CH Cyg

Alert Notice 639: CH Cyg coverage requested

Note from Aril 2020: Ongoing coverage continues to be extremely important, with V and particularly B being given priority over Rc and Ic. As always, visual observations are requested and encouraged. - Elizabeth O. Waagen, April 6, 2020

Note from August 2019: Ongoing coverage is extremely important, with V and particularly B being given priority over Rc and Ic. As always, visual observations are requested and encouraged. - Elizabeth O. Waagen, August 28, 2019

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.

Alert Notice 195: Symbiotic stars AND Cataclysmic variables AND 1510+83 Z Ursae Minoris

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

AAVSO ALERT NOTICE 195 (November 23, 1994)

SYMBIOTIC STARS

Alert Notice 222: Extreme fading of 1921+50 CH Cygni AND Reminder - Request to monitor 2138+43 SS Cygni for Observations with HST, EUVE, and RXTE

THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
INTERNET:  aavso@aavso.org
Tel. 617-354-0484       FAX 617-354-0665

AAVSO ALERT NOTICE 222 (June 25, 1996)

EXTREME FADING OF 1921+50 CH CYGNI

The brightest Z And-type symbiotic star known, CH Cyg, is undergoing a
significant fading as indicated by the following observations:

Alert Notice 244: 1140+48 Supernova 1998S in NGC 3877 AND Fading of 1921+50 CH Cygni

THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
INTERNET:  aavso@aavso.org
Tel. 617-354-0484       FAX 617-354-0665

AAVSO ALERT NOTICE 244 (March 13, 1998)

1140+48 SUPERNOVA 1998S IN NGC 3877

Special Notice #294: CH Cyg observing campaign continued through 2012

September 11, 2012:  As announced in AAVSO Alert Notice 454 (http://www.aavso.org/aavso-alert-notice-454) and updated in AAVSO Special Notices #267 and #268 (http://www.aavso.org/aavso-special-notice-267 and -268), Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) is carrying out a multiwavelength campaign on the symbiotic variable CH Cyg this year. The satellite observations have taken place, and Dr.

Special Notice #268: Chandra observations scheduled for CH Cyg and monitoring urgently needed

23 March 2012: The Chandra X-ray satellite observations of the symbiotic variable CH Cyg have been scheduled as part of Dr. Margarita Karovska's (Harvard-Smithsonian Center for Astrophysics) campaign. Please see AAVSO Alert Notice 454 and AAVSO Special Notice #267 for complete details on this observing campaign. The HST observations of CH Cyg have already been made.
 

Special Notice #267: HST observations of CH Cyg scheduled and monitoring urgently needed

March 15, 2012:  As announced in AAVSO Alert Notice 454 (http://www.aavso.org/aavso-alert-notice-454), Dr. Margarita Karovska, Harvard-Smithsonian Center for Astrophysics, has requested multiband photometry (all possible bands), high-speed photometry, spectroscopy, and visual observations of the symbiotic variable CH Cyg in support of HST and Chandra observations. She is studying the central region of CH Cyg and its jet.