GCN Circular 29603

Veli-Pekka Hentunen and Markku Nissinen (Taurus Hill Observatory, Varkaus, 

Finland) report:

 

We have detected GRB 210306A optical afterglow using iTelescope T24 

(0.61-m f/6.5 + CCD) telescope in Sierra Remote Observatory  (Auberry, 

California, USA). The observations were started at 2021-03-06 05:02:41 (UT).

We used Luminance filter and 300 sec exposures. 

 

The afterglow was detected at the position RA 08 39 50.11 DEC +60 12 18.8.  

The following magnitudes were measured from comparison of  a nearby star

(r = 16.974) from Pan-STARRS DR1 catalogue (Chambers et al., 2016):

 

Tmid (h:min:sec)+T0    Mag     Mag_err            

01:11:12                      18.08   0.08

01:16:55                      17.97   0.06

01:22:47                      18.13   0.07

02:06:55                      18.41   0.10

02:14:53                      18.44   0.09

02:18:53                      18.52   0.10

02:24:37                      18.63   0.10

03:03:34                      18.82   0.11

03:09:13                      18.85   0.11

03:20:45                      18.87   0.12

03:26:56                      18.91   0.12

03:32:55                      18.84   0.13

04:33:44                      19.33   0.19

04:39:39                      19.22   0.18

05:03:57                      19.33   0.21

05:27:40                      19.61   0.38

 

Magnitudes were not corrected for galactic extinction.

 

URL link for the L filter 300s image:

https://www.kassiopeia.net/2021/03/06/grb-210306a-havainto/