BATSE Pulsar Studies

New Transient Pulsars
Nov 1998: XTE J0111.2-7317 , a new pulsar in the SMC with a period 31 seconds, has been detected by BATSE since October 30. XTE and BATSE observations are reported in IAU Circ. 7048.
Sep 1998: A new source (GRO J 1944+26) with a pulse period of 15.83 s was discovered in the daily FFT search of BATSE 20 - 50 keV data. The source was independently detected by XTE (XTE J1946+274). Both observations are reported in IAU Circ. 7014.

GRO J1944+26 Pulse Profile (2cycles)

The full-sky viewing of BATSE enables the nearly continuous observation of all pulsars brighter than about 15 mCrab. Most of the known accretion - powered x-ray pulsars have periods in 1 - 1000 seconds, so the 1.024 s samples BATSE continually returns in the telemetry can be used to measure the current state of previously known sources, and search for new ones. By detecting the pulse arrival time (which can usually be done to an accuracy of a few percent of the pulse period), we can measure the orbit of the neutron star around the companion, and the rotation period of the neutron star itself.

Overview Hunting for new pulsars BATSE Pulsar Team - Who We Are
Publications Pulse profiles
BATSE Pulsar Monitor

Transient Outburst Summary

 The plot at right summarizes all outbursts of transient pulsed sources seen by BATSE since launch of the CGRO (using optimal analysis techniques and longer observation intervals than 1 day where necessary, not directly obtained from standard daily Monitor).
Transient Outbursts
(last updated Sep 1,1998)

Individual Sources
We search for transient emission from sources listed below. Source frequency and intensity histories,pulse profiles,etc. for sources we have detected are marked by a . Sources marked have been detected, but histories are not presently available online. Search parameters are shown for these and undetected sources):

RX J0059-713 4U0115+634 V 0332+53 GRO J1750-27
Cen X-3 1E 1048-593 1E 2259+586 4U 1626-67
2S 1553-542 GS 0834-430 LMC X-4 2S 1417-624
GRO J1948+32 OAO 1657-415 EXO 2030+375 GRO J1008-57
A0535+262 GX 1+4 GRO J2058+42 Vela X-1
4U 1145-619 1E1145-614 GS 1843+00 GX 301-2
Her X-1 GRO J1744-28 Cep X-4 (GS 2138+56) GRO J1944+26(XTE J1946+274)

What's active now We began on Feb. 1,1997 public distribution of the reports of times of source detection for a set of candidate sources we search for on a daily basis using 1s time resolution data. The purpose is to inform observers at all wavelengths of the current pulse period and approximate source intensity for sources above the detection threshold of about 15 mCrab. The reports will normally be posted twice weekly.

Authors:BATSE Pulsar Team
Responsible Manager:Dr. Thomas A Parnell
Web Curator: Robert B. Wilson