Astronomy 1010 Final Exam Test Questions and Answers Rated A+
One of the most important earlier steps in colored bands in the plot background. -
understanding stars was to group them into ANSWER --Redder main-sequence stars
classes called spectral types that could offer are fainter on average than bluer main-sequence
clues as to why they are different from one stars.
another. Shown here are spectra of some main- -The spectral type of a star uniquely determines
sequence stars. Before stars were very well its color.
understood, they were classified into an order
that was based on the relative strength of
hydrogen absorption lines, marked by arrows the The spectral type of a star is directly related to its
image shown. color. Recall that a star emits light as a
blackbody, which has a particular shape to its
Look at the spectra for stars of different spectral spectrum, as shown in this figure.
type. Choose the list of spectral types that are in Based on this, what basic property of a star
order of decreasing strength of their hydrogen determines its color (and thus its spectral type)? -
lines, as indicated by the arrows (strongest ANSWER -temperature
absorption first, weakest last). - ANSWER -
A0, B0, F0, G0, K0
The majority of stars, including the Sun, are on
the main sequence. The masses and sizes of
Measurements of various properties of stars main-sequence stars in the H-R diagram are
allowed astronomers to determine a more indicated in this figure.
physically meaningful way of ordering the Study how the various properties of a main-
different spectral types than just by the strength sequence star are related to one another in the
of their hydrogen absorption lines. figure. Then select the properties in the list that
would increase if the mass of a main-sequence
Study this table of properties, and use it to star is increased. - ANSWER --temperature
determine how the stars should be ordered. Click -luminosity
on the spectrum for each spectral type in order of -radius
decreasing strength of whatever property or
properties you choose to use from the table. -
ANSWER -top to bottom Spectral type correlates directly with the
c, b, d, e, f, g, a temperature of the star. This is not enough to
completely classify stars, however, because the
luminosity of a star, and thus its exact position on
Hertzsprung and Russell were the first to plot the H-R diagram, depends on something else in
stellar luminosities as a function of their spectral addition to temperature. This is apparent from the
type. When placed in the OBAFGKM order, an H-R diagram because of the different populations
interesting pattern emerged. of stars that exist in addition to the main
sequence—they may have the same temperature
The following figure shows one of these plots, as a main-sequence star, but a completely
named a Hertzsprung-Russell, or H-R, diagram different luminosity
after its founders. Each dot represents a single Based on the figure, what other property can we
star, with green, yellow, and red dots simply use to further classify stars? - ANSWER -
indicating regions where there are a larger radius
number of stars in that part of the plot. The color
of the stars is roughly given by the vertical
1/9
, Astronomy 1010 Final Exam Test Questions and Answers Rated A+
A star can be fully classified with two descriptors:
its spectral type (determined by temperature) and
its luminosity class (determined by size). These When observed from two widely separated
two together give the location of the star on the locations, an object appears to move _____
H-R diagram, and all other basic properties against the background than when observed from
(except composition) follow from that. Luminosity two locations near one another. -
classes are given by roman numerals I through ANSWER -more
V, plus WD. The locations of these classes are
shown in the figure here, along with the terms
describing what type of stars they are (i.e., main When an object is farther away, it appears to
sequence, supergiant, etc.). move _____ against the background than a
Based on this figure, rank the following closer object. - ANSWER -less
luminosity classes in order of increasing size. -
ANSWER -smallest largest
WD Astronomers cannot use parallax to find the
V distance to most stars. This is because the stars
IV are - ANSWER -too far away
III
II
I From the vantage point of Earth in the diagram
shown, how will the parallax of Star A compare to
that of Star B? - ANSWER -Star A has twice
Based on its position in this H-R diagram, which
the parallax of Star B.
of the following best describes the complete
classification of the Sun?
If Stars 1, 2, and 3 all have the same apparent
Note: The numbers after the letter for each
magnitude, rank the stars according to their size,
spectral type run from 0 through 9 for each type
(e.g., the following would read from left to right from largest to smallest - ANSWER -star 3
on the diagram: O0 through O9, then B0 through star 2
star 1
B9, etc.). - ANSWER -G2 V
This image was taken in infrared light by Hubble's
Both spectral type and luminosity class are
NICMOS camera in September 1997. It shows a
needed to determine roughly where any
young star cluster within the Milky Way Galaxy
particular star will lie on the H-R diagram. In this
Why do the stars appear to be different colors? -
diagram, label where a K5 I star and a K5 V star
ANSWER -difference in temp
might be located. - ANSWER -k5 I star- k5
104
k5 V star- k5 10-1
Sort each of the graphs shown into the bin
describing the type of spectrum plotted. -
Which of the following statements is true, based ANSWER -emission- rainbow steady
on the position of the stars in this H-R diagram? - decline
planck- black graph
ANSWER -A K5 I star has a larger radius
absorption- rainbow spike at beginning
than a K5 V.
