[vsnet-grb-info 21317] GRB 181110A: optical observations from iTelescope SSO

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23416
SUBJECT: GRB 181110A: optical observations from iTelescope SSO
DATE:    18/11/10 12:45:01 GMT
FROM:    Denis Denisenko at SAI MSU  <d.v.denisenko at gmail.com>

D. Denisenko (SAI MSU), M. Gnetov, E. Guskov, M. Orlova, V. Smirnov,
I. Vodolazskiy, N. Zlobin, D. Fernandez Ortiz (Center on Donskaya,
Moscow) report:

GRB 181110A: optical observations from iTelescope SSO

The field of bright long GRB 181110A (Evans et al., GCN Circ. 23413)
was observed remotely from Siding Spring using iTelescope.Net T17
instrument (0.43-m f/6.8 reflector + FLI PL4710 CCD) on 09:49-09:55
UT. Four unfiltered 60-sec exposures were obtained, until the
telescope was occupied by the other scheduled user. The optical
transient is well detected on 4 images and slowly fading, in
accordance with Yamanaka et al., GCN Circ. 23414. The following
magnitudes were measured using the nearby star USNO-B1.0 0531-0876625
as a reference with R2=14.80 in USNO-B1.0:

TIME-OBS, JD T-T0,s  Mag. Error
-------------------------------
2458432.9093  3952  15.60  0.02
2458432.9105  4055  15.64  0.01
2458432.9117  4156  15.68  0.01
2458432.9128  4257  15.77  0.02
-------------------------------

Comparison of T17 iTelescope.Net image and 1990-09-19 DSS Red plate is
uploaded to http://scan.sai.msu.ru/~denis/GRB/GRB181110A-T17-DSS-anim.gif
(FOV 5'x5', 2x zoom).