Research on the Proper Motion in CSO OQ208

The compact symmetric object (CSO)OQ208 was observed with Very Long Baseline Array (VLBA)at 5GHz and 8GHz bands.The obtained total intensity images show that OQ208 consists of a southwestern and a northeast structures.Both of them are resolved into two components at 5GHz, while one more component is detected in the northeast region at 8GHz band.Analyzing images at 5GHz band taken in 5 epochs from 1993 to 2001, an estimate of separation velocity 0.037±0.006mas/a(year) is derived as the relative motions of components A and D.Moreover, on the basis of the images in 9 epochs from 1994 to 2002, the proper motion 0.0 4 6±0.009mas/a of component C moving away from component A at 8GHz band is also found.