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Related papers: Revisiting Stellar Orbits and the Sgr A$^*$ Quadru…

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Measuring the astrometric and spectroscopic data of stars orbiting the central black hole in our galaxy (Sgr A*) offers a promising way to measure relativistic effects. In principle, the "no-hair" theorem can be tested at the Galactic…

Astrophysics of Galaxies · Physics 2026-03-11 K. Abd El Dayem , F. H. Vincent , G. Heissel , T. Paumard , G. Perrin

The spin and quadrupole moment of the supermassive black hole at the Galactic center can in principle be measured via astrometric monitoring of stars orbiting at milliparsec (mpc) distances, allowing tests of general relativistic "no-hair"…

Astrophysics of Galaxies · Physics 2010-05-18 David Merritt , Tal Alexander , Seppo Mikkola , Clifford M. Will

Monitoring the orbits of stars around Sgr A* offers the possibility of detecting the precession of their orbital planes due to frame dragging, of measuring the spin and quadrupole moment of the black hole, and of testing the no-hair…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Dimitrios Psaltis , Gongjie Li , Abraham Loeb

Observations of the precessing orbits of stars very near the massive black hole in the galactic center could provide measurements of the spin and quadrupole moment of the hole and thereby test the no-hair theorem of general relativity.…

General Relativity and Quantum Cosmology · Physics 2011-11-04 Laleh Sadeghian , Clifford M. Will

The no-hair theorem characterizes the fundamental nature of black holes in general relativity. This theorem can be tested observationally by measuring the mass and spin of a black hole as well as its quadrupole moment, which may deviate…

High Energy Astrophysical Phenomena · Physics 2016-08-24 Tim Johannsen

The black hole in the center of the Milky Way, Sgr A*, has the largest mass-to-distance ratio among all known black holes in the Universe. This property makes Sgr A* the optimal target for testing the gravitational no-hair theorem. In the…

High Energy Astrophysical Phenomena · Physics 2016-02-24 Dimitrios Psaltis , Norbert Wex , Michael Kramer

According to the no-hair theorem, all astrophysical black holes are fully described by their masses and spins. This theorem can be tested observationally by measuring (at least) three different multipole moments of the spacetimes of black…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Tim Johannsen , Dimitrios Psaltis

According to the no-hair theorem, astrophysical black holes are uniquely described by their mass and spin. In this paper, we review a new framework for testing the no-hair hypothesis with observations in the electromagnetic spectrum. The…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Tim Johannsen , Dimitrios Psaltis

According to the no-hair theorem, astrophysical black holes are uniquely described by their masses and spins. An observational test of the no-hair theorem can be performed by measuring at least three different multipole moments of the…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Tim Johannsen , Dimitrios Psaltis

According to the no-hair theorem, an astrophysical black hole is uniquely described by only two quantities, the mass and the spin. In this series of papers, we investigate a framework for testing the no-hair theorem with observations of…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Tim Johannsen , Dimitrios Psaltis

According to the general-relativistic no-hair theorem, astrophysical black holes depend only on their masses and spins and are uniquely described by the Kerr metric. Mass and spin are the first two multipole moments of the Kerr spacetime…

High Energy Astrophysical Phenomena · Physics 2016-05-27 Tim Johannsen

One avenue for testing the no-hair theorem is obtained through timing a pulsar orbiting close to a black hole and fitting for quadrupolar effects on the time-of-arrival of pulses. If deviations from the Kerr quadrupole are measured, then…

General Relativity and Quantum Cosmology · Physics 2015-11-09 Pierre Christian , Dimitrios Psaltis , Abraham Loeb

General relativity has been widely tested in weak gravitational fields but still stands largely untested in the strong-field regime. According to the no-hair theorem, black holes in general relativity depend only on their masses and spins…

Astrophysics of Galaxies · Physics 2016-05-25 Tim Johannsen

Recently, a perturbative calculation to the first post-Newtonian order has shown that the analytically worked out Lense-Thirring precession of the orbital angular momentum of a test particle following a circular path around a massive…

General Relativity and Quantum Cosmology · Physics 2025-02-07 Lorenzo Iorio

If a class of stars orbits the central black hole in our galaxy in short period (~ 0.1 year), high eccentricity (~ 0.9) orbits, they will experience precessions of their orbital planes induced by both relativistic frame-dragging and the…

Astrophysics · Physics 2009-11-13 Clifford M. Will

Theoretical investigations have provided proof-of-principle calculations suggesting measurements of stellar or pulsar orbits near the Galactic Center could strongly constrain the properties of the Galactic Center black hole, local matter,…

Astrophysics of Galaxies · Physics 2021-06-22 Hong Qi , Richard O'Shaughnessy , Patrick Brady

We perform an observational test of no-hair theorem using quasi-periodic oscillations within the relativistic precession model. Two well motivated metrics we apply are Kerr-Q and Hartle-Thorne metrics in which the quadrupole is the…

General Relativity and Quantum Cosmology · Physics 2021-10-13 Alireza Allahyari , Lijing Shao

The multipole moments of black holes in general relativity obey certain consistency relations known as the no-hair theorems. The details of this multipolar structure are imprinted into the gravitational waves emitted by binary black holes,…

General Relativity and Quantum Cosmology · Physics 2024-09-11 Nicholas Loutrel , Richard Brito , Andrea Maselli , Paolo Pani

The spins of a number of supermassive and stellar-mass black holes have been measured based on detections of thermal continuum emission and relativistically broadened iron lines in their x-ray spectra. Likewise, quasiperiodic variability…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Tim Johannsen

The discovery of radio pulsars in compact orbits around Sgr A* would allow an unprecedented and detailed investigation of the spacetime of the supermassive black hole. This paper shows that pulsar timing, including that of a single pulsar,…

High Energy Astrophysical Phenomena · Physics 2015-06-03 K. Liu , N. Wex , M. Kramer , J. M. Cordes , T. J. W. Lazio
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