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MRes spectrograph

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andrew.j.smith1905's picture
Last seen: 2 weeks 2 days ago
Joined: 02/12/2016 - 12:22
MRes spectrograph

After far to long due a combination of learning IRAF, changing mount and perma-cloud I have now been able to capture echelle spectra and process them with the minimum of intervention using my home made MRes echelle spectrograph.

Using The Sky X (TSX) to control the mount and cameras I can slew to a list of targets, center them on the fiber guide head and capture the spectra, including Th Ar calibration, by running a Python program that send Java scripts to TSX. All I need do is open the observatory roof and switch on the power. (I also set up the temperature control on the spectrograph.)

To reduce the spectra I have tamed IRAF well enough to just have to enter the target details and it will reduce the spectra by again just running a script.

I have just added a spectra of Rho Cas to the database and if th weather is as predicted should have more to add after tonight.

The attached image shows the split pair of Na D lines at a resolution of R ~ 10000

Regards Andrew

PS Since posting the image I found the software I used to create the image caused on offset in the wavelength scale.

Andy Wilson's picture
Last seen: 9 hours 39 min ago
Joined: 29/03/2014 - 16:05
MRes spectrograph

That is a major accomplishment Andrew! To both build an echelle spectrograph as well as create the processing pipeline. I look forward to seeing your future results with this impressive instrument.


Anthony Rodda's picture
Last seen: 2 weeks 3 days ago
Joined: 01/09/2014 - 14:15
Now that is good.

Andrew, I like anything that automates processes and this is truly impressive.

(I use SGPro for photometry which off the shelf and I like Demetra for its spectro workflow/processing automation).

Any plans to 'publish'?



Robin Leadbeater's picture
Last seen: 3 hours 7 min ago
Joined: 05/03/2014 - 00:50
I take my hat off to you sir !

Each part of this project is a signficant accomplishment. The whole must be unparalleled in spectroscopy at an amateur level.

I take my hat off to you sir! 

andrew.j.smith1905's picture
Last seen: 2 weeks 2 days ago
Joined: 02/12/2016 - 12:22
Thanks for the comments

Thanks Andy and Robin for your kind words. I enjoy tinkering as much as using which is just as well given the near perma-cloud here. One advantage of the fiber feed is I can play with new bits without disturbing the telescope and it's pointing.

Sorry Tony, I don't have any plans as such I basically read all I could find and then pinched the ideas. I then drew a layout on paper and transferred it to ceramic base, drilled holes, and fiddled about until it worked. The optical layout it is similar to the Shelyak Instruments eShel but on its side.  I went for high thermal mass so it is in a large plywood box covered in 2" back insulation. It has an air to air peltier cooler controlled by a Laird Tehnologies PID controller. Once stabilised it is better than +/- 0.02 degrees so the calibration remains stable during a nights observing.

Happy to answer any specific question or help anyone trying to do similar things.

Regards Andrew

jack martin's picture
Last seen: 2 weeks 2 days ago
Joined: 20/01/2017 - 12:41


Congratulations on your achievement.

To be able to build an echelle spectrograph and get it to work is not easy.

With a special interest in Spectroscopy I feel so privileged to be amongst such a talented bunch of like minded people.

Perhaps one day you will give a presentation to the BAA on how you accomplished such a worthwhile project.

I am especially interested in the technical side.



Essex UK