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Venus visible in daylight
"Mike Dworetsky" wrote in message news "MichaelJP" wrote in message . .. "Mike Dworetsky" wrote in message ... It is hardly news to those who read uk.sci.astronomy, but this morning the sky is unusually clear and blue, so I went out just before sunrise and marked a position where Venus was lined up with a chimney, then looked again 40 minutes later. Venus is easy to see in a clear blue sky as long as you know approximately where to look. Clearly visible and bright, at 0740, well after sunrise this morning 5 October. Just looked again at 0750, still there despite having the Sun shining directly on me. Earlier, I went out and saw an impressive line-up of planets and waning crescent Moon, with bright and very orange Mars high up near Castor and Pollux, brilliant Venus, and fainter Saturn. Predictions suggest we are in for a few clear days and nights, so grab 'em. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) I was looking for Andromeda (the galaxy) last night through 10x50 binoculars. I could definitely see it but it was very faint, would I need to use a telescope to discern the disk structure or just dark skies? You would need to take a long exposure (3-4 mins) with a CCD using a telescope of at least 6-inches aperture. You would need to have a larger format CCD to take in enough galaxy to see the spiral arms, or a focal reducer, or both. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) OK, thanks for the tips. Looks like it was pretty futile trying to see the disk with the binoculars then! |
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Venus visible in daylight
On or about 2007-10-05,
Pete Lawrence illuminated us with: On Fri, 5 Oct 2007 20:35:49 +0100, "Mike Dworetsky" wrote: You would need to take a long exposure (3-4 mins) with a CCD using a telescope of at least 6-inches aperture. You would need to have a larger format CCD to take in enough galaxy to see the spiral arms, or a focal reducer, or both. You can get it nicely with smaller refractors Mike. A ZS66 or ED80 (80mm) fitted with a focal reducer will record the core plus the brighter spiral arms with a DSLR or CCD camera in a couple of minutes. A 3 minute exposure with a 76mm f/4 scope http://www.digitalsky.org.uk/DSO/200..._IMG_9925b.jpg A stacked result using an 80mm ED80 refractor and focal reducer http://www.digitalsky.org.uk/DSO/M31-2006.html A hybrid result using data from both scopes... http://www.digitalsky.org.uk/DSO/200...ybrid_1024.jpg Wow! I think the evidence Pete is that _you_ can get it with that equipment, but I'd not be so sure that _anyone_ can! Amazing By the way, how come the first one says "unguided" on it? Surely a 3 minute exposure has to be using a telescope with some sort of drive, so what does "unguided" mean in this context? -- Mark Real email address | Love is real if you and the other person stick together is mark at | like peanut butter and jelly. ayliffe dot org | (child's response to "what is love?) |
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Venus visible in daylight
On Mon, 08 Oct 2007 11:39:35 GMT, Mark Ayliffe wrote:
A 3 minute exposure with a 76mm f/4 scope http://www.digitalsky.org.uk/DSO/200..._IMG_9925b.jpg A stacked result using an 80mm ED80 refractor and focal reducer http://www.digitalsky.org.uk/DSO/M31-2006.html A hybrid result using data from both scopes... http://www.digitalsky.org.uk/DSO/200...ybrid_1024.jpg Wow! I think the evidence Pete is that _you_ can get it with that equipment, but I'd not be so sure that _anyone_ can! Amazing Strangely I'd be sure that if I can get it then anyone can! By the way, how come the first one says "unguided" on it? Surely a 3 minute exposure has to be using a telescope with some sort of drive, so what does "unguided" mean in this context? Unguided means that the shots were not auto-guided. It's a bit of a confusing term but that's what it means. However, they were equatorially driven at the sidereal rate of couse otherwise the stars would have trail. |
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Venus visible in daylight
"MichaelJP" wrote in message m... "Mike Dworetsky" wrote in message news "MichaelJP" wrote in message . .. "Mike Dworetsky" wrote in message ... It is hardly news to those who read uk.sci.astronomy, but this morning the sky is unusually clear and blue, so I went out just before sunrise and marked a position where Venus was lined up with a chimney, then looked again 40 minutes later. Venus is easy to see in a clear blue sky as long as you know approximately where to look. Clearly visible and bright, at 0740, well after sunrise this morning 5 October. Just looked again at 0750, still there despite having the Sun shining directly on me. Earlier, I went out and saw an impressive line-up of planets and waning crescent Moon, with bright and very orange Mars high up near Castor and Pollux, brilliant Venus, and fainter Saturn. Predictions suggest we are in for a few clear days and nights, so grab 'em. