A numerical study of Galactic Centre stars

Oscar Salcido, Carlos Calcaneo-Roldan*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We present a simulation of the orbits of Galactic Centre stars, also known as 'S-stars', with the purpose of describing the motion of those bodies for which complete orbits are known with greater accuracy. The aim is to have a better understanding of the inner parts of the Galactic potential. The simulation assumes that the spacetime around the central black hole of the Galaxy may be modelled by the Schwarzschild metric, while stellar interactions are approximated classically. We model the central object as a black hole with mass 4.31 × 106 M⊙, fix the Galactic Centre distance at R = 8.33 kpc and include 37 orbiting stars, all of which have masses of 10 M⊙, except for S2, which has a mass of 20 M⊙. Our method allows us to predict the semimajor axis, a; eccentricity, ϵ; and period, T for these stars and predict their periastron shift, δΘ. In particular for S2, the most scrutinized star, we find δΘ = 11.9342 arcmin, in strong agreement with the observed value.

Original languageEnglish
Pages (from-to)2418-2423
Number of pages6
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - 1 Feb 2021

Bibliographical note

Funding Information:
The authors would like to thank Joaquim Stadel for his generous permission to continue using the original version of PKDGRAV. OS acknowledges the support of CONACYT (Consejo Nacional de Ciencia y Tecnologiá) through a grant for postgraduate training. We would also like to thank the reviewer of this paper whose comments have greatly improved our understanding of the problem and have allowed us to present the ideas more clearly. This project was made possible, in part, by a grant from the División de Ciencias Exactas y Naturales of the Universidad de Sonora, grant no: USO315001752.

Publisher Copyright:
© 2021 The Author(s).


  • Galaxy: centre
  • black hole physics
  • methods: numerical
  • stars: kinematics and dynamics


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