
D.   C type stars.
Question #15
The nearest stars to Earth have parallax angles that are the
A.   smallest
B.   closest to 0 mas
C.   largest
D.   most difficult to measure
Question #16
A star's parallax is measured to be 0.93". What is the distance to this star?
A.   1350 light years away
B.   A little less than 1 pc.
C.   1350 parsecs away
D.   A little more than 1 pc.
Question #17
The star Spica is around 250 ly away. What would its parallax angle be?
A.   1300 mas
B.   0.013"
C.   13"
D.   0.013 mas

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