CH Cygni

[James Foster]

Here is my first CH Cyg Ha spectra with the LihresIII using the 2400 l/mm grating on the CDK17 telescope with a 23 micron slit:

I used an Ha Vega spectra (same night) to generate the IR file. I also used another set of flats (10x at adu 59K each) taken right after the last set of the calibration lamp images.

Processed in Isis V5.90 using the 3 Ne-Ar lines seen in the calibration lamp set. I didn't eliminate the telluric/h2o lines. I have an Hb spectrum as well, but that will take a little more practice to reduce since the calibration lines in blue are so dim and need to be identified against my Ne-Ar reference chart. Let me know if anything seems amiss.

James

[James Foster]

Here is my H-Beta spectrum on 12Oct17 using the LihresIII and 2400 l/mm grating on the CDK17 telescope with a 23 micron slit: (R= 13283):

Processed in Isis v5.9.1. Will post more as I go through my last 10 nights of data.

James

[Francois Teyssier]

Hi James,

Very impressive absorption in the blue edge of H beta
It should be interesting to show the profile according to radial velocity

Of course, I'm waiting for the fits

François

[Francois Teyssier]

Spectrum obtained on Nov, 28
with a correct SNR in the bue (SNR 30 at 4200 A)
Absorption in the blue edge of H beta,with max velocity ~ -3000 km/s
but less deep than in James' spectrum

chcyg_20171128_735_FMTeyssier1.png (19.6 KiB) Viewed 5824 times

Blue region

chcyg_20171128_735_2.png (18.53 KiB) Viewed 5824 times

Commented H beta range. Note the broad Cr II lines (FWHM ~ 80 km/s)

After strong variation at a time scale of minutes, CH Cyg current state shows important variation of the absorption in thye Balmer lines
A fascinating star!

François

[James Foster]

This is probably my one of my last high resolution spectra of CH Cyg in 2017, as it heads behind my house within 1 hour of darkness:

I got a LISA spectra of it tonight I'll try to get one more LhiresIII H-Alpha then head for more easterly targets.

James