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symbiotic star

Alert Notice 600: Dates for R Aqr Chandra and HST observations

October 1, 2017 : Further to AAVSO Alert Notice 589, the likely windows for the Chandra and HST observations of the symbiotic variable R Aqr have been set as follow:

Chandra: 2017 October 11 - October 15
HST: 2017 October 13

Special Notice #201: Outburst of the symbiotic star V407 Cyg

March 12, 2010: Further to Maehara et al. (CBET 2199, D.W.E. Green, editor), the presumed symbiotic star V407 Cyg appears to be undergoing a very bright outburst, well outside of its previous range. This outburst was discovered independently by the team of K. Nishiyama (Fukuoka, Japan) and F. Kabashima (Saga, Japan), and by T. Kojima (Tsumagoi, Agatsuma-gun, Gunma-ken, Japan). Nishiyama and Kabashima observed the star at an unfiltered magnitude of 6.8 on 2010 March 10.813 (JD 2455266.313) and magnitude 6.9 on 2010 March 10.814 (2455266.814).

Special Notice #202: Classical nova event in V407 Cyg

March 14, 2010: Further to Munari et al. (CBET 2204, D.W.E. Green, editor), the presumed symbiotic star V407 Cyg is exhibiting spectral features clearly indicating a classical nova of the He/N type. This strongly suggests that the white dwarf component of the system is currently undergoing a nova outburst rather than a symbiotic-type outburst. The spectral evolution of this nova may be very fast given the likely large mass loss rate of the Mira-type donor star. We urgently request observations of V407 Cyg to provide photometric coverage of this unique event.

Special Notice #375: Symbiotic variable AS 270 in outburst

November 13, 2013: The symbiotic star AS 270 is in outburst, according to observations reported to vsnet-alert by Berto Monard (MLF; Calitzdorp, South Africa) and to the AAVSO International Database (AID) by Steve O'Connor (OCN; St. George's, Bermuda). O'Connor reports the star at V=11.72 +/-0.03 on 2013 November 13.405 UT (JD 2456609.905), well above its normal minimum magnitude of 14.2V.

Special Notice #219: Eclipse of the symbiotic star CI Cygni

October 12, 2010: As noted by U. Munari et al (ATel #2913, 2010 October 9), the symbiotic star CI Cygni is currently undergoing an eclipse of the outbursting star.  CI Cyg has declined from about magnitude 9.7 in late August 2010 to V=11.1 currently.

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