Deck 9: The Family of Stars

Question 1

Absolute visual magnitude is

A) the apparent magnitude of a star observed from Earth.
B) the luminosity of a star observed from a distance of 1000 pc.
C) the apparent magnitude of a star observed from a distance of 10 pc.
D) the luminosity of a star observed from Earth.
E) c and d

Answer 1

the apparent magnitude of a star observed from a distance of 10 pc.

Question 2

A star's absolute magnitude depends only on the star's

A) distance and diameter.
B) temperature and distance.
C) distance.
D) temperature and diameter.
E) apparent magnitude.

Answer 2

temperature and diameter.

Question 3

Use the following chart to answer the questions below:


-Which star in Table 9-1 is most distant from Earth? Note that the distance may be calculated if it is not given explicitly.

A) 65 Tau
B) HR 4621
C) ( $\alpha$ Pic)
D) 58 Ori
E) HR 2491

Answer 3

58 Ori

Question 4

The distance to Rigel is 250 pc.Which of the following statements is true based on this information?

A) The distance to Rigel can be determined by measuring its parallax.
B) Rigel's apparent visual magnitude has a smaller value than its absolute visual magnitude.
C) The absolute bolometric magnitude of Rigel is nearly equal to its absolute visual magnitude.
D) Rigel is located in the upper right corner of the HR diagram.
E) none of the above

Question 5

If a star has a parallax of 0.02 seconds of arc,then its distance will be

A) 20 pc
B) 50 pc
C) 2 pc
D) 5 pc
E) 500 pc

Question 6

Use the following chart to answer the questions below:


-Which star in Table 9-1 is the closest to Earth? Note that the distance may be calculated if it is not given explicitly.

A) 65 Tau
B) HR 4621
C) ( $\alpha$ Pic)
D) 58 Ori
E) HR 2491

Question 7

We can determine the surface temperature of a star

A) only by studying its continuous spectrum (color).
B) only by studying its line absorption spectrum.
C) Either "a" or 'b" will work but "b" is more precise

Question 8

If a star with an absolute magnitude of -5 has an apparent magnitude of +5,then its distance is

A) 1 pc.
B) 10 pc.
C) 100 pc.
D) 1000 pc.
E) 10,000 pc.

Question 9

Parallax would be easier to measure if

A) Earth's orbit was larger.
B) the stars were farther away.
C) Earth moved slower along its orbit.
D) all of these
E) none of these

Question 10

Use the following chart to answer the questions below:
NARREND

-Which star in Table 9-2 would appear the faintest in the night sky?

A) 65 Tau
B) HR 4621
C) ( $\alpha$ Pic)
D) 58 Ori
E) HR 2491

Question 11

The ____ of a star is a measure of the total energy radiated by the star in one second.

A) absolute visual magnitude
B) apparent visual magnitude
C) luminosity class
D) spectral type
E) luminosity

Question 12

The absorption lines in the ultraviolet portion of the spectrum of a star that are produced by hydrogen are from the

A) Lyman series.
B) Balmer series.
C) Paschen series.
D) isotopes of hydrogen.
E) ions of hydrogen.

Question 13

The absorption lines in the visible portion of the spectrum of a star that are produced by hydrogen are from the

A) Lyman series.
B) Balmer series.
C) Paschen series.
D) isotopes of hydrogen.
E) ions of hydrogen.

Question 14

Use the following chart to answer the questions below:

Refer to Table 9-1.The star HR 4621 is

A) closer than 10 pc.
B) farther than 10 pc.
C) No way to tell.

Question 15

We know that giant stars are larger in diameter than the sun because

A) they are more luminous but have about the same temperature.
B) they are less luminous but have about the same temperature.
C) they are hotter but have about the same luminosity.
D) they are cooler but have about the same luminosity.
E) they have a larger absolute magnitude than the sun.

Question 16

Use the following chart to answer the questions below:
NARREND

-Which star in Table 9-2 has the greatest luminosity?

A) 65 Tau
B) HR 4621
C) ( $\alpha$ Pic)
D) 58 Ori
E) HR 2491

Question 17

The absorption lines in the infrared portion of the spectrum of a star that are produced by hydrogen are from the

A) Lyman series.
B) Balmer series.
C) Paschen series.
D) isotopes of hydrogen.
E) ions of hydrogen.

Question 18

The correct sequence of spectral type letters from hot on the left to cool on the right is

A) M,K,G,F,A,B,O
B) O,B,A,F,G,K,M
C) G,K,M,F,O,B,A
D) A,B,O,F,G,K,M

Question 19

The star Sadir has an absolute magnitude of -5.3,and the absolute bolometric magnitude of the sun is +4.7.Based on this information,which of the following statements is true?

A) Sadir has a greater surface temperature than the sun.
B) Sadir has a larger diameter than the sun.
C) Sadir is 10,000 times more luminous than the sun.
D) Sadir is 100 parsecs from Earth.
E) all of the above

Question 20

The spectra of the coolest stars contain strong absorption features (or lines)of

A) TiO molecules
B) ionized helium
C) helium
D) hydrogen.
E) All of the above

Question 21

Sheat is an M2 II star.Based on this information,which of the following are true?

