Electronic Telegram No. 5015 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 RS OPHIUCHI Further to CBET 5013, E. Guido, M. Rocchetto, and A. Valvasori report that CCD images taken on Aug. 9.42 UT with a "Telescope Live" 0.1-m f/3.6 astrograph located at the "Heaven's Mirror" Observatory (near Yass, NSW, Australia) show the variable at mag about 4.8 (approximate R-band) at R.A. = 17h50m13s.20, Decl. = -6d42'28".2 (equinox 2000.0; UCAC4 reference stars for the astrometry), noting that 10-s exposures show saturated images. Their image can be viewed via the following website URL: https://tinyurl.com/rsoph2021. R. H. McNaught, Coonabarabran, NSW, Australia, reports the following unfiltered magnitudes for RS Oph from 60-s survey exposures taken with a Canon 6D camera (+ 135-mm-f.l. lens at f/2.8), using comparison-star magnitudes from AAVSO RS Oph charts: Aug. 1.466 UT, 10.8; 1.568, 10.8; 3.486, 10.7; 5.522, 10.4; 6.442, 11.2; 6.550, 10.6; 8.538, 9.6; 8.630, 7.6. E. O. Waagen, AAVSO, provides the following visual magnitude estimates: Aug. 6.910 UT, 11.1 (G. Poyner, Birmingham, UK); 7.969, 11.2 (A. Amorim, Florianopolis, Brazil); 9.028, 4.9 (C. Marcos da Silva, Luminarias, Minas Gerais, Brazil); 9.190, 5.1 (L. Herrington, Ketchum, OK, USA); 9.444, 4.6 (A. Pearce, Nedlands, WA, Australia); 9.542, 4.5 (R. Stubbings, Tetoora Road, Vic., Australia); 9.639, 4.6 (F. Romanov, Yuzhno-Morskoy, near Nakhodka, Russia); 9.662, 4.5 (D. Benn, Klemzig, S. Australia). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2021 CBAT 2021 August 9 (CBET 5015) Daniel W. E. Green