Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J18104219-1534184

TCP J18104219-1534184   2020 02 22.8389*  18 10 42.19 -15 34 18.4  12.1 U             Ser       9 0

2020 02 22.839

Discovered by Hideo Nishimura, Kakegawa, Shizuoka-ken, Japan, who found this star on three frames (limit mag.= 13.2) taken with Canon EOS 6D digital camera + 200-mm f/3.2 lens, who writes Nothing is visible at the discovery position on three frames taken on 2020 February 20.860 UT by same instrument under the limiting mag.= 12.5. Nishimura writes a faint star at this location on DSS.

2020 02 22.94

A progenitor candidate is Gaia DR2 4145991274399007104 with position end figures 42.030s, 18.20" (equinox J2000.0, epoch 2015.5; Gmag. 19.42, parallax 2.7823 ± 0.4946 mas); another designation is PSO J181042.030-153418.320 (gmag. 21.62, rmag. 20.29). Dwarf nova outburst (with an amplitude of 8 magnitudes)? No previous outbursts were recorded by the ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) between 2015 Feb. 1 and 2019 Nov. 6; complete light curve at https://asas-sn.osu.edu/light_curves/4c8667cb-96dc-40c9-87f8-46b3994f0a52 --- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

2020 02 22.811

Mag.= 11.8 by T. Kojima, Tsumagoi, Gunma-ken, Japan, with Canon EOS 6D + 200-mm f/3.2 lens, pre-discovery image.

2020 02 23.3814

TCP J18104219-1534184 has been observed by ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) at 13.86g magnitude on 2020 Feb 23.3814 UT. Light curve: https://asas-sn.osu.edu/light_curves/ef9a17f3-7feb-4cd0-a75a-0e319bf8b605 -- Róbert Fidrich (Budapest, Hungary)

2020 02 23.8248

Photometry results were V=13.18, Rc=11.50 and Ic=10.16 with 0.25m SCT + Apogee Alta F47 CCD at TAO, Kamagaya, Chiba, Japan. Position end figures were 42.51 and 18.41 in R.A. and Dec. http://meineko.sakura.ne.jp/ccd/TCP_J18104219-1534184.jpg Seiichiro Kiyota(Kamagaya, Japan)

2020 02 23.86

Please ignore the progenitor candidate (from Gaia DR2) suggested by me above. PSO J181042.471-153419.060 with position end figures 42.471s and 19.09" (J2000.0; imag. 20.8, zmag. 19.8, ymag. 19.4) is 0.9" SW of the nova position reported by Kiyota-san. --- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

2020 02 24.5184

Photometry results were V=13.896V, and Ic=10.841 with 0.25m iTelescope.net reflector + SBIG ST-10XME CCD at Mayhill, New Mexico, US. Position end figures were 42.29 and 18.5 in R.A. and Dec. https://www.dropbox.com/s/tumszwlsfrhfxdc/nser2020v60s2add_t_crop_x.jpg?dl=0 -- Róbert Fidrich (Budapest, Hungary)