Alert Notice 708: Test exposures requested for symbiotic binary candidates

Note: The target table was edited to add the range.  -  Elizabeth O. Waagen, 18 June 2020

June 17, 2020

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports: https://www.aavso.org/test-exposures-for-symbiotic-binary-candidates-campaign

Adrian B. Lucy (Columbia University) requests the assistance of AAVSO observers, and writes:

"We request observations to determine the current V, B, and U band magnitudes of the following candidate symbiotic stars, to help with planning for future observations. A single observation in each available filter would be sufficient; we are not requesting monitoring at this time, just approximate current magnitudes. Many of these targets have plenty of archival data, but we cannot assume that they have varied in predictable ways, so we require new test exposures."

In the table of targets below, the fields "V", "B", and "U" indicate that one of each of those observations is needed for a star. This table will be posted on the AAVSO discussion forum thread for this campaign (URL above). It will be updated as observations have been submitted and coverage is complete for a band for a particular star.

Observers are requested to monitor this thread to see the status of the table.

Observers are also requested to use the AAVSO Light Curve Generator (LCG) to monitor incoming observations of the targets. Be sure to use 2459018 (17 June 2020) as the starting JD for the LCG. (Some stars already have data, but what is crucial for this campaign is measurements from today forward.)

Name RA (2000) Dec (2000) Range      V          B         U    
ASAS J150924-5303.5 15:09:24.01 -53:03:27.9  10.006(3.045)Ic      
ASAS J152058-4519.7 15:20:58.29 -45:19:44.4 12.3-13.6V      
NSV 20400 15:47:50.77 -32:43:59.4 12.9-14.6:V      
Gaia DR2 6043925532812301184 16:27:49.76 -29:16:45.5 14.2-15.3V      
ASASSN-V J163807.84-284207.6 16:38:07.84 -28:42:07.6 13.74-13.87V      
Gaia DR2 5917238398632196736 17:07:10.56 -56:53:17.5 14.3-15.9V      
V3005 Oph 17:36:59.41 -18:06:26.6 13.0-14.6:V      
ASASSN-V J175047.54-390117.8 17:50:47.54 -39:01:17.8 13.00-13.13V      
V589 CrA 18:25:40.00 -42:14:22.8 11.8-<15.9V      
ASAS J182647-2415.8 18:26:46.86 -24:15:47.3 12.9-14.4V      
ASASSN-V J183449.60-382456.9 18:34:49.60 -38:24:56.9 12.14-12.85V      
V1918 Sgr 18:37:34.79 -20:53:25.0 13.6-14.7V      
ASAS J185604-2327.2 18:56:04.01 -23:27:14.0 12.7-13.6V      
2MASS J18572355-0643282 18:57:23.55 -06:43:28.2 14.7-?V      
IRAS F19019-1733 19:04:51.81 -17:28:39.9 13.0-<17.7V      
GSC 05140-03255 19:05:48.04 -06:05:49.5 13.5-15.3V      
ASAS J190559-2109.4 19:05:59.12 -21:09:25.1 12.4-13.3V      

Note: Coordinates are from the VSX pages for these stars

Charts with comparison stars for the targets may be created using the AAVSO Variable Star Plotter (VSP). Please use the name in the table to create charts.

Please submit observations to the AAVSO International Database using the names given in the table.

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