Forum der Vereinigung der Sternfreunde

Hi all, is here anybody who is familiar with the Shelyak eShel spectrograph? I am looking for the (mechanical) stability and drift of calibration line radial velocities in km/s. Cheers, Thomas

Hi Thomas,
Some years ago, I have try to mesure the shift of Thorium/Argon lines on my eShel spectrograph (without any temperature regulation, just ambiant air).

You can find here the result : (sorry this page is in French only...)
http://o.garde.free.fr/astro/Spectro1/L ... -Shel.html

Now my spectrograph is inside a cooler wine cellar with a PID regulation :
http://www.spectro-aras.com/forum/viewt ... f=8&t=1141

The regulation now is about +/- 0,1°C but I have not yet done any measurement to check drift with this thermal regulation.

For beter accuracy, I use also Th/Ar line with 4 digit after dot (comme from Harps spectrograph)

And I will try (as soon as possible) an exo-planet like Tau Boot with this set up to check if I can have good result

But I know is it possible, Christian Buil had done this kind of measure a few years ago with an eShel spectrograph :
http://www.astrosurf.com/buil/extrasolar/obs.htm

Very nice, Olivier! So, your drift is about 750m/s/°C or 75m/s if you can bring it to 0.1°C temperature stability. Right?
Salut, Thomas

PS: Pas de problème avec la langue. J'ai fait mon PhD a Montréal. Donc, je peux lire mais pas bien ecrire...