Telescope catches 'echoes' from 8 invisible monsters

Just like how bats emit sound waves and see objects through reflected waves, NASA's NICER telescope accidentally discovered 8 invisible monsters right in the Milky Way.

According to Sci-News, those are eight stellar-mass black holes, belonging to X-ray binaries, in which the black hole itself is gobbling up material from its red giant companion.

Graphic depicting a stellar-mass "monster" devouring material from its companion and creating "echoes" - frantic mid-meal burps

NICER was originally created to discover another type of cosmic monster - neutron stars, which are a "zombie" form of massive stars that have run out of energy. However, this time it has made a "lifetime" discovery because the stellar-mass black hole is so elusive. Not only are they invisible, but their effects on surrounding objects are often not obvious.

A team led by the MIT Kavli Institute for Astrophysics and Space Research (USA) used an automated search engine they call an "echo catcher" to analyze the NICER data, which is being placed on the International Space Station ISS.

The X-ray "echo" they were trying to capture was the source of the X-rays emitted by the black hole as it "burped" in the middle of its incessant meal. When swallowing matter, black holes often emit jet streams, sending something back into space. In this case, X-ray and reflected gas are included.

By comparing the data they received from the black hole's halo itself and the "echo", which arrived at the telescope not at the same time but at a certain distance, scientists were able to calculate the scale black holes, understand a lot about its properties and activities.

The researchers selected 26 potential pairs and eight black hole "monsters" that resonated the way they expected.