GCN Circular 35807

Viraj Karambelkar (Caltech), Danielle Frostig (MIT), Robert Stein
(Caltech), Nathan Lourie (MIT), Geoffrey Mo (MIT), Tomas Ahumada (Caltech),
Robert Simcoe (MIT), Mansi Kasliwal (Caltech)

We observed the location of the X-ray flare EPW20240219aa (Zhang et al.,
ATel #16463; Zhang et al., GCN #35773) in the near-infrared J-band with the
Palomar 1-m telescope, equipped with the 1 square degree WINTER camera
(Lourie et al. 2020).

Our observations started at UTC 2024-02-25T03:24:23, and covered the 3
arcmin localization region of the X-ray flare.  The images were processed
through the WINTER data reduction pipeline implemented using mirar (
https://github.com/winter-telescope/mirar), with image subtraction
performed relative to reference images built from the UKIRT Galactic Plane
Survey (Lucas et al. 2008).


No new sources are detected to a depth of J = 18.5 mag (AB). Of the 7 radio
sources detected by the VLA in this region (Ho et al. GCN #35788), source 6
is detected in both the WINTER and archival UKIRT images, but does not show
significant variability between the two epochs (consistent with that
reported in Ferro et al. GCN #35803).