Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J18022164-3310319

TCP J18022164-3310319   2025 03 24.0555*  18 02 21.64 -33 10 31.9  12.2 U             Sgr       9 0

2025 03 24.0555

The CV=12.2 transient is discovered in three 20s exposure images obtained on 2025-03-24.0555 UT with the NMW survey's wide-field camera (135mm f/2.0 telephoto lens + unfiltered ST-8300M CCD). The transient is also visible in images obtained 23 minutes later on 2025-03-24.0714 with the second NMW camera (135mm f/2.0 telephoto lens + unfiltered STL-11000M CCD) having CV=12.8 +/-0.2. The transient is located near the dark nebula LDN 1762. The latest NMW image of the field obtained on 2025-03-15.081 shows nothing brighter than CV=13 at the transient's location. The latest available ASAS-SN data show no object brighter than g=15 at this location on 2025-03-16.293. The NMW discovery images are available at http://scan.sai.msu.ru/~kirx/img/TCPJ18022164-3310319/ 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 03 23.763

Independent Discovered by Tadashi Kojima, Tsumagoi,Gunma-ken, Japan, on three frames(4_s exp) , mag.= 13.5 2025 Mar 23.7635UT taken by Canon EOS 6D digital camera + 300mm f/2.8 lens. mag=13.5 Nothing is visible at this location taken on 2025 Mar 09.794UT under limiting mag.=14.2 with same instrument,end figures 21s.65,34.0". mag=13.5 on 2025 Mar 23.776UT.

2025 03 24.8337

Follow-up photometry results were B =12.15, V =11.02, Ic =9.28. position end figures 21s.68, 31".8 using 0.20-m f/8 Ritchey-Chretien + CMOS + f/5.4 focal Reducer. An image at URL http://orange.zero.jp/k-yoshimoto/TCP_J18022164-3310319_20250324.jpg object is brightened. observed by K. Yoshimoto, Yamaguchi, Japan.

2025 03 25.713

Position end figures 21s.67, 31.9" measured with Perth Observatory RCOP 0.35m f/6 refractor + CCD. J2000, Gaia DR3 positions. Transient position within 2.62" of Gaia 4042846015583977472 (magnitude 18.04 G). No other source appears closer to the position. Photometry - magnitude 10.62 (V), 11.91 (B), 9.83 (R) and 8.94 (I). Andrew Pearce, Nedlands, Western Australia