GCN Circular 41992

Subject

GRB 250925A: Optical Observations via Virtual Telescope Project, Italy

Event

GRB 250925A

Date

2025-09-26T00:08:38Z (7 days ago)

From

Gianluca Masi at Virtual Telescope Project <gianluca@bellatrixobservatory.org>

Via

Web form

Gianluca Masi, Virtual Telescope Project (Italy), reports:

We attempted to observe the optical counterpart (Dichiara et al., GCN 41985Loading...
 
 ) of GRB 250925A with the 14” robotic unit available at the Virtual Telescope Project facility in Manciano, Italy, equipped with a KAF-3200E based CCD camera, its QE peaking (90%) in the red part of the spectrum.

We collected 9, 300-second unfiltered exposures, then we averaged them. The central time of the resulting stack was 25 Sept., 23:27 UTC, that is about 6.38 hours after the burst.

We detected a faint object at the following position (J2000.0):

RA: 22 44 51.32
Decl.: +46 33 20.7
R= 21.5 (assuming R-mags from Gaia DR2 for the reference stars).

This position is consistent with Corcoran et al., GCN 41990Loading...
 
  and Bochenek et al., GCN 41991Loading...