Central Bureau for Astronomical Telegrams
IAUC 6929: SGR 1900+14
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 6930
.dvi or
.ps format.
Circular No. 6929
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
Phone 617-495-7244/7440/7444 (for emergency use only)
SGR 1900+14
K. Hurley, Space Sciences Laboratory, on behalf of the Ulysses
Gamma-Ray Burst Team; C. Kouveliotou, Universities Space Research
Association, on behalf of the Gamma-Ray Observatory BATSE team; and
E. Mazets and T. Cline, on behalf of the KONUS-WIND team, report:
"This soft gamma-ray repeater has entered an extraordinary new
phase of activity with a previously unobserved frequency and
intensity of bursts. Activity began on May 26 and has continued at
least through May 30. Triangulation with Ulysses and BATSE gives a
preliminary annulus whose center is at R.A. = 21h58m18s, Decl. =
-11o18'.4 (equinox 2000.0), and whose radius is 47.269 +/- 0.019
deg. This annulus includes the network synthesis error box (Hurley
et al. 1994, Ap.J. 431, L31), the ROSAT source proposed as a
possible quiescent x-ray counterpart to the soft repeater (Hurley
et al. 1996, Ap.J. 463, L13), and the peculiar double M star system
coincident with the ROSAT source (Vrba et al. 1996, Ap.J. 468, 225).
As all these locations are mutually consistent, we conclude that
the ROSAT source and M star system are indeed the counterparts to
the soft gamma-ray repeater, and urge that observations at other
wavelengths be undertaken immediately, while the source remains
active. An image may be found at
http://ssl.berkeley.edu/ipn3/sgr1900+14/."
C. Kouveliotou, Universities Space Research Association; P.
Woods, M. Kippen, and M. S. Briggs, University of Alabama in
Huntsville; and K. Hurley, Space Sciences Laboratory, write: "On
May 30, BATSE triggered on an extremely intense outburst from this
source that comprised at least 38 bursts of varying intensity and
duration; the series of bursts started at May 30.37759 UT and
lasted for about 350 s. The peak flux of each of the three major
bursts in the series is 1.1 x 10E-4 erg cmE-2 sE-1 (between 25 and
300 keV, integrated for 128 ms). Assuming a distance of about 12
kpc for SGR 1900+14 (Vrba et al. 1996, Ap.J. 468, 225), this
corresponds to a luminosity of about 2 x 10E42 ergs/s for each
burst. This bunching of emission is very similar to the behavior
of SGR 1806-20, as detected with the Rossi X-Ray Timing Explorer in
1996 (IAUC 6503). Overall, between May 26 and June 1, we have
detected over 50 bursts from SGR 1900+14. The frequency and
intensity of emissions are unlike any previously seen behavior from
this source. We strongly encourage follow-up observations at
infrared and radio wavelengths, while the source is still active."
(C) Copyright 1998 CBAT
1998 June 3 (6929) Daniel W. E. Green
Read IAUC 6930
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
