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Posted (edited)

Wow,  I could get hooked on this, lol. Just did a run on Three star's, Gamma Casseopia, Deneb and Alpheratz. Just a screen shot for tonight, but could clearly see absorption lines on each and in different positions with each star. Will try and process tomorrow. It's all a new learning curve. Another gain from this, is I'm learning the star name's too, lol. 

IMG_20191002_220240.jpg

Edited by Nigella Bryant
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Nigella,

Well done!

Looks like you're of to a good start.

Onwards and Upwards.

 

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Very nice. I am planning to do some too at some point. 

  1. Are you using the Star Analyser 100 (SA100) ?
  2. What software are you using for the processing of the spectra ?

BTW - if you want to get a screenshot within MS-Windows, press and hold the 'Windows logo' and 'Prt Scr/Sys Req' keys. The screen will dim or flash for a second when done. The image will be saved in the Screenshots folder and named 'screenshot (xx).png' 

 

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6 minutes ago, Merlin66 said:

Nigella,

Well done!

Looks like you're of to a good start.

Onwards and Upwards.

 

Thanks Merlin66, I did find capture rather easy, I guess the hard part will be calibration and getting some data from the spectras. 

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1 minute ago, Philip R said:

Very nice. I am planning to do some too at some point. 

  1. Are you using the Star Analyser 100 (SA100) ?
  2. What software are you using for the processing of the spectra ?

BTW - if you want to get a screenshot within MS-Windows, press and hold the 'Windows logo' and 'Prt Scr/Sys Req' keys. The screen will dim or flash for a second when done. The image will be saved in the Screenshots folder and named 'screenshot (xx).png' 

 

Thanks Philip R, didn't know I could do screen shot like that, I'm a numpty, lol. Yes I'm using the star analyser 100 and BASS software.  

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Posted (edited)

Nigella,

Just drop the image into BASS Project and you'll immediately see a spectral profile. Use the selections to just select the height of the spectrum (this will automatically remove the background).

Calibrate by using the zero order as "0" wavelength, and pick a second prominent absorption line - usually H beta but look at what you've got - Gam Cass should show a peak, this is H alpha.

Once you're happy with a calibration select a reference spectrum to match the type and look for similarities........

One step at a time........

We're here to help you on your journey.

Ken

 

Edited by Merlin66
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2 minutes ago, Merlin66 said:

Nigella,

Just drop the image into BASS Project and you'll immediately see a spectral profile. Use the selections to just select the height of the spectrum (this will automatically remove the background).

Calibrate by using the zero order as "0" wavelength, and pick a second prominent absorption line - usually H beta but look at what you've got - Gam Cass should show a peak, this is H alpha.

Once you're happy with a calibration select a reference spectrum to match the type and look for similarities........

One step at a time........

We're here to help you on your journey.

Ken

 

Thanks very much Ken, appreciate this, will be doing the profiles and calibrations tomorrow, off to the land of nod now, lol. 

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So just a question.  I used a zwo ASI224mc to capture the spectra. Do I process the avi file's in the same way as normal in autostakker before I use BASS Project? 

 

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Nigella,

If you’re happy with the AS! results, then do what you do and import the image into. BASS Project.

Ken

 

 

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14 minutes ago, Merlin66 said:

Nigella,

If you’re happy with the AS! results, then do what you do and import the image into. BASS Project.

Ken

 

 

Thanks Ken. 

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Not scientific but a comparison of my first efforts processing some spectrum. Top spectrum is produced from my image and the bottom spectrum is of a reference star. pleased that absorption lines pretty well match. 

nigellabryant-021019.bass-2.png

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Posted (edited)
40 minutes ago, Philip R said:

Well done @Nigella Bryant.

To quote a well known supermarket chain... "Every little helps!"

Thanks, lol. Pretty chuffed what can be done with the star analyser 100 and a 12inch f4 Newtonian. Considering Alpheratz is 97 light years away. 

Edited by Nigella Bryant
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Posted (edited)

Nigella,

Good start!

Looking closely at your spectrum.... the dark lines at the left hand side are obviously the Balmer Series lines of Hydrogen. Playing around with possible solutions I can get a reasonable answer when the dispersion is around 40 A/ pixel (based on your ASI 224mc, 3.75 micron) but with a 100 l/mm grating this infers a distance from the filter to the chip of around 10mm - ie the filter is mounted inside the camera!

