TITLE:   GCN CIRCULAR
NUMBER:  37515
SUBJECT: EP240913a: VLT/HAWK-I near-infrared upper limits
DATE:    24/09/15 14:13:04 GMT
FROM:    Benjamin Schneider at MIT <bschn@mit.edu>

B. Schneider (MIT), Z.P. Zhu (NAOC), A. J. Levan (Radboud), P. D'Avanzo (INAF-OAB), D. Xu (NAOC), D. B. Malesani (Radboud and DAWN/NBI) report on behalf of the Stargate collaboration:

We observed the field of EP240913a detected by Einstein Probe (EP, Li et al., GCN 37492) with the ESO Very Large Telescope, equipped with the HAWK-I near-infrared camera. We obtained 10 min exposure in both the Y and Ks bands, as well as 8 min exposure in J and H. Observations started at 06:54:36 UT on 2024-09-14, i.e. 19.2 hr after the EP trigger.

No new source is detected within the error circle of the proposed X-ray counterpart (Jiang et al., GCN 37497) in any of the four bands. We obtained a 3-sigma limiting magnitude of J ~ 23.7 (Vega), calibrated against nearby sources from the 2MASS catalog.

We acknowledge the excellent support provided by the Paranal staff, in particular Marco Berton and Fuyan Bian.