What evidence do we have that the center of our galaxy is a powerful source of energy and a supermassive black hole?
What will be an ideal response?
Astronomers have been able to use large infrared telescopes and adaptive optics to follow the motions of stars orbiting around Sgr A*. The size and period of the orbit allows astronomers to calculate the mass of Sgr A* using Kepler's third law. The orbital period of the star SO-2, for example, is 15.2 years, and the semimajor axis of its orbit is 950 AU. The motions of the observed stars indicate that Sgr A* has a mass of 4 million solar masses. Only a single supermassive black hole could contain so much mass in such a small region.
You might also like to view...
What do astronomers think is the eventual fate of a white dwarf?
What will be an ideal response?
What happens to centripetal force when speed decreases, in the special case that the object continues moving in a circle of the same radius?
a. The force also decreases. b. The force increases. c. The radius cannot stay the same. d. The force sometimes stays the same and sometimes decreases. e. Speed does not affect centripetal force.
If a 500-W heater carries a current of 4.00 A, what is the resistance of the heating element?
a. 85.7 ? b. 42.8 ? c. 31.3 ? d. 11.2 ?
Einstein's theory of relativity tells us that travelers who make a high-speed trip to a distant star and back will
A) age less than people who stay behind on Earth. B) age more than people who stay behind on Earth. C) have more fun than people who stay behind on Earth. D) never be able to make the trip within their lifetimes.