TITLE:   GCN CIRCULAR
NUMBER:  32649
SUBJECT: Swift J1913.1+1946: Early Optical Photometry
DATE:    22/10/10 10:13:16 GMT
FROM:    Mohammad Odeh at Al Khatim Observatory M44  <mshodeh@gmail.com>

Following the detection of the bright hard X-ray and optical transient
Swift J1913.1+1946 (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634),
photometric observations were obtained using a 0.36 meter SCT telescope
equipped with a ASI2600MM Pro CCD camera and photometric infrared filter
(Ic).

The observations started at 15:30:59 UT on 09 October 2022 and ended at
18:05:46 UT the same day. In the beginning, the magnitude of the transient
was 15.5, then it faded at 15:49:49 UT to 15.6, and gain it faded at
17:14:13 UT to 15.9:

Twelve 180 s exposures were taken during the period, with the following
details:

JD                   Mag                 MagErr
2459862.148 15.495154      0.11745
2459862.154 15.489504      0.075239
2459862.161 15.669481      0.056841
2459862.168 15.669936      0.055772
2459862.219 15.883595      0.047614
2459862.221 15.910906      0.044903
2459862.223 15.875109      0.049559
2459862.226 15.872771      0.048612
2459862.249 15.927693      0.057741
2459862.251 15.873584      0.051357
2459862.253 15.904383      0.051412
2459862.255 15.89597        0.055238