Alert Notice 792: R Aqr photometry and spectroscopy requested in support of Chandra observations

Note: The Chandra observations of September 26 were carried out successfully. Additional Chandra observations are scheduled for October 3 and 4. Please continue to monitor R Aqr through the end of the observing season and through 2023.  -  Elizabeth O. Waagen, 3 October 2022

September 21, 2022

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Dr. Margarita Karovska (Center for Astrophysics|Harvard & Smithsonian) requests the assistance of AAVSO observers in monitoring the symbiotic binary (Mira + white dwarf) R Aqr in support of upcoming Chandra observations.

The Chandra observations are scheduled for September 26, 2022 UT.

Starting now, Dr. Karovska requests photometry (UBVRIH, mid-IR if at all possible), high speed photometry (UB), and spectroscopy. Visual observations are welcome. The cadence requested is nightly from now through September 26, then twice a week through October 10.

R Aqr has a V range of 5.2 - 12.4. The most recent magnitudes from the AAVSO International Database show R Aqr at magnitude 9.32 V +/-0.006 on 2022 September 19.9033 UT and 10.832 B +/-0.009 on September 19.9042 UT (S. Dufoer, Brussels, Belgium).

Coordinates (J2000):  R.A. 23 43 49.46  Dec. -15 17 04.2  (from VSX entry for R Aqr)

Charts with comparison stars for R Aqr may be created using the AAVSO Variable Star Plotter (VSP).

Please report all photometry observations to the AAVSO International Database using the name R AQR.

Spectroscopy reports should be submitted to the AAVSO Spectroscopy Database and to Dr. Karovska (

Additional Chandra observations of R Aqr are planned for later this season.

R Aqr is presently undergoing the eclipse that occurs about every 40 or so years.

This Alert Notice was compiled by Elizabeth O. Waagen.


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