TITLE:   GCN CIRCULAR
NUMBER:  38587
SUBJECT: EP241217a: Gemini-North detection of the likely optical counterpart
DATE:    24/12/17 11:04:54 GMT
FROM:    Andrew Levan at Radboud University <a.levan@astro.ru.nl>

A. J. Levan (Radboud/Warwick), J. C. Rastinejad (Northwestern), D. B. Malesani (DARK/NBI & Radboud), P. G. Jonker (Radboud), J. A. Quirola-Vasquez (Radboud) report for a larger collaboration: 

We obtained observations of EP241217a (Zhou et al., GCN 38586) with the GMOS instrument on the Gemini North telescope. Observations in the z band began at 08:04 UT, approximately 2.5 hr after the EP-WXT detection. 

Within the EP-FXT error circle (Zhou et al., GCN 38586) we clearly identify a new source, not present in the Pan-STARRS imaging of the field, with an approximate magnitude of z ~ 19.9 and a position of

RA(J2000) = 03:07:46.20
DEC(J2000) = +30:55:45.9

with an uncertainty of <0.5". We suggest this is the optical counterpart of EP241217a.

We thank the staff of Gemini for rapidly obtaining these observations.