TITLE: GCN CIRCULAR NUMBER: 33799 SUBJECT: GRB 230512A: Zwicky Transient Facility non-detection of GRB afterglow candidate DATE: 23/05/14 17:10:39 GMT FROM: Tomas Ahumada at U. of Maryland Tomas Ahumada (CIT), Michael Coughlin (UMN), Igor Andreoni (UMD), Varun Bhalerao (IITB) on behalf of the ZTF collaboration: We analyze the ZTF images containing the afterglow candidate (Belkin et al., GCN Circ. 33796) and no sources were found up to the following limits: UTC observation , t-t0 , filter, upper limit 2023-05-13 06:33:14, 1.003 , r , 21.02 mag 2023-05-13 06:25:09, 0.998 , g , 20.83 mag ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019) and Kowalski (Duev et al. 2019). GROWTH India telescope is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA). GROWTH-India project is supported by SERB and administered by IUSSTF, under grant number IUSSTF/PIRE Program/GROWTH/2015-16 and IUCAA. -- Tomás Ahumada (he/him) Ph.D. Candidate Department of Astronomy University of Maryland, College Park NASA Goddard Space Flight Center, Code 661 B.Sc. Astronomy, Pontificia Universidad Católica de Chile