Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J20210770+2914093

TCP J20210770+2914093   2021 07 16.4919*  20 21 07.70 +29 14 09.3  12.0 U             Vul       I 0

2021 07 16.54490

F. Watanabe (Nayoro Observatory, Nayoro, Japan) performed a follow-up observation for this transient using a 0.4-m f/10 Meili telescope (Meade LX200-40ACF) + R-filtered CCD (SBIG STL-1001E) on Jul. 16.545 UT. The magnitude is measured to be R = 11.8 +/- 0.1 (reference stars from UCAC4 Rmag) and the position end figures are given as 7s.67, 10”.0.

2021 7 16.5647

Photometry results were B=13.13, V=12.28, Rc=11.68 and Ic=11.15 with 0.25m (F6.3) SCT + QSI632 CCD. My image is available at http://meineko.sakura.ne.jp/ccd/TCP_J20210770+2914093.jpg Seiichiro Kiyota, Kamagaya, Japan

2021 07 16.1473

Recent ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) data (g magnitudes): 2021 July 14.395 UT, fainter than 17.0; 16.147, 13.19; 16.178, 13.05; 16.190, 13.02; no previous brightenings had been recorded since 2015 February 27; complete data and light curve at https://asas-sn.osu.edu/sky-patrol/coordinate/6a416e47-e48e-4fa8-9701-47bc79367ba7 —— At J2000.0 position RA 20 21 07.707 DEC +29 14 09.02 the transient ZTF21abmbzax (rmag. 19.6 on 2021 July 15.380 UT) was detected by the Zwicky Transient Facility (Masci et al., 2019PASP..131a8003M); light curve and data via Lasair (Smith et al., 2019RNAAS...3...26S) at https://lasair.roe.ac.uk/object/ZTF21abmbzax/ —— Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

2021 07 16.62

The likely progenitor is catalogued as Gaia EDR3 1861166838700691968 (RA 20 21 07.704 DEC +29 14 09.09, equinox J2000.0, epoch J2016; Gmag. 21.05), SDSS J202107.70+291409.0 (gmag. 22.3, rmag. 21.7, imag. 21.4), and as Pan-STARRS1 source PSO J202107.703+291409.136 (gmag. 21.85, rmag. 21.29, imag. 21.13). Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

2021 07 16.915

A low resolution (R~500) spectrum shows strong Balmer lines in emission showing P Cygni profiles with an estimated velocity of ~1400km/s. There are other broad emission lines including He. The spectrum can be viewed here https://britastro.org/specdb/data_graph.php?obs_id=10094 Robin Leadbeater Wigton UK

2021 07 16.492

Discovery:2021 07 16.475 (180mm camera lens + CCD ), Confirmed:2021 07 16.492 (0.5-m F/6.0 + CCD ), Image:http://k-itagaki.jp/images/2021-Vul.jpg (K.Itagaki)

2017 07 16.492

2021 07 15.489 [14.2 (180mm camera lens + CCD )K.Itagaki

2021 07 16.7553

Astrometry and photometry with the 0.6m SAI Moscow State University telescope (Kislovodsk, Russia): 20:21:07.703 +29:14:09.25 +/-0.10 J2000; JD(UT)2459412.25529 B=12.77, 2459412.25584 V=12.19, 2459412.25610 Rc=11.46, 2459412.25633 Ic=11.24. The photometric uncertainty is about 0.01 mag in all bands, the magnitude scale is calibrated against APASS stars in the field (Rc and Ic magnitudes of comparison stars are color-transformed from APASS r and i). ---- N. Ikonnikova, K. Sokolovsky

2021 07 17.584

Mag : 2021 07 17.461 = 12.4 . 2021 07 17.584 = 12.6 (K.Itagaki)

2021 07 16.8995

July 16.8995 UT 12.42TG magnitudes (using green filters) remotely with a 150mm http://iTelescope.net APO Refractor in Nerpio, Spain. Image: https://twitter.com/fidusz/status/1416585687558725639 -- Robert Fidrich, Budapest, Hungary

2021 07 20.8883

This transient was observed by Gianluca Masi, remotely using the 17" robotic unit part of the Virtual Telescope Project facility in Ceccano, Italy. Unfiltered, 60-second images show the source at mag. 11.7 (R mags for the reference stars from Gaia DR2). We also performed astrometry, getting the following end figures: 07.70s; 09”.0 (J2000.0, mean residuals of 0.2" on both axes)

2021 07 24.85

Follow-up observations remotely using 0.355-m f/6.2 Schmidt-Cassegrain telescope of Abbey Ridge Observatory (Canada): 2021 Jul. 24.20152 = 12.10 V; Jul. 24.20234 = 12.73 B; Jul. 24.20318 = 11.44 Rc; Jul. 24.20401 = 10.84 Ic. Filipp Romanov (Russia).

2021 07 29.9

It is getting brighter. New observations remotely using 0.355-m f/6.2 Schmidt-Cassegrain telescope of Abbey Ridge Observatory (Canada): 2021 Jul. 29.24669 = 10.946 V; Jul. 29.24751 = 11.623 B; Jul. 29.24836 = 10.38 Rc; Jul. 29.24918 = 9.778 Ic. Filipp Romanov (Russia).