2 replies to this topic

[smiller]

I noticed that the Asteroid Thisbe was going to be traveling through the Jellyfish nebula region, and sure enough, the skies were clear...  poor seeing, but clear.

 

So I got about 6 hours of data of the event, and later added another 6 hours of data and some RGB stars to create an image, plus a couple of videos of the Asteroid.

 

 First the image, captured with my Orion XT12G Dobsonian, ASI2400MC camera, and L-Ultimate filter:

 

<Click on link for astrobin image>

 

Here is the nebula with the Asteroid, but the asteroid is pretty small:

 

<Click on link for astrobin video>

 

So here is more of a closeup of the Asteroid:

 

<Click on link for astrobin video>

 

 

The capture stats are in the astrobin image page, but the image was composed from about 5700 * 8 second lights of L-Ultimate and about 320 * 6 second lights of RGB for the stars.

 

Captured with NINA, stacked in SIRIL/APP, processed in APP/PI/Affiniity with the Xterminators.

 

The video was created in PIPP and Handbrake.  To create the asteroid, I stacked 10 minute sections for each asteroid frame and used the stars from each of those for star layer of the asteroid area.

 

Oh, Thisbe will be skimming just over the top of the Jellyfish again the last 3 days of March.

 

As always, comments and feedback on the image and my processing choices is appreciated.

 

Cheers!

Edited by smiller, 10 February 2025 - 09:18 PM.

[Jim Thommes]

Beautiful Jellyfish on its own Steven! Thisbe is a nice bonus.

 

So, to make the image, I assume you integrated with some form of pixel rejection. Then you had to add the motion of the asteroid compiled from subs??

[smiller]

Beautiful Jellyfish on its own Steven! Thisbe is a nice bonus.

 

So, to make the image, I assume you integrated with some form of pixel rejection. Then you had to add the motion of the asteroid compiled from subs??

Thanks Jim!

 

Yes, when I integrated all the data from all nights, the pixel rejection eliminated the asteroid.

 

Since I take so many short exposures, my normal process is to stack these 10 minute "sub stacks" and it turns out those were just the right amount to get stills of the asteroid without much motion (the asteroid was nearly round, only slightly oblong in some cases).  Pixel rejection didn't reject the asteroid for only 10 minutes of data because it had hardly moved over that time.   I used these directly for the asteroid animation but only replaced the star field along the asteroid path for each frame of the animation.  So it's a composite as you can imagine.

 

This is unlike my animation of 671 Carnegie going near the Crystal Ball Nebula for which I directly used 10 minute "sub stacks" for the asteroid AND the nebula because the nebula was bright enough to show up fairly well even with 10 minutes of data:

 

 

In that case you can see a band of high clouds pass by during the capture.   In this case, although I stacked 10 minute chunks, I did twice as many interleaving them by 5 minutes (i.e. 10 minute integrations offset by 5 minutes) to create a smoother asteroid animation.   I didn't bother doing that on JellyFish.    Also unlike the Jellyfish example, the Crystal Ball/Asteroid capture was a chance encounter.  I luckily noticed it as the pixel rejection wasn't 100% effective and I noticed a streak.

 

- Steven

Edited by smiller, 12 February 2025 - 02:16 PM.