ASTRO 7N TEST 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
A high-luminosity star .... - CORRECT ANSWER - emits more light than a low-
luminosity star
If a red giant appears the same brightness as a red main star sequence, which one is father away?
- CORRECT ANSWER - the red giant
the heaviest nuclei of all are formed... - CORRECT ANSWER - during a supernova
explosion
Fill in the blank in the following chemical reaction that occurs in the Sun: Hydrogen-2 + proton
= ___________ + energy: - CORRECT ANSWER - Helium-3
Which of the following has the smallest radius? - CORRECT ANSWER - neutron star
Why does the main sequence of a star's life end? - CORRECT ANSWER - the hydrogen in
the core is exhausted
which of the following will have the shortest lifetime on the main sequence? - CORRECT
ANSWER - main sequence star with surface temperature 20000 K
Many of the brightest 100 stars viewed from Earth are not on the main sequence (even though
most stars are) because ... - CORRECT ANSWER - the most luminous stars are giants and
supergiants that have already finished their main sequence lifetimes
A 2-solar-mass main sequence star is at the distance as a 0.2-solar-mass main sequence star.
What star appears brighter? - CORRECT ANSWER - the 2 solar mass main sequence star
appears brighter
, The temperature of the photosphere of the sun is closest to ... - CORRECT ANSWER -
6000 Kelvin
An estimate of the number of communicating/technological civilizations that we expecting our
galaxy would be a larger number if... - CORRECT ANSWER - the average number of
planets that could support life for each star were larger
if the sun had twice its mass, then which of these planets would be in its habitable zone? -
CORRECT ANSWER - Jupiter
what is the exoplanet's orbital period, and the percent brightness drop in light, for the case in the
image above from the Kepler Exoplanet Transit Hunt activity? - CORRECT ANSWER -5
days and 0.30%
how do astronomers measure the temperature of stars? - CORRECT ANSWER - by
looking at which absorption lines are present in the star's spectrum
what would the wattage of the top lightbulb need to be, such that it appeared as bright as the
bottom lightbulb which is a 25-watt-bulb - CORRECT ANSWER - 100 watts
the largest fraction of nearby stars (e.g., within 100 light years) are .... - CORRECT
ANSWER - red main sequence stars
which of the stars, in the diagram above, is the hottest? - CORRECT ANSWER - D (in the
O5 area and 100,000 luminosity)
if they were all formed at the same time, which of the stars in the diagram above will live the
longest? - CORRECT ANSWER - B (in M5 area and 0.001 luminosity)
the parallax angle of a nearby star is measured to be 0.02 arc seconds. what is the distance to the
star? - CORRECT ANSWER - 50 parsecs
Exam Questions and CORRECT Answers
A high-luminosity star .... - CORRECT ANSWER - emits more light than a low-
luminosity star
If a red giant appears the same brightness as a red main star sequence, which one is father away?
- CORRECT ANSWER - the red giant
the heaviest nuclei of all are formed... - CORRECT ANSWER - during a supernova
explosion
Fill in the blank in the following chemical reaction that occurs in the Sun: Hydrogen-2 + proton
= ___________ + energy: - CORRECT ANSWER - Helium-3
Which of the following has the smallest radius? - CORRECT ANSWER - neutron star
Why does the main sequence of a star's life end? - CORRECT ANSWER - the hydrogen in
the core is exhausted
which of the following will have the shortest lifetime on the main sequence? - CORRECT
ANSWER - main sequence star with surface temperature 20000 K
Many of the brightest 100 stars viewed from Earth are not on the main sequence (even though
most stars are) because ... - CORRECT ANSWER - the most luminous stars are giants and
supergiants that have already finished their main sequence lifetimes
A 2-solar-mass main sequence star is at the distance as a 0.2-solar-mass main sequence star.
What star appears brighter? - CORRECT ANSWER - the 2 solar mass main sequence star
appears brighter
, The temperature of the photosphere of the sun is closest to ... - CORRECT ANSWER -
6000 Kelvin
An estimate of the number of communicating/technological civilizations that we expecting our
galaxy would be a larger number if... - CORRECT ANSWER - the average number of
planets that could support life for each star were larger
if the sun had twice its mass, then which of these planets would be in its habitable zone? -
CORRECT ANSWER - Jupiter
what is the exoplanet's orbital period, and the percent brightness drop in light, for the case in the
image above from the Kepler Exoplanet Transit Hunt activity? - CORRECT ANSWER -5
days and 0.30%
how do astronomers measure the temperature of stars? - CORRECT ANSWER - by
looking at which absorption lines are present in the star's spectrum
what would the wattage of the top lightbulb need to be, such that it appeared as bright as the
bottom lightbulb which is a 25-watt-bulb - CORRECT ANSWER - 100 watts
the largest fraction of nearby stars (e.g., within 100 light years) are .... - CORRECT
ANSWER - red main sequence stars
which of the stars, in the diagram above, is the hottest? - CORRECT ANSWER - D (in the
O5 area and 100,000 luminosity)
if they were all formed at the same time, which of the stars in the diagram above will live the
longest? - CORRECT ANSWER - B (in M5 area and 0.001 luminosity)
the parallax angle of a nearby star is measured to be 0.02 arc seconds. what is the distance to the
star? - CORRECT ANSWER - 50 parsecs
