Scratting around the Leo Trio in the noise February 2022
An examination of a Leo Triplet image for asteroids.
WARNING! YOU NEED TO VIEW THIS PAGE ON A DECENT DISPLAY AT THE OPTIMUM ANGLE TO HAVE A CLUE AS TO WHAT'S GOING ON.
WARNING! SOME ASSERTIONS REGARDING VISIBILITY MAY BE CONSIDERED, BY THE REASONED READER, TO BE OVERLY OPTIMISTIC.
INFORMATION: FOR ALL THE SMALL SQUARE IMAGES ON THIS PAGE, YOU CAN TOGGLE BETWEEN TWO IMAGES BY CLICKING ON THEM.
In my attempts to find minor planets (asteroids) or comets etc. in the Leo Trio picture, I went through the following process:
I went online to the Minor Planet search facility (MPChecker), for a list of things that could be in the image.
Here's the list, re-ordered by the values in the magnitude column:
Expecting to be able to see at least the first one in this list, I embarked on a search through the image for suitable candidates.
This involved "blinking" between two images, one a stack of frames from 23:04 to 23:27 (Set 1), the other a stack of frames from 23:28 to 00:10 (Set 2).
And of course, doing this by scanning through the images at 100% resolution in small chunks.
The two full resolution images I used were stacked in Astro Art 6 with minimal manipulation (just a linear histogram transform).
I found four candidates doing this.
Next I took a reduced version of my overall image, and put yellow circles around the positions of the objects identified. And then pasted in a Right Ascension/Declination grid from Stellarium (my planetarium software of choice).
As well as re-ordering the list above, I've also changed the R.A and Dec coordinates, which are sensibly reported by the MPC in epoch 2000 values, to the "on date" equivalents used by the Stellarium grid.
I could then run through the MPC list to see if they corresponded to any of the objects I had identified.
Unsurprisingly, the first one did. Here it is... (note, for the rest of the images clicking on them toggles between the two stacked sets)
(71832) 2000 UQ63, magnitude 17.4, motion R.A -21 Dec +7
Pleasingly, so did the second one...
(24525) 2001 CS4, magnitude 18.2, motion R.A -17 Dec +24
The third one didn't. I had a look back at the images. Don't know how I missed it...
(15840) Hiroshiendou, magnitude 18.2, motion R.A -18 Dec +17
This is marked on the image above with the blue circle.
The fourth in the list was there...
(15638) 2000 JA65, magnitude 18.2, motion R.A -15 Dec +11
But the fifth wasn't. I went back to the images, but couldn't see it. We are now down from magnitude 18.2, to 18.3. But it is close to the centre of the image. I'm surprised it's not there...
because, sixth in the list (magnitude 18.6) could be seen...
(71406) 2000 AK173. magnitude 18.6, motion R.A. -19 Dec +24
So all my discoveries accounted for. I really hadn't expected to have seen the last one at magnitude 18.6. So I carried on down the list looking back at the images for any evidence of these.
You won't be surprised that I didn't find any.
Still perturbed by the fact that I had not seen the 18.3 magnitude entry in the MPC list, I looked for it in two Deep Sky Stacker based images.
It is there...
So I'm looking at some very faint pixels moving about just below and to the left of the brightest star in the image.
This really is scratting around in the noise.
I would be gobsmacked if any of A, B, C, D, F and G were not asteroids orbiting in the main asteroid belt between Mars and Jupiter.
They are all in the same part of the sky with very similar motions.
You may have noticed there is no Object E. Actually, there is. I lied about find four potential asteroid candidates, Object E is something I spent ages looking at and thinking about on my first run through the images, before convincing myself it represented something that was moving.
After going through the MPC list, I spent ages looking at it and thinking about it, and twiddling the alignment before deciding it didn't represent something moving.
Have a look and see what you think...
Some concluding remarks:
I have long thought that on a good night, with good focus, you could see stuff down to magnitude 17.5 from my back garden, with the setup I have.
I've also thought that some of the 'stars' you could see in the image are actually down to magnitude 18.
I think that is fair enough. The only object here that would have attracted my attention if I hadn't been 'blinking' images is Object A, at magnitude 17.4 (maybe Object B as well).
What is true though is that 'blinking' is a good way to find faint moving objects (not faint stationary ones). 4 out of 6 without me referencing the MPC list positions is not bad.
