GCN Circular 29269
I observed the field of GRB 210104A (Troja et al., GCN Circ. 29233) with remote telescope T11 (0.50-m f/6.8 reflector + CCD + f/4.5 focal reducer) of iTelescope.Net in New Mexico Observatory. Three images with AstroDon Luminance filter and with 300 seconds exposure time were obtained on 2021-01-05. Start time of exposures: 06:46:48 UT (~19.3 h. after trigger; Binx1), 06:52:21 UT (Binx2) and 06:57:44 UT (Binx1). I did not detect any optical transients (magnitude limit of about 21.0 in stacked image).