1999/04/12 by F. Yusef‐Zadeh, F. Yusef-Zadeh, D. Choate +2 · 4 citations
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #Mechanics and Biomechanics Studies #astro-ph
paper · pdf · doi:10.1086/312058
11 pages, one figure and one table. ApJL (in press)
arxiv created 1999/04/12 · openalex publication_date 1999/06/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The absolute position of the compact radio source at the dynamical center of the Galaxy, Sgr A^*, was known only to an accuracy of 0.2'' in spite of its accurate location with respect to near-IR stellar sources to within 30 milliarcsecond (mas). To remedy this poor positional accuracy, we have selected 15 high-resolution, high-frequency VLA observations of Sgr A^* carried out in the last 13 years and determined the weighted average position with the average epoch 1992.4 to be at α, δ[1950] = 17\rm h 42\rm m 29\dsec3076±0.0007, -28^∘ 59^′ 18.484±0.014′′, or α, δ [2000] = 17\rm h 45\rm m 40\dsec0383±0.0007, -29^∘ 00^′ 28.069±0.014′′ which agrees with earlier published values to within the 0.2'' error bars of the earlier measurements. An accurate absolute position of Sgr A^* can be useful for its identification with sources at other wavelengths, particularly, in soft and hard X-rays with implications for the models of a massive black hole at the Galactic center.