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 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.