[Alun Halsey]

Hi Andy,

   Thank you

    Really got to start taking flats and darks,got no excuses now that the system to capture them is built into the Lhires 🙂

      Regards

         Alun

           

 

 

[Alun Halsey]

Hi David,Andy

  Thank you both once again for your help and advice,have also taken you up on your invite to add my profile to your database. Have sent Email with the 1D FITS file of NGC 2903,I do have others but they are just the usual stars I used for getting aquainted to the world of spectroscopy (Vega,Capella a couple of Be stars).

   Regards

     Alun

  

[Alun Halsey]

Thank you Andy,will post result on this Forum if and when I get any data:)  Also thank you all for your advice and tips on calibrating the profile of NGC 2903, in particular David for your help and guidance:) Here is my final attempt at this ,once again calibrated and instrument response corrected using BASS. Have labelled the Hb and Ha lines to show the redshift position of the two points.

  Regards

    Alun

[Alun Halsey]

Hi David,

   Again thank you for this,I haven’t as yet carried out an instrument response,will return to the data and attempt the two corrections and see what I end up with:) 

   Regards

      Alun

[Alun Halsey]

Here is an image of M87 I took using a QHY5L-II,it is a stack of 20 subs at exposure time of 20 seconds and the plume came out quite clearly so reckon it is do-able 🙂

  Regards

    Alun

       

[Alun Halsey]

Hi Andy,

     I know of those plumes as I try to capture them in my H-alpha images:) Very interesting project you had there,will have to follow in your footsteps and have a go with the ALPY and my DIY 1200l/mm classical. One other target I have in mind,when Virgo gets a bit higher in the spring,M87, galaxy with a plume of material extending from a super massive black hole.

 Regards

    Alun

[Alun Halsey]

Hi David,

     No I didn’t go to the expense of the calibration module,hence the use of the Balmer lines as you suggeted. Had another go at calibrating in BASS,but this time I subtracted the sky background leaving the profile for the galaxy rather noisey,but then I realised it would be because the captured spectrum isn’t as defined as that of a star..Doh!!  Anyway I have uploaded the resulting profile showing both the A class star and the galaxy,the sodium line has shrunk and the Ha emission line has risen.

   Regards

     Alun

[Alun Halsey]

Hi Andy,

     Thank you,I actually came by this galaxy by chance as I’d captured a few other targets earlier in the session and sat looking at the star map on PC and thought what next,slew to NGC2903 and was surprised to see the emission lines. Spectroscopy is by far much more interesting than just taking astro images :))

      Regards

        Alun

[Alun Halsey]

Hi Robin,

      Thank you for the link,I often visit this forum to learn more from you professionals 🙂  I had a look at Etienne’s threads and to be honest the math was waaaaayyy over my head (never was my best subject!) 🙁

  Regards

     Alun

[Alun Halsey]

Hi David,

     Thank you for your reply.

     No, I have left the data of NGC2903 as is,I will return to it and do a subtraction. You are right though the much stronger lines are from my sky background and I used the sodium D (5896A) to match up with the sodium in the A class star,or am I wrong in doing this?  I feel a lot happier now though that I have got the calibration nearly right if there is indeed a redshift 🙂

   Regards

       Alun

[Alun Halsey]

I don’t give up easily and hate failing,so have set up the rig again as per photo above. I have a feeling all the flexure was coming from the focuser on the Kson triplet,they are only held in place by a run or two of plumbers PTFE tape!! So have now bonded the focuser to the tube and have also beefed up the guidescope mount by adding a spring under alt adjuster. Fingers crossed everything holds position this time:)

[Alun Halsey]

Tonight was the last straw for attempting to use my dual scope/spectroscope setup. No matter how tight I bolted down the skywatcher guide scope mount,something would shift causing a mis-alignment of the slits. Even changed guide scope mount out for guide scope rings and that was even worse!:(   Works great if working on a small area of sky,but any meridian flips etc causes a shift and I am spending more time re-aligning the slits than actual observing……So now back to C9.25 on the EQ6 and swopping out spectroscopes each session.

[Alun Halsey]

Hi Richard,

     I will need a few more sessions to iron out any problems that may arise with the kit,(most of those are more likely coming from my DIY unit)  But I would be more than happy to offer material for the Journal,thank you 🙂

[Alun Halsey]

Hi Andy,

 Thank you:)

     Dual bar side by side to keep CofG low helps the EQ6 carry the kit with no problems (though scary bit is having to loosen lock nuts on mount head to shift all the kit whilst using one hand to hold the whole lot in place when sorting out the balance!). One of those Skywatcher guide scope mounts carries the 80/ALPY (just slightly over recommended capacity,so could do with one of the beefier baader units). Last night was first light for the rig and so far,so good:)  Have attached a photo to explain better.

    Regards

       Alun

[Alun Halsey]

Hi Robin.

 Thank you,wanted to arrange a way in that I can take lo-res and hi-res in a session without the hassle of swopping out spectroscopes and re-arranging the counterweights etc. So I have the SCT carrying the hi-res unit and the 80mm taking the ALPY /guide unit on a side by side dual bar. Both scopes are aligned so I know that if star is center of ALPY slit then it will be in the slit of the hi res unit. Then I just guide as if I were using the ALPY,seems to work so far and I’ve managed 5min exposure times with no problems:)

  Regards

    Alun

 

[Alun Halsey]

Thank you David 🙂

 The Alpy is a nice bit of kit,anyone contemplating getting one will not be disappointed (definately needs the guide unit though).

[Alun Halsey]

Thank you Andy,just been trying to get my head round adding a Planck temp curve,but will stick to just calibrating and response calibration for a while longer! 🙂

   Alun

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