Observations of Orbiting Hot Spots around Naked Singularities

TL;DR

This paper explores how hot spots orbiting naked singularities produce distinctive observational signatures, such as multiple image tracks and pronounced peaks, which can help differentiate them from black holes.

Contribution

It introduces new observational features of hot spots around naked singularities, highlighting differences from black hole signatures in imaging and light curves.

Findings

Multiple additional image tracks within critical curves.

More pronounced second-highest peak in temporal magnitudes.

Distinct observational signatures compared to black holes.

Abstract

Recently, it has been reported that photons can traverse naked singularities in the Janis-Newman-Winicour and Born-Infeld spacetimes when these singularities are appropriately regularized. In this paper, we investigate observational signatures of hot spots orbiting these naked singularities, with a focus on discerning them from black holes. In contrast to Schwarzschild black holes, we unveil the presence of multiple additional image tracks within critical curves in time integrated images capturing a complete orbit of hot spots. Moreover, these new images manifest as a more pronounced second-highest peak in temporal magnitudes when observed at low inclinations.