CH Cyg at high resolution

Campaign on the request of Dr Ausgustin Skopal
H alpha line at R > 10,000
and low res spectra
Tim Lester
Posts: 168
Joined: Fri Apr 04, 2014 6:31 pm
Location: Arnprior Ontario

CH Cyg at high resolution

Post by Tim Lester »

Hi all

I had to wait for snow flurries to clear but I finally managed to get CH Cygni with my new 1800 lpm grating.
ISIS reports a resolution of 8898 so not quite 10,000, but good S/N.

Image

Image

Tim
Tim Lester
Posts: 168
Joined: Fri Apr 04, 2014 6:31 pm
Location: Arnprior Ontario

Re: CH Cyg at high resolution

Post by Tim Lester »

CH Cyg on Dec 19 - showing changes for Halpha since last observation on the 2nd.
_chcyg_Halpha.png
_chcyg_Halpha.png (7.75 KiB) Viewed 16985 times
Tim
Christian Buil
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Re: CH Cyg at high resolution

Post by Christian Buil »

Hi tim,

Excellent spectra of red region!

(can you give more about your spectrograph setup : optical configuration, components, weight, images (?))


Christian
Francois Teyssier
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Re: CH Cyg at high resolution

Post by Francois Teyssier »

Hello Tim,

EXcellent. That perfectly responds to the request of Dr Skopal.
Of course, the fit is welcome in the database !

François
Tim Lester
Posts: 168
Joined: Fri Apr 04, 2014 6:31 pm
Location: Arnprior Ontario

Re: CH Cyg at high resolution

Post by Tim Lester »

Thanks Christian and Francois.

Christian,
Shortly after I joined the ARAS group I posted a description of my setup with photos here: http://www.spectro-aras.com/forum/viewt ... ?f=8&t=811
The important details are:
Telescope:
311cm home built corrected f9.8 Dall Kirkham with a 45mm dia. diffraction limited field.
Spectrograph:
- classical home built designed for low resolution
- f6.6 focal reducer built in to spectrograph mount
- 23 um slit (an APLY slit) gives 2.3 arcsec width after the f6.6 reducer. Reducer delivers an image circle of 1 arcsec from 400 to 750 nm.
- collimator - Edmund spherical mirror with 101.6 mm fl (203.2 mm radius)
- gratings - Edmund 25x25 mm, 600 and 1200 lpm and an Optometrics 25x50 mm 1800lpm
- collimator to camera angle - 38 degrees
- camera - 85 mm f1.8 Nikon lens (internal focus). Better than average resolution - got lucky!
- imager - QSI583 (5.4 um pixels)
Calibration source:
- Relco lamp behind a frosted aperture and motor driven into beam so as to illuminate the spectrograph identically to the telescope.

Weight of the spectrograph with the reducer guide and calibration assembly but without the imagers is 1.5 Kg

Originally I had some flexure problems that resulted in small orientation dependent wavelength shifts but these were
tracked down to flexure of the front face of the QSI 583 and movement at the camera lens mount. Both were solved.
With the 1800 lpm grating I have pushed this classical design to the limit. The 0.63 anamorphic factor results in a 14 um slit image on the CCD.
Focus is thus critical and I had to change the imager mounting to allow a precise tilt to be dialed in for each grating rotation.
I now have a table of tilts versus grating rotation that enables me to set this up quickly.

Tim
Tim Lester
Posts: 168
Joined: Fri Apr 04, 2014 6:31 pm
Location: Arnprior Ontario

Re: CH Cyg at high resolution

Post by Tim Lester »

CH Cyg on Dec 28th - compared to my last two spectra.

Image

Tim
Francois Teyssier
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Location: Rouen
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Re: CH Cyg at high resolution

Post by Francois Teyssier »

H alpha CH Cyg 10-03-2015

eShel + SC 10" + ATIK 460EX
Traitement : ISIS
_chcyg_20150312_139_ha.png
_chcyg_20150312_139_ha.png (15.12 KiB) Viewed 16718 times
Comparison with Tim Lester's spectrum
CHCyg_Comp.png
CHCyg_Comp.png (19.23 KiB) Viewed 16717 times
Rappel : H alpha campaign for Augustin Skopal : at least 1 spectrum a month
Low resolution spectra are welcome

François Teyssier
Tim Lester
Posts: 168
Joined: Fri Apr 04, 2014 6:31 pm
Location: Arnprior Ontario

Re: CH Cyg at high resolution

Post by Tim Lester »

CH Cyg on 25-03-2015.
H alpha and H beta compared to Christian's last eShel spectrum on the 17th.
H alpha
H alpha
CH Cyg_Ha.png (6.6 KiB) Viewed 16661 times
H beta
H beta
CH Cyg_Hb.png (6.71 KiB) Viewed 16661 times
Tim
Francois Teyssier
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Re: CH Cyg at high resolution

Post by Francois Teyssier »

Excellent !
The campaign begins well
There are several absorptions on the blue edge as your spectrum shows
CHCyg.png
CHCyg.png (15.58 KiB) Viewed 16658 times
Note : Augustin Skopal prefers that the spectra are corrected for heliocentric velocity
(I'll precise this point in the next letter)


François
Olivier GARDE
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Re: CH Cyg at high resolution

Post by Olivier GARDE »

Another animation of CH Cyg : time serie of 64 exposures of 180s each (3H)

For Halpha
Image


For H Beta (see the small emission line near 4888 Â)
Image
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
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