Central Bureau for Astronomical Telegrams
IAUC 7003: SGR 1900+14; N Sgr 1998
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Circular No. 7003
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)
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Phone 617-495-7244/7440/7444 (for emergency use only)
SGR 1900+14
C. Kouveliotou, Universities Space Research Association (USRA)
at Marshall Space Flight Center (MSFC), NASA; T. Strohmayer,
Goddard Space Flight Center (GSFC), NASA; T. Takeshima, USRA at
GSFC; J. H. Swank, GSFC; and P. Woods, University of Alabama in
Huntsville, report on behalf of a larger collaboration: "We have
observed SGR 1900+14 with the RXTE/PCA and RXTE/HEXTE, following
the possible RXTE/ASM detection of this source (Remillard et al.,
IAUC 7002); reactivation of the source has been observed with
BATSE/CGRO. The RXTE observation started on Aug. 28.55 UT and
lasted for 5760 s. We detect a source with average persistent flux
of 6 mCrab, which was strongly pulsed (roughly 23-percent peak-to-
valley amplitude) at 5.16 s (not yet corrected to the barycenter).
During the observation, multiple short-duration bursts were
observed (< 0.125 s), one with intensity above 1.4 Crab. Analysis
of scans carried out to localize the source is hampered by its
variability. While no improvement on the ASM position has been
obtained, the pulse period and the bursts identify the source as
SGR 1900+14, the pulsing burst source observed in June 1998 (IAUC
7001), but with 10 times the persistent flux. No evidence was seen
of the 89.17-s pulse period reported in data of a 1996 obervation
of SGR 1900+14 (IAUC 6882). Additional observations are being
carried out."
C. Kouveliotou, USRA; G. J. Fishman, NASA/MSFC; and P. Woods
and M. Kippen, UAH, communicate on behalf of the BATSE/CGRO team:
"BATSE did not detect the burst of Aug. 27.432148 UT (Cline et al.,
IAUC 7002) due to earth occultation of the source. However, we
have detected a dozen short (about 1-s) bursts starting on about
Aug. 27.4456 UT and continuing to the present. Several of these
bursts have been intense (BATSE did not trigger because the trigger
channels were set to 300-1000 keV). On Aug. 29.4282 UT, BATSE
triggered (no. 7031) on a very intense event with fluence about 7 x
10E-6 erg cmE-2 (25-300 keV); the event lasted roughly 3.5 s and
exhibited two main peaks, after which weak evidence of pulses
during its decay can be seen. We have reset the BATSE trigger
energy channels to 25-100 keV in anticipation of further activity
from SGR 1900+14."
NOVA SAGITTARII 1998
Visual magnitude estimates by K. Hornoch, Lelekovice, Czech
Rep.: July 24.87 UT, 11.6; Aug. 9.87, 11.6; 10.88, 11.7; 25.83,
11.6; 30.81, 11.6.
(C) Copyright 1998 CBAT
1998 August 31 (7003) Daniel W. E. Green
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