spectro-aras.com

Well done on such a faint star Robin, even with that SN ratio it looks fairly conclusive.
Regards Andrew

I assume you will try for a spectrum. If I ever get to see the stars again ! With this weather I have only observed on 6 nights so far this year and I think only none with conditions good enough for faint objects like this :( Yes that's why I decided to take the rig to Pixelskies in Castillejar! I ...

Certainly looks similar Robin, it is too faint for my slitless system. I assume you will try for a spectrum.
Regards Andrew

Good points Robin, I have been looking at subtracting the pre flare spectra from the flare spectra I go of HIP25953 as both the continuum and lines are changing significantly. The attached is the result at the peak.
Regards Andrew

Robin is there still an issue with how you normalise the spectra especially if the continuum is changing?

Not that there is an ideal answer

Regards Andrew

It depends on the details but it can include astigmatism, coma and spherical aberrations. I suspect they get more expensive the better the correction.

I don't think one implementation should necessarily condem them. I might have a play now the rest of my kit is out of reach!

Regards Andrew

As per the title has any one any experience of building and or designing astronomical spectrographs with flat field, aberration corrected, concave gratings. They do seem to offer a compact solution with minimal additional components. I am aware of the Starlight Xpress spectrograph and have looked at...

Just some thoughts. Have you checked/cleaned the fibres? Do you shake the fibre to reduce modal noise. With my guide head I found misaligned calibration optics in the guide head I produced considerable modal noise.
Regards Andrew

Just scanned "Physics of the interstellar and intergalactic medium" which did not turn up anything obvious. The ones which might have been in the visible are also in our atmosphere and show as the teluric lines!

Maybe others know better

Regards Andrew

Not sure if this counts but you get absorption due to interstellar sodium in the spectra of some stars e.g. Rho Cas which I have captured.
Regards Andrew