No bright optical counterpart to the GeV transient Fermi J1623-1752 near U Sco
ATel #14941; Kirill Sokolovsky, Elias Aydi, Vincenzo Donofrio (MSU)
on 29 Sep 2021; 05:01 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)
Subjects: Optical, >GeV, Nova, Transient
Following the report of GeV transient detected by Fermi on
2021-09-28 00:00-06:00 UTC (ATel #14939) we used the 0.6m telescope
of the Michigan State University observatory to search for
a possible optical counterpart of the transient. The unfiltered
images taken between 2021-09-29 00:31-01:03 cover most of
the 0.16deg 95% Fermi error circle down to V~16. The visual
comparison with DSS2 red image revealed no new sources. We obtained
a deeper exposure centered on U Sco finding it at CV=18.6 +/-0.1
(unfiltered observation with V zero-point) on 2021-09-29 00:35,
around its quiescent magnitude.
The stacked image of the Fermi J1623-1752 field may be found here
