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6. “Cosmic rays” are particles out in space traveling at 90% of the speed of lig

ID: 289644 • Letter: 6

Question

6. “Cosmic rays” are particles out in space traveling at 90% of the speed of light hit the Earth’s atmosphere often. What type of events, far away, is thought to send these particles flying toward us? A) Supernova explosions B) Secondary rays C) births of stars D) the big bang E) storms on the sun

7.A neutron star is a highly compressed ball of neutrons, about 10-15 miles wide, that is left after certain supernova explosions. If it is spinning fast and flashing a beam periodically in our direction, then what additional one-word name can we give it? A) Pulsar B) black hole C) magnetar D) white dwarf e) lighthouse model

8.What is the limit around a black hole, beyond which no light or information or anything else can escape? A) schwarzchild radius B) roche lobe C) event horizon D) Ergoregion

9.Consider a black hole that is not currently feeding. In the “ergoregions” area just outside the event horizon of a spinning black hole, what does the black hole drag around itself? A) gas and dust B) spacetime C) radiation D) neutrinos

10. In 1920, a great debate was held between Harlow Shapley and Heber Curtis. Which of these two astronomers falsely believed “spiral nebulae” to be small objects inside the Milky Way Galaxy? A) weber curtis B) harlow shapely

Explanation / Answer

6) A supernova explosion

cosmic rays are atoms fragments which rain down from outside solar system. It is caused by the supernovea event which is the explosion of star when it becomes unstable and cannot withstand its own gravity.

7) A  pulsar

As the star's core collapses, its rotation rate increases as a result of conservation of angular momentum, hence newly formed neutron stars rotate at up to several hundred times per second. Some neutron stars emit beams of electromagnetic radiation that make them detectable as pulsars

8)C Event horizon

An event horizon is a boundary in spacetime beyond which events cannot affect an outside observer.The points at which the gravitational pull becomes so great as to make escape impossible, even for light. Event horizon, boundary marking the limits of a black hole.

9) B spacetime

As a black hole rotates, it twists spacetime in the direction of the rotation at a speed that decreases with distance from the event horizon.

10) B harlow shapley

Shapley believed that distant nebulae were relatively small and lay within the outskirts of the Earth's home galaxy