The distance to the Galactic centre: Globular clusters and SEKBO RR Lyrae survey stars

Evgeny Griv, Michael Gedalin, Ing Guey Jiang

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


One of the long-standing problems in astronomy is the exact distance of the Sun from the Galactic centre, r0. The recent estimates yield the distances within the wide range 7.5-8.9 kpc. We use the maximum likelihood statistical method originally suggested by Rastorguev et al. in the middle of 1990s to derive r0 from the space distribution of halo objects. The latest edition of the Harris catalogue of 157 globular clusters and the Southern Edgewort-Kuiper Belt Object (SEKBO) survey catalogue of 2016 RR Lyrae stars by Keller et al. are exploited. Space distribution modelling of clusters yields r0 = 7.0 ± 0.3 kpc or r0 = 7.3 ± 0.3 kpc, depending on one's assumptions about the object metallicity, the 'Oosterhoff dichotomy'. It is impossible to understand which value of r0 is the most probable. Moreover, such a solar distance is systematically smaller than currently accepted values. A more accurate estimate by using the RR Lyraes leads persuasively to r0 = 8.1 ± 0.2 kpc.

Original languageEnglish
Pages (from-to)218-225
Number of pages8
JournalMonthly Notices of the Royal Astronomical Society
Issue number1
StatePublished - 21 Mar 2019


  • Galaxy
  • Kinematics and dynamics - Galaxy
  • Spiral
  • Structure - galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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