CH Cygni survey 2013

Updated: June, 2013

Symbiotic star CH Cygni has been detected in high state by F. Teyssier on 2013 June 30th, with noticely [OI], [OIII] in emission and numerous iron lines in the blue/green.According to AAVSO observations, CH Cygni is currently increasing in luminosity.

Call for observations from Dr Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) to see how the current state evolves

Both low and high (especially eShel) resolution spectroscopy is valuable.

Comparison with a spectrum acquired during 2012 campaign

Target CH Cyg
AD (2000) 19 24 33.07
DE (2000) +50 14 29.1
Mag (V) 7.6 (2013 june)
Resolution low (~ 600 to 1000) and high (especially eShel)
Range of interest visible
SNR > 100
Purpose of investigation Survey of the high state of the star
Flux calibration

Reference star :

AD 2000
Dec 2000
Mag V
Sp. Type
HD 183534
19 27 26.0
+ 52 19 13.6


Frequency 2/3 per week

AAVSO light curve (V Band)






Recommandations :

In order to be able to maintain consistency and benefit the most from the data it would be beneficial if the following could be provided for each observation:

Observation details:
• Date/time in UT
• Location
• System details (aperture, instrument used)
• Target and standards observed (Name, HD number or RA/Dec)


How to submit your spectra

Mail your FIT file(s) to François Teyssier francois.teyssier [at]   to be added to this data repository.


Reduce your spectra with all your instrumental defect but do not correct from heliocentric velocity and do not remove telluric lines.

Use as much as possible BeSS FITS file format. Specially:

* BSS_SITE = your location

* BSS_INST = your instrument

* BSS_TELL = did you remove telluric lines

* BSS_VHEL = helioventric velocity correction on your spectrum.

* BSS_NORM = is your spectrum normalized (continuum corrected)?

* BSS_ITRP = your spectrograph typical resolving power

If possible, put exposure time in [s] seconds.

Fill-in SITELAT (Latitude) and SITELONG (Longitude) in your FITS header if possible.

Respect DATE-OBS format: yyyy-mm-dd hh:mm:ss...

For echelle or eShel spectra, please provide a merged spectrum in a single file (xxx.FIT) and all your individual orders in a compressed archive (xxx.ZIP).

Use if possible .FIT as FITS file extension.


See also ARAS forum topic:

Field of CH Cyg - FSQ-85ED (D = 0.085 m)  @ F/3.8 - QSI-583 - Exposure 4 x 60 sec. for each three RGB spectral bands. Ch. Buil, Catanet obs. Date: 15/03/2012.


CH Cygni with a staranalyser (John Briol) 08-08-2013


Log of observations