Why did scientist conclude that a black hole is the center of the Milky Way

while exploring a cloud of molecular gas located near the center of the Milky Way, in which the gas moved at vastly different speeds. As they studied the cloud, the researchers saw a clump of gas toward the center of the cloud that appeared to be moved around by massive gravitational forces.  

Explanation:

Answer :

"He had a long white beard and bushy eyebrows that stuck out beyond the brim of his hat."

Direct characterization is a technique of introducing a character by directly describing the character. It may not necessarily involve character sketching through his or her actions.

In the lines given above the author is directly describing the character by using images and phrases. So it is an example of direct characterization.