The galactic center black hole as a possible retro-lens for the S2 orbiting star

Abstract

Holz & Wheeler (\cite{hw}) have recently proposed that a Schwarzschild black hole may act as a retro-lens which, if illuminated by a powerful light source, deflects light ray paths to large bending angles and a series of luminous arcs (or rings in the case of aligned objects) centered on the black hole may form. Obviously, the most convenient geometry to get retro-lensing images would be that of a very bright star close to a massive black hole, say the putative $\sim 4\times 10^6$ M${}_{\odot }$ black hole at the galactic center. Recent observations of the galactic center region in the $K$-band have revealed the presence of a very bright main sequence star (labelled S2) with mass $\sim 15$ M${}_{\odot }$ orbiting at close distance (130-1900 AU) from Sgr A${}^{\ast }$. The relatively vicinity of S2 to the central massive black hole may offer a unique laboratory to test the formation of retro-lensing images. The next generation of space-based telescopes in the $K$-band (like NGST) may have high enough limiting magnitude necessary to observe such retro-lensing images.

4 pages, 2 Postscript figures, accepted for pubblications on Astronomy and Astrophysics

References in corpus (2)

• The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth
• Retro-MACHOs: Pi in the sky?

Cited by in corpus (34)

• Gravitational Lensing by Black Holes
• Stellar Processes Near the Massive Black Hole in the Galactic Center
• Constraints on a charge in the Reissner--Nordström metric for the black hole at the Galactic Center
• Gravitational lensing by Einstein-Born-Infeld black holes
• Strong field limit analysis of gravitational retro-lensing
• Sgr A* and General Relativity
• Gravastar Shadows
• Braneworld black hole gravitational lens: Strong field limit analysis
• Mirages around Kerr black holes and retro-gravitational lenses
• Direct Measurements of Black Hole Charge with Future Astrometrical Missions
• Testing the No-Hair Theorem with Observations of Black Holes in the Electromagnetic Spectrum
• Gravitational Lensing by Black Holes: a comprehensive treatment and the case of the star S2
• Relativistic Images in Randall-Sundrum II Braneworld Lensing
• Retrolensing by a charged black hole
• Lensing By Sgr A* as a Probe of Modified Gravity
• Retrolensing by a wormhole at deflection angles $\pi$ and $3\pi$
• Sgr A${}^{\ast }$: a laboratory to measure the central black hole and cluster parameters
• Retrolensing by two photon spheres of a black-bounce spacetime
• Gravitational Lensing of stars in the central arcsecond of our Galaxy
• Testing the No-Hair Theorem with Observations of Black Holes in the Electromagnetic Spectrum
• Estimating the parameters of the Sgr A* black hole
• Strong Gravitational Lensing by Sgr A*
• The Galactic Center as a laboratory for theories of gravity and dark matter
• Gravitational lensing by using the 0th order of affine perturbation series of the deflection angle of a ray near a photon sphere
• Gravitational lensing of stars orbiting the Massive Black Hole in the Galactic Center
• Gravitational lensing of transient neutrino sources by black holes
• Kerr black holes as retro-MACHOs
• The Scales of Gravitational Lensing
• Implications for the hierarchy problem, inflation and geodesic motion from fiber fabric of spacetime
• Retrolensing by light rays slightly inside and outside of a photon sphere around a Reissner-Nordström naked singularity
• The impact of gravitational lensing in the reconstruction of stellar orbits around Sgr A*
• Stars lensed by the supermassive black hole in the center of the Milky Way: predictions for ELT, TMT, GMT, and JWST
• Gravitational Lensing from a Spacetime Perspective
• Never bet against Einstein