GRB 000416
GCN Circular 635
Subject
X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
Date
2000-04-17T18:36:17Z (25 years ago)
From
SAX Science Operations at IAS/CNR Frascati <saxsci@ias.rm.cnr.it>
On April 16 at 14:32:54 UT a burst was detected in WFC n.2
with a peak flux of about 2 Crab in the 2-26 keV range.
The burst lasted about 25 s.
Preliminary position is:
R.A.= 258.76
Decl.= -71.56
with an error radius of 4'.
We name the source 1SAXJ1715.0-7134.
A marginal detection of the burst in the GRBM (40-700 keV) would lead to
classify the event as an X-Ray rich GRB, although we could not exclude a
type I X-ray burster on the basis of the WFC hardness ratio.
A fast TOO observation was technically feasible but we could not perform
it because of budget reduction of BeppoSAX operations (see GCN n.634)
L. Piro
BeppoSAX Mission Scientist
GCN Circular 638
Subject
GRB000416 BRJK observations
Date
2000-04-18T14:48:46Z (25 years ago)
From
Brad Schaefer at Yale U <schaefer@grb2.physics.yale.edu>
Bradley E. Schaefer (Yale) reports:
"I have taken images of the improved (2' radius) error box for GRB000416
(Gandolfi, BeppoSAX mail 00/08) in the B, R, J, and K bands with the Yale
1-m telescope on Cerro Tololo. Images started at UT 05:18 on 18 April.
At this time, the only comparison is with the Digital Sky Survey, even
though my images go considerably deeper. My images do not show any optical
transient in this comparison. Further observations or radio images might
yet reveal a counterpart."
GCN Circular 639
Subject
BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
Date
2000-04-18T19:02:56Z (25 years ago)
From
R. Marc Kippen at BATSE/UAH/MSFC <marc.kippen@msfc.nasa.gov>
R. M. Kippen (University of Alabama in Huntsville) and P. M. Woods
(Universities Space Research Association) report on behalf of the
CGRO-BATSE team:
The fast x-ray transient (possible gamma-ray burst) 1SAXJ1715.0-7134
observed with BeppoSAX-WFC on April 16.60618 UT (Piro et al., GCN 635)
was detected with BATSE, having significant flux in the 20-100 keV
energy range. The event did not activate the BATSE on-board trigger
system (currently operating in the >100 keV energy range), but was
recorded in continuous data mode with 1.024-s temporal resolution.
Furthermore, the BATSE location is consistent with that of the WFC.
The event consisted of a single weak pulse lasting about 8 seconds.
The peak flux was 0.14 (-/+ 0.04) ph/cm2/s (50-300 keV; 1.024 s), with
a total fluence of 2.9 (-/+ 0.3) E-7 erg/cm2 (>20 keV). The spectrum
is consistent with a single power-law model with photon index -2.7
(-/+ 0.2). About 1% of BATSE gamma-ray bursts have such soft spectra.
If this event is a gamma-ray burst, it ranks in the lower ~2% (10%) of
the BATSE flux/fluence distribution.
This notice is citeable.
-eof-
GCN Circular 640
Subject
GRB000416 Optical Observations
Date
2000-04-20T03:06:20Z (25 years ago)
From
Paul Price at Res. School of Astro.and Astrophysics (Mpap@mso.anu.edu.au <pap@mso.anu.edu.au>
Paul Price, Tim Axelrod and Brian Schmidt report that
we have imaged the error-circle of GRB000416 / 1SAXJ1715.0-7134 with the
50-inch telescope at Mount Stromlo Observatory. Exposure details are:
Date Exp Time Limiting Mag.
April 18.47 3 x 300s R_M ~ 19.5
April 18.70 6 x 300s R_M ~ 20.7
where R_M refers to the MACHO red passband.
We see no new variable candidates within the error circle, either from
comparison of both epochs with the DSS, or from subtraction of the two
epochs.