@article{12221,
  keywords = {Space and Planetary Science, Astronomy and Astrophysics},
  author = {R. Abuter and A. Amorim and M. Bauböck and J. Berger and H. Bonnet and W. Brandner and Y. Clenet and Coudé Foresto and P. de Zeeuw and Jason Dexter and G. Duvert and A. Eckart and F. Eisenhauer and N. Schreiber and P. Garcia and F. Gao and E. Gendron and R. Genzel and O. Gerhard and S. Gillessen and M. Habibi and X. Haubois and T. Henning and S. Hippler and M. Horrobin and Alejandra Jimenez-Rosales and L. Jocou and P. Kervella and S. Lacour and V. Lapeyrère and J.-B. Le Bouquin and P. Léna and T. Ott and T. Paumard and K. Perraut and G. Perrin and O. Pfuhl and S. Rabien and Rodriguez Coira and G. Rousset and S. Scheithauer and A. Sternberg and O. Straub and C. Straubmeier and E. Sturm and L. Tacconi and F. Vincent and S. von Fellenberg and I. Waisberg and F. Widmann and E. Wieprecht and E. Wiezorrek and J. Woillez and S. Yazici},
  title = {A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty},
  abstract = {We present a 0.16% precise and 0.27% accurate determination of R-0, the distance to the Galactic center. Our measurement uses the star S2 on its 16-year orbit around the massive black hole Sgr A* that we followed astrometrically and spectroscopically for 27 years. Since 2017, we added near-infrared interferometry with the VLTI beam combiner GRAVITY, yielding a direct measurement of the separation vector between S2 and Sgr A* with an accuracy as good as 20 mu as in the best cases. S2 passed the pericenter of its highly eccentric orbit in May 2018, and we followed the passage with dense sampling throughout the year. Together with our spectroscopy, in the best cases with an error of 7 km s(-1), this yields a geometric distance estimate of R-0 = 8178 +/- 13(stat.) +/- 22(sys.) pc. This work updates our previous publication, in which we reported the first detection of the gravitational redshift in the S2 data. The redshift term is now detected with a significance level of 20 sigma with f(redshift) = 1.04 +/- 0.05.},
  year = {2019},
  journal = {Astronomy & Astrophysics},
  volume = {625},
  pages = {L10},
  month = {2020-05},
  publisher = {EDP Sciences},
  issn = {0004-6361, 1432-0746},
  doi = {10.1051/0004-6361/201935656},
}