TITLE:   GCN CIRCULAR
NUMBER:  8909
SUBJECT: Swift Trigger 343319 is not a GRB
DATE:    09/02/19 17:06:42 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

D. N. Burrows (PSU), M. M. Chester (PSU), P. A. Evans (U Leicester),
H. A. Krimm (CRESST/GSFC/USRA), V. Mangano (INAF-IASFPA),
J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (NASA/UMBC),
P. Schady (MSSL-UCL), M. Stamatikos (NASA/ORAU), G. Stratta (ASDC),
M. C. Stroh (PSU), G. Tagliaferri (INAF-OAB), E. Troja (INAF-IASFPA)
and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 16:48 UT, Swift lost star tracker lock, leading to a false trigger
due to a misidentification of Cygnus X-1 (trigger #343319). 

This is not a GRB.  Recovery operations are underway. 
There may be further false triggers in the next few minutes.