GCN Circular 27754

B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester),
K.L. Page (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo
(INAF-OAB), M.G. Bernardini (INAF-OAB), J. D. Gropp (PSU) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 200517A (Niwano et al. GCN Circ. 27750
Not found
 
 
) in a series of
observations tiled on the sky. The total exposure time is 1.1 ks,
distributed over 7 tiles; the maximum exposure at a single sky location
was 388 s. The data were collected between T0+8.0 ks and T0+8.3 ks, and
are entirely in Photon Counting (PC) mode. 

An uncatalogued X-ray source is detected and is above the RASS limit,
and is therefore likely the GRB afterglow. Using 366 s of PC mode data
and 2 UVOT images, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 17.69837, -50.92242 which is equivalent to:

RA (J2000): 01h 10m 47.61s
Dec(J2000): -50d 55' 20.7"

with an uncertainty of 3.3 arcsec (radius, 90% confidence). This
position is 20.7 arcmin from the MAXI position.  We cannot determine at
the present time whether the source is fading.

The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/xrt_products/TILED_GRB00090/Source1.php.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00090.

This circular is an official product of the Swift-XRT team.