AST 1002
Test 3, Spring 2008
1
QQ Star A has a larger apparent visual magnitude 
than Star B.  Which star has the larger apparent 
brightness in the visual (looks brighter)?
AA S 1 (1) Star B
(2) Star A
(3) [can't tell without more information]
(4) NVA
(5) NVA

2
QQ A star having a bluish color would be most 
likely to have a (B - V) color index that is 
AA S 1 (1) somewhat negative, like -0.4
(2) large, 1.0 or larger
(3) near zero (0.0)
(4) NVA
(5) NVA

3
QQ The Harvard stellar spectral classification, 
in order of decreasing temperature from 
left to right, is:
AA S 1 (1) OBAFGKM
(2) MKGFABO
(3) OMKGFBA
(4) NVA
(5) NVA

4
QQ Which MK luminosity class applies to the 
largest stars of a given Harvard type?
AA 1 (1) I   (2) V   (3) III   (4) NVA  (5) NVA

5
QQ Which kind of binary star system cannot be 
used to determine the masses of the two stars?
AA S 1 (1) astrometric
(2) visual, distance known
(3) eclipsing+double-line spectroscopic
(4) NVA
(5) NVA

6
QQ Which method for finding the distances of stars 
involves determining the target star's absolute 
magnitude from its spectral type (including its 
luminosity class) and relating that to its 
apparent magnitude?
AA S 1 (1) spectroscopic parallax 
(2) trigonometric parallax 
(3) NVA
(4) NVA
(5) NVA

7
QQ The smallest stars (those with the smallest 
radii) are located in the Hertzsprung-Russell 
diagram 
AA S 1 (1) in the lower left region
(2) in the upper right region
(3) along the main sequence
(4) NVA
(5) NVA

8
QQ The main sequence runs from upper left to 
lower right in the Hertzsprung-Russell 
diagram, which is from 
AA S 1 (1) high luminosity and surface 
temperature to low luminosity and surface 
temperature 
(2) high luminosity and low surface temperature 
to low luminosity and high surface temperature 
(3) low luminosity and surface temperature to 
high luminosity and surface temperature
(4) NVA
(5) NVA

9
QQ A star cluster that has a main sequence 
turnoff point very low on the main sequence 
is almost certain to be a/an 
AA S 1 (1) globular cluster
(2) open or galactic cluster
(3) NVA
(4) NVA
(5) NVA

10
QQ Star formation occurs in molecular clouds, 
where the density is high and the temperature 
is low; these conditions cause hydrostatic 
equilibrium to fail so that 
AA S 1 (1) gravity is stronger than pressure 
force and causes the region inside the cloud 
to contract
(2) pressure force is stronger than gravity 
and causes the region inside the cloud to 
expand 
(3) pressure force is stronger than gravity 
and forces the region inside the cloud to 
contract even faster than with gravity alone 
(4) NVA
(5) NVA

11
QQ The kind of pressure which depends only on 
temperature and not on the density of matter 
is 
AA S 1 (1) radiation pressure 
(2) degeneracy pressure 
(3) gas pressure
(4) NVA
(5) NVA

12
QQ The kind of pressure that determines 
whether a low-mass protostar will become a 
star or a brown dwarf (by preventing the 
onset of nuclear fusion) is 
AA S 1 (1) electron degeneracy pressure 
(2) neutron degeneracy pressure 
(3) radiation pressure 
(4) NVA
(5) NVA

13
QQ The fusion process which converts helium 
into carbon at temperatures above 100 
million Kelvins is 
AA S 1 (1) the triple-alpha process 
(2) the CNO or carbon cycle 
(3) the proton-proton chain
(4) NVA
(5) NVA

14
QQ The evolutionary stage at which a star 
like the Sun is converting hydrogen to helium 
in a shell around a helium core (hydrogen 
shell-burning) is the 
AA S 1 (1) red giant stage 
(2) main sequence stage 
(3) horizontal branch stage 
(4) NVA
(5) NVA

15
QQ When a massive star's core has been 
converted to iron by fusion, it has reached 
the point 
AA S 1 (1) of nuclear exhaustion and will 
undergo core collapse and explode as a 
Type II supernova
(2) where it will switch from energy 
generation by fusion to energy generation 
by fusion, breaking down the iron into 
lighter elements 
(3) at which it will undergo a "helium 
flash" and eject a planetary nebula
(4) NVA
(5) NVA

16
QQ Which of the following is not 
associated with a neutron star?
AA S 1 (1) a nova explosion
(2) a pulsar
(3) a "flickering" X-ray source (very 
short timescale)
(4) NVA
(5) NVA

