Electronic Telegram No. 5245 Central Bureau for Astronomical Telegrams Mailing address: Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network V1716 SCORPII = NOVA SCORPII 2023 = PNV J17224490-4137160 Andrew Pearce, Nedlands, Western Australia, reports his discovery of an apparent nova on three images (limiting mag 12.5) taken with a Canon 800D digital camera (+ 85-mm-f.l. f/1.2 lens) on Apr. 18.693 and 19.690 UT. Pearce observed the star visually on Apr. 20.705 at magnitude 8.0. Pearce measured approximate position R.A. = 17h22m44s.9, Decl. = -41d37'16" (equinox J2000.0) and unfiltered mag 8.0 on Apr. 20.678. When he posted this position to the Central Bureau's TOCP webpage, the designation PNV J17224490-4137160 was automatically assigned to the variable. CCd imaging by Pearce on Apr. 20.724 with a 0.35-m R-COP reflector at Perth Observatory yielded position end figures 45s.04, 16".5 and magnitudes V = 7.60 and B = 8.50, adding that the position of the variable appears to correspond to that of a 19th-magnitude star (Gaia DR3 5959616875349110656). Further photometry by Pearce using the 0.35-m R-COP reflector at Perth: Apr. 20.756, V = 7.53, B = 8.51; 20.818, V = 7.40, B = 8.35; 20.855, V = 7.32, B = 8.22. Additional visual magnitude estimates by Pearce: Apr. 20.722, 7.9; 20.760, 7.6; 20.860, 7.6. Reports of an independent discovery of PNV J17224490-4137160 by Hideo Nishimura (Kakegawa, Shizuoka, Japan) have been received from S. Naito and I. Endoh, National Astronomical Observatory of Japan, and via S. Nakano. Nishimura obtained three 10-s exposures (limiting mag 13) on Apr. 20.801 UT with a Canon EOS 6D digital camera (+ 200-mm-f.l. f/3 lens) that reveal magnitude 9.9 and position end figures 45s.08, 16".8. E. Guido, L. Izzo, and A. Valvasori give details from CMOS imaging observations remotely with a "Telescope Live" 0.1-m f/3.56 astrograph located in Yass, NSW, Australia on Apr. 21.5 UT, noting magnitude R = 7.8 and position R.A. = 17h22m45s.01, Decl. = -41d37m15s.6 (equinox J2000.0; Gaia DR2 catalogue reference stars for astrometry). They have posted an image at website URL https://tinyurl.com/novasco23 and an animation via comparison to a Palomar Sky Survey plate at URL https://tinyurl.com/novascoanimation. Additional visual magnitude estimates of PNV J17224490-4137160 reported to the Central Bureau: Apr. 21.12 UT, 7.3 (J. G. de S. Aguiar, Campinas, Brazil); 22.042, 7.0 (W. Souza, Sao Paulo, Brazil); 22.12, 7.1 (Aguiar); 22.125, 7.1 (Souza); 22.156, 7.0 (Souza); 22.356, 7.6 (A. Amorim, Florianopolis, Brazil); 23.16, 8.0 (Aguiar); 23.292, 8.1 (Amorim); 24.04, 8.4 (Aguiar); 24.052, 8.3 (Souza). O. Garde writes, on behalf of the Southern Spectroscopic Observatory Project Team (2SPOT), which uses a "Deep Sky Chile" telescope at Ruo Hurtado, Chile, that spectroscopy of PNV J17224490-4137160 was obtained on Apr. 22.25 UT with an RC12 reflector (+ sShel echelle fibre spectrograph; resolution 11000) at Deep Sky Chile Observatory, revealing complex lines including Balmer lines with strong absorption (H_alpha velocity -1800 km/s). Na I D shows as a single strong absorption (-1700 km/s) with a broad P-Cyg-like emission, and it indicates a signification interstellar extinction. Iron, Mg, and Ca lines are also visible. The spectrum appears to be that of a classical nova, and it can be viewed at website URL http://www.spectro-aras.com/forum/viewtopic.php?f=36&t=3090. E. Kazarovets writes that the permanent GCVS designation V1716 Sco has been assigned to this nova. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2023 CBAT 2023 April 24 (CBET 5245) Daniel W. E. Green