No bright optical counterpart to the X-ray transient SRGA J144459.2-604207

ATel #16476; Kirill Sokolovsky (UIUC), Stanislav Korotkiy (Astroverty, Ka-Dar), Rodolfo Zalles (National Astronomical Observatory and Juan Misael Saracho Autonomous University, Tarija, Bolivia)
on 23 Feb 2024; 14:31 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)

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We imaged the field of the newly identified neutron star-hosting low-mass X-ray binary SRGA J144459.2-604207 (ATel #16464, #16469, #16474, #16475) on 2024-02-22.230 UT with a 0.25m wide-field optical telescope located at Tarija, Bolivia. The telescope is equipped with an unfiltered FLI-PL9000 CCD camera. Comparison with the archival DSS2 Red image shows no new optical source brighter than magnitude 15.5 within the 3.5" Swift/XRT error circle (ATel #16471). The magnitude zero-point was set using V magnitudes of APASS stars in the field. An unrelated red irregular variable star IRAS 14409-6029 located 1'12" from the X-ray transient stands out in the DSS image comparison.

The near-infrared source 2MASS 14445957-6042066 suggested as a possible host of the X-ray transient in ATel #16470 is 14" from the XRT position reported in (ATel #16471). Given the high source density in this field, the probability of finding a 2MASS source within the XRT error circle by chance is about 0.3, while multiple 2MASS sources are present within the 10" SRG/ART-XC error circle.

Plate-solved FITS images of the SRGA J144459.2-604207 field