Astro 7N Exam 2 (copper questions)
open clusters are less concentrated, younger, and have fewer stars - correct answer-what
are the differences between open star clusters and globular star clusters?
E - correct answer-Which of the following is FALSE:
a) a supernova is an explosion of a high mass star at the end of its life
b) a nova can be caused by a white dwarf gaining material from a nearby companion star
c) a type la supernova is caused by addition of hydrogen-rich material on a white dwarf
d) a light echo is caused by light from an exploding star that gradually reaches different
layers of gas around the star
e) a nova is more luminous than a supernova
the gas cloud must have a mass that exceeds the jeans mass so that gravity overcomes
internal pressure in the cloud - correct answer-what kind of gas cloud can collapse and form
stars?
4 million solar masses - correct answer-what is the mass of the black hole at the center of
the milky way?
look at the orbits of nearby stars and apply Kepler's third law - correct answer-how do you
measure the mass of the supermassive black hole at the center of the milky way?
about 100,000 years - correct answer-about how long does light take to cross the milky way
galaxy?
E (all of above) - correct answer-what does our galaxy look like?
a) it has a large disk with spiral arms, and is relatively flat and thin
b) it has clouds of gas and dust in the spiral arms
c) older yellow stars are found mostly in the central bulge
d) old stars and globular clusters are located in a spherical halo above and below the disk
e) all of the above
halo stars were formed before those elements were made - correct answer-why do stars in
the halo of the galaxy have almost no heavy elements such as carbon, nitrogen, and
oxygen?
in the disk - correct answer-where do stars form in the galaxy today?
in the disk - correct answer-where are open clusters found?
the presence of a bar - correct answer-in the symbol for the Hubble type of galaxy, SBc, the
'B' denotes ...
open clusters are less concentrated, younger, and have fewer stars - correct answer-what
are the differences between open star clusters and globular star clusters?
E - correct answer-Which of the following is FALSE:
a) a supernova is an explosion of a high mass star at the end of its life
b) a nova can be caused by a white dwarf gaining material from a nearby companion star
c) a type la supernova is caused by addition of hydrogen-rich material on a white dwarf
d) a light echo is caused by light from an exploding star that gradually reaches different
layers of gas around the star
e) a nova is more luminous than a supernova
the gas cloud must have a mass that exceeds the jeans mass so that gravity overcomes
internal pressure in the cloud - correct answer-what kind of gas cloud can collapse and form
stars?
4 million solar masses - correct answer-what is the mass of the black hole at the center of
the milky way?
look at the orbits of nearby stars and apply Kepler's third law - correct answer-how do you
measure the mass of the supermassive black hole at the center of the milky way?
about 100,000 years - correct answer-about how long does light take to cross the milky way
galaxy?
E (all of above) - correct answer-what does our galaxy look like?
a) it has a large disk with spiral arms, and is relatively flat and thin
b) it has clouds of gas and dust in the spiral arms
c) older yellow stars are found mostly in the central bulge
d) old stars and globular clusters are located in a spherical halo above and below the disk
e) all of the above
halo stars were formed before those elements were made - correct answer-why do stars in
the halo of the galaxy have almost no heavy elements such as carbon, nitrogen, and
oxygen?
in the disk - correct answer-where do stars form in the galaxy today?
in the disk - correct answer-where are open clusters found?
the presence of a bar - correct answer-in the symbol for the Hubble type of galaxy, SBc, the
'B' denotes ...
