Saturn 16th Feb 2013

[jnp]

Finally a clear sky albeit not ideal.

My objective was to determine the difference in spectra between the rings and main sphere of Saturn.

I created three profiles from the FITS of a stacked video. Each profile had background subtraction.

A slit would have improved things but the objective is met. I can see

1. stronger methane bands in the sphere and

2. stronger Hydrogen beta and metals in the rings.

Next I will experiment by merging top & bottom profiles and dividing with a nearby G2V star (if I can get the vid to stack properly that is).

Odd that the bottom ring spectra has more blue than the top. The Doppler shift is not that pronounced!

Thanks for looking

John

[the rev]

Great image. How did you get 3 separate spectra, mine comes out as one? Is this purely that you are using an8 inch and I am using a 5 inch?

Kate

[Gasman]

That's a beauty John! . Interesting how you managed to get three spectra from what usually would be one image . Well done

Steve

[Merlin66]

Normally a slit spectroscope is used to get this type of separation...

Interested to hear about your method.....

[jnp]

Hi Kate and Steve,

Thanks for your kind feedback. The multiple synthetic spectra are just a feature of the app I'm using. It shows one per loaded profile.

The screenshots below should help explain what I did.

Basically I start off with a Saturn spectra which was orientated such that the rings and planet can be distinguished.

I select the 1st region for binning across the centre (plus two regions for automatic background subtraction) and then export. This is then repeated for the top and bottom of the spectra.

thanks for looking

John

[Merlin66]

Hmmmm

That's VERY interesting!!!

What optical set up were you using to get that plate scale?

I must compliment you on the experiment....certainly "boldy going......"

Well done!

[jnp]

Hi Ken,

I'm just using an sa100 about 70mm in front of a QHY5 sensor. A 10mm + a 15mm t-spacer behind the 1.25" nosepiece does the trick. It fills the 1280 pixels of the QHY5 quite nicely with a range of 9500 Angstroms and a dispersion of 7.4 Angstroms per pixel. The previous screenshots posted show the actual size.

I have posted the actual fits if you or any one else wants a a go.

http://dl.dropbox.com/u/87095951/Spectro/BASS%20Project/stuff/2013_02_16/Saturn/saturn_00001.fit.zip

thanks

John

[nytecam]

Good work - a slit [and longer exposure] will greatly improve the resolution