Back to Main Page
Observation Date (UT) Observation Lat

Canonical Name:PSR B1259-63
TeVCat Name:TeV J1302-638
Other Names:LS 2883, HESS J1302-638
Source Type:Binary
R.A.:13 02 49.3 (hh mm ss)
Dec.:-63 49 53 (dd mm ss)
Gal Long: 304.19 (deg)
Gal Lat: -0.99 (deg)
Distance: 2.7 kpc
Flux:0.07 (Crab Units)
Energy Threshold:380 GeV
Spectral Index:2.81
Discovery Date:2005-10
Discovered By: H.E.S.S.
TeVCat SubCat:Default Catalog

Source Notes:

Source position and its uncertainty:
From Abramowski et al. (2013):
The test region was centred at:
R.A. (J2000): 13 02 48
Dec. (J2000): -63 50 09
No information on positional uncertainty.
From Aharonian et al. (2009):
- R.A. (J2000): 13 02 41 +/- 6s(stat)
- Dec. (J2000): -63 49 01 +/- 41"(stat)
From Aharonian et al. (2005):
- R.A. (J2000): 13 02 49.3 +/- 2.3s(stat)
- Dec. (J2000): -63 49 53 +/- 17"(stat)
- systematic error on pointing is 20"

Binary Period:
From Miller-Jones et al. (2018):
- "Seven such binaries with confirmed high-energy gamma-ray emission
are currently known, but only in two systems is the nature of the
compact object confirmed, via the detection of radio pulsations from
the neutron star (Johnston et al. 1992; Lyne et al. 2015). The most
well-studied of these two systems is PSR B1259−63/LS 2883, comprising
the radio pulsar PSR B1259−63 in a wide, eccentric orbit:
P_orb = 1236.9 days, e = 0.87 (Shannon, Johnston & Manchester 2014)
with the rapidly-rotating, massive, late Oe-type companion star,
LS 2883 (Negueruela et al. 2011)."

Source Notes:
From Chang et al. (2018):
- "The gamma-ray flare events were firstly discovered by Fermi-LAT
around the 2010 periastron passage, which was repeated for 2014 and
2017 periastron passages. We analyzed the Fermi-LAT data for all the
three periastron passages and found that in each flare the energy
spectrum can be well represented by a simple power law. The gamma-ray
light curves show that in 2010 and 2014 after each periastron there
are two main flares, but in 2017 4 flares including one precursor
about 10 days after the periastron passage. The first main flares of
2010 and 2014 are located at around 35 days after the periastron
passage, and the main flare in 2014 was delayed by roughly 1.7 days
with respect to that in 2010. In 2017 flare, the source show precursor
about 10 days after the periastron passage, but the following two
flares become weaker and lag those in 2010 by roughly 5 days. The
strongest flares in 2017 occurred 58 days and 70 days after the
periastron passage. These results bring challenge to previous models."
From Tam et al. (2018):
- "Here we present a detailed analysis of the observational data taken
by the Fermi and Swift observatories over the 2017 September
periastron passage. For the first time, we find short-lived but
powerful GeV flares on time scales of down to three hours. The onset
of the GeV flaring period in 2017 is also delayed compared to those
seen in 2011 and 2014."
From Miller-Jones et al. (2018):
- "We use our measurement of the inclination angle to constrain the
mass of the stellar companion to lie in the range 14.2-29.8 M_Sun. Our
measured distance and proper motion are consistent with the system
having originated in the Cen OB1 association and receiving a modest
natal kick, causing it to have moved approx. 8 pc from its birthplace
over the past approx. 3 x 10e5 years. The orientation of the orbit on
the plane of the sky matches the direction of motion of the X-ray
synchrotron-emitting knot observed by the Chandra X-ray Observatory to
be moving away from the system."
From The Fermi-LAT Collaborations (2017):
- "... we have detected a flare in >100 MeV gamma rays from
PSR B1259-63 over the time interval 2017-11-13 07:12:26 UTC to
2017-11-14 07:36:40 UTC with a significance of approximately 9
sigma. Our likelihood analysis yields a preliminary photon flux (from
100 MeV to 300 GeV) of (2.5 +/- 0.4) x 10^-6 ph/cm^2/s, and a
power-law photon index of 2.7 +/- 0.2, quoted uncertainties throughout
are statistical only."
"In the four days leading up to this most-recent flare, only the
previous day yields a significant detection of approximately 3 sigma
with a flux of (0.8 +/- 0.3) x 10^-6 ph/cm^2/s. The 95%
confidence-level flux upper limits for the three days prior to that
detection are 0.7, 0.6, and 1.0 x 10^-6 ph/cm^2/s, respectively."
"Similar to the recent flare reported in ATels #10924 and #10925,
dividing the time interval into 6-hour bins reveals that the emission
was concentrated in just one out the four 6-hour intervals, from
2017-11-13 13:12:26 to 19:12:26 UTC. The peak flux in this 6-hour bin
is (6.9 +/- 1.2) x 10^-6 ph/cm^2/s, assuming the same photon
index. The other three intervals had 95% confidence-level upper limits
of 2.1, 1.6, and 2.1 x 10^-6 ph/cm^2/s. At a distance of 2.3 kpc, the
peak 6-hour flare corresponds to a gamma-ray luminosity of (1.8 +/-
0.3) x 10^36 erg/s, about twice the spin-down power of the pulsar (8.3
x 10^35 erg/s). This implies that the emission can not be solely
powered by the rotation of the pulsar and/or significant beaming is

The distance quoted in TeVCat was updated from 1.5 kpc to 2.70 kpc on 180425
to reflect the results of Miller-Jones et al. (2018).
From Miller-Jones et al. (2018):
- "Using the Australian Long Baseline Array we have conducted very
long baseline interferometric observations of PSR B1259-63 over 4.4
years, fully sampling the 3.4-year orbital period. Inverting our
measured parallax gives a distance of 2.59 +0.37 -0.28 kpc, which when
modified to account for the Lutz-Kelker bias gives a corrected
distance of 2.70 +0.41 -0.31 kpc. We find that the binary orbit is
viewed at an angle of 153.4 +3.2 -3.0 degrees to the line of sight,
implying that the pulsar moves clockwise around its orbit as viewed on
the sky."

Spectral Properties:
From Abramowski et al. (2013):
- 2010 Data - Spectral index: 2.92 +/- 0.30(stat) +/- 0.20(sys)
- 2004 Data - Spectral index: 2.81 +/- 0.10(stat) +/- 0.20(sys)
From Aharonian et al. (2009):
- 2007 Data - Spectral index: 2.8 +/- 0.2(stat) +/- 0.2(syst)
From Aharonian et al. (2005):
- 2004 Data - Spectral index: 2.7 +/- 0.2(stat) +/- 0.2(sys)

Emission Characteristics:
From Sushch et al. (2013):
- "These new observations partially overlap with the beginning of a
spectacular gamma-ray flare reported by the Fermi-LAT (here too). The
H.E.S.S. observations show both flux and spectral properties similar
to those reported in previous periastron passages, without any
signature of the emission enhancement seen at GeV energies. A careful
statistical study based on the Fermi and H.E.S.S. lightcurves leads to
the conclusion that the GeV and TeV emission during the flare have a
different physical origin."

Seen by: H.E.S.S.
Want a reference added? Send a bibtex entry to the TeVCat Team
Try TevCat 2.0 Beta!