2/9
One of the most important earlier steps in colored bands in the plot background. -
understanding stars was to group them into ANSWER --Redder main-sequence stars
classes called spectral types that could offer are fainter on average than bluer main-sequence
clues as to why they are different from one stars.
another. Shown here are spectra of some main- -The spectral type of a star uniquely determines
sequence stars. Before stars were very well its color.
understood, they were classified into an order
that was based on the relative strength of
hydrogen absorption lines, marked by arrows the The spectral type of a star is directly related to its
image shown. color. Recall that a star emits light as a
blackbody, which has a particular shape to its
Look at the spectra for stars of different spectral spectrum, as shown in this figure.
type. Choose the list of spectral types that are in Based on this, what basic property of a star
order of decreasing strength of their hydrogen determines its color (and thus its spectral type)? -
lines, as indicated by the arrows (strongest ANSWER -temperature
absorption first, weakest last). - ANSWER -
A0, B0, F0, G0, K0
The majority of stars, including the Sun, are on
the main sequence. The masses and sizes of
Measurements of various properties of stars main-sequence stars in the H-R diagram are
allowed astronomers to determine a more indicated in this figure.
physically meaningful way of ordering the Study how the various properties of a main-
different spectral types than just by the strength sequence star are related to one another in the
of their hydrogen absorption lines. figure. Then select the properties in the list that
would increase if the mass of a main-sequence
Study this table of properties, and use it to star is increased. - ANSWER --temperature
determine how the stars should be ordered. Click -luminosity
on the spectrum for each spectral type in order of -radius
decreasing strength of whatever property or
properties you choose to use from the table. -
ANSWER -top to bottom Spectral type correlates directly with the
c, b, d, e, f, g, a temperature of the star. This is not enough to
completely classify stars, however, because the
luminosity of a star, and thus its exact position on
Hertzsprung and Russell were the first to plot the H-R diagram, depends on something else in
stellar luminosities as a function of their spectral addition to temperature. This is apparent from the
type. When placed in the OBAFGKM order, an H-R diagram because of the different populations
interesting pattern emerged. of stars that exist in addition to the main
sequence—they may have the same temperature
The following figure shows one of these plots, as a main-sequence star, but a completely
named a Hertzsprung-Russell, or H-R, diagram different luminosity
after its founders. Each dot represents a single Based on the figure, what other property can we
star, with green, yellow, and red dots simply use to further classify stars? - ANSWER -
indicating regions where there are a larger radius
number of stars in that part of the plot. The color
of the stars is roughly given by the vertical
1/9
, Astronomy 1010 Final Exam Test Questions and Answers Rated A+
A star can be fully classified with two descriptors:
its spectral type (determined by temperature) and
its luminosity class (determined by size). These When observed from two widely separated
two together give the location of the star on the locations, an object appears to move _____
H-R diagram, and all other basic properties against the background than when observed from
(except composition) follow from that. Luminosity two locations near one another. -
classes are given by roman numerals I through ANSWER -more
V, plus WD. The locations of these classes are
shown in the figure here, along with the terms
describing what type of stars they are (i.e., main When an object is farther away, it appears to
sequence, supergiant, etc.). move _____ against the background than a
Based on this figure, rank the following closer object. - ANSWER -less
luminosity classes in order of increasing size. -
ANSWER -smallest largest
WD Astronomers cannot use parallax to find the
V distance to most stars. This is because the stars
IV are - ANSWER -too far away
III
II
I From the vantage point of Earth in the diagram
shown, how will the parallax of Star A compare to
that of Star B? - ANSWER -Star A has twice
Based on its position in this H-R diagram, which
the parallax of Star B.
of the following best describes the complete
classification of the Sun?
If Stars 1, 2, and 3 all have the same apparent
Note: The numbers after the letter for each
magnitude, rank the stars according to their size,
spectral type run from 0 through 9 for each type
(e.g., the following would read from left to right from largest to smallest - ANSWER -star 3
on the diagram: O0 through O9, then B0 through star 2
star 1
B9, etc.). - ANSWER -G2 V
This image was taken in infrared light by Hubble's
Both spectral type and luminosity class are
NICMOS camera in September 1997. It shows a
needed to determine roughly where any
young star cluster within the Milky Way Galaxy
particular star will lie on the H-R diagram. In this
Why do the stars appear to be different colors? -
diagram, label where a K5 I star and a K5 V star
ANSWER -difference in temp
might be located. - ANSWER -k5 I star- k5
104
k5 V star- k5 10-1
Sort each of the graphs shown into the bin
describing the type of spectrum plotted. -
Which of the following statements is true, based ANSWER -emission- rainbow steady
on the position of the stars in this H-R diagram? - decline
planck- black graph
ANSWER -A K5 I star has a larger radius
absorption- rainbow spike at beginning
than a K5 V.
2/9
