A supernova is almost always associated with
a. a very massive star.
b. a very young star.
c. a star undergoing helium flash.
d. a white dwarf in a close binary system.
e. a solar-like star that has exhausted its hydrogen and helium.
Question 2If a quasar has a recessional velocity of 2.7 105 km/s and is determined to be 3600 Mpc, what is the Hubble constant based on this quasar alone? Hint: Note that the units of your result should be (km/s)/Mpc to see what arithmetic process you need to perform.
a. 50 km/s/Mpc
b. 9.7 108 (km/s)Mpc
c. 75 km/s/Mpc
d. 0.013 km/s/Mpc
e. 273,600 km/s/Mpc
Question 3Synchrotron radiation is produced by
a. objects with temperature below 10,000 K.
b. high-velocity electrons moving through a magnetic field.
c. cold hydrogen atoms in space.
d. the collapsing cores of massive stars.
e. a helium flash.
Question 4If Hubble's constant is taken to be 70 km/s/Mpc, and a quasar is found with a radial velocity of 0.95 times the speed of light, how far away is the quasar?
a. 4100 Mpc
b. 0.014 Mpc
c. 67 Mpc
d. 74 Mpc
e. 300,000 Mpc
Question 5The theory that the collapse of a massive star's iron core produces neutrinos was supported by
a. the size and structure of the Crab nebula.
b. laboratory measurements of the mass of the neutrino.
c. the brightening of supernovae a few days after they are first visible.
d. underground counts from solar neutrinos.
e. the detection of neutrinos from the supernova of 1987.
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