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

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."

Dr. Karovska continues: "R Aqr is the nearest symbiotic system at a distance of only about 200 pc. It contains a white dwarf accreting from a mass-losing Mira-type star with binary separation of about 20 AU. The aim of the multiwavelength observations of this fascinating object is to study the physical characteristics of this system and including the multi-scale components of the powerful jet, from the central binary region to the jet-circumbinary material interaction region and beyond.

"AAVSO observations are requested in order to monitor the state of the system and correlate with the satellite observations.

"Visual observations and CCD/PEP observations in the U, B, V, I, J, and H bands are requested." DSLR photometry is also welcome.

"Optical spectroscopy, including in the Halpha, [OIII]5007A region is  also requested.

"Also requested is high-speed photometry in U and B bands (a cadence of as low as a few seconds would be ideal, but a cadence of about a minute may also be all right) to reveal any possible high-speed variations in the central binary.

"Weekly observations now through...November would be very much appreciated, with increased frequency of observations to twice a week..." beginning four weeks before the Chandra and HST observations and continuing at that frequency until the end of the campaign. "This [level of coverage] will provide solid optical data crucial to interpreting the satellite data."

Observers will be notified when the exact times of the Chandra and HST observations have been set. Please begin observations twice a week in mid-September if the Chandra and HST observation times have not been announced by then.

R Aqr, which has a range of ~ V = 5.2 - 12.4, is currently at magnitude V = 8.5 and fading, according to observations in the AAVSO International Database.

Coordinates for R Aqr (2000):  R.A.  23 43 49.46    Dec.  -15 17 04.2

Charts: Finder charts for R Aqr with a comparison star sequence may be created using the AAVSO Variable Star Plotter (VSP).

Submit observations: Please submit observations to the AAVSO International Database using the name R AQR.

This campaign is being followed on the Campaigns and Observation Reports Forum at https://www.aavso.org/r-aqr-chandra-hst-campaign.

Observers are reminded that R Aqr is the target of another AAVSO observing campaign underway, this one to detect the next eclipse of this symbiotic system, predicted for 2022 but which may come early (AAVSO Alert Notice 535).

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen from information provided by Dr. Margarita Karovska.

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