ECS1501 ASSIGNMENT 6 QUESTIONS AND ACCURATE ANSWERS 2023/2024 NEW UPDATE

ECS1501 ASSIGNMENT 6 QUESTIONS AND ACCURATE ANSWERS 2023/2024 NEW UPDATE You would expect millisecond pulsars to be a) most common in open clusters. b) collapsing rapidly. c) part of a binary system. d) rotating slowly. e) isolated in space. - CORRECT ANSWER ==c) part of a binary system. An observer on a planet sees a spaceship approaching at 0.5c (where c is the speed of light). A beam of light projected by the ship would be measured by this observer to travel at a) 2.5c. b) c. c) 1.5c. d) 0.25c. e) 0.5c. - CORRECT ANSWER ==b) c. For a white dwarf to explode entirely as a Type I supernova, its mass must be a) 3 solar masses, the Schwartzschild limit. b) 20 solar masses, the Hubble limit. c) at least 0.08 solar masses. d) 100 solar masses, the most massive known stars. e) 1.4 solar masses, the Chandrasekhar limit. - CORRECT ANSWER ==e) 1.4 solar masses, the Chandrasekhar limit. What can you conclude about a Type I supernova? a) Its spectrum will show large amounts of hydrogen. b) It was originally a low-mass star. c) The star never reached the Chandrasekhar limit. d) Its core was mostly iron. e) It was originally a high -mass star. - CORRECT ANSWER ==b) It was originally a low- mass star. Which stars in globular clusters are believed to be examples of mergers? a) eclipsing binaries b) planetary nebulae cores c) blue supergiants d) brown dwarfs e) blue stragglers - CORRECT ANSWER ==e) blue stragglers In the Lighthouse Model, a) if the beam sweeps across us, we will detect a pulse of radiation. b) the period of pulsation slows down due to the drag of the remnant on its field. c) all pulsars must have their poles pointed directly toward us. d) the star literally turns on and off like a lighthouse beacon. e) the period of pulsation must speed up as the neutron star continues collapsing. - CORRECT ANSWER ==a) if the beam sweeps across us, we will detect a pulse of radiation. Pulsars a) spin very slowly when they're young, and gradually spin faster as they age. b) are the cause of gamma -ray bursts. c) emit radio in all directions. d) spin very rapidly when they're young. e) generally form from 25 -solar -mass stars. - CORRECT ANSWER ==d) spin very rapidly when they're young. Most pulsars are observed only as sources. a) visible lighthouse b) radio c) gamma -ray burster d) ultraviolet repeating e) X-ray - CORRECT ANSWER ==b) radio A hypernova creates a) a neutron star. b) a black hole. c) millisecond -duration gamma -ray bursts. d) a pulsar. e) Both B and C are correct. - CORRECT ANSWER ==b) a black hole. The mass range for neutron stars is about a) 0.08 to 0.4 solar masses. b) 0.4 to 3 solar masses. c) 6 to 11 solar masses. d) 1 to 3 solar masses. e) 3 to 8 solar masses. - CORRECT ANSWER ==d) 1 to 3 solar masses. X-ray bursters occur in binary star systems. The two types of stars that must be present to make up such an object are a) two neutron stars in a mass transfer binary. b) a white dwarf and a neutron star. c) a contact binary system of two red giants. d) a white dwarf and a main -sequence star.