MSU ISP 205 FINAL EXAM
Which of the following objects were first discovered as pulsars? -
ANSWERS-Neutron star
Which of the following objects are NOT supported by degeneracy
pressure? - ANSWERS-Black hole
What discovery would contradict current models of a white dwarf? -
ANSWERS-Discovery of a white dwarf with more than 1.4 solar
masses.
Which of the following events does NOT require mass transfer from a
companion? - ANSWERS-massive star supernova
Which of the following lists objects in the proper order, from smallest
to largest? - ANSWERS-Neutron Star, Moon, White Dwarf, Sun
Which of the following objects has the largest escape velocity from its
surface? - ANSWERS-Neutron star with a mass of 1 solar mass
Which of the following objects has the largest escape velocity from a
circular orbit with a radius of 0.1 AU? - ANSWERS-All of these
objects have the same escape velocity
,Which observation would be strong evidence for a black hole? -
ANSWERS-A binary star with a dark companion exceeding 3 solar
masses.
Suppose you drop a clock toward a black hole. As you look at the
clock from a high orbit, what will you notice? - ANSWERS-Time on
the clock will run slower as it approaches the black hole, and light
from the clock will be increasingly redshifted.
The parallax angle of a star A is 0.1 arcseconds; the parallax angle of
star B is 0.01 arcseconds. What can you conclude? - ANSWERS-Star
A is 10 times closer than star B.
If Star A and Star B are identical, and Star A is 4 times brighter than
Star B, what can we conclude about the distance of star A? -
ANSWERS-It is two times closer than star B.
Cepheid variable stars that have longer periods have higher
luminosities (are intrinsically brighter) and those with shorter periods
have lower luminosities (are intrinsically fainter). So if you observe
two Cepheid stars with different periods, but the same apparent
brightness (same flux), which of the following is true? - ANSWERS-
The Cepheid variable star with the shorter period is closer than the
Cepheid variable star with the longer period, if they have the same
apparent brightness.
A white dwarf supernova event is very important to calibrating
Hubble's Law. Why? Choose the best answer for the question. -
ANSWERS-It is a very luminous standard candle.
, The very first stars in the universe were made of: - ANSWERS-
Hydrogen and helium
Why do stars in the disk of a spiral galaxy orbit in roughly the same
direction, in the same plane in space? - ANSWERS-The gas that
formed the stars was shaped as a giant, rotating disk.
Which of the following descriptions are characteristic of elliptical
galaxies? - ANSWERS-Are extremely common in the central regions
of galaxy clusters.
Which image (picture) shows a galaxy while it is at its youngest? -
ANSWERS-The image of a very distant galaxy.
Sam measures a Hubble constant of 20 km/sec/million light-years.
Molly measures a Hubble constant of 25 km/sec/million light-years.
All other assumptions being the same, which person would estimate a
LARGER age to the universe? - ANSWERS-Sam
Ming measures a recession velocity of 1000 km/sec for a galaxy.
About how far away is that galaxy if the Hubble constant is 20
km/sec/million light years? (Hint: be sure to check the units in your
calculation.) - ANSWERS-50 million light years.
We can measure the distance and speed for the following objects. For
which set of these objects does their distance and speed allow us to
estimate their age? - ANSWERS-galaxies (age of the universe)
Which of the following objects were first discovered as pulsars? -
ANSWERS-Neutron star
Which of the following objects are NOT supported by degeneracy
pressure? - ANSWERS-Black hole
What discovery would contradict current models of a white dwarf? -
ANSWERS-Discovery of a white dwarf with more than 1.4 solar
masses.
Which of the following events does NOT require mass transfer from a
companion? - ANSWERS-massive star supernova
Which of the following lists objects in the proper order, from smallest
to largest? - ANSWERS-Neutron Star, Moon, White Dwarf, Sun
Which of the following objects has the largest escape velocity from its
surface? - ANSWERS-Neutron star with a mass of 1 solar mass
Which of the following objects has the largest escape velocity from a
circular orbit with a radius of 0.1 AU? - ANSWERS-All of these
objects have the same escape velocity
,Which observation would be strong evidence for a black hole? -
ANSWERS-A binary star with a dark companion exceeding 3 solar
masses.
Suppose you drop a clock toward a black hole. As you look at the
clock from a high orbit, what will you notice? - ANSWERS-Time on
the clock will run slower as it approaches the black hole, and light
from the clock will be increasingly redshifted.
The parallax angle of a star A is 0.1 arcseconds; the parallax angle of
star B is 0.01 arcseconds. What can you conclude? - ANSWERS-Star
A is 10 times closer than star B.
If Star A and Star B are identical, and Star A is 4 times brighter than
Star B, what can we conclude about the distance of star A? -
ANSWERS-It is two times closer than star B.
Cepheid variable stars that have longer periods have higher
luminosities (are intrinsically brighter) and those with shorter periods
have lower luminosities (are intrinsically fainter). So if you observe
two Cepheid stars with different periods, but the same apparent
brightness (same flux), which of the following is true? - ANSWERS-
The Cepheid variable star with the shorter period is closer than the
Cepheid variable star with the longer period, if they have the same
apparent brightness.
A white dwarf supernova event is very important to calibrating
Hubble's Law. Why? Choose the best answer for the question. -
ANSWERS-It is a very luminous standard candle.
, The very first stars in the universe were made of: - ANSWERS-
Hydrogen and helium
Why do stars in the disk of a spiral galaxy orbit in roughly the same
direction, in the same plane in space? - ANSWERS-The gas that
formed the stars was shaped as a giant, rotating disk.
Which of the following descriptions are characteristic of elliptical
galaxies? - ANSWERS-Are extremely common in the central regions
of galaxy clusters.
Which image (picture) shows a galaxy while it is at its youngest? -
ANSWERS-The image of a very distant galaxy.
Sam measures a Hubble constant of 20 km/sec/million light-years.
Molly measures a Hubble constant of 25 km/sec/million light-years.
All other assumptions being the same, which person would estimate a
LARGER age to the universe? - ANSWERS-Sam
Ming measures a recession velocity of 1000 km/sec for a galaxy.
About how far away is that galaxy if the Hubble constant is 20
km/sec/million light years? (Hint: be sure to check the units in your
calculation.) - ANSWERS-50 million light years.
We can measure the distance and speed for the following objects. For
which set of these objects does their distance and speed allow us to
estimate their age? - ANSWERS-galaxies (age of the universe)
