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Alexandros

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Everything posted by Alexandros

  1. Thank you for your replies! I was thinking of getting the star hopping book before I developed this new interest, so I think I will get that!
  2. If you wish to start from basics, the Backyard Astronomer's Guide, 2nd edition by Terrence Dickinson and Alan Dyer is a good starting point. I've heard great things about Nightwatch by Terrence Dickinson as well, but it is a little bit more basic than my other suggestion. Kind regards, Alexandros
  3. Hello all, I've recently developed an interest to learn about the star lore, the different cultures and civilizations developed and used over the years. Could you recommend a good book or site/ educational videos on this subject? (Sorry if this is the wrong forum, I was not sure as to where to post this question :) )
  4. OK, so for now my objective is to get a new barlow, possibly something a bit cheaper than the one suggested by alacant . I was thinking of getting this one from skywatcher https://www.planitario.gr/barlow-2x-759.html (there is an english version of the site on the top right that you can access if it is not already), which appears to be better from the one I already have. Do you think that this will reduce the abberation to imperceptible levels for my scope, or should I go for something else? I would certainly like to shorten the barrel of my scope but I am sure that would void the warranty, wouldn't it? Also Alan, when I reach that point I will most certainly ask you for help. I will probably have some good photos to share by that time
  5. Hi all, thanks for your replies! I do not think my problem is atmospheric dispersion, I think I am a little too inexperienced to even hit that limitation with my current cheap equipment. It looks like lateral chromatic aberration and generally bad quality of the Barlow that is limiting me right now. When I mentioned Venus, I noticed that the colour fringing changed when I was looking at Venus from different angles, which is the symptom of a simple lens if I am not mistaken. If it was atmospheric dispersion, should the colour fringing be the same no matter where in my field of view I had Venus?
  6. I think you just broke my brain with the focal length . I have to think about that!
  7. Thanks for your suggestions Alacant. I think I will go with the better Barlow for now. I don't think I am ready to modify my scope as of yet, maybe when I get a new one I will get back on that . Wouldn't that also lead to a decrease in focal length as well as the aperture of my scope?
  8. Quick session for astrophotography, it appears that the culprit was the barlow. I can see the abberation getting worse in the edges when I was pointing at venus and moving the scope slightly. Also I could see it going from red to blue when I was defocusing to one side and then the other. So it is definitely a refractive issue there, which must be the barlow. So now I am stuck with a three way dilemma. Should I a) Buy an adapter for afocal photography? b) Get a better barlow? c) Get a shorter focuser? What do you suggest as the best course for right now?
  9. Wow that looks great! I will try to learn that software and try to do it on my own next time! I want to try stacking but as I don't have a tracking mount I don't know if it will be easy to do. Also finally, the sun just went down so I'm off to set up my scope and try again!
  10. Hi Pompey Monkey, thanks for your reply. Yes I was thinking the same thing, however my scope has a spherical mirror so I don't know the effects of that in astrophotograph. I have tried cleaning my barlow today, in order to make sure there was nothing blurring my view. I will try again tonight with the eclipse and see what results I can achieve.
  11. Hi Terry, thanks a lot for the answer. I agree, the photo does not look focused, I will try next time to play with the focus a little back or front from the point I was last time, just to be sure. The eclipse should be fun to try and image as well. However, one thing to mention is that my mount is not tracking and does not have any motor to correct for the rotation so I attributed the lack of focus to the motion of the sky. I tried to compensate for it by using a fast shutter speed, 1/250 and high ISO. Should I got for a faster shutter speed? Nevertheless, I will try again tonight and report my findings. Collimation on the other hand is something I did not consider. I am not very proficient in that matter, so that could be the issue. Could it be sensor bloom as well?
  12. Hello everyone, I just yesterday received the equipment I was missing in order to start taking short exposure prime focus astrophotographs and I set it up last night in order to get some photos of the moon. After a while of figuring out how everything fit, I tried to focus up the image using my cameras live view and zooming in the display to make sure the focus is as good as it can get. Focusing was not as hard, as I had read that with my scope, an 130/900 skywatcher explorer newtonian scope, a barlow lens is necessary as there is not enough inward travel on the focuser. After verifying image was focused I took the picture and to my surprise the colours seemed to have been focused differently, or somehow refracted after taking the photograph. This was not visible in the live view feed on my camera beforehand however. Specifically the blue colour seems to have been the most unfocused as you can see it fringing on the edge of the moon, as well as if you zoom in the ridges and edges of the craters, in the photograph I took yesterday, you can see all the spectrum of colours appearing there. I am using the barlow included in my scope which might be of bad quality so I think the issue is that, but I would like your opinion as well. What do you think the problem is?
  13. I am waiting impatiently for your report! Happy sightings! Alex
  14. I wish I could see that but, seeing the aurora as south as down to Greece, that would be very disturbing! I am planning to see it at least once though it's on my bucket list.
  15. Ahh thanks for sharing your experience! Sadly a 12" scope is way far from my budget right now, let alone a 16". I still want to get a good solid go-to mount first because while it is fun to star hop, when you are in light polluted skies, the experience is not that enjoyable!
