Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 31999

GRB 220430A: Nanshan/NEXT optical upper limit
2022-05-06T04:58:07Z (2 years ago)
Dong Xu at NAOC/CAS <>
S.Q. Jiang (NAOC), Z.P. Zhu (NAOC,HUST), S.Y. Fu, X. Liu, D. Xu (NAOC), 
X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:

We observed the field of GRB 220430A detected by Swift (Ambrosi et al., 
GCN 31972) and AGILE (Ursi et al., GCN 31975) using the NEXT-0.6m 
telescope located at Nanshan, Xinjiang, China. Observations started at 
14:13:38 UT on 2022-04-30 (i.e., 20.39 min after the BAT trigger). We 
obtained 3x40, 6x60, 3x90, 6x200 s frames in the Sloan r-band and 
3x60,3x90,6x200 s frames in Sloan z-band.

No optical source is detected in our stacked image at the XRT enhanced 
position (Osborne et al., GCN 31973), with upper limits as follows

Tmid-T0 (hr) Filter   UpperLimit (3sigma)
    0.953           r         >20.7
    0.923           z         >19.0

calibrated with the nearby PanSTARRS field.
Looking for U.S. government information and services? Visit