T0 Period [s] Reference
40963.4  3.6146246 +0.0000043 -0.0000043 Kelley et al. (1981) 
42283.2  3.6142 +0.0001 -0.0001 Whitlock et al. (1989) 
43540.951  3.6145737 +0.0000009 -0.0000009 Rappaport et al. (1978) 
44589  3.6146643 +0.0000018 -0.0000018 Ricketts et al. (1981) 
47941.530  3.614690 +0.000002 -0.000002 Tamura et al. (1992) 
49485.5  3.6145107 +0.0000010 -0.0000010 Scott et al. (1994) 
50041.5  3.614499 +0.000003 -0.000003 Finger et al. (1995) 
51221.5  3.614523 +0.00001 -0.00001 Wilson et al. (1999) 
51250  3.614512 +0.000033 -0.000033 Heindl et al. (1999) 
51257  3.6144 +0.0001 -0.0001 Santangelo et al. (1999) 
53260.5  3.614 +0.003 -0.003 Zurita-Heras et al. (2004) 
53266.29  3.616 +0.001 -0.001 Tueller (2004) 

T0 Pdot Reference
40963.4  -2.02x10x10-6 1/yr  Kelley et al. (1981) 
42270  -3.4x10x10-5 1/yr  Whitlock et al. (1989) 
43521.0  -3.2x10x10-5 1/yr  Rappaport et al. (1978) 
Long-term frequency history see, e.g., Bildsten et al. (1997). The period change is given as PDOT/P. Note that the PDOT/P values are not consistent with all derived pulse periods.
Last modification date: Fri Aug 3 01:06:13 2007