An image of Comet Ison or is it really a comet?

Wow you guys are still discussing this, cool.

So what's the verdict is it a comet or an alien spaceship?

I'm hoping it's a spaceship but it's probably just a big dirty snowball.

Originally posted by nataylor

Originally posted by abeverage
reply to post by nataylor

 

So ntaylor how long was the exposure to lsp_ison_hst_wfc3_130430_f606w-f814w_v1?

It's a total of 2300 seconds (three exposures of 440 seconds with the F606W filter and two exposures of 490 seconds with the F814W filter).

And lsp_ison_hst_wfc3_130430_f606w-f814w_v1 is part of IC7I11010?

Originally posted by abeverage
And lsp_ison_hst_wfc3_130430_f606w-f814w_v1 is part of IC7I11010?

It is, as you can see here: archive.stsci.edu...

Originally posted by nataylor

Originally posted by abeverage
And lsp_ison_hst_wfc3_130430_f606w-f814w_v1 is part of IC7I11010?

It is, as you can see here: archive.stsci.edu...

A simple yes or no please...

Originally posted by abeverage

Originally posted by nataylor

Originally posted by abeverage
And lsp_ison_hst_wfc3_130430_f606w-f814w_v1 is part of IC7I11010?

It is, as you can see here: archive.stsci.edu...

A simple yes or no please...

"It is" means "Yes, it is a part of the ICI11010 data set."

Originally posted by nataylor

Originally posted by abeverage

Originally posted by nataylor

Originally posted by abeverage
And lsp_ison_hst_wfc3_130430_f606w-f814w_v1 is part of IC7I11010?

It is, as you can see here: archive.stsci.edu...

A simple yes or no please...

"It is" means "Yes, it is a part of the ICI11010 data set."

Cool so if lsp_ison_hst_wfc3_130430_f606w-f814w_v1 is part of data set IC7I11010

Originally posted by nataylor

Originally posted by abeverage
reply to post by nataylor

 

So ntaylor how long was the exposure to lsp_ison_hst_wfc3_130430_f606w-f814w_v1?

It's a total of 2300 seconds (three exposures of 440 seconds with the F606W filter and two exposures of 490 seconds with the F814W filter).

and like you said it is 2300 seconds why is IC7I11010 shown as having 1320 second exposure?

IC7I11010 ISON-FIXED 06 41 21.697 +29 29 40.28 0 2013-04-30 03:35:43 2013-04-30 04:24:07 1320.000

archive.stsci.edu...



While I appreciate the non-condesending lesson on how a proposal is made and how datasets are created I already knew and had that information.

Here is one area I am confused if IC7I11010 is a composite image (which it is)

Either their math is incorrect or yours is because I am pretty sure a data set of 1320 seconds cannot contain one image that is 2300 seconds long. So you can see where that might cause a bit of confusion...

Oh and by the way are you an Astronomer? Yes or No will do.

reply to post by abeverage


I see your problem. The data set contains multiple products. Specifically, that data set contains all products that contain data taken with the F606W filter. That includes the file that contains the the 5 combined exposures.

As I said, the same exact product is also part of the IC7I11020 data set as well. Obviously it can't contain only data from one filter if it it's included In the data sets for both filters.

hmmm... i am very perplexed by this whole thing too... This website attempts to explain how the scientists take the RAW hubble data to produce the release images... but looking at it, it looks to me like they smoothed out a lot of the comet to make it look like a comet... funny how this RAW hubble data (from the hubble legacy archive) can transform into this highly edited picture released by NASA... remember these are the exact same photos from the exact same day (april 30, 2013)

reply to post by Yummy Freelunch


If you do it to all the pictures of the comet for the months you specified you will notice sometimes it's only 1 line, another it's 2 lines and in that one pic it's 3... Interesting but I don't think it's aliens, I'm pretty sure it has to do with modifying the picture and the way the photos are taken and then compiled together, I'm no photo expert, someone can explain it. Hopefully that someone is an ATS member.

nataylor

Originally posted by filledcup
i can see how ISON can appear to change direction in a matter of months. but.. from the viewpoint, the position of the earth and its motion in orbit around the sun.. and the very very tiny angle of difference the hubble makes as it orbits.. i dont see a 90 degree angle appearing in just 43 minutes of exposure. let's round it off to an hour.

edit on 20-8-2013 by filledcup because: (no reason given)

The plot on the left side of the animation showing ISON's position over the those 48 minutes perfectly lines up with the path seen in the photo from Hubble:

It's just coincidence that the positions as plotted by my Starry Night Pro software happen to match up exactly, because you have some kind of gut feeling that it wouldn't move like that? I've provided software-plotted diagrams and calculations to back up my position. All you can say is you don't feel like it would move like that. If you can provide calculations or plots from other software that show something different, please do so.

edit on 20-8-2013 by nataylor because: (no reason given)

Way to go man, I really feel you have explained it very well, it's a pity the truth gets lost in masses of posts from people wanting to believe in something. Thanks for the work, it wasn't lost on me.

Originally posted by nataylor
reply to post by abeverage

 

I see your problem. The data set contains multiple products. Specifically, that data set contains all products that contain data taken with the F606W filter. That includes the file that contains the the 5 combined exposures.

As I said, the same exact product is also part of the IC7I11020 data set as well. Obviously it can't contain only data from one filter if it it's included In the data sets for both filters.

Can you answer my question on the Astronomer part please? Are you an Astronomer?

reply to post by abeverage


I'd consider myself an amature anstronomer. I'm certainly not a professional, though.

Harkening back to my post here, let's visually look at all the science products in the IC7I11010 and IC7I11020 data sets. You can find them on this page: archive.stsci.edu...

