brightness dropping - new call for spectra

[Robin Leadbeater]

From: Margarita Karovska
Sent: Saturday, June 11, 2016 7:01 PM
To: Margarita Karovska
Cc: François Teyssier ; Thierry Garrel ; Robin Leadbeater ; Stéphane Charbonnel ; karovska@cfa.harvard.edu
Subject: Re: CH Cygni spectroscopic campaign


Dear Friends of CH Cyg,

Our friend seems to be dropping abruptly in B and V in the recent weeks which may indicate a significant change in the activity in the system (including a new jet).

Do you have recent spectra of this system?

It would be very helpful if you could monitor it spectroscopically (at least once a week if it is possible). We are trying to understand what is causing this activity (as well as several similar events observed in the past decade or so).

As before, H alpha, [O III] 5007A, (or any part of the spectrum ) will be great!

It is about V~7.5 and B~9.2 or so at this point.

AAVSO has sent a notice last week asking for photometric monitoring in B and V (and other photometry)
https://www.aavso.org/aavso-special-notice-417


Coordinates: RA 19 24 33.07 Dec. +50 14 29.1 (J2000.0)

With gratitude, wishing you clear skies,
Margarita

[Francois Teyssier]

CH Cygni spectra are archived in ARAS database : http://www.astrosurf.com/aras/Aras_Data ... /CHCyg.htm
341 spectra since 2011
284 spectra in 2015 and 2016 (plus time series)

Monthy summary in ARAS information letter for eruptive stars : http://www.astrosurf.com/aras/novae/Inf ... etter.html

See notably issues with notes from Dr Augustin Skopal about the behavior of this enigmatic star :

http://www.astrosurf.com/aras/novae/Inf ... 014-11.pdf

http://www.astrosurf.com/aras/novae/Inf ... 015-01.pdf

http://www.astrosurf.com/aras/novae/Inf ... 015-03.pdf

http://www.astrosurf.com/aras/novae/Inf ... 015-04.pdf

A poursuivre !

François Teyssier

[Robin Leadbeater]

Hello François,

The link "H alpha profiles and time series" at the bottom of the database page is pointing to a local file

Cheers
Robin

[Francois Teyssier]

Fixed
http://www.astrosurf.com/aras/Aras_Data ... chcyg.html
Thank you, Robin

François

[Francois Teyssier]

Message from Dr Augustin Skopal

Thank you very much for informing me about recent behaviour of CH Cyg. I am also glad that others are interested in your (ARAS) spectra, and that they are publicly available. This shows importance of your observations made with a high cadence and continuously, which is of particular importance for the research of objects showing not-repeatable events on time-scales from minutes to decades of years, such as, for example, symbiotic stars.

As concerns to observations of the current CH Cyg event, all types of observations are important. Low-resolution spectroscopy within the largest wavelength range as possible (for modelling SED) and the medium-resolution spectra (R~11000) covering a standard range of 420--720 nm. As CH Cyg is now somewhat fainter and without any strong emissions, a larger exposure can be applied.

Good luck and best regards (to all),



So let''s go on, including low resolution spectra as far as possible in the near UV, with the better instrumental/atmospheric response as possible.

Cet intérêt grandissant de plusieurs professionnels pour les résultats que nous obtenons est la meilleure réponse que nous pouvons apporter aux propos mensongers et malveillants formulés sur spectro-l à l'égard des bases ARAS et BESS.

François Teyssier

[Olivier GARDE]

Ok François,

Je refait CH Cyg en time série avec l'eshel dés que possible (pas terrible la météo en ce moment...)

[Francois Teyssier]

Update

Changes in [OIII] lines in July

asdb_chcyg_20160811_950_[O III 5007].png (35.19 KiB) Viewed 18196 times

The last spectrum was obtained during OHP meeting with a Newton 20 cm. I works.

More lines : http://www.astronomie-amateur.fr/Docume ... g-2016.pdf

Margarita thanks all obersvers
A weekly coverage, low and high resolution is requested

François

[Olivier GARDE]

Nice results François !!!