The Black Star

In 1924, Edwin Hubble proved that there are galaxies beyond the Milky Way. Thus, Wellsian and other early sf was set in a universe comprising only the Milky Way and there was no possibility of intergalactic travel. 

In the 18th century, John Mitchell and Pierre-Simon Laplace considered objects with gravity too great for light to escape.

In 1916, Karl Schwarzschild found a solution of general relativity that characterized black holes.

In 1958:

Poul Anderson's "We Have Fed Our Sea" was published, referring merely to a black star that might be a remnant from a previous cosmic cycle;

David Finlestein interpreted "black hole" as a volume of space from which nothing can escape.

In the 1960s, it was realized that black holes were a prediction of general relativity.

In 1967, Jocelyn Bell Burnell discovered neutron stars.

In 1971, several researchers independently identified Cygnus X-1, the first black hole.

There is a consensus that there is a supermassive black hole at galactic centre.

Sf has to be read in context.