CH Cygni (2)

On july 25th I made a long (around 3h) serie of acquisition on CH Cygni; then I did another one last night (almost 2h, limited by clouds that came around 1h local time).

It is interesting to look at the spectra as they change very quickly. Here is a comparison between july 25th and july 27th (48h after):

And an animation just for july 25th showing drastic changes within minutes!

CH Cygni is a target for an intensive spectroscopic observation campaign at the moment; see for exemple:
* François Teyssier "Low resolution spectroscopy Observers's guide" - a must have document!:
http://www.astronomie-amateur.fr/index.htm
* François Teyssier web on syumbiotic stars (french):
http://www.astronomie-amateur.fr/Projets%20Spectro1%20SySt.html
* ARAS database on CH Cygni (my spectra should soon appear there):
http://www.astrosurf.com/aras/Aras_DataBase/Symbiotics/CHCyg.htm
* Article from Augustin Skopal on CH Cygni:
http://www.astrosurf.com/aras/novae/InformationLetter/ARAS_EruptiveStars_2015-04.pdf


A key extract from Skopal's article: Strong absorption/emission features observed mainly on the blue side of the Balmer lines, evolving on a time-scale of days or even shorter, reflect the complex mass ejection by the WD in CH Cyg as in a slow-motion movie. This is a great opportunity to follow the process of the mass ejection From_the active WD in more detail than in the case of the abrupt and violent nova outbursts.


As usual, some pictures of the telescope during the observations & screen shots (Aladin is a CDS tool that display the star field, very useful when field recognition is required):