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alan4908 last won the day on September 9 2019

alan4908 had the most liked content!

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About alan4908

  • Rank
    Sub Dwarf

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  • Gender
  • Interests
    Astrophotography ! ....at the moment I'm concentrating on deep space imaging
  • Location
    East Sussex

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  1. alan4908

    Deep Sky III

    Images taken with a Trius 814 and a Esprit 150
  2. Thanks - I'm not at all keen on the Hubble Palette, so I think I shall have a go with just Ha and OIII. I do already have an Astrodon 3nm Ha filter but I don't think I can justify further spending on a NII filter. Alan
  3. Thanks Dave. Have you seen any good hi-resolution NB images which would point me in the direction of which filters to use for the acquisition. I'm currently guessing Ha and OIII. Alan
  4. Thanks - yes, it does look a little bubbly - I think acquiring some narrow band data would help capture a few more details. Alan
  5. NGC7008 is a planetary nebula located in Cygnus about 2800 light years distant and about 1 light year in size. The amateur astronomer Eric Honeycut named it the Fetus Nebula when he viewed it through his 22inch reflector. Planetary Nebula are one of the few astronomical objects that may appear green, so when processing this particular object you have to be careful when eliminating green from your image (eg SNCR green in PI) otherwise it will significantly change the colour balance of the object. Since it is so small and there's not much of interest in the background, I decided to crop it quite aggressively, so that a few details of the nebula can be seen more easily. So, here's an LRGB image consisting of 13 hours integration which was taken with my Esprit 150. Alan LIGHTS: L:26, R:17, G:17, B:18 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C.
  6. That is a very impressive image. Alan
  7. Thanks - I was pleased with the amount of detail - this was helped by the creation of a so called "super luminescence" which increased my SNR for the lum without impacting detail. This in turn allowed me to perform a stronger deconvolution, thereby extracting more detail. Alan
  8. NGC4725 is the brightest member of a galaxy group in the constellation Coma Berenices and is about 40million light years distant and 130,000 light years in diameter. The structure is somewhat unusual, consisting of just one spiral arm which is tightly wound around the core and can be followed for about 1.5 revolutions. The spiral arm consists of dust and gases including bright blue stars and pinkish Ha regions which indicate star forming regions. Towards the center, much older, yellow stars can be seen. The galaxy is classified as a Seyfert Galaxy, indicating that the center contains a supermassive black hole. The smaller galaxy on the right side is NGC4712 is within the galaxy group but is at the much greater distance of about 200million light years. The LRGB image below represents 12 hours integration time and was taken with my Esprit 150. Alan LIGHTS: L:21, R:13, G:20, B:18 x 600s; DARKS:30, FLATS:40, BIAS:100 all at -20C.
  9. Hi Adam Whilst I don't have an Esprit 100, I do own an Esprit 150 which is set up for automated imaging using filter offsets. I explored the details of this a couple of years ago and understanding the theory a little more greatly improved my results. So, you might want to take a look at this post:
  10. alan4908


    Thanks Alan Thanks for your detailed comments. In acquiring the image, I did wonder if I could detect some star forming regions, so in acquiring the image, I also decided to try to capture some emission data via my 3nm Astrodon Ha filter. Unfortunately, even after 7.5 hours (15 x 1800s), the resultant stacked Ha image just looked like a grainy version of the stacked red channel. So, unfortunately, no more detail, only noise was revealed. I therefore decided not to use the Ha data. I should point out that I'm not implying that there aren't any star forming regions in M109 - it is just that I didn't detect any On a general point, it is quite interesting trying to compare my image with others, high resolution M109 images seem to be in short supply. Thanks for the comment ! Alan
  11. alan4908


    Thanks for the comment. Yes, I was quite happy with the amount of detail that I managed to acquire. Thanks for the comment. On your blue processing point, I believe the blues are an accurate representation. For instance, take a look at these images from three accomplished astrophotographers: Adam Block - http://www.caelumobservatory.com/obs/m109.html Robert Gendler - http://www.robgendlerastropics.com/M109.html On the small blue stars and the blue tint of the small background galaxies, these also appear accurate - for instance, have a look at this APOD from Bob Franke: http://www.star.ucl.ac.uk/~apod/apod/ap130523.html Thanks Geoff ! Alan
  12. alan4908


    My first attempt at M109, a galaxy located in Ursa Major which is about 55 million light years distant. In the image below you can also see quite a few other background galaxies - the ones marked PGC37553, PGC37700 and PGC37621 have recession velocities very similar to M109 and are classified as dwarf companion galaxies. The LRGB image below represents 16.5 hours integration and was taken with my Esprit 150. Alan M109 M109 (annotated) LIGHTS: L:37, R:21, G:23, B:18 x 600s. DARKS: 30, BIAS:100, FLATS: 40 all at -20C.
  13. Thanks Dave ! Alan
  14. Thanks Carole Hi John Yes - masks are interesting objects to experiment with.. In Pixinsight, I found that the free GAME script (http://www.skypixels.at/pixinsight_scripts.html) is very flexible, allowing you to create "elliptically holes" of specific sizes in your black mask at specific locations. Alan
  15. Good luck with your processing, I'm sure you will get there ! By the way, I didn't understand your comment on applying multiple masks simultaneously, could you elaborate ? Alan
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