Vega spectra 27th August

[dark star]

Hi

some Vega spectra taken between the clouds on Friday night.

Using an Orion Optics UK 250mm f/4.8 reflector, a Rainbow Optics 200 line grating and a DMK41 CCD camera.

Around 50 AVI frames stacked in Registax6, processed in IRIS and calibrated in Vspec.

I cannot get the star and the spectra in the same image so I calibrated using the H beta 4861 and H gamma 4341 hydrogen lines.

I am pleased with the result as I was tracking by hand using a Tal 2M mount.

For the first time I got the H alpha 6563 hydrogen line (I think!).

The spectra matches the library spectra from Vspec quite well.

I have ordered a shorter nose piece for the camera from Modern Astronomy which should mean I can get the star and the spectra in the same image.

Any comments or suggestions for improvement welcome.

After a few months of taking spectra of Vega I think I can try another star next, maybe Deneb, as I think it is the same spectral type.

David

[Merlin66]

Well done!

Looking pretty good....

If you're happy calibrating the spectrum from known features (Hb and Ha etc) then you don't need the zero order star image in the field.

Also, if you don't change anything the dispersion in A/pixel will be a constant, so you only need to calibrate with one known absorption line.....

You can use this result to generate an instrument/ camera response curve for the DMK. Then this can be used on future spectra to correct the intensity curve.

Onwards and upwards.

[jsandse]

Nice looking spectra of Vega David.

Spectral type of Deneb is a bit different to Vega in terms of spectral type: A2Ia as opposed to A0V

As Deneb is a supergiant when you take its spectra you should hopefully see that the Hydrogen absorption lines are narrower than those in Vega.

cheers

John