  16. Thank you very much for this information! I have already started looking at it!
  17. Yes, that was exactly what I meant, thanks for clearing that up. I realise from your posts that I am slightly behind on our capabilities with respect to what we can image, as I thought that we could not even see the other planets, just infer their existence from dips in light curves. I have some studying to do!
  18. While a 39m telescope is by no means miserly, I have been wondering what the necessary apperture would be required to view the nearest planet. It turns out that the necessary apperture would be 200 Km, which is veeeeeery big compared to what we can build today. So I would not expect any ground-breaking results, unless a major step up in optics and computing occurs, like the array used to image the black hole, I think for now there won't be any visually striking new images. Also with such a large telescope, I think skyglow would be a limiting factor.
  19. Hello Dusty! I live in a part of Greece near Athens, which means I have severely light polluted skies. I would classify it as a Bortle 6-7 ( https://en.wikipedia.org/wiki/Bortle_scale ). I own a 130mm reflector and with it I managed to separate the colours of Albireo. The thing is that since they are stars they are easier to see and discern their colours because they produce their light and are pinpoint sources. From my experience, I have found out I can discern colour of up to mag 5 stars. If you want, I can go on a binary star search and report my results as to how far down I can push the apparent magnitude and still notice the difference in colour. I will however re-iterate the aforementioned point, viewing throught the eyepiece of your telescope will be a lot different than the astrophotographs you may have seen. A good post that was recently suggested to me was this ( https://stargazerslounge.com/topic/196278-what-can-i-expect-to-see/ ). Do not lose your enthusiasm, though. The universe is a sight to behold and there are many things to see in it! Sure, light pollution is very annoying, but when you finally get that glimpse of the item you were hunting down, it is even more exciting. I remember my excitement when I managed to get a glimpse of the Sombrero galaxy. Plus when you finally get to a dark site you will be able to discern many more things from that hunting experience.
  20. Thanks! I have had my seeings of open clusters, they were very nice! Especially the Sagittarius star cloud. I will check out the nebula now that you told me!
  21. Hello all! Following your suggestions I went on a stargazing adventure last night! I focused on Albireo and the easiest planetary nebula I could find, which was the ring nebula. Albireo's orange and blue stars were great and as appeared in all their coloury glory. The ring nebula however was not coloured. I had difficulty even noticing structure. With averted vision I was able to make out the ring, but that meant that no colour was available. Even that way however, the ring was a sight to behold!! I tried viewing Bode's Nebula as well, but that was very faint as well. I think I have a severe light pollution problem at my house, sadly. I think I'll organize an excursion soon to another island with a better sky! Is there anything else you think I should try to view?
  22. First of all, WOW so many posts, thank you all for the insightful replies! I am delighted to find out that it is possible to see faint hues and more, when it comes to DSOs. My initial expectations were that it was not at all possible, so this is a very pleasant surprise. I managed to get a glimpse of the Omega Nebula, it was an uncontainable thrill to see the internal bright triangular portion of it. Sadly, it sits at the skies right above Piraeus and Athens, so the light pollution is literally something that depresses me (I sometimes look at the hills around me and see the skyglow, it's like the sky is gray and not black). I am sure the reason it appeared orangey was because of that and not its actual colour. I was unable to see the lagoon and eagle nebula because of this. I am gonna try my hand at planetary nebulae, but I am unsure if my 130mm newtonian would be able to see them. I hope in the future I will be able to upgrade my gear and get the observations flowing much more easily. Thank you all for the tutorials and links, I will be sure to read them. Seeing michael's observation summary, a new question has arisen. What about supernovae? Can you see colour in them? What is the most colourful/ contrasty object you've ever seen?
  23. We have all seen in the internet and many of the people in the forum have taken themselves, beautiful cosmic photos of many deep sky objects, like the deep red lagoon nebula or the colourful eagle nebula. However, from what I have learned here, when we are observing with a telescope and are fully dark adapted, the objects are so faint that our eyes are not great dark colour cameras and are unable to use cones and therefore use rods to sense the light coming from them. So my question is, is it possible to see deep sky objects in colour, especially nebulas, like they appear in photos? I'm refering to a scenario where you are at a very dark site, with very little atmospheric disturbance and with a very good telescope. If such a scenario exists, what are the requirements?
  24. As a fellow noob I can share how I separate them. I do it with the help of my computer or my phone. I have not discovered yet how I can identify them if I see them without any help. If anyone knows, I would be VERY interested in learning it! With my computer I use the software stellarium which shows you how the sky will be at night or at any time of the day. ( It even shows you how the stars will look like in the future so I had a blast looking at how constellations will change over time). There has been (recently as far as I can tell) an online version of stellarium, but that is not the same as the one you can download. The differences however, have not influenced me at all, However I prefer my phone, which I can easily take outside when viewing. I use the stellarium mobile plus app (paid). There are free options as well. Star Walk 2 shows the 4 jovian moons but since it has a paid planets expansion, if I can describe it as such, I doubt it will have many more. If I remember correctly, Star Chart does not show them, unless you purchase them. You can purchase an expansion for most of the apps which will show the location of most of the solar system objects. Here are some screenshots from Stellarium (not the online version,Edit: Whoops, sorry for greek characters didn't notice them), Stellarium mobile plus and Star Walk 2.
  25. At least Thursday through Sunday, you get the sunshine you wanted!
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