TITLE:   GCN CIRCULAR
NUMBER:  26876
SUBJECT: GRB 200125A: Swift detection of a burst
DATE:    20/01/25 11:44:25 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Y. Lien (GSFC/UMBC), C. Gronwall (PSU), J.D. Gropp (PSU),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
K. K. Simpson (PSU), A. Tohuvavohu (U Toronto) and
E. Troja (NASA/GSFC/UMCP) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 11:31:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200125A (trigger=952164).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 228.047, -8.148 which is 
   RA(J2000) = 15h 12m 11s
   Dec(J2000) = -08d 08' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of at least 40 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 11:33:30.7 UT, 111.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 228.0471, -8.1436 which is equivalent to:
   RA(J2000)  = 15h 12m 11.30s
   Dec(J2000) = -08d 08' 37.0"
with an uncertainty of 4.9 arcseconds (radius, 90% containment). This
location is 15 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 3.86e-09 erg cm^-2 s^-1 (0.2-10
keV). 

There are no UVOT data available at this time. 

Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)