ASTRONOMY 1010 FINAL EXAM
2025/2026 NEWEST EXAM
CURRENTLY TESTING
COMPLETE 400 QUESTIONS WITH
DETAILED VERIFIED ANSWERS
EXPERTLY VERIFIED FOR A+
GRADE
What can we learn about a star from its life track on an H-
R diagram?
A) where it is located
B) what surface temperature and luminosity it will have at
each stage of its life
C) how long ago it was born
D) when it will die
E) all of the above - ....ANSWER...B) what surface
temperature and luminosity it will have at each stage of its
life
Which of the following statements about degeneracy
1
,pressure is not true?
A) Degeneracy pressure can halt gravitational contraction
of a star even when no fusion is occurring in
the core.
B) Degeneracy pressure varies with the temperature of the
star.
C) Degeneracy pressure keeps any protostar less than 0.08
solar mass from becoming a true, hydrogen-fusing star.
D) Degeneracy pressure is a consequence of the laws of
quantum me - ....ANSWER...B) Degeneracy pressure
varies with the temperature of the star
What percentage of a star's total lifetime is spent on the
main sequence?
A) 10% B) 20% C) 50% D) 90% E) 100% -
....ANSWER...D) 90%
What happens when a star like the sun exhausts its core
hydrogen supply?
A) Its core contracts, but its outer layers expand and the
star becomes bigger and brighter.
B) Its core contracts, with the star becoming hotter and
brighter.
C) The core expands, and the star becomes bigger but
2
,dimmer.
D) The core contracts, with the star becoming smaller and
dimmer.
E) Its core contracts, but its outer layers expand and the
star becomes bigger but cooler and therefore
remains at the same brightness. - ....ANSWER...A) Its
core contracts, but its outer layers expand and the star
becomes bigger and brighter
Star X has an apparent magnitude of 3, and star Y has an
apparent magnitude of 8. How do they compare in
observed brightness?
A) Star X is 100 times brighter than star Y.
B) Star X is 5 times brighter than star Y.
C) Star Y is 100 times brighter than star X
D) Star Y is 5 times brighter than star X. -
....ANSWER...A) Star X is 100 times brighter than star Y
Which star has the lowest surface temperature?
3
, A) Sun, G2 V
B) Sirius, A1V
C) Proxima Centauri, M5.5 V
D) Betelgeuse, M2I - ....ANSWER...C) Proxima centauri,
M5.5 V
Careful measurements reveal that a star maintains a
steady apparent brightness at most times, except that at
precise intervals of 73 hours the star becomes dimmer for
about 2 hours. The change in brightness alternates
between a small change and a large change. The most
likely explanation is that .
A) the star is a Cepheid variable
B) the star is a member of an eclipsing binary star system
C) the star is periodically ejecting gas into space every 73
hours
D) the star is a white dwarf - ....ANSWER...B)the star is
a member of an eclipsing binary star system
The star Vega has an absolute magnitude of about 4 and
an apparent magnitude of about 0. Based on the
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2025/2026 NEWEST EXAM
CURRENTLY TESTING
COMPLETE 400 QUESTIONS WITH
DETAILED VERIFIED ANSWERS
EXPERTLY VERIFIED FOR A+
GRADE
What can we learn about a star from its life track on an H-
R diagram?
A) where it is located
B) what surface temperature and luminosity it will have at
each stage of its life
C) how long ago it was born
D) when it will die
E) all of the above - ....ANSWER...B) what surface
temperature and luminosity it will have at each stage of its
life
Which of the following statements about degeneracy
1
,pressure is not true?
A) Degeneracy pressure can halt gravitational contraction
of a star even when no fusion is occurring in
the core.
B) Degeneracy pressure varies with the temperature of the
star.
C) Degeneracy pressure keeps any protostar less than 0.08
solar mass from becoming a true, hydrogen-fusing star.
D) Degeneracy pressure is a consequence of the laws of
quantum me - ....ANSWER...B) Degeneracy pressure
varies with the temperature of the star
What percentage of a star's total lifetime is spent on the
main sequence?
A) 10% B) 20% C) 50% D) 90% E) 100% -
....ANSWER...D) 90%
What happens when a star like the sun exhausts its core
hydrogen supply?
A) Its core contracts, but its outer layers expand and the
star becomes bigger and brighter.
B) Its core contracts, with the star becoming hotter and
brighter.
C) The core expands, and the star becomes bigger but
2
,dimmer.
D) The core contracts, with the star becoming smaller and
dimmer.
E) Its core contracts, but its outer layers expand and the
star becomes bigger but cooler and therefore
remains at the same brightness. - ....ANSWER...A) Its
core contracts, but its outer layers expand and the star
becomes bigger and brighter
Star X has an apparent magnitude of 3, and star Y has an
apparent magnitude of 8. How do they compare in
observed brightness?
A) Star X is 100 times brighter than star Y.
B) Star X is 5 times brighter than star Y.
C) Star Y is 100 times brighter than star X
D) Star Y is 5 times brighter than star X. -
....ANSWER...A) Star X is 100 times brighter than star Y
Which star has the lowest surface temperature?
3
, A) Sun, G2 V
B) Sirius, A1V
C) Proxima Centauri, M5.5 V
D) Betelgeuse, M2I - ....ANSWER...C) Proxima centauri,
M5.5 V
Careful measurements reveal that a star maintains a
steady apparent brightness at most times, except that at
precise intervals of 73 hours the star becomes dimmer for
about 2 hours. The change in brightness alternates
between a small change and a large change. The most
likely explanation is that .
A) the star is a Cepheid variable
B) the star is a member of an eclipsing binary star system
C) the star is periodically ejecting gas into space every 73
hours
D) the star is a white dwarf - ....ANSWER...B)the star is
a member of an eclipsing binary star system
The star Vega has an absolute magnitude of about 4 and
an apparent magnitude of about 0. Based on the
4
