It’s amazing how much astronomers and astrophysicists are learning about the cosmos each and every day – with the newest and best powerful technology, it’s an exciting time to be in the field.

Now, researchers say they’ve detected a new class of black holes that are defined by the fact that they are too large to be born from normal stars, but too small to anchor galaxies.

Astrophysicist Krystal Ruiz-Rocha says these new black holes were observed using gravitational-wave detectors LIGO and Virgo, and are 100-300 times the mass of the sun.

LIGO and Virgo help scientists compute the masses and spins of colliding objects by registering ripples in spacetime that last less than half a second.

Most known black holes are either below 50 solar masses or are millions of solar masses, with very few falling in between. A black hole’s mass preserves clues about how the first heavy stars lived and died, so researchers are keen to be able to study more of them.

These intermediate black holes are hard to find because their signals fall into the low-frequency range, and ground-based detectors struggle with noise interference.

In 2019-2020, the network hit a jackpot.

Lead scientists at Vanderbilt’s Lunar Labs Initiative, Karan Jani and his team used a Bayesian code named RIFT to test each event with three waveform families and find five mergers between 110 and 350 solar masses.

These findings suggest that repeated mergers in dense clusters can sidestep the supernova ceiling. This is when smaller black holes build larger ones inside young star clusters, which leads to high escape speeds and plenty of fresh companions. This points to stacking predicting spins that point opposite the orbital motion, which strengthens the case for a dynamical origin.

Post-doctoral fellow Anjali Yelikar, as well as other research teams, are excited for NASA and ESA to launch their Laser Interferometer Space antenna in the mid-2030s, as it will be able to measure low-frequency waves not accessible on the ground.

“Access to lower frequencies from the lunar surface could allow us to identify the environments these black holes live in.”

These intermediate black holes could be the missing link between the well-known populations of stellar and supermassive black holes, and in turn help astrophysicists refine their models for galaxy growth and the history of the universe’s matter.

Some think these intermediate black holes could grow into the type of supermassive black holes that anchor galaxies, but others posit they could be relics from the first generation of stars.

Researchers are after those clues to the origins of the galaxies that formed the universe as we know it.

Every step forward in understanding black holes is one step closer to that all-important knowledge.

If you thought that was interesting, you might like to read about a second giant hole has opened up on the sun’s surface. Here’s what it means.