A) I & II
B) II & IV
C) II,III,& IV
D) I,II,& III
E) I,II,III,& IV

Question 22

Binary (double)stars can be detected by

A) being seen as two separate stars with a telescope.
B) one star traveling a wiggly proper motion path across the sky.
C) one star dimming abruptly as another passes in front of it.
D) pairs of absorption lines seen in the spectrum of what appears to be one star.
E) all of the above

Question 23

Vega is an A0 V star.Based on this information which of the following are true?

A) I & II
B) II & III
C) II,III,& IV
D) I,II,& III
E) I,II,III,& IV

Question 24

NARRBEGIN: Diagram 09-01
Diagram 9-1
Use the following HR diagram to answer the questions below: NARREND
Which star in Diagram 9-1 has the greatest surface temperature?

A) Alnilam
B) Antares
C) Arcturus
D) HR 5337
E) Sirius B

Question 25

In the H-R diagram,90 percent of all stars are

A) in the giant region.
B) in the supergiant region.
C) among the B stars.
D) among the G stars.
E) on the main sequence.

Question 26

The mass of a visual binary pair of stars can be obtained from

A) the time in years for them to orbit one another.
B) the size of their orbit.
C) their apparent magnitudes.
D) both a and b

Question 27

Spectroscopic and eclipse duration observations of an eclipsing binary star can enable astronomers to calculate____ of its individual stars.

A) the masses
B) the sizes
C) both a and b
D) neither a nor b

Question 28

Giant stars are

A) I & II
B) II & IV
C) I,II,& IV
D) II,III,& IV
E) I,II,III,& IV

Question 29

Compared with the spectral lines in the solar spectrum,lines in a supergiant spectrum are

A) sharper.
B) broader.
C) weaker.
D) stronger.
E) b and c

Question 30

The best true sample of the true members of different stars consists of

A) stars that appear brightest in the sky to an observer on the Earth.
B) all of the stars within our solar system.
C) all the stars within a given distance from Earth.

Question 31

Doppler shift observations of a spectroscopic binary star can enable astronomers to calculate ____ of its individual stars.

A) the masses
B) the sizes
C) both a and b
D) neither a nor b

Question 32

The hydrogen lines in spectral type A stars

A) are most narrow for supergiants.
B) are most narrow for main sequence stars.
C) cannot be used to estimate the luminosity of the star.
D) are very weak and difficult to see.
E) are useful in determining the apparent magnitude of the star.

Question 33

Use the following chart to answer the questions below:


-Which star in Table 9-3 has the greatest diameter?

A) 65 Tau
B) HR 4621
C) ( $\alpha$ Pic)
D) 58 Ori
E) HR 2491

Question 34

NARRBEGIN: Diagram 09-01
Diagram 9-1
Use the following HR diagram to answer the questions below: NARREND
Which of the stars in Diagram 9-1 has the brightest absolute visual magnitude?

A) Alnilam
B) Antares
C) Arcturus
D) HR 5337
E) Sirius B

Question 35

A pair of stars orbit around one another in an elliptical orbit with a semimajor axis,"a",of 1 AU with an orbital period,"P",of 1 year.What is the mass of the pair of stars?

A) m₁ + m₂ = a³ / P² = 1 solar masses
B) m₁ + m₂ = a³ / P² = 2 solar masses
C) m₁ + m₂ = a³ / P² = 4 solar masses
D) m₁ + m₂ = a³ / P² = 8 solar masses
E) m₁ + m₂ = a³ / P² = 16 solar masses

Question 36

NARRBEGIN: Diagram 09-01
Diagram 9-1
Use the following HR diagram to answer the questions below: NARREND
Which star in Diagram 9-1 above is most like the sun?

A) Alnilam
B) Antares
C) Arcturus
D) HR 5337
E) Sirius B

Question 37

Groombridge 34 is an M1 V star.Based on this information,which of the following are true?

A) I & II
B) II & IV
C) I & IV
D) I & III
E) II & III

Question 38

In an H-R Diagram,stars with the smallest radius are found in the ____ of the diagram.

A) center
B) upper left corner
C) upper right corner
D) lower left corner
E) lower right corner

Question 39

Use the following chart to answer the questions below:


-Which star in Table 9-3 has the greatest surface temperature?

A) 65 Tau
B) HR 4621
C) ( $\alpha$ Pic)
D) 58 Ori
E) HR 2491

Question 40

We know the white dwarf star Sirius B has a mass comparable to the Sun because of

A) its measured color
B) its measured temperature compared to Sirius A
C) it is part of binary star system with Sirius A.

Question 41

How can we tell that some stars are relatively close to us in the sky?

