Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J21173148+2225510

TCP J21173148+2225510   2026 07 23.5577*  21 17 31.48 +22 25 51.0  14.8 U             Vul       9 7

2026 07 23.5577

Discovered by Yuji Nakamura, Kameyama, Mie, Japan, on four frames (20-s exp. limiting mag. 16.0) using 0.10-m F3.0 refractor + unfiltered cooled CMOS camera. Nothing is visible at this location on the frames taken on 2026 Jul. 16.5743 UT (20-s exp. limiting mag. 16.0) by same instruments. --- Isao Endoh and Mikiya Sato (NAOJ)

2026 07 22.3838

Pre-discovery photometry with the NMW-TexasTech survey cameras (two identical Rokinon 135mm f/2.0 telephoto lenses + unfiltered QHY600PH-M CMOS): 2026-07-21.3829 >16.1 2026-07-22.3838 15.21 0.11 2026-07-22.3846 15.34 0.13 2026-07-23.3781 15.16 0.13 2026-07-23.4081 15.37 0.13 The dates are UTC. The unfiltered magnitude scale is calibrated against V magnitudes of Tycho-2 stars in the field. ---- Kirill Sokolovsky, Katie Barnhart, Darien Perla, Pragati Acharya, John Worley, Vallia Antoniou, Elias Aydi (Texas Tech University)

2026 07 24.5059

Follow-up photometry results were B =15.76, V =15.25, R =15.12, I =14.55. position end figures 31s.53, 50".7 using 0.3-m f/4 reflector + CMOS. PanSTARRS image, there is a faint star at the same position. observed by K. Yoshimoto, Yamaguchi, Japan (P87).