First go at a Spectrum (Albireo)

[Macavity]

Inspired by Ken H's book, I finally got around to trying out my SA100 Filter Grating

- A very rough and ready spectrum of the two components of Albireo!

The setup - MAK150 into a Watec 120N+ - Raw images looked something like this:

(overexposing the Orange primary to record the Blue secondary).

After a lot of devious (manual!) manipulation, I get some hints of better things to come?

Still haven't quite got the "rotation" right, which I sense is half the battle.

At this stage, just some faint lines into which not much should be read...

[samtheeagle]

Alas it's all Greek to me, but it does look all very scientific next to the pretty pictures I try to take I'll be interested to hear how you get on with your adventures into spectroscopy.

[Macavity]

Heheh... Well, might not make a "career" of this. But interesting to try it out?

As they used to say in the Black & White television era. In the top image:

"The yellow ball (star) is sitting above the blue ball (star)..."

Tip: The blue end of the spectra are to the left, I hope...

As anecdotally, the Albireo Primary is "Golden Yellow", the "Companion is Blue"?

The slow MAK150 (large stars?) and the big-pixel'd Watec may be non-ideal

Idem the current level of observer skill - And I always blame the software!

Next step, I'll try my 200mm / F4 Photo-Newt... Remove the UV / IR block?

Always admire the purveyors of "pretty pictures" though...

Whatever, it's a lot of SKILLS to bring together?

[samtheeagle]

We sure did pick a complicated hobby! Still, it's the technicalities that interest me Maybe one day I'll have a throw at spectroscopy, I do keep looking at the star analyser every now and then. Perhaps once my obsy is built, and I'm not spending half of my hobby time setting up and taking apart, I'll be able to invest some of the saved time into these other areas of interest?

[jsandse]

Hi Macavity,

nice first try :0). I can see that several of the dark lines in the B star (in your second image) are Hydrogen lines. I tried to process the B star in Vspec but the distance between the zero order (the star) and the H lines appears to be wrong. Did your processing change the position of the zero order. I can make out some of the tellurics too.

So well done

cheers

John

[Macavity]

Hi John (folks)

Yes, I suspect I did change the position of the zero order line... mostly by

rotating the spectrum to compensate for the grating being at an angle.

But the grating is now better aligned. Put in a bit of thought this time too. LOL. Increased the chip -> grating distance slightly to 60mm. But, most of all put an f/3.3 focal reducer into the MAK150. Also realising that, with spectra, the brightness / contrast setting is a bit more critical. So, after a bit of fiddling:

I suspect there are still distortions - This time due to the focal reducer! But aesthetically it begins to look more pleasing? Yes indeed, now to try and identify some of those lines...

Aside: Trying to think of a "interesting" stars. If it's still clear

tomorrow night: Delta²_Lyrae (M4 II) might be possible?

Chris / Macavity

[Gasman]

Nicely presented spectra there Chris!. What software did you use to process it to that stage?

Steve

[Macavity]

Hi Steve... It's a "Cover Disk" version of a very dated Graphics Program.

(Better not say more?) But I do need to investigate / buy a decent one.

Certainly Software aspects re. Spectra processing need to be addressed too!

... And also (as ever!) properly noting the various scope / cam settings?

[Merlin66]

Chris,

Looks like you're off to a good start!

The faster f ratio gives smaller star images, and with a slitless configuration, i.e. a grating, this helps. Down to f4 is OK.

Keeping the spectrum horizontal on the chip also reduces artifacts.

You can use any of the "standard" astro imaging programs - I use AA5 to obtain the spectra and freeware programs like Valerie's VSpec or Benji's SPCaudACE will do the processing and calibrations.

Onwards and upwards!