[vsnet-grb-info 25640] Optical transient ZTF20aazpphd is unrelated to GRB 200514B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27740
SUBJECT: Optical transient ZTF20aazpphd is unrelated to GRB 200514B
DATE:    20/05/14 22:45:08 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria at usra.edu>

C. Malacaria (NASA/MSFC-USRA) and E. Burns (GSFC) report on behalf of the Fermi-GBM Team:

At 09:07:37 UT on 14 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) 
triggered and located GRB 200514B (GCN 27736, Fermi-GBM Team). 

Follow-up observations by the Zwicky Transient Facility identified ZTF20aazpphd 
as a potential optical counterpart to GRB 200514B (Ahumada et al., GCN 27737).
ZTF20aazpphd was subsequently observed by ATLAS, 
who found no evidence for rapid decline (Smartt et al., GCN 27738),
contrary to what expected for a short GRB afterglow.

We also verified that, when GBM triggered on GRB 200514B, the source position for 
ZTF20aazpphd as observed by GBM was occulted by Earth and therefore unobservable. 
We therefore conclude that the optical transient ZTF20aazpphd is unrelated to GRB 200514B.