TITLE:   GCN CIRCULAR
NUMBER:  36007
SUBJECT: X-ray transient EP20240331a: MeerLICHT optical upper limits
DATE:    24/04/01 19:41:53 GMT
FROM:    Paul Groot at Radboud University Nijmegen <p.groot@astro.ru.nl>

Paul Groot (Radboud/UCT/SAAO), Peter Jonker (Radboud), Andrew Levan
(Radboud), Danielle Pieterse (Radboud) and Paul Vreeswijk (Radboud)
report on behalf of the MeerLICHT consortium:

The 0.6m MeerLICHT optical telescope, located at Sutherland, South
Africa, observed the error box of EP20240331a (Pan et al.,2024, ATel
#16564) using two of its predefined sky-grid tiles to cover the
reported error box. Observations started on 2024-04-01 18:16UT,
approximately 20 hours after the Einstein Probe detection. The
telescope cycled through the u,q (440-720nm) and i-band filters on
each field alternatingly using 60s integrations per exposure. Data was
processed immediately through the BlackBOX/ZOGY pipeline, running at
the South African Inter-university Institute for Data Intensive
Astronomy (IDIA),

No transient is detected in the full 20'-radius error box region with
respect to the MeerLICHT reference images dating from
2020-02-24. Image-averaged 5-sigma point-source limiting magnitudes
for transients were 20.4 (q-band), 18.7 (u-band) and 19.1 (i-band).

Further analysis will follow.

MeerLICHT is built and run by a consortium consisting of Radboud
University, University of Cape Town, the South African Astronomical
Observatory, the University of Oxford, the University of Manchester and
the University of Amsterdam.