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carldr

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  1. Hey Alexxx, The orbit of the Moon around the Earth, and orbit of the Earth around the Sun, aren't circular, nor concentric. The distance between the Moon and the Earth varies by about 15%, and the distance between the Sun and Earth varies too (although I'm not sure by how much.) You may have heard at the start of the May about a "Super Moon", where the Moon appeared larger than normal. That's because the Moon was at its closest point to Earth in its orbit (called perigee), and it so happened it corresponded with a Full Moon, so the difference was noticeable. 15 days later, the Moon was at its farthest point in its orbit around the Moon (called apogee), and it so happened that that corresponded with a New Moon, and this solar eclipse. So on this occasion, the Moon appeared smaller than the Sun, and it resulted in the "ring of fire" around the Moon. This type of eclipse is called an "annular solar eclipse". Regards, Carl.
  2. Sorry the delay in getting these up, I've only just found the time to sort the images out! As mentioned above, we decided to drive north of Tokyo on the night before the eclipse due to Tokyo being forecast to be covered in cloud. We picked a place called Utsunomiya. It had Sun in the name, it seemed an ideal choice! It was slightly cloudy when we awoke in Utsunomiya, so had to drive another 15 miles or so to get clear skies. It turns out it was raining lightly in Tokyo at the start of the eclipse, but it cleared during it was happening, and the cloud was patchy at the point of maximum eclipse (Is that the term for an annular eclipse?!) So given that, I'm happy we drove out, even though it sacrificed the Moon being dead centre on the Sun. It would have been too risky to stay in Tokyo. There was one slight hiccup while imaging - We had parked up on a small industrial estate, and it turns out the car park we picked was owned by Honda. The company's director came out, and although he was interested in what we were doing, because we were in a Toyota, he asked us to move. He helped us find another site though, but it meant we lost about 10 minutes. The images were taken with a Takahashi FSQ85, Televue 2" Powermate x4 and Canon 5D Mk II camera, on a camera tripod which surprisingly handled the weight well. Seeing the eclipse makes lugging all the equipment out here worth it, although I'm not much looking forward to the return flight! But enough talk, here's the images! Regards, Carl.
  3. Hi guys, A quick, rough and ready image from over 500 I've just taken of the solar eclipse from Japan. We're about 100km north of Tokyo because of cloud cover, so we didn't get the moon dead centre on the Sun. Anyway, wanted to upload an image to beat the guys on the west coast of the US! I'll upload more later once I've got back to Tokyo and had a chance to go through the images I have. Regards, Carl.
  4. Yes, a very valid point I think, thanks for it. Do you think this is better? I'm going to start the processing from scratch at some point, as I say, I'm not sure I've done the best of jobs with it and I'm not sure tweaking levels and saturation is going to rescue it!
  5. I FINALLY had chance to take my Takahashi FSQ85 out for the night, but it coincided with one of those nights when I just couldn't be bothered and would rather watch some movies. I forced myself though, and in the end I'm glad I did. In my impatience, I didn't polar align the scope accurately, and it shows in the images I took as I got some rotation of the field while shooting. I also decided to use my DSLR rather than the CCD and filters, since I knew I only had a few short hours until the moon rose and ruined it all. I then forgot to take flats! Anyway, the results of my endeavours is below. I can't say I'm hugely pleased with it, but if nothing else, it's reminded me that I can't take shortcuts and hope to get decent images! It feels like I can get a better result out of the subs too, but for the life of me, I'm not able to. Image details : Takahashi FSQ85, Canon DSLR, 11 x 6m00 subs (I actually took 22), 11 x 6m00 darks, processing DeepSkyStacker and Photoshop. Cropped pretty significantly from original. All criticism gladly received!
  6. I have to admit, I got a little confused to what the equation was trying to achieve while writing my post! Drake's original equation was trying to find the number of civilisations in our galaxy with which communication might be possible, so considering whether we can detect them (or them us) is valid I think. If a civilisation doesn't want to be found, or isn't actively looking for other civilisations, or even they do find us but choose to not show themselves, I think they fall outside of "communication might be possible" on the basis that such civilisations are so rare that you won't find them by chance, and so you can't communicate with them. I think that's subtly different to your Nmax of course, which implies they would be counted. So perhaps a couple of those variables aren't valid for your updated equation, but as you say, it raises the question of whether they should be. I suppose it's more useful to try and estimate the number of civilisations, and from there we can calculate how likely it is we'll come across one, either by chance or by design, as it would allow us to determine a distance for how close the nearest civilisations ought to be. The milky way is about 39 million million cubic light years in volume. There could be millions of civilisations in our galaxy, and still the chances of us detecting any of them is minute given our current technology. This naturally overlaps with the Fermi Paradox, of course.
  7. In my opinion, at least one more variable needs to be added - The number of years that radio transmissions are made by a civilisation. For us, now we're moving away from analogue technologies, the number is something like 120 years. But even that's not really the whole story. Apart from one exception, we've never deliberately beamed transmissions into space, and it's debatable that any civilisation listening for us will have equipment sensitive enough to hear us. With our current technology, it's estimated our radio broadcasts would only be detectable from 0.3 light years away. So assuming the civilisations were even distributed throughout the galaxy, they would need equipment several orders of magnitudes more sensitive. Civilisations might deliberately decide to avoid broadcasting radio into space for the fear of being found - it's not guaranteed another civilisation will be friendly. This doesn't alter the number of civilisations out there of course, but it reduces the number we're likely to find. It's certain that advanced civilisation is rare enough that it can be assumed that if a civilisation doesn't want to be found, it won't be. So perhaps we need another variable indicating the number of civilisations who want to be found. Also, what about a variable to indicate how long a civilisation exists for? If an extinction event happens before we are able to populate other planets, or if we end up destroying ourselves, we might only be around for a relatively short period of time. So what are the chances that another civilisation finds us during that time period, assuming they have similar issues? C.
