Re: Stars Are Thousands Of Times Closer Than They Appear
They are there because this is a single photo?
Must be if the streaks are still there.
Where did you get that information ?
I'm making assumptions, I admit, as I get no replies to my requests for further information, but most astronomical CCDs they use are back-thinned. Hamamatsu seems to be the main supplier. http://sales.hamamatsu.com/assets/appli ... 004e01.pdf
fosborn
Re: Stars Are Thousands Of Times Closer Than They Appear
I'm making assumptions, I admit, as I get no replies to my requests for further information, but most astronomical CCDs they use are back-thinned. Hamamatsu seems to be the main supplier. http://sales.hamamatsu.com/assets/appli ... 004e01.pdf
I am checking out this vendor e2v.com
UK company e2v Technologies supplied the CCD sensors used in the orbiter's Mercury Dual Imaging System (MDIS). Those sensors comprise a multispectral, wide-angle camera and a monochrome narrow-angle camera, and will map the rugged landforms and spectral variations on the planet's surface in monochrome, color and stereo.
The instrument uses e2v's CCD TH7888A, a 1024 x 1024 pixel frame transfer sensor, allowing up to 30 images per second, with anti-blooming functionality and a possibility of 2x2 binning operation.
Re: Stars Are Thousands Of Times Closer Than They Appear
Thanks for the e2v link Frank. Seems they do produce the electron multiplication CCD for astronomy, and the Military of course. So a deep space shot with this technology should have a billion or two stars in it? http://www.e2v.com/products-and-service ... -l3vision/
fosborn
Re: Stars Are Thousands Of Times Closer Than They Appear
Seems they do produce the electron multiplication CCD for astronomy, and the Military of course.
I think ours is a frame-transfer CCD and it looks like it is a different animal.
The WAC consists of a 4-element refractive telescope having a focal length of 78 mm and a collecting area of 48 mm**2. The detector located at the focal plane is an Atmel (Thomson) TH7888A frame-transfer CCD
at this ev2 link for selecting a ccd, you can see its a different chip, not an electron multiplication CCD. You can see they are in different categories to select from. http://www.e2v.com/products-and-service ... atasheets/
Aardwolf
Re: Stars Are Thousands Of Times Closer Than They Appear
fosborn wrote:
I believe filter 2 is the wide range filter so includes infra-red. Is there a comparable image through one of the visible range filters only?
why? Do you have a link to show this. The clear was specifically for imaging stars for navigation.
Spectral Filter Design. A 12-position multispectral filter wheel provides color imaging over the spectral range of the CCD detector (395-1040 nm). Eleven spectral filters are defined to cover wavelengths diagnostic of common silicate minerals and glasses and have full-width half maximum (FWHM) bandwidths from 5-40 nm. A broadband clear filter was included for optical navigation imaging of stars.
By stating its for optical navigation does not exclude infra-red. Optical references in science refer to UV, visible and IR. The clear filter is as you highlighted 395-1040 nm. 750-1040 nm is all infra red. It may even pick up a little UV.
Aardwolf
Re: Stars Are Thousands Of Times Closer Than They Appear
It's interesting that they need the full range of the CCD for navigation. If stars are visible in space surely they could use any of the visible range filters for the job.
fosborn
Re: Stars Are Thousands Of Times Closer Than They Appear
I believe filter 2 is the wide range filter so includes infra-red. Is there a comparable image through one of the visible range filters only?
11 filters, one clear; filter #2, you want a filter blocking the IR ? The Len's are already coated with a block on some of it, to keep from overheating the CCD.
Aardwolf wrote: It's interesting that they need the full range of the CCD for navigation. If stars are visible in space surely they could use any of the visible range filters for the job.
The system was designed to capture at lest 3 stars in a background of a picture of mercury. So that maybe why its overdone. So is there anything not valid about the picture, as far as known facts go. We can't say its electron multiplication CCD or back-thinned. What is the disqualifying factor?
I've covered a lot of documents and online resources and can't disqualify it. GaryN has had a plenty of time to disqualify it and hasn't sense time Nic C posted it.
CW0181616382B_RA_3_stretch (1).JPG
It looks like we actualy have a camera in space doing exactly what you guys want and you still ain't happy.
Aardwolf
Re: Stars Are Thousands Of Times Closer Than They Appear
fosborn wrote:
I believe filter 2 is the wide range filter so includes infra-red. Is there a comparable image through one of the visible range filters only?
11 filters, one clear; filter #2, you want a filter blocking the IR ? The Len's are already coated with a block on some of it, to keep from overheating the CCD.
Aardwolf wrote: It's interesting that they need the full range of the CCD for navigation. If stars are visible in space surely they could use any of the visible range filters for the job.
The system was designed to capture at lest 3 stars in a background of a picture of mercury. So that maybe why its overdone. So is there anything not valid about the picture, as far as known facts go. We can't say its electron multiplication CCD or back-thinned. What is the disqualifying factor?
I've covered a lot of documents and online resources and can't disqualify it. GaryN has had a plenty of time to disqualify it and hasn't sense time Nic C posted it.
