A Possible Glitch of Gamma-Ray Pulsar Geminga?

Timing analyses of gamma-ray pulsar Geminga were made to check its rotating stability using released energetic gamma-ray experiment (EGRET) data. Phase motions of Geminga were found from EGRET data in 1995. Joint analysis of parameters searching and bootstrap testing showed that the parameters are getting worse when including EGRET data in 1995. Combination of these results may indicate that a small glitch of Geminga occured in 1995.