18. Drs. Harden, Petrie, and Rozyczka have found a lone star about 300 light
years away from us, with a mass of about 5 solar masses. They claim to have
discovered a white dwarf. Would you support their discovery?
a) Yes, it sounds perfectly reasonable.
b) No, a 5 solar mass object cannot be a white dwarf
c) No, a white dwarf 300 light years away would be much too faint (and
not visible in the optical anyway) to be seen
d) No, white dwarfs are only found in binary star systems.
19. After additional observations made with an optical telescope,
they recalculate the mass and distance to obtain 2.5 solar masses and 3000
light years. They conclude that it is a neutron star. Would you support
this conclusion?
a) Yes, it sounds perfectly reasonable.
b) No, a 2.5 solar mass object can not be a neutron star
c) No, a neutron star 3000 light years away would be much too faint to be
seen
d) No, neutron stars are only found in binary star systems.
20. After having observed this mystery star for a month, they find that the
first estimate of mass (5 solar masses) and the second estimate of distance
(3000 light years) are correct. They also find that the star's brightness
varies regularly, brightening for a few days, then fading back to its
original brightness. What must this star be?
a) A nova
b) A supernova type I
c) A supernova type II
d) A Cepheid variable