Astro 7N Final Exam 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 sequence star, which one is farther 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 - CORRECT
ANSWER - hydrogen-2 + proton = helium-3 + energy
which of the following has the smallest radius - CORRECT ANSWER - neutron star
why does the main sequence part 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 temp of 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 stat is at the same distance as a 0.2-solar-mass main sequence star.
Which star appears brighter? - CORRECT ANSWER - the 2 solar mass main sequence
star appears brighter
, the temp of the photosphere of the sun is closest to - CORRECT ANSWER - 6000 K
An estimate of the number of communicating/technological civilizations that we expect in 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 int he
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
In the inverse square law activity above, what would the wattage of the top lightbulb need to be,
such that it appeared as bright as the bottom lightbulb which is a 35-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
if they were all formed at the same time, which of the stars in the diagram above will live the
longest? - CORRECT ANSWER -B
The parallax angle of a nearby star is measured to be 0.02 arcseconds. 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 sequence star, which one is farther 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 - CORRECT
ANSWER - hydrogen-2 + proton = helium-3 + energy
which of the following has the smallest radius - CORRECT ANSWER - neutron star
why does the main sequence part 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 temp of 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 stat is at the same distance as a 0.2-solar-mass main sequence star.
Which star appears brighter? - CORRECT ANSWER - the 2 solar mass main sequence
star appears brighter
, the temp of the photosphere of the sun is closest to - CORRECT ANSWER - 6000 K
An estimate of the number of communicating/technological civilizations that we expect in 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 int he
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
In the inverse square law activity above, what would the wattage of the top lightbulb need to be,
such that it appeared as bright as the bottom lightbulb which is a 35-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
if they were all formed at the same time, which of the stars in the diagram above will live the
longest? - CORRECT ANSWER -B
The parallax angle of a nearby star is measured to be 0.02 arcseconds. What is the distance to the
star? - CORRECT ANSWER - 50 parsecs
