From the June 2009 issue

If a black hole crossed in front of a background star, could we see the black hole and determine its size?

Jared Collard, Fairfield Glade, Tennessee
By | Published: June 22, 2009 | Last updated on May 18, 2023
black hole
A top-down illustration of a black hole and its surrounding disk.

It is possible to detect and measure a black hole crossing in front of a star, although such alignments would be rare.