Alert Notice 678: V694 Mon (MWC 560) photometry and spectroscopy requested

Note: The Chandra observations took place, and Dr. Karovaska requests continued monitoring of V694 Mon (MWC 560) until further notice.  -  Elizabeth O. Waagen, 17 April 2020

Note: V694 Mon (MWC 560) is scheduled to be observed with Chandra the week of 2020-January-27 - February-03 UT. Please see AAVSO Alert Notice 692 for more information.  -  Elizabeth O. Waagen, January 22, 2020

September 11, 2019

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Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) is requesting BVRI photometry, visual observations, and spectroscopy of the symbiotic variable V694 Mon (MWC 560).

Dr. Karovska writes: "MWC 560 is a symbiotic system showing jet/outflow activity. The system has undergone several outbursts since 1990, including a recent one that started in late 2018."

An observation of V694 Mon in the AAVSO International Database (the first since May 2019, when it was visual magnitude 9.1 (C. Adib, Porto Alegre, Brazil)) shows the system at 8.795 V +- 0.008 on 2019 Sep. 09.43423 UT (S. Dvorak, Clermont, FL). Its range is 8.88-12.2 V.

Bi-weekly photometry will be very much appreciated. UBV (and RI if possible) coverage is needed. Visual observations are also encouraged.

One spectrum every two weeks is requested, focusing on the [OIII] 5007A line and the Halpha line regions. Spectroscopy reports (including plot, if possible) should be sent to Dr. Karovska ( and submitted to the AAVSO Spectroscopy Database (

Coordinates: R.A. 07 25 51.28  Dec. -07 44 08.2 (2000.0)

AAVSO finder charts for V694 Mon with comparison stars may be generated using the AAVSO Variable Star Plotter (VSP).

Please submit your observations to the AAVSO International Database using the name V694 MON.

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

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