Horizon-scale images of black holes (BHs) and their shadows have opened an
unprecedented window onto tests of gravity and fundamental physics in the strong-field …

In this work, we obtain the shadow images of spherically symmetric scalar boson and Proca
stars using analytical fittings of numerical solutions, when illuminated by a geometrically thin …

The optical appearance of a body compact enough to feature an unstable bound orbit, when
surrounded by an accretion disk, is expected to be dominated by a luminous ring of radiation …

The imaging by the Event Horizon Telescope (EHT) of the supermassive central objects at
the heart of the M87 and Milky Way (Sgr A⋆) galaxies, has marked the first step into peering …

Black bounces are spacetimes that can describe, depending on certain parameters, black
holes or wormholes. In this work, we use a method to obtain the matter content that …

Higher-order photon rings can be expected to be detected in a more detailed image of the
black hole found in future observations. These rings are lensed images of the luminous …

This study focuses on investigating a regular black hole within the framework of Verlinde's
emergent gravity. In particular, we explore the main aspects of the modified Simpson–Visser …

We study the dynamics and oscillations of electrically charged particles along stable circular
orbits around a nonrotating electrically charged spacetime. In this work, we consider a …

We study gravitational lensing of light by hairy black holes, which, in a certain parameter
regime, can possess two photon spheres of different size outside the event horizon. In …

Photon spheres play a pivotal role in the imaging of luminous objects near black holes. In
this paper, we examine observational appearances of a star freely falling in hairy black …