Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J18033733-2935266

TCP J18033733-2935266   2025 04 11.7783*  18 03 37.33 -29 35 26.6  12.7 U             Sgr       9 5

2024 04 11.965

Position end figures 37s.29, 26.6" measured with Skygems Observatory 0.10m f/5 refractor + CCD, Namibia. J2000, Gaia DR3 positions. Transient position is within 0.17" of Gaia 4050265008973474816 (magnitude 16.35 G). Unfiltered magnitude 12.7. Andrew Pearce, Nedlands, Western Australia

2025 04 11.006

The report prompted visual inspection of the NMW survey's wide-field camera (135mm f/2.0 telephoto lens + unfiltered ST-8300M CCD) images obtained on 2025-04-11.006 UTC, 18.5 h prior to discovery. The images show a faint new source having unfiltered magnitude CV=13.5 +/-0.3 that was not visible in images obtained with the same camera on 2025-04-05.024 (limiting magnitude CV~14). The plate-solved FITS images are available at http://scan.sai.msu.ru/~kirx/img/TCPJ18033733-2935266/ 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/ ---- Stanislav Korotkiy (Astroverty, Ka-Dar), Kirill Sokolovsky, Vladimir Belousov for the NMW team

2025 04 11.778

Discovered by Tadashi Kojima, Tsumagoi,Gunma-ken, Japan, on three frames(6_s exp) under limiting mag.= 13.5 taken by Canon EOS 6D digital camera + 300mm f/2.8 lens. Nothing is visible at this location taken on 2025 Apr 06.777UT under limiting mag.=14.3 with same instrument.

2025 04 11.7453

I proceeded with the reporting process carefully. Tomoo Kato Shimizu Shizuoka Japan. 2025 Apr 11.7453 UT Mag=12.0 U on three frames (8-s exp. limiting mag 13.2) taken by Canon EOS 6D digital camera + 200-mm lens. https://tomo-kato.jp/large_image.php?file=250412-01.jpg at this location on the frames taken on 2025 Apr. 08.7617 UT Mag<12.8 U by same instrument. https://tomo-kato.jp/large_image.php?file=250412-03.jpg 2025 Apr 11.7679 UT Mag=12.4 U Canon Eos 6D digital camera + 400-mm lens. (10s x 3 exp. limiting mag 14.2) https://tomo-kato.jp/large_image.php?file=250412-04.jpg

2025 04 11.778

This object is the same as AT 2025hfm by Transient Name Server (TNS).T Kojima

2025 04 13.3924

Follow-up photometry results were B =14.24, V =12.72, I =10.31. position end figures 37s.28, 26".4 using 0.51-m f/6.8 Corrected Dall-Kirkham + CCD (T72); remotely Deep Sky Chile. position is almost the same as Gaia EDR3 4050265008973474816. observed by K. Yoshimoto, Yamaguchi, Japan.