Precise Interplanetary Network Localization of the Bursting Pulsar GRO J1744–28

We analyze 426 observations of the bursting pulsar GRO J1744-28 by Ulysses and BATSE. Triangulating each burst and statistically combining the triangulation annuli, we obtain a 3 σ error ellipse whose area is 532 arcsec2. The accuracy of this statistical method has been independently verified with observations of the soft gamma repeater SGR 1900+14. The ellipse is fully contained within the 1' radius ASCA error circle of the soft X-ray counterpart and partially overlaps the 10′′ radius ROSAT error circle of a source which may also be the soft X-ray counterpart. A variable source which has been proposed as a possible IR counterpart lies at the edge of the 3 σ error ellipse, making it unlikely from a purely statistical point of view to be associated with the bursting pulsar.