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dokeeffe

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About dokeeffe

  • Rank
    Nebula

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  • Location
    Ireland
  1. One way to confirm if something in an image is a hot pixel or cosmic ray strike would be to have 2 telescopes and 2 cameras pointing at the same target. Both scopes with synchronized exposures. Say constantly taking 1min exposures each aat the same cadence. If something odd appears in both images in the same ra-dec coordinates then there's a good chance its some transient event rather than noise. If I could just get a second C11 and Atik383 I'd give it a shot
  2. Wow thats an impressive shot. You must have some pretty good seeing conditions too though. Are you at high altitude?
  3. Thanks Peter, Actually not much I can do with the spacing. There is a spacer between the camera and the corrector but this spacer was provided by starizona for this particular setup. No adjustment. I'll check the threads, maybe something loose. Derek
  4. Hello, This evening I put in some time collimating my C11 with the camera in place. The centre of the field is good, however the bottom left of the field is not good. I'm wondering if this is some sort of focal plane tilt? Although the star images look more like streaks than out of focus stars. The scope is a C11 (not EHD), Camera is an Atik383L+ and I'm using a starizona .63 reducer. Anyone out there have any ideas? Thanks, Derek TOP-LEFT TOP-RIGHT BOTTOM RIGHT BOTTOM LEFT
  5. On further investigation it looks like the signal is not astrophysical... That star's peak pixel values in my images were totally saturated, making any photometry unreliable.
  6. I was observing an exoplanet transit 2 nights ago and while looking through the data I decided to browse the light curves of other random stars in the same field of view. Then I came across this.....To me it does not look like random noise, although its hard to say for sure. Checking AAVSO's VSX for this coordinate, there is no known variable start there. Not sure what else to check or what to do with this..... For reference here is the exoplanet transit that I was targeting (missed a chunk of the start of the transit due to weather). The S/N ratio is not very good for this data. And here are some other random star light curves from the same field for comparison to get an idea of the noise.
  7. Yes, thats exactly what I was doing. Batch convert, review, then manually delete any bad frames. Hope it works for you. I've only tested it on Linux.
  8. https://github.com/dokeeffe/yaffv I needed a really basic file viewer in order to delete bad-quality images before feeding a data reduction pipeline. I couldnt find anything to do this quickly for hundreds of images, so I threw this together. Its very basic, Just left right cursor keys and delete key functions... Makes it possible to quickly preview hundreds of files and delete any bad ones. Hope its useful for someone else too.
  9. On the off chance anyone located in Ireland is looking for one of these.... Fork mount + handset + Wedge + Tripod €450 I'm deforking my C11 so this is the mount only, No C11 OTA. All in working order. Might suit an ATM project for someone or array of smaller scopes/lenses. located in Ireland. Collection only.
  10. I use this to find exoplanet transits to observe http://var2.astro.cz/ETD/predictions.php?delka=-8&submit=submit&sirka=52 And this for variable stars in need of observation https://filtergraph.com/aavso?ac=on&settype=true
  11. Great work! Its there alright. I'm wondering is there any way you could share the fits files? Maybe dropbox or something? Id love to run them through the system I used recently to plot exoplanet light curves. Its called Lemon (https://github.com/vterron/lemon) It uses a special algorithm to find the best comparison stars to use and generally I get a better light curve from it than astroimagej + manual comparison star selection. The only problem with lemon is that it has a lot of dependencies and its a nightmare to install. Derek
  12. Yes, and also other effects like limb darkening of the star combined with any tilt in the orbit. Its kinda hard to explain but if you imagine the planet crossing right through the midline of the star from our point of view, versus the planet crossing, closer to a polar region. If crossing right through the middle, the planet 'shadow' cuts right through the star's limb darkening quickly and crosses into the bright part of the star. If the planet's shadow cuts in closer to a pole or lower down, the shadow spends more time in the darkened limb area and therefore the change in brightness takes more time.. Its hard to explain. but imagine the difference between the top 'L' and middle 'L' below.
  13. It a fork mount, the CPC1100. Its the weak link in the chain now. Its got a lot of periodic error, roughness and backlash. So my stars are bigger than they should be on the images. Its contributing to the noise for sure. I'm thinking of de-forking it and getting something like an EQ8 or maybe an ioptron CEM120, the one with the encoder sounds good. No need to guide (or so I heard)
  14. Kind of luck alright :-) It was the first clear night here in Ireland in like months. So I took a look at EDT http://var2.astro.cz/ETD/predictions.php?delka=-8&submit=submit&sirka=52 which lists all the transits happening soon for my location and spotted this star with a large dip in mag (0.029) and also the timing was good as it was rising in the sky and was pretty high by mid transit. The first bunch of points are noisy because it was lower in the sky,
  15. all those measurements were taken on 1 night. The UTC time is on the x axis. about 23:30 to 2:30. However yes, as you say, it is possible to overlap several transits to get a much less noisy light curve and refine the orbit. I've never done this though.
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