[darrellx (Darrell)]

Hi All

Well, I am now beginning to look at a bit of success with my foray into spectroscopy, and I am quite pleased.

Last night, while it was clear, and before the equipment got foggy, I was able to have a go with my Star Analyser on three targets - Acrux (B class), Alpha Centauri (G class) and Sirius (A class). I was aiming to get an A and an M class. The telescope was a Megrez90 and the CCD was an Atik 314L+.

In the attached composite, I can at least see some banding. And they appear different with each of the three objects. So I figure I have finally captured my first spectrographs. I realise now that my focus was the issue. I had been focusing on the stars and not the spectra.

I am hoping someone might be able to answer a few questions for me, regarding what I have captured.

First, notice that there is a large "white strip" from the star to the first band (the blazed first order?). There are no features in here. Is this normal?

Second, notice that to the right, the spectra of Acrux fades to black quite quick, while AlphaCent has a pale line and Sirius is quite bright with some features. Is this simply a function of the brightness of the star (the Zero order?) coupled with my exposure time?

Thanks
Darrell