Prospects for the Determination of Star Orbits Near the Galactic Center

Abstract

We simulate the observations of proper motion of stars very close to the Galactic Center. We show that the speckle interferometry done with the Keck II telescope is accurate enough to obtain orbital parameters for stars with the period P about 10 y during 10 seasons of astrometric observations made once a year. The determination of a single orbit will give central mass estimate with the typical uncertainty of the existing mass determinations based on velocity dispersion measurements. A much higher precision orbits will be measured in several years when Keck Interferometer becomes operational, and fainter stars are discovered even closer to Sgr A*. Astrometry alone will provide accurate determination of the ratio: M/D^3, where M is the black hole mass and D is the distance to the Galactic Center. If spectroscopic orbits of the stars are also measured then both: M and D will be precisely determined.

13 pages, 5 figures, accepted by ApJ

References in corpus (4)

• High Proper Motion Stars in the Vicinity of Sgr A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy
• The Luminosity Function and Mass Function in the Galactic Bulge
• Near-Infrared Microlensing of Stars by the Super-Massive Black Hole in the Galactic Center
• Sgr A^*: A supermassive black hole or a spatially extended object?

Cited by in corpus (9)

• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• Stellar Processes Near the Massive Black Hole in the Galactic Center
• Improving Galactic Center Astrometry by Reducing the Effects of Geometric Distortion
• The Milky Way's Supermassive Black Hole: How good a case is it? A Challenge for Astrophysics & Philosophy of Science
• Reconstruction of Stellar Orbits Close to Sagittarius A*: Possibilities for Testing General Relativity
• Sgr A${}^{\ast }$: a laboratory to measure the central black hole and cluster parameters
• On Relativistic Corrections to Microlensing Effects: Applications to the Galactic Black Hole
• Observation of S4716 -- a Star with a 4 yr Orbit around Sgr A*
• Pinpointing the massive black hole in the Galactic Center with gravitationally lensed stars