Astronomy A BEGINNER’S GUIDE TO THE UNIVERSE EIGHTH EDITION CHAPTER 13 Neutron Stars and Black Holes Clickers © 2017 Pearson Education, Inc Question Pulsars usually show all of the following EXCEPT a) b) extremely rapid rotation high-temperature fusion reactions c) a narrow regular pulse of radiation d) high-speed motion through the Galaxy e) © 2017 Pearson Education, Inc an intense magnetic field Question Pulsars usually show all of the following EXCEPT a) b) extremely rapid rotation high-temperature fusion reactions c) a narrow regular pulse of radiation d) high-speed motion through the Galaxy e) an intense magnetic field Explanation: Pulsars are neutron stars no longer undergoing fusion in their cores © 2017 Pearson Education, Inc Question Many millisecond pulsars lie within a) b) c) d) e) © 2017 Pearson Education, Inc emission nebulae giant molecular clouds globular clusters planetary nebulae open clusters Question Many millisecond pulsars lie within a) b) c) d) e) emission nebulae giant molecular clouds globular clusters planetary nebulae open clusters Explanation: The cores of globular clusters are densely packed with stars, suggesting that millisecond pulsars might result from “spinning up” as a result of stellar encounters © 2017 Pearson Education, Inc The core of globular cluster 47 Tucanae Question The lighthouse model explains how a) b) c) d) © 2017 Pearson Education, Inc pulsars can be used as interstellar navigation beacons the period of pulsation increases as a neutron star collapses pulsars have their rotation axis pointing toward Earth a rotating neutron star generates an observable beam of light Question The lighthouse model explains how a) b) c) pulsars can be used as interstellar navigation beacons the period of pulsation increases as a neutron star collapses pulsars have their rotation axis pointing toward Earth d) a rotating neutron star generates an observable beam of light © 2017 Pearson Education, Inc Question One possible explanation for a gamma-ray burster is a) b) c) d) e) © 2017 Pearson Education, Inc matter spiraling into a large black hole the collision of neutron stars in a binary system variations in the magnetic fields of a pulsar repeated nova explosions All of the above are possible Question One possible explanation for a gamma-ray burster is a) b) c) d) e) matter spiraling into a large black hole the collision of neutron stars in a binary system variations in the magnetic fields of a pulsar repeated nova explosions All of the above are possible Explanation: Gamma-ray bursts vary in length, and the coalescence of two neutron stars seems to account for short bursts © 2017 Pearson Education, Inc Question Cygnus X-1 is a) b) c) d) e) © 2017 Pearson Education, Inc NASA’s latest X-ray orbiting telescope a millisecond pulsar with three planets the strongest X-ray eclipsing binary system a likely black hole binary star system the first gamma-ray burster spotted in X-rays Question Cygnus X-1 is a) b) c) d) e) NASA’s latest X-ray orbiting telescope a millisecond pulsar with three planets the strongest X-ray eclipsing binary system a likely black hole binary star system the first gamma-ray burster spotted in X-rays Explanation: Cygnus X-1 is an X-ray source with one visible star orbited by an unseen companion of at least 10 solar masses and very rapid changes in the signal indicating a small source © 2017 Pearson Education, Inc Question The force of gravity can pull on a) b) c) d) e) © 2017 Pearson Education, Inc a beam of light a massive object neutrinos antimatter All of the above are correct Question The force of gravity can pull on a) b) c) d) e) a beam of light a massive object neutrinos antimatter All of the above are correct Explanation: Gravity is described by general relativity as a bending of space, and all particles, including photons, move through warped space along curved paths © 2017 Pearson Education, Inc Question If the sun was replaced by a 1-solar-mass black hole, a) b) c) d) e) © 2017 Pearson Education, Inc Earth’s orbit would not change Earth would be pulled into the black hole X-rays would destroy Earth Earth would be torn apart from the tidal force life would be unchanged Question If the sun was replaced by a 1-solar-mass black hole, a) b) c) d) e) Earth’s orbit would not change Earth would be pulled into the black hole X-rays would destroy Earth Earth would be torn apart from the tidal force life would be unchanged Explanation: The force of gravity depends only on mass and distance, not the type of matter or its size © 2017 Pearson Education, Inc Question The event horizon of a black hole a) b) c) d) e) © 2017 Pearson Education, Inc is the point where X-rays emerge is the physical surface of the hole defines the outer edge of an accretion disk is measured by the Schwarzschild radius extends for millions of miles into space Question The event horizon of a black hole a) b) c) d) e) is the point where X-rays emerge is the physical surface of the hole defines the outer edge of an accretion disk is measured by the Schwarzschild radius extends for millions of miles into space Explanation: The event horizon is the surface of an imaginary sphere around a collapsed object inside of which nothing, including light, can escape © 2017 Pearson Education, Inc Question The equivalence between an accelerating windowless elevator in space and a stationary elevator in a gravity field a) b) c) d) e) © 2017 Pearson Education, Inc is a prediction of Newton’s theory of gravity explains why elevators don’t work in space explains why E = mc is true helps explain Einstein’s theory of gravity All of the above are correct Question The equivalence between an accelerating windowless elevator in space and a stationary elevator in a gravity field a) b) c) d) is a prediction of Newton’s theory of gravity explains why elevators don’t work in space explains why E = mc is true helps explain Einstein’s theory of gravity e) All of the above are correct Explanation: Einstein reasoned in his 1915 general theory of relativity that no measurements could distinguish between the two elevators That led to his description of gravity as a bending of space and time © 2017 Pearson Education, Inc ... navigation beacons the period of pulsation increases as a neutron star collapses pulsars have their rotation axis pointing toward Earth d) a rotating neutron star generates an observable beam of light... explains how a) b) c) d) © 2017 Pearson Education, Inc pulsars can be used as interstellar navigation beacons the period of pulsation increases as a neutron star collapses pulsars have their rotation... stars in a binary system variations in the magnetic fields of a pulsar repeated nova explosions All of the above are possible Question One possible explanation for a gamma-ray burster is a)