On Nov. 8, 2009, Dr. Cai Hongbing and researcher Chen Ding from the “Millisecond Pulsar Timing and Navigation Application” research group had conducted VLBI phase reference observation together with relevant researchers from Urumqi Astronomical Station of National Astronomical Observatories and Shanghai Astronomical Observatory. They have successfully observed the J0953+0755 and J1939+2134 pulsars by making use of 25-dimension radio telescope of Shanghai Astronomical Observatory 3,250 km from Urumqi Astronomical Station.

Among the two pulsars, J1939+2134 is millisecond pulsar with the cycle and change rate of cycle being 1.56ms and 1.051212E-19 respectively; as for J0953+0755, the cycle and change rate of cycle are 0.25s and 2.29758E-16. This is the first VLBI high-accuracy astrometry on millisecond pulsar by domestic telescope in China. The observation adopts wave band and 8MHz-wide base band, and lasts 17 hours. The observation data is under processing currently.

The observation has determined the coordinate position of the two pulsars at celestial sphere and given high-accuracy astrometry parameters. These parameters provide important data support for researches concerning automatic navigation application of pulsars, clock model establishment of millisecond pulsar, reference frame link of solar system and external galaxy, gravity radiation and supernova remnant, etc. and thus have significant application value.