Question 1

When a black hole is part of a close binary star system,the system may be a strong source of X-rays.Where do the X-rays come from?

Accepted Answer

A) The companion star,which is heated by the black hole 
B) A disk of hot matter around the black hole 
C) From the black hole itself 
D) From planets that are captured by the black hole 
A) The companion star,which is heated by the black hole 
B) A disk of hot matter around the black hole 
C) From the black hole itself 
D) From planets that are captured by the black hole B

Question 2

A light curve is a plot showing

Accepted Answer

A) Luminosity versus spectral type 
B) Brightness versus time 
C) Radial velocity versus magnitude 
D) Mass versus luminosity 
A) Luminosity versus spectral type 
B) Brightness versus time 
C) Radial velocity versus magnitude 
D) Mass versus luminosity B

Question 3

Under what conditions is it possible for a white dwarf star to produce a nova outburst?

Accepted Answer

A) If the white dwarf is rotating rapidly 
B) If the white dwarf completely evaporates,producing gamma rays 
C) If the white dwarf accretes matter from a binary companion 
D) If the white dwarf collides with another star 
A) If the white dwarf is rotating rapidly 
B) If the white dwarf completely evaporates,producing gamma rays 
C) If the white dwarf accretes matter from a binary companion 
D) If the white dwarf collides with another star C

Question 4

A type Ia supernova is caused by

Accepted Answer

A) The abrupt consumption of carbon in a white dwarf 
B) The expulsion of the accretion disk of a neutron star 
C) A black hole pulling its binary companion through its event horizon 
D) The collapse of the core of a neutron star in a binary system 
A) The abrupt consumption of carbon in a white dwarf 
B) The expulsion of the accretion disk of a neutron star 
C) A black hole pulling its binary companion through its event horizon 
D) The collapse of the core of a neutron star in a binary system

Question 5

The explosive burning of hydrogen on the surface of a white dwarf produces a

Accepted Answer

A) Supernova 
B) Nova 
C) Pulsar 
D) Splitting of the white dwarf into a binary system 
A) Supernova 
B) Nova 
C) Pulsar 
D) Splitting of the white dwarf into a binary system

Question 6

Gas shed by the companion of a neutron star or black hole normally

Accepted Answer

A) Flows out of the binary system 
B) Falls directly onto the neutron star or black hole 
C) Flows into an accretion disk 
D) Collects above the poles of the neutron star or black hole 
A) Flows out of the binary system 
B) Falls directly onto the neutron star or black hole 
C) Flows into an accretion disk 
D) Collects above the poles of the neutron star or black hole

Question 7

A pulsar will be produced if a neutron star is___________ .

Accepted Answer

A) in isolation,with no binary star companion. 
B) in the proximity of an evaporating binary companion. 
C) formed,regardless of the external conditions. 
D) more than one of the above 
A) in isolation,with no binary star companion. 
B) in the proximity of an evaporating binary companion. 
C) formed,regardless of the external conditions. 
D) more than one of the above

Question 8

Which type of binary star is revealed by changes in the relative directions to the two stars?

Accepted Answer

A) Spectroscopic binaries 
B) Eclipsing binaries 
C) Visual binaries 
D) Common envelope binaries 
A) Spectroscopic binaries 
B) Eclipsing binaries 
C) Visual binaries 
D) Common envelope binaries

Question 9

What kind of objects are thought to be identified with flickering X-ray sources?

Accepted Answer

A) Binary star systems containing black holes 
B) Supernova remnants like the Crab Nebula 
C) Pre-main sequence stars 
D) Main sequence stars on which flares occur 
A) Binary star systems containing black holes 
B) Supernova remnants like the Crab Nebula 
C) Pre-main sequence stars 
D) Main sequence stars on which flares occur

Question 10

A star that is discovered to be a binary system on the basis of the variations in its brightness is called a(n)

Accepted Answer

A) Spectroscopic binary 
B) Astrometric binary 
C) Visual binary 
D) Eclipsing binary 
A) Spectroscopic binary 
B) Astrometric binary 
C) Visual binary 
D) Eclipsing binary

Question 11

Our determination of stellar masses comes from

Accepted Answer

A) Observations of binary stars 
B) The mass luminosity relation 
C) Measurement of stellar colors and use of blackbody radiation 
D) Precise measurements of the diameters of stars 
A) Observations of binary stars 
B) The mass luminosity relation 
C) Measurement of stellar colors and use of blackbody radiation 
D) Precise measurements of the diameters of stars

