AST104 Homework 2 Exam Questions
and Answers
After a nice dinner around the campfire on a camping trip, you and a friend
decide to get away from the fire to observe the stars. As you get farther and
farther away, you see the brightness of the fire - ✅✅decrease as the distance
squared.
Colliding neutron stars emit an enormous flash of electromagnetic radiation
across all wavelengths. Which type of electromagnetic radiation reaches Earth
first? - ✅✅You can't fool me. All of these travel through space at the same
speed.
An astronomer discovers a new star and wants to measure its temperature. She
would typically do this by - ✅✅making a blackbody curve and finding the
wavelength of the peak.
Wien's Law relates the wavelength at which a star gives off the greatest amount
of energy to the star's - ✅✅temperature
The Stefan-Boltzmann Law relates the energy flux coming from a blackbody (such
as a star) to its - ✅✅temperature
An incandescent light bulb (the old-fashioned kind with a hot wire inside) glows
yellow-white. The burner on an electric stove glows red hot. Which has the higher
temperature? - ✅✅The light bulb.
, Two stars have the same diameter and are at the same distance from us (but in
different parts of the sky.) Star A has a temperature of 4000 K, while star B has a
temperature of 8000K. Which of the following statements is true? - ✅✅Star B
has 16 times the luminosity that Star A has.
Why is an absorption spectrum especially useful for astronomers? - ✅✅It has
dark lines in it that allow astronomers to determine what elements are in the star.
An artist who likes working with sources of light decides to make a modern
sculpture out of electrified glass tubes that contain very thin (rarified) neon gas.
When the sculpture is finished, and the electricity is turned on, the tubes glow
with a rich red color. What we are seeing is - ✅✅an emission spectrum.
What happens when an electron transitions from a higher energy level to a lower
energy level in an atom? - ✅✅A photon is given off.
When an astronomer rambles on and on about the luminosity of a star she is
studying, she is talking about - ✅✅how much energy the star gives off each
second.
Two stars have the same luminosity, but Star B is three times farther away from
us than Star A. Compared to Star A, Star B will look - ✅✅nine times fainter.
Two stars have the exact same luminosity, but Star Y is four times dimmer looking
than Star X. This means that - ✅✅Star Y is twice as far away as Star X.
Using a good pair of binoculars, you observe a section of the sky where there are
stars of many different apparent brightnesses. You find one star this appears
and Answers
After a nice dinner around the campfire on a camping trip, you and a friend
decide to get away from the fire to observe the stars. As you get farther and
farther away, you see the brightness of the fire - ✅✅decrease as the distance
squared.
Colliding neutron stars emit an enormous flash of electromagnetic radiation
across all wavelengths. Which type of electromagnetic radiation reaches Earth
first? - ✅✅You can't fool me. All of these travel through space at the same
speed.
An astronomer discovers a new star and wants to measure its temperature. She
would typically do this by - ✅✅making a blackbody curve and finding the
wavelength of the peak.
Wien's Law relates the wavelength at which a star gives off the greatest amount
of energy to the star's - ✅✅temperature
The Stefan-Boltzmann Law relates the energy flux coming from a blackbody (such
as a star) to its - ✅✅temperature
An incandescent light bulb (the old-fashioned kind with a hot wire inside) glows
yellow-white. The burner on an electric stove glows red hot. Which has the higher
temperature? - ✅✅The light bulb.
, Two stars have the same diameter and are at the same distance from us (but in
different parts of the sky.) Star A has a temperature of 4000 K, while star B has a
temperature of 8000K. Which of the following statements is true? - ✅✅Star B
has 16 times the luminosity that Star A has.
Why is an absorption spectrum especially useful for astronomers? - ✅✅It has
dark lines in it that allow astronomers to determine what elements are in the star.
An artist who likes working with sources of light decides to make a modern
sculpture out of electrified glass tubes that contain very thin (rarified) neon gas.
When the sculpture is finished, and the electricity is turned on, the tubes glow
with a rich red color. What we are seeing is - ✅✅an emission spectrum.
What happens when an electron transitions from a higher energy level to a lower
energy level in an atom? - ✅✅A photon is given off.
When an astronomer rambles on and on about the luminosity of a star she is
studying, she is talking about - ✅✅how much energy the star gives off each
second.
Two stars have the same luminosity, but Star B is three times farther away from
us than Star A. Compared to Star A, Star B will look - ✅✅nine times fainter.
Two stars have the exact same luminosity, but Star Y is four times dimmer looking
than Star X. This means that - ✅✅Star Y is twice as far away as Star X.
Using a good pair of binoculars, you observe a section of the sky where there are
stars of many different apparent brightnesses. You find one star this appears
