Double Images from a Single Black Hole

TL;DR

This paper demonstrates that octupole distortions of a Schwarzschild black hole can cause a single black hole to appear as two separate shadows or images to a local observer, revealing a novel eyebrow-like structure.

Contribution

It introduces the new finding that single black holes with octupole distortions can produce dual shadows, challenging previous assumptions about multi-black hole systems.

Findings

Single black holes can produce dual images due to octupole distortions.

Eyebrow-like shadow structures can occur in single black hole scenarios.

The dual images are observable as two dark regions in the black hole's shadow.

Abstract

In the simulations of the multi-black holes and merging black holes a larger primary image and a secondary smaller image which looks like an eyebrow and the deformation of the shadows have been observed. However, this kind of eyebrow-like structure was considered as unique feature of multi black hole systems. In this paper, we illustrate the new result that in the case of octupole distortions of a Schwarzschild black hole the local observer sees two shadows or two images for this single black hole, i.e., also an eyebrow-like structure. Presence of two images in our case is remarkable, as we have only one black hole, however, the observer sees two dark images of this single black hole.