First 43 GHz VLBI detection of the compact source SGR A in the Galactic Center.

The Galactic Center radio source Sgr A^* was detected for the first time with VLBI at 43 GHz. Observations made with four antennas of the Very Long Baseline Array suggest a size of the source exceeding that of a scatter-broadened unresolved object by a factor of 2-3. The data indicate that the structure is elongated along PA. = -25 ± 10°. A first image was made, with an angular resolution of ∼1 mas (corresponding to 8.5 AU at r₀ = 8.5 kpc).