[vsnet-grb-info 10386] GRB 110328A: a second trigger, probably a hard X-ray transient (Swift J164449.3+573451)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11824
SUBJECT: GRB 110328A: a second trigger, probably a hard X-ray transient (Swift J164449.3+573451)
DATE:    11/03/28 14:33:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at milkyway.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
E. A. Hoversten (PSU), H. A. Krimm (CRESST/GSFC/USRA),
F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester),
K. L. Page (U Leicester), T. Sakamoto (NASA/UMBC),
C. J. Saxton (UCL-MSSL), E. Sonbas (GSFC/USRA/Adiyaman Univ.),
R. L. C. Starling (U Leicester), M. C. Stroh (PSU) and
C. A. Swenson (PSU) report on behalf of the Swift Team:

At 13:40:41 UT, the Swift Burst Alert Telescope (BAT) re-triggered on
what we are tentatively calling GRB 110328A (trigger=450161).  
The BAT on-board calculated location is consistent with the coordinates
reported for GRB 110328A (GCN Circ 11823; Cummings et al). 
Both this trigger and the earlier trigger (450158) were image triggers, 
so the light curves do not show any significant features. The current 
trigger was on the rise to the SAA.  The source is brightening. 

It is quite rare for BAT to trigger a second time on a GRB, so this 
is either an unusually long GRB, GRB 110328A, or a new galactic transient, 
Swift J164449.3+573451.  The galactic coordinates are longitude=86.71, 
latitude=+39.44. 

We note that the XRT was in Windowed Timing mode during the entire 
previous observing window, indicating that the X-ray counterpart 
was quite bright (> 10 cps).  This also suggests either a very 
long-lived GRB or a galactic transient. 

We encourage observations at other wavelengths to help determine 
the nature of this object.