In what sense are the quasars "quasi-stellar"?
A) Their energy production is hydrogen-helium fusion, like main sequence stars.
B) They are upscale versions of O stars, yet hundreds of times more massive.
C) Their luminosity comes from the millions of supergiants that compose them.
D) Their spectra is like that of ordinary stars.
E) In short time exposures, their images looked stellar.
E
You might also like to view...
Part of the current atmosphere of Earth is believed to be
a. the remnants of the original hydrogen and helium gas from the solar nebula attracted by the protoplanet. b. the result of the melting and vaporizing of the glaciers from the last ice age. c. composed primarily of hydrogen and helium. d. composed of gases that were outgassed from the heated rocks sometime after the planet formed. e. the result of a collision between the Sun and another star.
When two pieces of fissionable material are assembled, the average distance that a neutron travels before escaping will
A) decrease. B) increase. C) be the same.
RBMK reactors are inherently safe because their graphite moderator gets smaller with increasing temperature
What will be an ideal response?
An astronaut is piloting a spacecraft, which is in a circular orbit around Earth. A space station is ahead, on the same circular orbit. If he fires his rockets briefly to decrease the forward speed of the rocket, what will happen?
What will be an ideal response?