[vsnet-grb-info 9176] Swift Trigger 420256: D50 optical limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10662
SUBJECT: Swift Trigger 420256: D50 optical limits
DATE:    10/04/23 20:04:40 GMT
FROM:    Jan Strobl at AI AS CR,Ondrejov  <jan at strobl.cz>

Jan Strobl (1), Martin Jelinek (2), Cyril Polasek (1), Petr Kubanek (2,3),
Martin Nekola (1), Matus Kocka (1), Michal Jakubec (1) and Rene Hudec (1)
(1. ASU AVCR Ondrejov, 2. IAA Granada, 3. GACE Valencia)

We observed the field of Swift trigger 420256 (Hoversten et al., GCNC 
10654) with the 0.5m telescope D50 in Ondrejov (Czech Republic), starting 
at 02:49:04 UT, i.e. 302s after the trigger. A sequence of 20s unfiltered 
images was obtained. We coadded 15x20s exposure, obtaining an image with a 
limitting magnitude Rc~18.0, with an effective exposure time 539s after 
the trigger. We do not detect any new source in combined or single images.

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