GCN Circular 45021

Subject

EP260623a: Las Cumbres discovery of the optical counterpart

Event

EP260623a

Date

2026-06-23T04:16:44Z (16 days ago)

Edited On

2026-06-23T06:49:50Z (16 days ago)

From

Wenxiong Li at NAOC <liwenxiong1992@gmail.com>

Edited By

Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Wenxiong Li at NAOC <liwenxiong1992@gmail.com>

Via

Web form

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 45020Loading...
 
 ) 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.