TITLE:   GCN CIRCULAR
NUMBER:  44015
SUBJECT: EP260314a: BOOTES-6/DPR optical upper limits at early times
DATE:    26/03/15 09:27:12 GMT
FROM:    I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg@iaa.es>

I. Pérez-García, E. Fernández-García, M.D. Caballero-García, M. Gritsevich, S. Guziy, R. Sánchez-Ramírez, S.-Y. Wu, and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, South Africa), A. Martín-Carrillo and L. Hanlon (UCD, Ireland), Y.-D. Hu (GXU), D. R. Xiong (Yunnan Observatories of CAS) and C. J. Pérez del Pulgar (UMA, Malaga), on behalf of a larger collaboration, report:

Following the detection of EP260314a by Einstein Probe (Zhao et al., GCNC 44010), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) responded to this event starting on Mar 14, 23:00:01 UT (~ 8.5 min after trigger) with a 10s clear filter image. No new source is detected at the position of the proposed optical counterpart by SVOM/VT (Li et al., GCNC 44013) up to magnitude 16.3 using Gaia DR3 Gmag magnitude as reference on our first image. Further images were gathered and using ATLAS REFCAT2 as reference (Tonry et al. 2018) we get upper limits of: 18.5 (60s clear, at 23:03 UT), 20.9 (300s clear, at 23:06 UT) and 21.7 (600s clear, at 23:18 UT), in agreement with the upper limit reported by LCO (Li et al. GCNC 44009).

We thank the staff at Boyden Observatory for their excellent support.