Towards an observational test of black hole versus naked singularity at the galactic center

TL;DR

This paper explores how star motion observations near galactic centers can differentiate between black holes with event horizons and naked singularities, potentially revealing the true nature of these compact objects.

Contribution

It proposes observational methods to distinguish black holes from naked singularities using star orbit data, analyzing recent star motion developments.

Findings

Star motions can indicate the presence or absence of an event horizon.

Fitting star orbit data with theoretical models helps identify the nature of the central object.

Precession of star orbits provides crucial clues about the compact object's characteristics.

Abstract

While the event horizon of a black hole could cast a shadow that was observed recently, a central singularity without horizon could also give rise to such a feature. This leaves us with a question on the nature of the supermassive black holes at the galactic centers, and if they admit an event horizon necessarily. We point out that observations of motion of stars around the galactic center should give a clear idea of the nature of this central supermassive object. We examine and discuss here recent developments that indicate intriguing behavior of the star motions that could possibly distinguish the existence or otherwise of an event horizon at the galactic center. We compare the motion of the S2 star with these theoretical results, fitting the observational data with theory, and it is seen that the star motions and precession of their orbits around the galactic center provide important clues on the nature of this central compact object.