Question 12

If the mass-losing star in a close binary system is the more massive star,the binary will

Accepted Answer

A) Decrease its separation 
B) Undergo a period of very slow mass exchange 
C) Immediately experience a supernova eruption 
D) Change the orbital plane of the two stars 
A) Decrease its separation 
B) Undergo a period of very slow mass exchange 
C) Immediately experience a supernova eruption 
D) Change the orbital plane of the two stars

Question 13

IN THE TEXT
-L1 refers to

Accepted Answer

A) The spectral type of the fainter star in a binary system 
B) The point through which gas flows from one star to the other 
C) The orbital period of an eclipsing binary 
D) The distance between the two stars in AU 
A) The spectral type of the fainter star in a binary system 
B) The point through which gas flows from one star to the other 
C) The orbital period of an eclipsing binary 
D) The distance between the two stars in AU

Question 14

What property of a star can almost never be determined unless it is a member of a binary star system?

Accepted Answer

A) Distance 
B) Luminosity 
C) Mass 
D) Chemical composition 
A) Distance 
B) Luminosity 
C) Mass 
D) Chemical composition

Question 15

Mass exchange in close binary systems can produce

Accepted Answer

A) X-ray emission from an accretion disk 
B) The formation of planets 
C) T-Tauri stars 
D) Dark markings like sunspots 
A) X-ray emission from an accretion disk 
B) The formation of planets 
C) T-Tauri stars 
D) Dark markings like sunspots

Question 16

What percentage of stars are members of binary or multiple star systems?

Accepted Answer

A) 1% 
B) 10% 
C) 50% 
D) 99% 
A) 1% 
B) 10% 
C) 50% 
D) 99%

Question 17

A visual binary system has an observed period of 5 years and a semi-major axis of 10 AU.What is the sum of the masses of the two stars?

Accepted Answer

A) 10 solar masses 
B) 5 solar masses 
C) 100 solar masses 
D) 40 solar masses 
A) 10 solar masses 
B) 5 solar masses 
C) 100 solar masses 
D) 40 solar masses

Question 18

A nova is produced by an explosion on the surface of a

Accepted Answer

A) Supergiant 
B) White dwarf 
C) Main sequence star 
D) Black hole 
A) Supergiant 
B) White dwarf 
C) Main sequence star 
D) Black hole

Question 19

A nova is produced by an explosion that ___________ .

Accepted Answer

A) only happens once,and results in the destruction of the white dwarf. 
B) can happen many times,and does not destroy the white dwarf. 
C) can only happen when the iron core collapses. 
D) is the end state of a star with eight times the mass of our Sun. 
A) only happens once,and results in the destruction of the white dwarf. 
B) can happen many times,and does not destroy the white dwarf. 
C) can only happen when the iron core collapses. 
D) is the end state of a star with eight times the mass of our Sun.

Question 20

What information about a binary star system is needed in order to calculate the sum of the masses of the two stars?

Accepted Answer

A) Orbital period and separation 
B) Distance and spectral type 
C) Age and temperature 
D) Magnetic field and rotation period 
A) Orbital period and separation 
B) Distance and spectral type 
C) Age and temperature 
D) Magnetic field and rotation period

Exam 21: Binary Star Systems

When a black hole is part of a close binary star system,the system may be a strong source of X-rays.Where do the X-rays come from?

A light curve is a plot showing

Under what conditions is it possible for a white dwarf star to produce a nova outburst?

A type Ia supernova is caused by

The explosive burning of hydrogen on the surface of a white dwarf produces a

Gas shed by the companion of a neutron star or black hole normally

A pulsar will be produced if a neutron star is___________ .

Which type of binary star is revealed by changes in the relative directions to the two stars?

What kind of objects are thought to be identified with flickering X-ray sources?

A star that is discovered to be a binary system on the basis of the variations in its brightness is called a(n)

Our determination of stellar masses comes from

If the mass-losing star in a close binary system is the more massive star,the binary will

IN THE TEXT -L1 refers to

What property of a star can almost never be determined unless it is a member of a binary star system?

Mass exchange in close binary systems can produce

What percentage of stars are members of binary or multiple star systems?

A visual binary system has an observed period of 5 years and a semi-major axis of 10 AU.What is the sum of the masses of the two stars?

A nova is produced by an explosion on the surface of a

A nova is produced by an explosion that ___________ .

What information about a binary star system is needed in order to calculate the sum of the masses of the two stars?

Journeys Start

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