Central Bureau for Astronomical Telegrams
CBAT "Transient Object Followup Reports"
TCP J22135399+3015357
TCP J22135399+3015357 2025 08 19.8461* 22 13 53.99 +30 15 35.7 13.6 U Peg 9 0
2025 08 19.8461
The CV=13.6 transient was detected in three dithered wide-field images obtained with the second NMW survey camera (135mm f/2.0 telephoto lens + unfiltered STL-11000M CCD) on 2025-08-19.8461 UTC. The transient is visible in confirmation images obtained 1h40m later on 2025-08-19.9153 with the same camera, having CV=13.8. The photometric uncertainty is about 0.1 mag. Visual inspection of the previous night's images obtained with the same camera on 2025-08-18.8460 reveal the transient having CV=14.4 +/-0.2 - clearly visible, but too faint to trigger our automated transient detection. Nothing brighter than CV~14.8 is visible at the transient position in images obtained with this camera on 2025-08-17.8395. The plate-solved FITS images and finder charts are available at http://scan.sai.msu.ru/~kirx/img/TCPJ22135399+3015357/ 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/ ---- NMW team
2025 08 21.5743
follow-up : mag is, V= +14.56(comparison star, APASS Vmag=+13.565 B-V=0.531), with 0.36m FLI 1001E 30 sec, object star position,RA:22h13m53.69s,DEC:+30o15'42.10",Nayoro Hokkaido Japan, obs by, Yasuo Sano, http://sn1997ef.web.fc2.com/sn/nova/peg_tcpj_20250821.html
2025 08 19.95
The astrometric position of the transient is 22:13:53.70 +30:15:42.0 J2000, derived as weighted average of individual image measurements obtained with three telescopes: 0.6m + FLI ML 3041 CCD (Stara Lesna Obs. AISAS), 0.6m + FLI 16803 CCD (CAS of SAI), 0.2m + ZWO ASI6200MM CMOS camera (Astroverty astrofarm). Multi-color photometry with the two 0.6m telescopes: 2025-08-19.95 V=13.86 U-B=-0.88 B-V=-0.16 V-R=0.01 R-I=-0.02 (CAS of SAI), 2025-08-20.05 V=13.87 U-B=-1.04 B-V=-0.12 V-R=0.08 R-I=0.07 (Stara Lesna), 2025-08-20.05 V=14.19 V-R=-0.06 (Stara Lesna). Preliminary analysis of the time series data confirms the presence of superhump-like modulation reported by Tonny Vanmunster in vsnet-alert 28100. ---- Nikita Dudin (FAST.AU), Stanislav Korotkiy (Astroverty, Ka-Dar), Sergey Shugarov (AISAS/SAI MSU), Kirill Sokolovsky (UIUC), Andrey Tatarnikov (SAI MSU)