Again, we're looking at the products from July 16th. Clicking on the Interactive Display link, let's center on the comet and darken the image until we can see the streaks. Now let's go over the images one by one.

First is hlsp_ison_hst_wfc3_130430a_f606w_v1. This is the "A" exposure, which is 440 seconds with the F606W filter:



Next is hlsp_ison_hst_wfc3_130430b_f814w_v1, the "B" exposure is 490 seconds with the F814W filter:



Then hlsp_ison_hst_wfc3_130430c_f606w_v1, the "C" exposure of 440 seconds with the F606W filter:



Then hlsp_ison_hst_wfc3_130430d_f814w_v1, the "D" exposure of 490 seconds with the F814W filter:



Then hlsp_ison_hst_wfc3_130430e_f606w_v1, the "E" exposure of 440 seconds with the F606W filter:



Then there is hlsp_ison_hst_wfc3_130430_f606w_v1, which is a combination of all 3 F606W exposures:



Next is hlsp_ison_hst_wfc3_130430_f814w_v1, which is a combination of both F814W exposures:



Finally, the product you've been focused on, hlsp_ison_hst_wfc3_130430_f606w-f814w_v1, which is a combination of all five exposures:



Putting them all together in an animation:



Looking at that visually, I don't see how you can think the hlsp_ison_hst_wfc3_130430_f606w-f814w_v1 product is anything but a combination of all 5 exposures, for a total exposure time of 2300 seconds.

Well, thanks to everybody that provided evidence to this thread, either way.

This thread sure has offered lots of opportunity to learn about a variety of subjects, and I sure did learn a lot. I don't know if this goes for all participants, but I hope it does.

reply to post by nataylor


ok so if im standing on the sun. or rather.. standing next to the sun.. hovering in space at the sun's equator and im looking in the direction of earth as it orbits. where in relation to the earth would comet ison be travelling according to the pics u posted above?

would earth be to the right of the comet.. and the hubble looking to the left and down at the time these images were taken? tracking the comet to it's left and lower than the level of the earth?

Originally posted by NeoParadigm
Well, thanks to everybody that provided evidence to this thread, either way.

This thread sure has offered lots of opportunity to learn about a variety of subjects, and I sure did learn a lot. I don't know if this goes for all participants, but I hope it does.

truly, i came into this discussion not knowing much more than the moon revolves around the earth and the earth revolves around the sun lol. but i have a decent math background.

reply to post by filledcup


I'm not entirely sure what you're asking. At the time the images were taken, here's Earth's position and ISON's position, as seen from directly above the solar system looking down:



In that image, the position of the Sun, Earth, and ISON are indicated. The green line represents the Earth's orbit around the sun and the blue line is ISON's orbit around the sun. Zooming in on Earth from that position, you can see HST's position and orbit:



These plots show the positions at 9:35:43 on April 30th, when the imaging started.

reply to post by nataylor


Just like the visual on the HST orbit causing the curve while imaging ISON. I was having a hard time visualizing the image being a multiple exposure and I wanted to be 100% sure. Because to be frank and honest I didn't have the time to pour over the data and on the surface it appears in the data set that those were one exposure images.

While I am not expert myself I am not a complete neophyte and have done some astrophotography and needed to know who I am dealing with for credibility and to understand the process. Also the reason I asked is if I could not get a good grasp on it I would just contact Zolt Levay the imaging lead. He does some spectacular images both professionally and personally!

I am sorry for any contention, but until I saw it visually I was not convinced, and while I may understand photography I am still learning when it comes to Satellite imagery. Thank you for taking the time (and patients) to compose this, it cleared up any misconceptions that I had and I learned a lot from it.

reply to post by nataylor


gotcha, it makes sense. i really wouldnt have thought that such small orbit of the hubble could create seemingly such an angle. but, it's nasa's fault.. sort of. they would have to edit the pictures to show it's true path. and i suppose they opted just to present it as it's observed.. and let the peasants work their minds around what's going on in space haha.

The earth is to the left of comet ISON at the time of photo and looking slightly downward at say a 30-60 degree angle from our equator.

hubble is moving towards the comet for about 22 minutes... and then hubble starts moving away from it in the last 20-26 minutes, this causes lines out of angle as i explained earlier since the camera optics has no choice but to represent the dot in the film as being further away. this was caused by using the long exposure method while the hubble is moving.

the green line in this picture i would say demonstrates what would be the true path and direction of the comet once the corrections to the individual dots that create the lines in long exposure are corrected. nasa would have to edit the photos to bring each pixel of the long exposure down to meet the green line.




while hubble is moving towards the comet it creates one line out of angle, and then when it move back away from the comet it corrects the angle by creating another angle. the confusion is caused by seeing more than one perspective on one picture. people would need to know the positioning of all elements at the time to visualize it properly and let their perception shift with the changing angle.

this is why multiple periods of observation would demonstrate a zigzag pattern as hubble is essentially reaching its peak point in orbit, of closeness to the 'moving point of observation' and then backing away from the peak as it continues it's orbit around the earth.

i guess, once all these positions are correct, then yes, this is normal.

so are we all professional astronomers now? hahah jk jk

reply to post by filledcup


What? Huh? Do you do this in real life? I mean... make things more complicated than they need to be... every time I think Nataylor has done a superb job of demonstrating what we are seeing you come back with another post that completely boggles the mind.

NATAYLOR: I commend your patience, I would have given up long ago.

based on what im seeing now.. i predict this to be the image for an August shot in another 43 minute period.

the angle of entry would be closer to vertical, and the angle of correction should also be less pronounced. creating an angle of oh say 150-160 degrees. vs June's 125 degree angle.