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symbiotic variable

Alert Notice 639: CH Cyg coverage requested

July 3, 2018: The symbiotic variable CH Cyg is undergoing a fade that began on June 25. Multicolor photometry is requested; V and particularly B should take priority over Rc and Ic. Observations made two to three times a week are sufficient; time series observations are not needed. Visual observations are also requested and encouraged. Spectroscopy would be very welcome and appreciated. Coverage should continue throughout the observing season.

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.

Special Notice #112: Support for CH Cygni observations with HST and Chandra

June 7, 2008

Special Notice #121: Outburst of the symbiotic star CI Cygni

August 31, 2008

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