symbiotic variable

Alert Notice 167: The symbiotic star 1810-00 FG Serpentis (AS 296) AND Forthcoming outburst of 0749+22 U Geminorum

THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
BITNET: aavso@cfa8 SPAN: nssdca::cfa8::aavso
INTERNET: aavso@cfa0.harvard.edu
Tel. 617-354-0484    FAX 617-354-0665

AAVSO ALERT NOTICE 167 (February 1, 1993)

THE SYMBIOTIC STAR 1810-00 FG SERPENTIS (AS 296)

Special Notice #429: V694 Mon (MWC 560) spectroscopy requested

May 2, 2017: Further to AAVSO Alert Notice 538, the campaign from 2016 on V694 Mon (MWC 560) has been continued, but with different requirements. Photometry is no longer specifically requested on a regular basis (although ongoing observations that do not interfere with other obligations are welcome). Spectroscopy on a cadence of a week or two is requested to monitor changes in the disk outflow. V694 Mon is presently nearing opposition, but the request for spectroscopy continues until further notice.

Alert Notice 572: AG Dra monitoring requested

April 3, 2017: Dr. Rudolf Gális (Pavel Jozef Šafárik University (Slovakia)) and colleagues have requested AAVSO assistance in observing the symbiotic variable AG Dra. Observations are requested as a follow-up to spectroscopic observations and in order to monitor the system for an anticipated outburst.

Special Notice #417: CH Cygni B and V photometry urgently requested

REQUEST CONTINUED THROUGH 2018

June 3, 2016: Dr. Margarita Karovska (Harvard-Smithosonian Center for Astrophysics) is urgently requesting B and V photometry of the symbiotic variable CH Cyg from now until at least the end of August. Observations made twice a week are sufficient; time series observations are not needed. Spectroscopy would also be very welcome and appreciated.