17
QQ The Sun will most likely end up as a 
AA S 1 (1) white dwarf 
(2) neutron star
(3) black hole
(4) NVA
(5) NVA

18
QQ If a white dwarf in a binary system goes 
over the Chandrasekhar mass limit because of 
mass transfer from its companion, it will 
AA S 1 (1) undergo gravitational collapse 
and explode as a Type Ia supernova because 
of carbon detonation
(2) shrink until it becomes stable as a 
neutron star 
(3) undergo an X-ray burst and blow away the 
excess mass
(4) NVA
(5) NVA

19
QQ Synchrotron radiation is produced in 
supernova remnants by 
AA S 1 (1) relativistic (very high energy) 
electrons in a magnetic field 
(2) hot gas
(3) dust particles that have been heated to 
extreme temperatures
(4) NVA
(5) NVA

20
QQ Which kind of binary system best exemplifies 
the Algol paradox?
AA S 1 (1) 4 solar mass main sequence star, 1 
solar mass giant star
(2) 1 solar mass main sequence star, 4 solar 
mass giant star
(3) two white dwarf stars each of 1 solar mass
(4) NVA
(5) NVA

21
QQ Time dilation in connection with black 
holes refers to 
AA S 1 (1) time running slow near the event 
horizon as seen by a distant observer  
(2) time running slow as seen by an observer 
located near the event horizon
(3) time running fast near the event horizon as 
seen by a distant observer
(4) NVA
(5) NVA

22
QQ The Sun's true position in the Milky Way, near the 
outskirts instead of at the center, was established 
by
AA 1 (1) Shapley  (2) Hubble  (3) Baade  (4) NVA  (5) NVA

23
QQ Orbits that are in one direction (galactic rotation) 
and nearly circular are typical of which region of the 
Milky Way?
AA S 1 (1) disk   
(2) central bulge
(3) Halo
(4) NVA
(5) NVA

24
QQ Baade's Population I, the disk population, typically 
has
AA S 1 (1) a high proportion of "metals" and mostly 
young to medium ages
(2) a low proportion of "metals" and old ages
(3) a low proportion of "metals" and young ages
(4) NVA
(5) NVA

25
QQ In which wavelength range is one least able 
to see in to the very center of the Milky Way?
AA S 1 (1) visible
(2) infrared
(3) radio wave
(4) NVA
(5) NVA

26
QQ Which type of "standard candle" is brightest?
AA S 1 (1) Type Ia (white dwarf) supernova
(2) Cepheid variable star
(3) globular cluster (million stars)
(4) NVA
(5) NVA

27
QQ According to the Hubble Law, on average a galaxy's radial 
velocity 
AA S 1 (1) is greater the farther away it is 
(2) is smaller the farther away it is
(3) depends on the Hubble type of the galaxy and not at 
all on its distance
(4) NVA
(5) NVA

28
QQ The correct interpretation of the Hubble Law when the 
Cosmological Principle is considered is that 
AA S 1 (1) the fabric of spacetime is expanding from a 
singularity, carrying galaxies with it
(2) Earth is located at the site of a gigantic explosion 
which blasted galaxies outwards, with the faster ones 
travelling farther
(3) the more massive galaxies have larger radial velocities 
because of the gravitational redshift effect
(4) NVA
(5) NVA

29
QQ The Hubble type of galaxy having Population II stars, 
the smallest percentage of gas and dust, and very little 
star formation at present is the 
AA S 1 (1) elliptical
(2) spiral 
(3) irregular (amorphous type)
(4) NVA
(5) NVA

30
QQ The largest assemblies of ordinary matter in the Universe 
are called 
AA S 1 (1) superclusters 
(2) voids
(3) clusters of galaxies
(4) NVA
(5) NVA

31
QQ The tool used to detect the presence of dark matter in 
clusters of galaxies based on the random motions of the 
member galaxies is 
AA S 1 (1) the virial theorem 
(2) hydrostatic equilibrium given the temperature 
(3) Newton's version of Kepler's Third Law with the 
rotation curve 
(4) NVA
(5) NVA

32
QQ The Friedman cosmological model (no cosmological constant) 
with a mean density that is less than the critical value 
expands more and more slowly 
AA S 1 (1) but never stops expanding and has negative curvature
(2) but never stops expanding and has zero curvature (flat space)
(3) until it stops and then contracts, with positive curvature
(4) NVA
(5) NVA

33
QQ The name that has been associated with 
the cause of the accelerating expansion of the 
Universe is 
AA S 1 (1) dark energy
(2) dark matter 
(3) sympathy
(4) NVA
(5) NVA

34
QQ The mass-luminosity relation for main sequence stars 
implies that the most luminous stars are 
AA S 1 (1) the most massive
(2) the least massive
(3) those having the same mass as the Sun
(4) NVA
(5) NVA

35
QQ Based on the observational data, the X-ray binary 
Cygnus X-1 is the best example we have of 
AA S 1 (1) a stellar black hole 
(2) a supermassive black hole 
(3) a neutron star
(4) NVA
(5) NVA