Black holes are known to exhibit a striking diversity in their size. At the lower end are stellar-mass black holes, typically ranging from about 3 to 150 solar masses (M☉).

In December 2019, researchers at the Zwicky Transient Facility (ZTF) identified the sudden brightening of the nucleus within galaxy SDSS J133519.91+072807.4 (hereafter Ansky).

It is not quite understood why we are able to observe supermassive black holes (SMBHs) early in our universe’s history. Leading theories can be separated into two camps.

Foundational cosmological models of structure formation, based on the growth of density perturbations in the early universe, do not account for the formation of objects as dense as black holes.

The final parsec problem is an astronomical puzzle involving the dynamical evolution of supermassive black holes (SMBHs) at the centres of most galaxies.

Theories about the first black holes suggest they formed shortly after the Big Bang, either as "heavy seeds" born from the direct collapse of massive gas clouds or as smaller "light seeds" from the remnants of early stars

Active Galactic Nuclei (AGNs) represent some of the most energetic phenomena in the cosmos. Their understanding is pivotal for astronomers, as they shed light on the dynamics at play in distant galaxies.

Earlier this year, on the 2nd of February 2022, the Zwicky Transient Facility (ZTF) identified a flash within the optical waveband, with an apparent magnitude of ~20.

For decades, astronomers had been scratching their heads about this mystery: how could objects with masses of thousands of solar masses at birth form so early in the cosmic timeline?