Nouveau Echelle Linx

[etienne bertrand]

Congratulations Joan, well done !

[Joan Guarro Flo]

Paolo and Etienne many thanks for your encoratgement,

These two graphs are from last night are the first light.

The wavelength calibration is good but there are still things to tune.

Going to change the collimator 100 F to F125 mm. to try to overcome the current R = 8000 and I reviewed the focus of the collimator and the CCD. See Martin Dubs,

https://meteorspectroscopy.files.wordpr ... matism.pdf

That will be next week.

For now, orders are 26 (the size of the chip ATIK460EX not support them any more), and the dynamic range was from 4064 to 7744 angstroms.

Friendly, Joan.

[Martin Dubs]

Congratulations Joan,

the LYNX gets better every day (I had the privilege to see some previous spectra). Maybe you make the collimator interchangeable with different focal length for higher resolution or fainter objects. My echelle was quite similar with a collimator f/6, which was too slow (a lot of light wasted).

Regards, Martin

[Andrew Smith]

Joan, you seem to be getting some very nice results. Your constructions make mine look very crude in comparison.

I was wondering about the effect on throughput with the change in collimator. What was the design focal ratio for the echelle? Did the original design under-fill the echelle grating and/or will the new collimator over-fill it. Maybe both are a happy compromise.

Do you have a specific program of work in mind that needs R~10000 rather than R ~ 8000?

Have you made any measurements on it's stability (temperature or time?)

Regards Andrew

[Joan Guarro Flo]

Hallo Martin, hi Andrew,

Now the Linx is already in the final phase of its commissioning note. The current resolution is R = 8000. This resolution is sufficient to be able to work in all existing observation programs. But this week will try to improve the resolution changing the collimator 100 mm. a 125 mm.

I hope not to have an excessive loss of light, otherwise return to the resolution of R = 8000. I prefer less resolution and to reach stars weakest. R = 8000 now enables very precise measurements in the work that our group takes place.

Temperature changes. For me, the temperature, there not is a worrying aspect in the vicinity of R = 10000, not in any way affect the results, as long as certain precautions are taken (these precautions are always necessary if you also include temperature controls).

A first example, see C.Buil observation, of the exoplanet Tau Boo.

http://www.astrosurf.com/buil/tauboo/exoplanet.htm

Another example are the following graphs represent the simultaneous observation of the star VVCep. One is a graph by Mussol, from Piera and the second with the Linx made from Sta. Maria (about 70 Km.). When observing the temperature deference between the two towns was a 3ºC. In addition, the two spectrographs had to endure daytime temperatures of around 28º.

During an observation session, for every star, take your flat tungsten and its calibration RELCO SC480. The most surprising is that the flat swapping and calibration, the number one star of the star number four (for example), the result is very good, very stable (better not change them). So far, the temperature is not a worrying fact for me. To mention a person, François Teyssier, lets not even one.

I know three commercial brands Échelles, two of them are direct injection to telescope, I have not seen that their use made no reference manual temperature control, (one of them with R = 20 000).

What is essential is the rigidity and strength of the mechanical assembly weak, is a bad montage.

I did not invent this is an application of my experiences.

Friendly, Joan.

[Joan Guarro Flo]

Hello,

Today I changed the collimator LINX. I retired achromatic lens of D 30mm. F 100mm. (Edmund Optics), and in its place I have placed an objective, of one finder, (Chinese) of D31.7mm. 125mm focal length.

Preliminary results (with daylight) are good, the Linx has passed a resolution, R = 9000 and have increased the number of orders. Now are of 29 to 55. Range = 3979.5 to 7760 Angstroms.

Now try to be a star ...

J.G.

[Joan Guarro Flo]

Hi,
A test in the sky, the star T CrB with the LINX and R=9000.
Cheers, JG.

[etienne bertrand]

Hello Joan,
It's possible to have some photos of your spectro on the telescope ?
Nice results !

[Joan Guarro Flo]

Bonjour Etienne,

These are both fotos of the LINX in the REMOT to Sta. Maria M.

Bien cordialement, Joan.

[Joan Guarro Flo]

Hi,

I present the comparison of two graphs, the star VV Cep. One is with the Linx from Sta. Maria and second with the Mussol from Piera.

The reason is a test to check the stability and confidence of both Échelles.

You know that VVCep is an M2, with little emission in the blue.

In the graph, from 4052 to 4175 Angs., The background noise is confused with the image (to improve the result and need more exposure time), the result is bad.

In the graph, from 4175 to 4300 Angso., The coincidences begin to be evident from the 4200 Angs.

In the graph, from 4300 to 4425 Angso. I think that I can improve.

Regards, J.Guarro.