Subject: Nova TCP J18385851-0351482
Date: 2025-07-21 10:15:00 UTC
From: Roger Hellot at AITP Observatory-San-Pedro-Atacama-Chili roger.hellot.astro@gmail.com
We observed the field of the optical transient TCP J18385851-0351482 found by the New Milky Way Survey (Sokolovsky, Korotkiy & Lebedev 2014, ASPC, 490, 395) at unfiltered magnitude 12 on 2025-07-17.9085 UTC, mentioned in the Astronomer’s Telegram n° 17292 from 21 Jul 2025; 11:21 UT.
TCP J18385851-0351482 was observed from 2025-07-21 07:11:28 UTC to 07:28:39 UTC with the 0.432m telescope at the AITP Observatory at SpacObs in San Pedro de Atacama in Chili, using a QHY268M CMOS camera. Respectively 6 pictures, with exposure time of 60 sec, were made through Sloan-g, Sloan-r and Sloan-i filters. Each set of 6 pictures has been calibrated with Tycho-Tracker and stacked in a median sum with AstroimageJ.
The 3 stacked frames have been uploaded to STDWeb, the web-based tool for photometry and transient detection in astronomical images, based on STDPipe library and developed by Sergey Karpov (Karpov, S. (2025). STDweb: simple transient detection pipeline for the web. Acta Polytechnica, 65(1), 50-64. STDweb: simple transient detection pipeline for the web | Acta Polytechnica) and hosted by the Observatoire de Bretagne Sud, 56390 Grand Champ and privately funded by Pierre-Yves Lechapelain.
The images were calibrated using the reference catalogue Pan-STARRS DR1.
Preliminary results are in the table below:
| Time UTC | MJD | Filter | Magnitude | Mag calc. | S/N |
|---|---|---|---|---|---|
| 2025-07-21 07:23:26.242 | 60877.307943 | Sloan-g | 14.11 +/- 0.02 | gmag + 0.04 (gmag - rmag) | 58.97 |
| 2025-07-21 07:25:05.080 | 60877.309083 | Sloan-r | 11.60 +/- 0.01 | rmag + 0.00 (gmag - rmag) | 76.62 |
| 2025-07-21 07:26:43.913 | 60877.310230 | Sloan-i | 10.02 +/- 0.02 | imag + 0.01 (gmag - rmag) | 62.39 |
The photometric observations were obtained by the AITP Observatory in San Pedro-Atacama-Chili, affiliated to AITP (Alsace Internet Telescope Project), 23 rue Sainte Odile, 67560 Rosheim, France. Position: W96, 068 10 47.98 W, 22 57 12.52 S, 2399m, (Long: -68°.1799944, Lat:-22°. Instrument: CMOS Camera QHY268M, cooled at -10°C. Observer, measurer and author: Roger HELLOT, AITP-member.