Radio source Sagittarius A*, which is the best physical marker of the true galactic center, is located at , (J2000). Rounded to the same number of digits as the table, , −29.01° (J2000), there is an offset of about 0.07° from the defined coordinate center, well within the 1958 error estimate of ±0.1°. Due to the Sun's position, which currently lies north of the midplane, and the heliocentric definition adopted by the IAU, the galactic coordinates of Sgr A* are latitude south, longitude . Since as defined the galactic coordinate system does not rotate with time, Sgr A* is actually decreasing in longitude at the rate of galactic rotation at the sun, , approximately 5.7 milliarcseconds per year (see Oort constants).