  8. Hi Tink, I think the video you mentioned is this one : I would also recommend this one too, to help demonstrate the massive scale of the Universe : .(Edit: There seems to be a more modern version narrated by Morgan Freeman : . I say more modern, it was made when there were still 9 planets!)I'm afraid I'll have to defer to other members' knowledge on how to download them to your Mac/PC so you can watch them offline. I would also take a look at Stellarium, which is a planetarium program. I'm sure I've seen "tours" set up in it, so it's like you're taking a flight through the solar system. Again, I'll have to defer to superior knowledge! You could also use Stellarium to show, for example, Jupiter and the Galilean moons at the exact time they look through the telescope, so they know which moons are which. It's a shame you're not closer, I would love to volunteer to help. Perhaps I should look up a local group. Regards, Carl.
  9. Luke, You've done very well to capture it on such a small sliver of the Moon! It's a shame it wasn't face on to you, I think it would have made a great image against the archetypal crescent moon. Good luck for future transits. C.
  10. My scope had its first light this evening. Not the best evening to do it really, we'd been out delivering presents so wasn't in the greatest of moods (Scrooge!), it was windy, the clouds kept rolling it, and I've got to be up early. But I just had to get it out! I started visually, with the 25mm eyepiece which came with my C9.25 with my Ascension star diagonal. I'm hesitant to draw any conclusions from it since I'm inexperienced visually, and I don't know how good the eyepiece and diagonal are. Also, in my haste, I hadn't given the tube time to cool down. But there is no doubting how flat the field is. Visually, in my other scopes (Equinox 80, C9.25) I hadn't really noticed the field not being flat, but pretty much the first thing I noticed with the Tak 85 is how "correct" it looked - It's just perfect! Crisp and flat and ... Nice! Everything looked so tight, even Sirius, more so that I remember from my other scopes. The focuser is great too, it's really easy to get great focus, and it just holds it - No backlash, no loseness to it, it's just lovely to use. It's SO much better than the Equinox's Crayford, or the C9.25s focuser. A world apart, it's a joy to use. I can see a focuser upgrade for the C9.25 coming on. I scanned around to M31, M42 and M45, but again, due to my inexperience, I can't really draw any conclusions from it other than I don't recall M42 being as clear in my Equinox. Jupiter was small in the wide field, but the bands were clearly visible and the four Galilean moons were lovely, tight spots. No false colour at all. But I didn't really buy the Tak 85 for visual, so how is it with a camera hung on the back? With the cloud and wind, I knew I wouldn't really get indicative results, so I didn't bother setting up a guide scope or using the CCD, so I used the full-frame Canon 5D II at prime focus. The field this gives is MASSIVE. 4.5x3.0 degrees, or thereabouts I think. The attached image is a single, unguided 30s exposure at ISO 1600, scaled to about 15% of the full size, with no processing. View the full, unscaled shot here (4.3MB, 5616x3744.) It's nothing special of course, but compared to a 25s exposure I have from the Equinox 80, the stars are so much tighter, and there isn't the crazy green haloes evident in the Equinox's shot. The second image I've attached is a comparison with the shot I have from the Equinox. On the left side, the Equinox's image was taken with a Canon 500D, 25s @ ISO 1600. On the right side, roughly the same area of the Tak 85's shot. It's rotated and of a slightly different scale, I've not tried to correct that. It's clear to me that the Tak 85 is superior to the Equinox 80, but from the very limited time I've had with it, I'm not sure what judgments I can make at the moment. I'm so glad I bought the Tak 85 though, I know I'm going to have a lot of fun with it.
  11. Ah right, so I shouldn't be worried about an exit pupil of, say, 1mm?
  12. Sorry to hijack the thread! Regarding exit pupil, is there a minimum I should be considering?
  13. So, my new baby arrived this morning. My new Takahashi "Baby Q" FSQ85! After many, many sleepless nights pondering over which new scope to get, I kept coming back to this one. Thanks to Olly and Euan (and others) for offering their thoughts and advice. I was a little worried when I saw the FedEx man with it, he definitely didn't have a delicate, dainty touch about him. I needn't have worried. First layer, a load of snow. I mean, foam : These were the boxes hiding inside. Left to right we have : tube holder, offset plate, box full of various adapters, and the lastly the matched Takahashi reducer and extender. The telescope was inside a box inside a box inside a box inside a box. It really couldn't have been better packaged. This is the scope, with its dew shield extended. A shot of the reducer and extender. I end up with focal lengths of 328mm, 450mm and 675mm with them. I'd been warned about 'adapter hell' with a Takahashi, and here's what it looks like! It has taken me a while to work out what everything is and how it fits together, and it's not quite as bad as it looks. I have everything I need to attach both Canon DSLRs and my CCD camera and filter wheel combo with (hopefully anyway) the correct spacing, with the reducer, with the extender, or at prime focus. My first impressions are good. The focuser feels a little tight, but is very smooth. It's very much better than my Equinox's focuser. I could hang myself off the back of it, and I doubt it'll move. There is a satisfying bulk to it, the overall quality feels great. The optics are virtually invisible. When the scope arrived, it was expected to be clear tonight for at least a few hours - how great would that have been? However, The Big Man realised his oversight, and it now looks like it's going to be cloudy all night. So, first light report when I get the chance. In the meantime, I'm going to research eyepieces with a view to buying two or three decent ones. I know nothing about them, I don't really know where to start.
  14. I'm inclined to think that is an internal reflection. It's much fainter, but the green makes me think of this : http://stargazerslounge.com/imaging-planetary/167678-uranus.html
  15. The only stupid questions are the ones you don't ask!
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