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) I was looking for Andromeda (the galaxy) last night through 10x50 binoculars. I could definitely see it but it was very faint, would I need to use a telescope to discern the disk structure or just dark skies? You would need to take a long exposure (3-4 mins) with a CCD using a telescope of at least 6-inches aperture. You would need to have a larger format CCD to take in enough galaxy to see the spiral arms, or a focal reducer, or both. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) OK, thanks for the tips. Looks like it was pretty futile trying to see the disk with the binoculars then! You would be able to see the inner region around the nucleus as a fuzzy elongated blob, brighter at the centre and fading out. Features further out would be too faint to see this way. With binoculars I doubt that you could see the dust lanes or spiral arms, which is what I took you to mean by "seeing the disk". (Maybe you could just manage to do this with very large binoculars in a very dark site.) -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) |
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Venus visible in daylight
"Mike Dworetsky" wrote in message ... "MichaelJP" wrote in message m... "Mike Dworetsky" wrote in message news "MichaelJP" wrote in message . .. "Mike Dworetsky" wrote in message ... It is hardly news to those who read uk.sci.astronomy, but this morning the sky is unusually clear and blue, so I went out just before sunrise and marked a position where Venus was lined up with a chimney, then looked again 40 minutes later. Venus is easy to see in a clear blue sky as long as you know approximately where to look. Clearly visible and bright, at 0740, well after sunrise this morning 5 October. Just looked again at 0750, still there despite having the Sun shining directly on me. Earlier, I went out and saw an impressive line-up of planets and waning crescent Moon, with bright and very orange Mars high up near Castor and Pollux, brilliant Venus, and fainter Saturn. Predictions suggest we are in for a few clear days and nights, so grab 'em. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) I was looking for Andromeda (the galaxy) last night through 10x50 binoculars. I could definitely see it but it was very faint, would I need to use a telescope to discern the disk structure or just dark skies? You would need to take a long exposure (3-4 mins) with a CCD using a telescope of at least 6-inches aperture. You would need to have a larger format CCD to take in enough galaxy to see the spiral arms, or a focal reducer, or both. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) OK, thanks for the tips. Looks like it was pretty futile trying to see the disk with the binoculars then! You would be able to see the inner region around the nucleus as a fuzzy elongated blob, brighter at the centre and fading out. Features further out would be too faint to see this way. With binoculars I doubt that you could see the dust lanes or spiral arms, which is what I took you to mean by "seeing the disk". (Maybe you could just manage to do this with very large binoculars in a very dark site.) -- Mike Dworetsky It was resolvable as a fuzzy blob, but not really elongated in any direction. It was at my semi-urban location though so next clear night I'm going to drive out to the peaks where its much darker and see if I can see any more. Must admit I'm far more interested in objects I can see directly through the binoculars or my 6" reflector than any CCD stuff. That is no doubt fascinating but a whole hobby in itself! |
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Nytecam |
#17
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Venus visible in daylight
"nytecam[_1_]" wrote in message
... I was looking for Andromeda (the galaxy) last night through 10x50 binoculars. I could definitely see it but it was very faint, would I need to use a telescope to discern the disk structure or just dark skies? You would need to take a long exposure (3-4 mins) with a CCD using a telescope of at least 6-inches aperture. You would need to have a larger format CCD to take in enough galaxy to see the spiral arms, or a focal reducer, or both. Mike Dworetsky Hi - ok Mike I'm 10 miles from central London but my 70mm f/5 OG [Meade ETX-70] + CCD does a fair job in M31 at http://tinyurl.com/yunhtd and more tiny scope stuff including Venus in daylight at http://www.astroman.fsnet.co.uk/etx70mg.htm Nytecam -- nytecam[_1_] Yes, OK, well that's a 32-min exposure. That's 10 times the exposure I suggested for the 6 inch, yours is a c. 3-inch, so I guess my original recommendation was comparable to what you might get with 15 mins (to detect spiral arms). I was taking into account that the OP was a "newbie". I'm old enough to remember getting similar results with a 1-hour photographic exposure in a very dark site. Darkness is less a requirement with CCDs, not from the S/N POV, but because to get a result you can digitally subtract background fogging. On film/plate photographs this is more difficult. Is that a photomontage artefact in the middle? -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) |
#18
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Nytecam |
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