Theta Gem Spectrum

[Glasspusher]

Hello, For low resolution spectroscopy with the star analyser 100 a star with strong Hydrogen Balmer lines is very useful for calibration purposes. Vega is often recommended for this purpose, but is a little low in the evening at this time of year. A useful alternative is Theta Gem which also shows strong Hydrogen Balmer lines. Below is an image showing its spectrum taken with a 10 inch Newtonian at F6.4 and a SXH-9 CCD camera. If any one is thinking trying low resolution spectroscopy with the SA 100 give it a go, I have been having lots of fun with one.

 

 

[tooth_dr]

@Glasspusher I bought a Star Analyser 100 a few months back but haven’t used it yet! What sort of exposures are you using?

[Glasspusher]

Hi tooth_dr, I used a single two second exposure to produce the above spectrum. You might need to stack several images for fainter stars, this can be done with registax or similar. Hope you manage to try your SA out, as I said, great fun.

John

[tooth_dr]

4 minutes ago, Glasspusher said:

Hi tooth_dr, I used a single two second exposure to produce the above spectrum. You might need to stack several images for fainter stars, this can be done with registax or similar. Hope you manage to try your SA out, as I said, great fun.

John

Thanks John. It’s been pretty poor here, and any clear nights I’ve been concentrating on deep sky imaging.  But if it only takes very little exposure time then it could be done on partially cloudy night!

 

Could you analyse a comet?

[Glasspusher]

Yes, this type of spectroscopy is well suited to our changeable weather.  The SA has been used to record the spectra of comets together with brighter supernova, being a slitless spectrograph it is not suited to extended objects although small planetary nebula are doable.

John

[tooth_dr]

35 minutes ago, Glasspusher said:

Yes, this type of spectroscopy is well suited to our changeable weather.  The SA has been used to record the spectra of comets together with brighter supernova, being a slitless spectrograph it is not suited to extended objects although small planetary nebula are doable.

John

Super John. Thanks for that.