The Galactic Center: An Improved Astrometric Reference Frame for Stellar Orbits around the Supermassive Black Hole

@article{Sakai2019TheGC,
  title={The Galactic Center: An Improved Astrometric Reference Frame for Stellar Orbits around the Supermassive Black Hole},
  author={Shoko Sakai and Jessica R. Lu and Andrea M. Ghez and Siyao Jia and Tuan Do and Gunther Witzel and Abhimat K. Gautam and Aur{\'e}lien Hees and Eric Edward Becklin and Keith Y. Matthews and Matthew W. Hosek},
  journal={The Astrophysical Journal},
  year={2019}
}
Precision measurements of the stars in short-period orbits around the supermassive black hole at the Galactic Center are now being used to constrain general relativistic effects, such as the gravitational redshift and periapse precession. One of the largest systematic uncertainties in the measured orbits has been errors in the astrometric reference frame, which is derived from seven infrared-bright stars associated with SiO masers that have extremely accurate radio positions, measured in the… 
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