[vsnet-grb-info 23960] GRB 191019A: Nanshan-0.6m optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26059
SUBJECT: GRB 191019A: Nanshan-0.6m optical observations
DATE:    19/10/22 13:58:53 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

Z.P. Zhu, B.Y. Yu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School) 
report:

We observed the field of GRB 191019A (Simpson et al., GCN 26031) using 
the 0.6m NEXT telescope located at Nanshan, Xinjiang, China. 
Observations started at 15:34:01 UT (i.e., 21.5 min after the BAT 
trigger) and ended at 18:22:51 UT on 2019-10-19, and a series of 60 s, 
200 s, 300 s Sloan r-band frames were obtain in a high airmass.

A source is detected in our images at the XRT position (Osborne et al., 
GCN 26043), which is already present in Pan-STARRS with m(r) = 19.12 +/- 
0.01. The source had m(r) = 18.96 +/- 0.10 at the beginning and decayed 
to m(r) = 19.19 +/- 0.10 in about an hour. Because the flux difference 
is small and observations were carried out in high airmass, it's not 
clear if there is a GRB afterglow contribution. Our measurements are in 
agreement with that by NOT (Perley et al., GCN 26039; Fynbo et al., GCN 
26041) and GROND (Guelbenzu et al., GCN 26042).