I can only therefore assume that the image posted has changed scale from the original? What spacing do you have?

I also think the 2nd order spectrum is overlapping the 1st order, giving the impression of a much longer spectrum.

If you can post the original spectral image we can better analyse your results.

Onwards and Upwards.

 

Nigella_021019.JPG

Edited by Merlin66
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1 hour ago, Merlin66 said:

Nigella,

Good start!

Looking closely at your spectrum.... the dark lines at the left hand side are obviously the Balmer Series lines of Hydrogen. Playing around with possible solutions I can get a reasonable answer when the dispersion is around 40 A/ pixel (based on your ASI 224mc, 3.75 micron) but with a 100 l/mm grating this infers a distance from the filter to the chip of around 10mm - ie the filter is mounted inside the camera!

I can only therefore assume that the image posted has changed scale from the original? What spacing do you have?

I also think the 2nd order spectrum is overlapping the 1st order, giving the impression of a much longer spectrum.

If you can post the original spectral image we can better analyse your results.

Onwards and Upwards.

 

Nigella_021019.JPG

Thanks Ken, it has been streached. Tbh I'm struggling to work out bass project at the moment. I'll post original spectrum sometime today. I've looked at the recent videos on the BAA website on the subject, I can get a chart OK but when I calibrate the calibration points are way off. Anything between 2.5 to 230+ with four calibration points and suggested wavelengths. Any help would be much appreciated. 

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Nigella,

softly, softly.....

what’s the grating spacing? This will help confirm the dispersion.

If you use the zero order as the “0” wavelength and the third absorption dip as H beta (see the profile above) should get you started.

 

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Posted (edited)
16 minutes ago, Merlin66 said:

Nigella,

softly, softly.....

what’s the grating spacing? This will help confirm the dispersion.

If you use the zero order as the “0” wavelength and the third absorption dip as H beta (see the profile above) should get you started.

 

lol, Ken, thanks, attached is the original input. I just used the original nose piece to the asi224mc. What would be a typical work flow in BASS project?

ALPHERAT22_35_50_e11111111_ap1.tif

Edited by Nigella Bryant

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Nigella,

ok, open the Spectral image in BASS Project.

Make sure it has the zero order image towards the left and horizontal to the chip.

use the selection icon to select the Spectral image.

look at the profile, the idea is to identify a prominent absorption line - say H beta

Go to calibration select the zero order as “0” and the H beta as 4861

This should give you a calibrated profile. Crop the ends just to leave the main Spectral  detail (roughly 3900 to 7000A).

That’s a good starting point.

I’ll have a look at your image........stay tuned.

 

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Nigella, That looks much better.....

It calibrates at 8.6A/pixel which is good! and matches a spacing of around 43mm with the 100 l/mm grating.

 

nigellabryant-021019_02.jpg

nigellabryant-021019_03.jpg

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Nigella,

The hump around 5900A is due to the RGB filters on the Bayer Matrix in the camera.....

 

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Posted (edited)
56 minutes ago, Merlin66 said:

Nigella, That looks much better.....

It calibrates at 8.6A/pixel which is good! and matches a spacing of around 43mm with the 100 l/mm grating.

 

nigellabryant-021019_02.jpg

nigellabryant-021019_03.jpg

Very much appreciated Ken, I'll have a go myself when I get back home later today. Thanks so much for your help. 

Edited by Nigella Bryant

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Nigella,

Just to show the selection screen used.......

nigellabryant-021019_04.jpg

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Posted (edited)

Been struggling with BASS project but managed this today. Not sure if this is correct. Spectrum of Vega analysis. Any comments welcome, gulp, lol. Just posted for any input. Thanks again for looking. 

 

 

vega-spectrum chart.png

Edited by Nigella Bryant

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Posted (edited)
44 minutes ago, Nigella Bryant said:

Been struggling with BASS project but managed this today. Not sure if this is correct. Spectrum of Vega analysis. Any comments welcome, gulp, lol. Just posted for any input. Thanks again for looking. 

 

 

vega-spectrum chart.png

Looks like the calibration is out. What you have identified as H alpha is most probably H beta.

Nearly there.

Regards Andrew 

Edited by andrew s
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7 minutes ago, andrew s said:

Looks like the calibration is out. What you have identified as H alpha is most probably H beta.

Nearly there.

Regards Andrew 

Thanks Andrew, appreciate your help. 

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