[vsnet-grb-info 7642] GRB 090422: Liverpool Telescope possible candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9197
SUBJECT: GRB 090422: Liverpool Telescope possible candidate
DATE:    09/04/23 00:12:49 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi at fe.infn.it>

C. Guidorzi (U. Ferrara), D. Bersier, C.G. Mundell (Liverpool JMU)
on behalf of a large collaboration report:

Following the distribution of the enhanced Swift-XRT position
(Beardmore et al. GCN Circ. 9194) of GRB 090422 (Ukwatta et al.
GCN Circ. 9185), we re-analysed the data acquired with the
Liverpool Telescope, mentioned in our previous report
(Guidorzi et al. GCN Circ. 9187).

Inside the enhanced XRT error circle we detect a single object
with magnitude of (21.7 +/- 0.3) in the r' filter, from 11 to 43
min post burst, at the following position (J2000):

RA=   19:38:59.91
Decl= +40:23:03.5

with an uncertainty of 0.7 arcsec. The calibration was done with
respect to nearby USNOB-1 stars, using the R2 magnitudes values.
This source is also detected in i' and z' filters.
At the moment we cannot assess whether the object is fading.
The source of r'~19 mag mentioned in our earlier report lies
outside the enhanced XRT error circle.
Further observations are planned.