Central Bureau for Astronomical Telegrams
IAUC 7110: GRB 990217; SGR 1900+14 = PSR J1907+0919
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Circular No. 7110
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)
GRB 990217
G. Tarei and G. Celidonio, BeppoSAX Science Operation Center,
Telespazio, Rome; J. in 't Zand and H. Muller, Space Research
Organization of the Netherlands, Utrecht; L. Piro and P. Soffitta,
Istituto di Astrofisica Spaziale, CNR, Rome; and M. Orlandini,
Istituto Tecnologie e Studio Radiazioni Extraterrestri, CNR,
Bologna, report: "A gamma-ray burst has been detected
simultaneously by the BeppoSAX Gamma-ray Burst Monitor (GRBM) and
the Wide Field Camera (WFC) no. 2 on Feb. 17.224618 UT. The GRBM
lightcurve is single-peaked with a duration of about 15 s and with
a peak intensity of about 150 counts/s in the energy band 40-700
keV. The WFC lightcurve is also single-peaked, with a peak
intensity of about 0.5 Crab (2-26 keV). The position derived by
the WFC image is R.A. = 3h02m52s, Decl. = -53o05'.6 (equinox
2000.0), with an error radius of 3'. A follow-up observation with
BeppoSAX narrow-field instruments is in progress."
SGR 1900+14 = PSR J1907+0919
Yu. P. Shitov, Pushchino Radio Astronomy Observatory, Astro
Space Center, Lebedev Physical Institute, Moscow, writes: "The
soft-gamma-ray repeater SGR 1900+14 was observed during 1998 Dec.-
1999 Jan. using the Pushchino Bol'shaya Steerable Array (BSA)
radiotelescope (area about 80 000 m**2) and 64x20-kHz filterbank
receiver at 111 MHz. In 14 observation days (BSA transit time is
200 s), we have detected the pulsed radio emission with the same
period (5.161 +/- 0.001 s) that was reported on IAUC 7001. The
width of the integrated pulse profile at half maximum intensity is
about 100 ms. The estimated mean flux density at 111 MHz is about
50 mJy from the best records. The dispersion-measure value was
determined as 281.4 +/- 0.9, which gives an estimate of the
object's distance as about 6 kpc. From our timing analysis of
observations made at the assumed position R.A. = 19h07m14s.2, Decl.
= +9o19'20" (equinox 2000.0; Murakami et al. 1999, Ap.J. 510,
L119), we find the following best-fit parameters: barycentric
period 5.161297854(83) s, period derivative dP/dt = 1.23228(34) x
10E-10 s/s, epoch 1998 Dec. 12.460500 UT (rms timing residuals
about 21 ms). Thus our results show that SGR 1900+14 is identical
with the radio pulsar PSR J1907+0919, representative of a new class
of pulsars with a superstrong magnetic field on the order order of
8 x 10E14 gauss, thereby confirming that this object is a
'magnetar' (Kouveliotou et al. 1999, Ap.J. 510, L115)."
(C) Copyright 1999 CBAT
1999 February 17 (7110) Daniel W. E. Green
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