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symbiotic variable

Alert Notice 695: HST to observe V694 Mon (MWC 560)

Note: Observations of V694 Mon are scheduled for 11 March 2020 with HST, and for 22 March 2020 with XMM. Please continue to observe as indicated below but with the high-intensity coverage taking place March 9 through March 14 and March 19 through March 25.  -  Elizabeth O. Waagen, 6 March 2020

February 3, 2020

Alert Notice 692: V694 Mon (MWC 560) to be observed with Chandra

Note: Note: Observations of V694 Mon are scheduled for 11 March 2020 with HST, and for 22 March 2020 with XMM. Please continue to observe as indicated in Alert Notice 695 but with the high-intensity coverage taking place March 9 through March 14 and March 19 through March 25.  -  Elizabeth O. Waagen, 6 March 2020

Alert Notice 689: R Aqr monitoring needed in support of HST and Chandra observations

Note:  Continued observations in all bands (particularly B and V) and spectroscopy are extremely important. Please continue nightly observations until further notice.  -  Elizabeth O. Waagen, 31 January 2020

Note: The exact schedules for the Chandra and HST observations of R Aqr (Alert Notice 689) are as follow:

Chandra (UT)  Note that this date is EARLIER than given in Alert Notice 689.
12 Jan 2020 00:13:21.409 - 12 Jan 2020 14:06:41

Alert Notice 665: R Aqr observations needed urgently

Note: Dr. Margarita Karovska (Center for Astrophysics|Harvard & Smithsonian) is also urgently requesting BVRI photometry, visual observations, and spectroscopy of R Aqr through (at least) the end of the observing season. - Elizabeth O. Waagen, August 5, 2019

Note: R Aqr is out of its seasonal gap and is increasingly observable. Continued coverage is requested as described below until further notice. - Elizabeth O. Waagen, May 3, 2019

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.

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