Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J18385851-0351482

TCP J18385851-0351482   2025 07 17.9085*  18 38 58.51 -03 51 48.2  12.0 U             Ser       9 0

2025 07 17.9085

The CV=12.0 transient was found in wide-field images obtained with the NMW camera (135mm f/2.0 telephoto lens + unfiltered STL-8300M CCD) on 2025-07-17.9085 UTC. Nothing brighter than CV~14 is visible at this position in the previous NMW image obtained on 2025-07-15.8055. The plate-solved FITS images and finder charts are available at http://scan.sai.msu.ru/~kirx/img/TCPJ18385851-0351482/ The NMW survey is operating at the Astroverty astrofarm in Nizhnii Arkhyz, Karachay-Cherkessia, Russia http://scan.sai.msu.ru/nmw/ https://astrovert.ru/astrofarm/ ---- Kirill Sokolovsky, Stanislav Korotkiy (Astroverty, Ka-Dar), Vladimir Belousov for the NMW team

2025 07 15.9858

ASAS-SN forced photometry at the transient position reveals pre-discovery detections: 2025-07-12.1743 g>15.94 2025-07-15.9858 g=15.79 2025-07-17.0089 g=14.64. ASAS-SN data: https://asas-sn.osu.edu/sky-patrol/coordinate/92cc936b-a1d4-4b82-8abb-a41ac8099501 ZTF has detected a transient ZTF25abbsdyb at 18:38:58.47 -03:51:49.5 (1.4" from the NMW position, well within the NMW astrometric uncertainty). ZTF photometry: 2025-07-17.2329 g=14.41 accessed via Lasair broker https://lasair-ztf.lsst.ac.uk/objects/ZTF25abbsdyb/ ---- Kirill Sokolovsky

2025 07 18.0044

The transient was also detected with the second NMW camera (135mm f/2.0 telephoto lens + unfiltered STL-11000M CCD) having CV=12.1 on 2025-07-18.0044 UTC. ---- Stanislav Korotkiy (Astroverty, Ka-Dar), Kirill Sokolovsky, Vladimir Belousov for the NMW team

2025 07 19.0776

Position end figures 58s.47, 49.2" measured with Skygems Observatory 0.45m f/4 reflector + CCD, Namibia. J2000, Gaia DR3 positions. No obvious progenitor within 4.5" of transient position. Unfiltered magnitude 12.0. Andrew Pearce, Nedlands, Western Australia