GCN 45021: EP260623a: Las Cumbres discovery of the optical counterpart

Wenxiong Li, Runduo Liang (NAOC), Iair Arcavi, Ido Keinan (TAU), David Sand (U of Arizona)

We observed the position of EP260623a (Wang et al. GCN 45020) with a Las Cumbres 1m telescope at Teide Observatory, Tenerife, 8 mins after the Einstein Probe WXT trigger. We took 2x300s exposures in the broad optical w-band.
We find an uncataloged source at RA=328.2698, Dec=12.7939 within the EP-FXT error circle and measure the following preliminary photometry calibrated to the r band: 
MJD 61214.12687 Mag 16.54 +- 0.01
MJD 61214.13064 Mag 15.62 +- 0.01
This target brightened by ~0.9 mag within 6 minutes.


The presented magnitudes are calibrated with Pan-STARRS sources in the field and not corrected for Galactic extinction. Additional follow-up is encouraged.