TITLE:   GCN CIRCULAR
NUMBER:  24556
SUBJECT: GRB 190515B: Kitab Observatory optical upper limit
DATE:    19/05/15 18:43:38 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Novichonok (KIAM), A. Pozanenko (IKI), E. Mazaeva 
(IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger 
IKI GRB FuN   collaboration:

We observed the field of the Swift GRB 190515B (Moss et al., GCN  24553) 
  with RC-36 0.36-m telescope of Kitab Observatory starting on May  15 
(UT) 16:13:02 in  Clear filter.    We do not find any optical source 
neither in the first image, nor in a stacked image  within prompt 
enhanced Swift-XRT position (Evans  et al., GCN  24554).
Preliminary photometry of the field is following.

Date       UT start   t-T0       Filter Exp.   OT  Err.   UL(3sigma)
                       (mid, days)        (s)

2019-05-15 16:13:02   0.00655    CR     1*90   n/d  n/d       18.6
2019-05-15 16:13:02   0.02686    CR    40*90   n/d  n/d       20.3

The photometry is based on the nearby USNO-B1 (R2) star:
USNO-B1.0_id R2
1422-0205150 15.02

The closest object which is not presented in any catalogs marginally 
detected in our stacked image  has  coordinates   (J2000) 06:35:24.07 
+52:19:12.4 with uncertainty of 1 arcsec in both coordinates and 
brightness of 20.4m (S/N =2). The position of the object is 12 arcsec 
apart from the the center of  prompt enhanced Swift-XRT position (Evans 
et al., GCN  24554). At this time we cannot say about variability of the 
object.

[GCN OPS NOTE(15may19): The GRB anme "190515A" was changed to "190515B"
in the Subject line and in the first sentence.]