symbiotic variable

Alert Notice 639: CH Cyg coverage requested

Note from Aril 2020: Ongoing coverage continues to be extremely important, with V and particularly B being given priority over Rc and Ic. As always, visual observations are requested and encouraged. - Elizabeth O. Waagen, April 6, 2020

Note from August 2019: Ongoing coverage is extremely important, with V and particularly B being given priority over Rc and Ic. As always, visual observations are requested and encouraged. - Elizabeth O. Waagen, August 28, 2019

Alert Notice 589: R Aqr coverage needed for HST and Chandra observations

Note: This campaign has been extended through the 2018 observing season.

August 4, 2017: Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) has requested "visual, photometric, and spectroscopic observations of the symbiotic variable R Aqr in preparation for and in support of Chandra and HST observations currently scheduled for October 2017."

Special Notice #70: Brightening of the symbiotic star AG Draconis

October 3, 2007: It was reported in CBET 1091 by U. Munari et al. that the symbiotic star AG Draconis is again in outburst following the decline from its April 2006 bright outburst. They note that the decline apparently halted on 2007 July 07, and has since brightened steadily. Their observations place AG Dra at V = 8.98 on 2007 September 30.8 UT (B = 9.69 and B-V = +0.71). They also note the presence of strong hydrogen and helium emission lines.