Question

black holes select an answer and submit. for keyboard navigation, use the up/down arrow keys to select an answer. a cannot be detected because they emit no radiation. b have been detected because infalling matter emits x-rays. c have been detected because they block starlight. your answer d have been detected as pulsing radio sources.

Answer 1

Black hole have been detected because in falling matter emits X-rays.

What is a black hole?

• A black hole is a cosmic object with an incredibly strong gravitational pull, from which nothing—not even light—can escape.
• A huge star's demise can result in the formation of a black hole.
• Such a star's core gravitationally collapses inward onto itself at the end of its existence when its internal thermonuclear fuels run out, destroying the star's outer layers in the process.
• The dying star is compressed to a point with zero volume and infinite density, known as the singularity, by the crushing weight of constituent matter crashing in from all directions.
• The general theory of relativity, developed by Albert Einstein, is used to compute the specifics of a black hole's structure.

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