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About beka

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    Star Forming

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    Besides astronomy, all science, computers
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  1. Congrats on your decision. I am at about 2300m altitude and judging from the discussions on this forum the seeing at my location seems to be better than most folks in UK have, so I am in favor of larger apertures and pushing my equipment to get the best resolution and to pull in the faintest objects. While by no means scientific I tried to look at images I had done with a Canon D700 (30sec subs) on Celestron 102SLT and C11 scopes to compare to faintest stars captured and it was 15.95 and 17.95 mags respectively - which also appears to align roughly with theory. On the exoplant observing, this reference A Practical Guide to Exoplanet Observing basically says that size matters - fainter and therefore more stars will be observable. All the Best!
  2. If it maybe interests you now or in the future you can also do serious science with the 16" like exoplanet transits...
  3. Hi All, My two cents, the larger aperture should capture fainter point sources like stars regardless of seeing - so for example clusters will be better the larger the aperture. Although I have not tried it there is also deep sky lucky imaging where the resolution of the larger aperture will be an advantage. I guess it depends how much imaging of these kinds of objects are of interest to you. Best.
  4. Very interesting shots, what was your camera? Best
  5. beka

    DSLR M31

    Hi Science562h, Nice widefield image and thanks for the tips. Feels like a lifetime is required to learn and try the different features and options available in all the software packages! So what exactly does the "Pick all black points for all channels" option do to the image. Maybe one trade off is between an aesthetically pleasing image versus one in which you try not to lose any detail. Best
  6. beka

    DSLR M31

    I had a master flat from some time back and it seemed to work correctly for a picture of the lagoon Lagoon Nebula I had posted then. I used the workflow on Siril so I imagine it applied the master flat to each light before the stacking and derotation. I did not take any bias or dark frames but that should probably be the next step. Another question that came to mind is, do I have to match the ISO setting on the camera for the flats and lights. If this is the case I have to do another set of flats. Thanks for the tips.
  7. Hi baggywrinkle, Nice pictures. The one of Andromeda shows a number of small trails when viewed at full size. Are they all satellite trails - maybe Starlink? Best
  8. beka

    DSLR M31

    I stretched and adjusted curves separately for each channel then my mistake was to just merge down the layers for each color channel in Gimp. Here is a version where I recomposed properly I hope - but it brought our the chromatic aberration in the stars. I am still kind of a novice when it comes to astrophotography and processing. I prefer this version because it has some color and the central bulge looks more natural, as does M32. Cheers.
  9. beka

    DSLR M31

    Maybe the flats didn't work but I am thinking it might be due to the derotation that Siril does resulting in the corners not stacking. You can see some of this in the lower left though I tried to crop it out.
  10. Hi BiggarDigger, You must have a seriously dark sky. What would you estimate you naked eye limiting magnitude to be? Best
  11. Hi All, Was just thinking that it should not be that hard to put a Nasmyth focus on some of the bigger alt-az mounted SCT's. It would have the advantage of have a fixed viewing height and you could say, have one side for visual and the other for astrophotography with a flip mirror. I imagine some would not mind the additional cost - considering that people are buying the Celestron RASA's. Any ideas? Cheers
  12. Hi george7378, While doing lot of subs, hours of processing and expensive gear will of course get you better images, I am also in favor of doing quick imaging like these you have done because you do get to "see" things you wouldn't at the eyepiece and you also have some record of your observing sessions. Best
  13. beka

    DSLR M31

    Hi All, Having had to move to an apartment where I could not use my CPC 1100, I decided that I have to see what I could do with my NexStar SLT 102 (alt-az achromatic 102mm f6.47 refractor). Setting up on my narrow balcony was challenging and the altitude bearing was so loose that it almost moved from the weight of the Canon 700D. I could not see M31 in the estimated 3.5 magnitude sky so I did a two star alignment and used the live-view to focus on a bright star. I then took a 15 second exposure after slewing to M31 which allowed me to see that I had it in the field of view. After a few more 15 second exposures and playing with the motion controls I managed to get it centered. The resulting picture is from 39 subs of 30 seconds at ISO 1600, 9 flats. The images were stacked and stretched with Siril and then I played with the curves on Gimp, cropped and scaled. Not too unhappy.
  14. Hi Comet71217, I have the SLT 102 that I use once in a while. It is really a wide field scope - very good for things like the brighter messier objects - Pleiades, Beehive, Butterfly clusters and so on. I have found low power views with something like a 32mm eyepiece of areas of the Milky Way or the Orion Belt area quite spectacular under magnitude 5 skies. Under these low magnifications the mount seems to be stable enough. I have tried higher power views of the Moon and Jupiter (like with a 9mm eyepiece and 2X barlow giving 146X) but chromatic and spherical aberrations start to become obtrusive and focusing is more difficult with the unsteady mount. Filters might help a lot - for example a the dark green filter in the Celestron Eyepiece and Filter kit seemed to make the view of Jupiter much sharper with banding and the GRS easily visible. Regarding durability I have had it for several years and it has not failed at all. Alignment (I usually do the two star) works like a charm. If high magnification planetary viewing is not high on your requirements I think you can be quite happy with this scope. All the best
  15. While The Register do try to put some humor in the titles and content of their stories, they do seem to be credible. In the case of 2006 QV89 I did a quick search and the Wikipedia article on it corroborates what is reported by The Register. More seriously, it looks like there is room for improvement in our ability to reliably track Near Earth Objects that might be a threat. For this object the VLT had to be used to rule out the chance of impact and I am sure getting observing time on telescopes of this class is very competitive. The LSST which is supposed to be starting operation in 2020 has tracking of Near Earth Objects as on of its scientific goals so should improve our abilities in this regard. But maybe we should be more worried by being struck by an Unmanned Autonomous Vehicle.https://www.theregister.co.uk/2019/07/19/selfdriving_bus_injuries
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