You can see a nice picture of the Leo Triplet in the best of 2022 post.
WARNING! YOU NEED TO VIEW THIS PAGE ON A DECENT DISPLAY AT THE OPTIMUM ANGLE TO HAVE A CLUE AS TO WHAT'S GOING ON.
WARNING! SOME ASSERTIONS REGARDING VISIBILITY MAY BE CONSIDERED, BY THE REASONED READER, TO BE OVERLY OPTIMISTIC.
INFORMATION: FOR ALL THE SMALL SQUARE IMAGES ON THIS PAGE, YOU CAN TOGGLE BETWEEN TWO IMAGES BY CLICKING ON THEM.
In my attempts to find minor planets (asteroids) or comets etc. in the Leo Trio picture, I went through the following process:
I went online to the Minor Planet search facility (MPChecker), for a list of things that could be in the image.
Here's the list, re-ordered by the values in the magnitude column:
Expecting to be able to see at least the first one in this list, I embarked on a search through the image for suitable candidates.
This involved "blinking" between two images, one a stack of frames from 23:04 to 23:27 (Set 1), the other a stack of frames from 23:28 to 00:10 (Set 2).
And of course, doing this by scanning through the images at 100% resolution in small chunks.
The two full resolution images I used were stacked in Astro Art 6 with minimal manipulation (just a linear histogram transform).
I found four candidates doing this.
Next I took a reduced version of my overall image, and put yellow circles around the positions of the objects identified. And then pasted in a Right Ascension/Declination grid from Stellarium (my planetarium software of choice).
As well as re-ordering the list above, I've also changed the R.A and Dec coordinates, which are sensibly reported by the MPC in epoch 2000 values, to the "on date" equivalents used by the Stellarium grid.
I could then run through the MPC list to see if they corresponded to any of the objects I had identified.
Unsurprisingly, the first one did. Here it is... (note, for the rest of the images clicking on them toggles between the two stacked sets)
(71832) 2000 UQ63, magnitude 17.4, motion R.A -21 Dec +7
Pleasingly, so did the second one...
(24525) 2001 CS4, magnitude 18.2, motion R.A -17 Dec +24
The third one didn't. I had a look back at the images. Don't know how I missed it...
(15840) Hiroshiendou, magnitude 18.2, motion R.A -18 Dec +17
This is marked on the image above with the blue circle.
The fourth in the list was there...
(15638) 2000 JA65, magnitude 18.2, motion R.A -15 Dec +11
But the fifth wasn't. I went back to the images, but couldn't see it. We are now down from magnitude 18.2, to 18.3. But it is close to the centre of the image. I'm surprised it's not there...
because, sixth in the list (magnitude 18.6) could be seen...
(71406) 2000 AK173. magnitude 18.6, motion R.A. -19 Dec +24
So all my discoveries accounted for. I really hadn't expected to have seen the last one at magnitude 18.6. So I carried on down the list looking back at the images for any evidence of these.
You won't be surprised that I didn't find any.
Still perturbed by the fact that I had not seen the 18.3 magnitude entry in the MPC list, I looked for it in two Deep Sky Stacker based images.
It is there...
So I'm looking at some very faint pixels moving about just below and to the left of the brightest star in the image.
This really is scratting around in the noise.
I would be gobsmacked if any of A, B, C, D, F and G were not asteroids orbiting in the main asteroid belt between Mars and Jupiter.
They are all in the same part of the sky with very similar motions.
You may have noticed there is no Object E. Actually, there is. I lied about find four potential asteroid candidates, Object E is something I spent ages looking at and thinking about on my first run through the images, before convincing myself it represented something that was moving.
After going through the MPC list, I spent ages looking at it and thinking about it, and twiddling the alignment before deciding it didn't represent something moving.
Have a look and see what you think...
Some concluding remarks:
I have long thought that on a good night, with good focus, you could see stuff down to magnitude 17.5 from my back garden, with the setup I have.
I've also thought that some of the 'stars' you could see in the image are actually down to magnitude 18.
I think that is fair enough. The only object here that would have attracted my attention if I hadn't been 'blinking' images is Object A, at magnitude 17.4 (maybe Object B as well).
What is true though is that 'blinking' is a good way to find faint moving objects (not faint stationary ones). 4 out of 6 without me referencing the MPC list positions is not bad.
That's the end folks.
You can see a nice picture of the Leo Triplet in the best of 2022 post.
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