General Information

    PSR       RA	   DEC	  P0	   P1	  F0	     F1     Age	  Dist  Edot       CODES (see below)
J2333-5526 353.32  -55.44  0.0021   7.7e-21  475.6  -1.74e-15  4.4e9        3.3e34      RUP mbrk

Quick Info


This pulsar was discovered by TRAPUM's Fermi Sources working group using MeerKAT, targeting the optical redback candidate identified by Swihart et al. .

Radio Discovery


Gamma-ray follow-up Discovery


A radio timing solution from PKS + MeerKAT timing + Gaia astrometry results in H=40 gamma-ray detection with a single fold:

Gamma-ray timing


Like most redbacks, J2333-5526 exhibits significant orbital period variability that is making it very hard to time! After some tweaking to F0/F1 from the radio ephemeris, a sliding-window search over TASC/PB/FB1 gives us a timing solution requiring 25 orbital frequency derivatives, more than tempo2 can cope with. The ephemeris expresses the orbital phase evolution as an "ORBIFUNC" interpolation.


Left and right plots: Gamma-ray pulse profile and photon phases versus time. Right plot shows orbital timing solution from light-blue curve in TASC-panel.

Middle plots: Sliding window plots.

SED (Spectral Energy Distribution) from the 4FGL-DR3 catalog:

Derived Parameters


Spin period                       2.10 ms
Observed spin period derivative   7.8e-21 s/s

Characteristic age                4.3e9 yr
Spin-down luminosity              3.3e+34 erg/s
Surface magnetic field            1.3e+08 G

DM distance (YMW16)               0.9 kpc
DM distance (NE2001)              2.5 kpc

Gamma-ray efficiency (YMW16)      0.01
Gamma-ray efficiency (NE2001)     0.08

"4FGL" is the  Incremental Fermi Large Area Telescope Fourth Source Catalog  Abdollahi, S. et al. 2022, ApJS, 260, 53   doi: 10.3847/1538-4365/ac6751  arXiv: 2201.11184     ADS: 2022ApJS..260...53A    

Link to ATNF psrcat   

Pulsar History and Characteristics codes:

'G'    'Discovered in Fermi-LAT gamma-ray data.'

'R'    'Discovered in the radio and/or gamma-ray pulsations detected using the radio ephemeris.'

'X'    'Discovered in the X-ray and/or gamma-ray pulsations detected using the X-ray ephemeris.'

'E'    'Pulsar was detected in gamma rays by EGRET/COMPTEL.'

'P'    'Pulsar was discovered by the Pulsar Search Consortium.'

'U'    'Discovered using a Fermi-LAT seed position.'

'r'    'Pulsations detected in the radio band.'

'x'    'Pulsations detected in the X-ray band.'

'm'    'Millisecond pulsar.'

'b'    'Pulsar is in a binary system.'

'w'    'Pulsar is in a black-widow system.'

'k'    'Pulsar is in a redback system.'

'q'   'Gamma pulsar with no radio detection'




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