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Triton's retrograde rotation is also clear.
Last night:
Just now:
(5 seconds @ ISO 1600)
Last night:
Just now:
(5 seconds @ ISO 1600)
Andy Resnick said:retrograde rotation
Vanadium 50 said:And what (if anything) is the significance of the colors?
Vanadium 50 said:Neptune (bottom right, right) is whiteish with a blue-violet halo. The stars are redder.
Vanadium 50 said:How can you tell from two pictures prograde that covers 90 degrees from retrograde that covers 270 degrees?
jim mcnamara said:Great job.
However I'm with Vanadium 50 on this - which dot is in retrograde? ...and other than that retrograde motion is known how can we see what you mean?
jim mcnamara said:Intent: see if "dot was the right one." So I could see something I never saw before. Nothing Earth shattering... so which dot IS Triton?
Vanadium 50 said:I'm genuinely curious. If you have multiple moons you can use Kepler's laws, but if you have only a few hours of good visibility per night, how can you tell the direction?
I am new to this game. Are you having a problem with a possible discrepancy between apparent 90° and expected 62.39°? I think you can get a whole range of apparent angles if not viewing along axis of orbit. It could be resolved with more views which could give an ellipsoidal locus - or not, depending.jim mcnamara said:Great job.
However I'm with Vanadium 50 o° this - which dot is in retrograde? ...and other than that retrograde motion is known how can we see what you mean? Period of Triton's orbit is about 5.77 days - I'm looking really close to the brightest dot, Neptune. A fuzzy blob very close to Neptune moved about 70 degrees counterclockwise. Started at 9 o'clock -> went to about 7 o'clock. Wrong blob?
360 degrees / 5.77
62.39 degrees of arc per day ( 24 hours between images)
- NASA photo on wikipedia.com
Thanks!Andy Resnick said:Triton is the faint dot adjacent to the super-bright blob located at 9:00 on the top photo and 6:00 in the lower photo.
I only spotted one at first but, now you mention it, there are smaller ones there too. This astronomy business seems to involve a lot of fuzzy images and (well informed) imagination / picking the most likely interpretation. I have seen a number of 'stars' that just won't focus and, when I look em up, the book tells me they're Galaxies. At least that's my story. (200p Dobs)jim mcnamara said:Several dots moved, AFAIK.
Could that just be due to the spreading of the images due to the limitation of the optics?OmCheeto said:I noticed an anomaly in Post #7. Triton is too close to Neptune in that image.
OmCheeto said:From my calculations, Triton, in your image, seemed too near to Neptune.
It's maximum distance should be about 6.7 times the diameter of Neptune.
sophiecentaur said:@Andy Resnick
Can you give us some idea of the equipment and exposures used for this? I fear my Kodak box brownie might do as well as that.
jim mcnamara said:<snip>
sophiecentaur said:<snip>
Vanadium 50 said:<snip>
OmCheeto said:<snip>
That's a nice big piece of glass. (Did you spot the Freudian slip in my question? There's a missing "not".) I was considering getting an 80ED and launching into some astrophotography. From your comments and those of others, it's pretty clear that good results are only obtainable with skill and true grit. Astro montages are probably not as problematical as regular snaps with difficult backgrounds and moving subjects - but that's small consolation. Remember the doctored photos of Chairman Mao, bathing in the Yangtze river, published when his health was in doubt? ( Perhaps you are too young.) It's quite possible to make a similar hash of things, even with the lovely Photoshop.Andy Resnick said:My usual lens- 800/5.6 (400/2.8 + 2x tele),
sophiecentaur said:I've already seen that loads more stars emerge with stacking. Needless to say, since I took delivery of an Ioptron Tracker for my camera, I have had about 1 hour of clear sky at a suitable time but it seems to deal with star trails ok, afaics.
Andy Resnick said:Lots of good discussion, let's see if I can provide some clarifications. Some of the issues appear related to the quality of my posted images- blooming and underexposure, but also the fact that I haven't posted 'final' versions.
Blooming is a common problem- bright objects appear larger than they should.
http://info.adimec.com/blogposts/ccd-versus-cmos-blooming-and-smear-performance
On my images, this means the planet's bloom obscures nearby moons. The images of Jupiter + moons is a composite- the bloomed blobs of Jupiter were replaced by separate images of correctly-exposed Jupiter. A source of error is placing the correct exposure image correctly- at the correct location in the overexposed image. Unfortunately, the bloom pattern is not circularly symmetric when the blob is off axis.
For the outer planet images, the moons are barely observable- and this time of year the seeing is particularly bad. This makes it even harder to resolve the moons. Here's the result of stacking 6 images of Uranus on Saturday (10/22) night:
Two moons are clearly visible- there may be a third, but it's partially obscured by bloom. Replacing the overexposed planet with a correct exposure yields
You can at least see the size of the blooming problem (puns absolutely intended).
FWIW, here's what I have so far- 4 nights of viewing for Uranus, with the whole image scaled 50% to fit the planet's track in 800 x 600 pixels:
And 4 nights of Nepture, but this time the image is at 100%:
You can kinda see the moons in the these images, but it's not great- some nights are better than others. My vision for these is that when I have a good-sized track (say over a month or two), I can go in and individually replace the bloomed planets with correct exposures, or even replace the moons if needed. And add dates, etc...
Creator said:Nice pics, Andy. Do you have CCD or CMOS imaging?
Creator said:Thanks Andy;
In light of that article you linked with regards to eliminating blooming, it may be helpful to know precisely what you have:
I'm not an imaging expert, but...
... do you know how many megapixels you have?? From this list of Sonys any sensor that has 12 MP or better appears to be CMOS, less than 12 MP is CCD. I suspect yours is 24 or greater? D-800 series corresponds to 36 MP.
http://nikonrumors.com/2015/12/16/l...s-and-their-sensor-manufacturerdesigner.aspx/
"Aaaannd.... here's Neptune" is a phrase that was used by the Voyager 2 spacecraft team in 1989 when they discovered and captured images of Neptune for the first time. It has since become a popular meme and phrase used to announce something new or exciting.
Neptune is the eighth and farthest planet from the sun in our solar system, making it difficult to detect with the naked eye. It was first observed by Galileo in 1612 but was mistaken for a star. It wasn't until 1846 that Neptune's existence was confirmed through mathematical predictions and observations made by astronomers.
Neptune is the smallest of the gas giants in our solar system and is known for its deep blue color due to the presence of methane in its atmosphere. It also has the strongest winds in the solar system, reaching speeds of up to 1,500 miles per hour. Neptune also has the most active weather patterns, with large storms and dark spots constantly forming and dissipating on its surface.
No, humans cannot live on Neptune. It is a gas giant with no solid surface, only a thick atmosphere of hydrogen, helium, and methane. The temperatures on Neptune are also extremely cold, reaching as low as -353°F (-214°C), making it impossible for humans to survive without advanced technology.
The only spacecraft to ever visit Neptune was Voyager 2 in 1989. It captured the first images and data of the planet, providing valuable insights into its atmosphere and moons. There have been no other missions planned to explore Neptune in the near future, but scientists continue to study it through telescopes and space probes.