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gorann

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gorann last won the day on March 18

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About gorann

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    Brown Dwarf

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    http://www.mn.uio.no/ibv/english/people/aca/gorann/index.html

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    Male
  • Interests
    Astrophotography
  • Location
    Värmland, Sweden (59.77 °N)
  1. So now my confusion now is that I had 63.5 mm including the 8 mm adaptor from the actual focuser to the chip (55.5 from the adaptor to the chip) which should be spot on if I take into account that I have a Baader filter inside (if the efect of the Baadre filter is that I need to slightly increase the flattener to chip distance). I guess I just have to start playing with T2 rings to see what happens. Fortunately I have a lot of different rings laying around.
  2. Thank you both! I check my distances carefully nex time. Does anyone know how much I should add or subtract with a Baader NB filter in the system?
  3. PS. Just to check that the oval stars were not a stacking error in PI, I now looked at one of the subs, and they are clearly there, as seen in this crop from a corner. It cannot be guiding error since the oval stars are only in the corners and in different directions in each corner. It really looks very much like a probelm with flattener distance.
  4. Thanks Dave! On the FLO web site it says "The spacing for dedicated CCD imaging cameras is 55 mm from mating surface (69.8 mm from centre of rear element)" so I can only assume that they mean from the mating surface of the flattener to the chip (and the rear element is the last lens in the flattener). They cannot mean the "cameras mating surface" as you suggest since that differs between camera models. The same distance is given as 63 mm in the SW manual. I used the 63 mm distance (or rather 63.5 mm which was the closest I could get, with filter wheel and T2 rings giving 56 mm and a further 7.5 mm inside the ASI1600). And got quite oval stars in the corners and perfect ones in the centre, which suggest an error in distance. I cannot believe that the 0.5 mm would have such an effect. I also have an Esprit 150 and there I was told by FLO that the distance (mating survace of flattener to chip) should be 98 mm (as on their net site) and not 96 mm as stated in the SW manual. They told me straight out that it was an error in the SW manual. I attach an image showing the stars in the corners before cropping, star fixing and further processing. I will post what FLO says about it (I sent them the question late Friday so I guess I have an answer early next week).
  5. Thanks Wim. I have a version where I added colour from the Esprit 150 with ASI071MC pro to this Ha data. No other chance to add colour soon due to travel and the moon:
  6. It really shines through that you are now at a much darker site. And excellent framing. For some reason M31 is immedeately recognisible even if we only see a fration of it. And who cannot like that poor little galaxy that is being slowly sucked into it? Actually, that fatal attraction is so clear in your image that I think you should submit it to APOD - I am sure the NASA astronomers could make an interesting story about it.
  7. Last weekend I had my first session with my new Esprit 100 and my new ASI1600MM pro. I used a Baader 7nm Ha filter and aimed at Sh2-115 and got the small Sh2-116 as a bonus. Less of a bonus was that I hade oval stars in the corners. I then remeber that FLO had told me that the flattener to chip distance in the Esprit 150 manual was slightly wrong. When I now checked the distance given for the Esprit 100 flattener on the FLO site (55 mm) I realize that this is quite a bit from the 63 mm stated in the Esprit 100 manual from SW (which I should not have trusted). So mystery probably solved and easily fixed by removing 8 mm of T2 extenders. What I cannot understand is why SW cannot get these distances right in their manuals (no new priniting needed as they are available as pdf on their site). So, I had to crop quite a bit in the corners and still fix the worst stars in PS. Also the seeing was not the best. This is 53 x 5 min lights, so a bit over 4 hours. Stacked in PI (and 35 x 5 min darks subtracted as Master dark) and processed in PS. C & S most welcome!
  8. gorann

    M33 in HaRGB

    Really great to see that you finally are up and running after moving out of town. I think I can see in your image how dark the new sky is. Very nice colours and details. Congratulations!
  9. Good idea. I add it to future things to do!
  10. Thanks Peter! Yes, I regard it as an ok start.
  11. Thanks! You made me just change the title of the post. It is slightly irritating that the plate solving routine in Astrobin apparently does not recognize Sh2 objects.
  12. Clouds are now back again but I managed to collect a bit of first light data with my new rig on Saturday night. It is made up of two Esprits with CMOS cameras. The Esprit 150 was connected to my ASI071MCpro for RGB (ZWO 2" UV/IR block filter) and my new Esprit 100 was connected to my new ASI1600MMpro for Ha (Baader 2" Ha 7nm). 50x5min RGB and 53x5min Ha, so totally 8.6 hours. The night started nice and dark but with progressive deterioration in seeing (mist) that finally stopped me around midnight, but with two scopes I still got a desent amount of data. I struggled more than usual with processing but it ended in a relatively presentable image I think (mostly done in PS with stacking and a bit of deconvolution done in PI). Ha mainly put into the red channel mixed in as Lighten in PS as @ollypenrice prescribes and it worked best (so thanks Olly!) and a bit Ha into lum. Only calibrated with master darks and no flats as I have no detectible dust bunnies yet and the filters are big (2") so I can place them a few centimeters from the chips. Info from the APOD site: Sharpless 115 stands just north and west of Deneb, the alpha star of Cygnus. Noted in the in the 1959 catalog by Stewart Sharpless (as Sh2-115) the faint but lovely emission nebula lies along the edge of one of the outer Milky Way's giant molecular clouds, about 7,500 light-years away. The nebular glow is powered by hot stars in star cluster Berkeley 90. The cluster stars are likely only 100 million years old or so and are still embedded in Sharpless 115. But the stars' strong winds and radiation have cleared away much of their dusty, natal cloud. I have so far not made an effort to find out what that possible planetary nebula to the right is called. I am sure some SGLer knows. The FOW of this combination is not a perfect match and my Ha data is more wide field and I may have an additional go at processing it separately. Comments and suggestions most welcome!
  13. Interesting! To be sure that you are not only measuring changes in your atmosphere that affects the brightness of the star that you interpret as an exoplanet passing (especially when it only involves a 2 % drop in brightness) it would be more convincing to do several measurements during transist and between transits and compare these.
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