A) Some stars are occasionally eclipsed by the Moon,so they must be nearby.
B) Some stars vary in brightness caused by sunspots we can see because they are so close.
C) Some stars appear to be extremely bright and must therefore be very close to us.
D) Some stars appear to move periodically back and forth against the background stars because of the Earth's movement around the Sun

Question 42

Stars in the upper right part of the Hertzsprung-Russell diagram are always ____ when compared to stars near the middle of the diagram.

A) cooler
B) brighter as seen from Earth.
C) larger.
D) smaller.
E) more massive.

Question 43

If two stars are emitting the same amount of light,the star that is farther will appear

A) brighter.
B) dimmer.
C) redder.
D) bluer.
E) They will have the same brightness as seen from Earth.

Question 44

Giant stars are members of luminosity class III.

Question 45

The most common stars are

A) supergiants.
B) giants.
C) upper main sequence stars.
D) white dwarfs.
E) lower main sequence stars.

Question 46

The most accurate way to determine the surface temperature of a star is to study

A) the pattern of absorption lines from various atoms.
B) the relative intensities of light measured through different photometric filters.
C) the peak wavelength of the star's continuum blackbody spectrum.
D) pattern of emission lines that are on the star's spectrum.

Question 47

Which stars always have large positive absolute magnitude?

A) Stars of high luminosity.
B) Stars of low luminosity.
C) Nearby stars.
D) Distant stars.
E) Not enough information given.

Question 48

The two stars near one another on the sky,MizarA,are shown.Positions of one member areshown relative to the other star at different times.From plots like this one,astronomers concude that ...

A) the stars are in an elliptical orbit around one another
B) the mass of the pair can be estimated
C) one star is passing by the other never to return
D) both A and B

Question 49

In the list below,the least common stars are

A) upper main sequence stars.
B) white dwarfs.
C) lower main sequence stars.

Question 50

If you compare two stars,

A) the one with the larger radius will always have the greater luminosity.
B) the one with the higher surface temperature will always have the greater luminosity.
C) the one with the smaller absolute magnitude will always have the greater luminosity.
D) the one with the larger surface area has the greater energy flux from its surface.

Question 51

How is a luminosity class assigned to a star?

A) By combining the apparent magnitude with the star's parallax.
B) By measuring the period of variability in the star's apparent magnitude.
C) By studying the absorption lines in the spectrum of the star.
D) By observing the angular size of the star's image in a photograph or digital image.

Question 52

The method of spectroscopic parallax cannot be applied to stars beyond about 100 pc.

Question 53

If a star is twice as hot as the sun and only half the sun's diameter,it will be less luminous than the sun.

Question 54

A star whose parallax is 0.01 seconds of arc is at a distance of 1,000 pc.

Question 55

The location of a star in the HR diagram indicates its temperature and intrinsic brightness.

Question 56

The absolute magnitude of a star is the apparent magnitude it would have if it were 10 pc from Earth.

Question 57

A star's apparent magnitude is a measure of ...

A) how bright it appears to us if it is at its actual distance.
B) how bright it appears to us at a standard distance of 10 pc.
C) its energy output per second compared to the sun.
D) its mass in solar masses.
E) its surface temperature in degrees Kelvin.

Question 58

Lines in the spectra of supergiant stars are broader than the same spectral lines in main sequence stars of the same spectral type.

Question 59

Which one of the methods below enables astronomers to measure the distance of a star near the sun in our galaxy?

A) sound echoes knowing the speed of sound and time
B) parallax using the earth's orbit
C) human binocular vision
D) Balmer series
E) none of the above

Question 60

How do humans use their eyes to measure relative distance by parallax?

A) By continuously focusing our eyes on distant objects we can determine distance.
B) Since our eyes are separated the brain interprets the relative look angles of these eyes in terms of distance to the object viewed.
C) Our eyes can measure the time it takes light to travel from an object and from this we get distance.
D) By moving our heads from side to side our brain compares look angles from each of these positions to obtain the distance to the object viewed.

Question 61

The most common kinds of stars are low-luminosity stars.

Question 62

Stars of spectra type K have strong Balmer lines.

Question 63

The largest of the red stars are the ____________________ stars.

Question 64

Most stars on the H-R diagram are on the ____________________.

Question 65

An M star is hotter than an O star.

Question 66

Supergiants are about as common as the sun.

Question 67

____________________ can be used to determine the distance to a star when the spectrum of the star can be used to determine its spectral type and luminosity class.

Question 68

Hydrogen lines are weak in the spectra of hot stars because many of the hydrogen atoms have their electrons in levels above the second level.

Question 69

Luminosity class IV objects are known as ____________________.

Question 70

A G2 I star is ____________________ in diameter and ____________________ luminous than the sun.

Question 71

White dwarfs have such a low luminosity that even the nearest white dwarfs are not visible to the naked eye.

Question 72

On the HR diagram below,indicate the location of the white dwarf stars.

Question 73

On the H-R diagram,lines of constant radius slants down from left to right.

Question 74

The Lyman series lines of hydrogen all lie in the infrared.

Question 75

The luminosity of a star is the total amount of energy it radiates each second.

Question 76

To observe a spectroscopic binary,we must be able to see both stars individually.