symbiotic star

Alert Notice 719: Light curves for symbiotic star ASAS J190559-2109.4

August 26, 2020

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Alert Notice 696: R Aqr photometry (especially B) and spectroscopy needed

PLEASE GO TO AAVSO ALERT NOTICE 738 FOR THE CURRENT R AQR OBSERVING CAMPAIGN

Note: Continued observations, particularly in B, V, and visual, are needed now and through the coming year. R Aqr is presently approaching solar conjunction and observations are very difficult, but they are extremely important as R Aqr is also approaching minimum. Please observe as long as possible now and pick up again as soon after conjunction as possible.  -  Elizabeth O. Waagen, 1 February 2021

Alert Notice 631: Coverage requested for current outburst of AG Dra

Note: Please continue to observe AG Dra until further notice.  -  Elizabeth O. Waagen, 30 July 2021

April 24, 2018: Drs. Jaroslav Merc and Rudolf Gális (both of the Pavel Jozef Šafárik University (Slovakia)), on behalf of their scientific team, have requested AAVSO assistance in observing the symbiotic variable AG Dra as a follow-up to spectroscopic observations and in order to monitor the system in its current outburst, which began in early April.

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.