CW0181616382B_RA_3_stretch (1).JPG
It looks like we actualy have a camera in space doing exactly what you guys want and you still ain't happy.
The point was that it's possible that stars are not visble in space. This photo doesn't alter that posiblility because it is imaging visible and IR. No-one is disqualifying the picture for stating what it states it is; that it's an image of the spectrum 395-1040 nm.
The question is if they took this photo through the visible filter alone, would anything apart from earth show up.
fosborn
Re: Stars Are Thousands Of Times Closer Than They Appear
The point was that it's possible that stars are not visble in space.
Can you quantify possible, like remotely possible? How possible ( compared to Nic C's facts laid out through this whole thread)? I won't be concerned if its just remotely possible.
Aardwolf
Re: Stars Are Thousands Of Times Closer Than They Appear
fosborn wrote:
The point was that it's possible that stars are not visble in space.
Can you quantify possible, like remotely possible? How possible ( compared to Nic C's facts laid out through this whole thread)? I won't be concerned if its just remotely possible.
Because we have very little, if any, evidence that it is possible to see stars in space.
fosborn
Re: Stars Are Thousands Of Times Closer Than They Appear
Because we have very little, if any, evidence that it is possible to see stars in space.
So you think 99.9%? I will be impressed. But to be honest from what I accept, its about 25% as fact and about 25% faith, so 50% total. You win, wish I had a 20 to give ya.
Lloyd
Re: Stars Are Thousands Of Times Closer Than They Appear
Aardwolf said: Because we have very little, if any, evidence that it is possible to see stars in space.
* As I said before, the fact that Mars, the Moon, Venus, the Sun etc look the same colors in photos from space and from naked-eye observations on Earth, seems to me to prove entirely that space transmits visible light, as well as other frequencies. It's only the matter of shutter speed that accounts for the frequent absence of stars in space photos. I don't see any credibility in the suspicion that space doesn't transmit visible light. * Also, that's not what this thread is about anyway. So please start a new thread, if you want to persist with this discussion of light transmission in space.
fosborn
Re: Stars Are Thousands Of Times Closer Than They Appear
Lloyd wrote:
Aardwolf said: Because we have very little, if any, evidence that it is possible to see stars in space.
* As I said before, the fact that Mars, the Moon, Venus, the Sun etc look the same colors in photos from space and from naked-eye observations on Earth, seems to me to prove entirely that space transmits visible light, as well as other frequencies. It's only the matter of shutter speed that accounts for the frequent absence of stars in space photos. I don't see any credibility in the suspicion that space doesn't transmit visible light. * Also, that's not what this thread is about anyway. So please start a new thread, if you want to persist with this discussion of light transmission in space.
Lloyd, GaryN didn't seem to think that, and he is the main driver on this train. And the guy who created the thread didn't say anything. I don't understand your angst ?
I think the final question of % of certainty is a good question from a scientific view. Its a self diagnostic. Because when you honestly answer it, it resets your prospective on the whole concept, on what ever we are impassioned by.
Aardwolf
Re: Stars Are Thousands Of Times Closer Than They Appear
fosborn wrote:
Because we have very little, if any, evidence that it is possible to see stars in space.
So you think 99.9%? I will be impressed. But to be honest from what I accept, its about 25% as fact and about 25% faith, so 50% total. You win, wish I had a 20 to give ya.
I'm not sure what your point is here. All I've stated is that there is very little, if any, evidence (eye-witness accounts, photos in visible light alone etc.) that light can be seen in the visible range. I not sure that I understand why it isn't nor that it's even important, but the fact remains there just isn't any real evidence. As far as I can tell none of the photos provided here show stars in visible light spectrum alone.
Aardwolf
Re: Stars Are Thousands Of Times Closer Than They Appear
Lloyd wrote:
Aardwolf said: Because we have very little, if any, evidence that it is possible to see stars in space.
* As I said before, the fact that Mars, the Moon, Venus, the Sun etc look the same colors in photos from space and from naked-eye observations on Earth, seems to me to prove entirely that space transmits visible light, as well as other frequencies. It's only the matter of shutter speed that accounts for the frequent absence of stars in space photos. I don't see any credibility in the suspicion that space doesn't transmit visible light. * Also, that's not what this thread is about anyway. So please start a new thread, if you want to persist with this discussion of light transmission in space.
Not sure that anyone stated the visible light doesn't travel in space. Obviously visible light only photos exist of planets and moons. It just the stars that we have no evidence for.
The Voyager images of the solar system are the most notable. Images that required very long over-exposure to see Uranus and Neptune yet not a single star was picked up in the field. The exposures were so long the images were smeared due to motion. Surely there should have been thousands of stars picked up. Uranus and Saturn are seen just as well as stars from Earth yet Voyager needed very long exposures to pick them out becasue they were so dim from its increased distance, yet not a single star was picked up. Stars would not have dimmed becasue another 40 AU would be irrelevant to their brightness. It doesn't make any sense.
I'm not stating the stars are not there, but maybe visible light is shifted over extreme distances. I'm sure that could be relevant to distance measurements and probably many other measurements.
