Electronic Telegram No. 620 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Z ANDROMEDAE AND AG DRACONIS T. Iijima, Astronomical Observatory of Padova, Asiago, reports that, in the course of the monitoring of spectral variations of symbiotic stars, significant changes of Z And and AG Dra were found in their recent spectra. The symbiotic star Z And may have entered in the outburst stage in June 2006 (see AAVSO photometric data on this star at http://www.aavso.org/vstar/). High-dispersion spectra of Z And were taken on Sept. 1.09 and 2.12 UT with an echelle spectrograph mounted on the 1.82-m telescope at Mount Ekar. The spectra show that the emission line of He II 468.6-nm is fairly weakened, with its intensity relative to that of H-beta being 0.08, which was about 0.5 in February, and the Raman emission line at 683 nm has disappeared. High-velocity emission wings are detected in the emission lines of H-alpha and H-beta. The radial velocities of the blue and red emission wings relative to the main emission bodies are -1330 km/s and +1140 km/s. On the other hand, P-Cyg-type absorption components, blueshifted by about -100 km/s, are seen in the emission lines of He I and in H-beta and the higher numbers of Balmer lines. These spectral features were not seen on the spectra taken in and earlier than Feb. 2006. The recent brightening of AG Dra apparently started in early July (e.g., see CBET 577). High-dispersion spectra of AG Dra were taken with the same instruments on Aug. 31.87 and Sept. 1.86. The Raman emission line at 683 nm has disappeared, and the emission line of He II 468.6-nm has weakened, its intensity relative to that of H-beta being about 0.4 (having been 0.5 in April). Wide-spread, weak emission tails, whose full width at zero intensity is about 3000 km/s, are noticed in H-alpha, H-beta, and probably He II 468.6-nm, while the emission lines of He I are accompanied by P-Cyg-type absorption components, which were not seen on the spectra taken in and earlier than April 2006. The blueshifts of the absorption components are -120 km/s for He I 587.6-nm and -90 km/s for He I 447.1-nm. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 September 12 (CBET 620) Daniel W. E. Green