Hi Charles,

Interested to hear your take on things! 

Perhaps you could share your non-detection images? If you can demonstrate the nonexistence of these features, it would be important. I think more likely is that your images are deficient either in depth or resolution to show them. These are not, after all, features that jump out with casual imaging; not that I am suggesting that yours is, but you take my point!

Cheers

Nick

From: baa-comet@simplelists.com <baa-comet@simplelists.com> on behalf of Charles S Morris - cometguy3783 at yahoo.com <baa-comet@simplelists.com>
Sent: 03 May 2020 04:54
To: baa-comet@simplelists.com <baa-comet@simplelists.com>
Subject: Re: [BAA Comets] C/2019 Y4 (ATLAS) new fragment
 
Hi Nick,

I appreciate the fact that you are asking for confirmation of your observation.  I can say that there is no such object on my image taken on May 2.196 UT with my 41 cm SCT + CCD.  I processed my image every possible way and ran brightness profiles through the coma.  Nothing was there.

I have no idea what is on your image.

Now for a reality check - I apologize for this Nick, but a few weeks ago everyone, regardless of instrument size, was claiming to have imaged "the comet and fragment ."  I threw cold water on that and finally, that ended.  Now I have to end this before it starts again.

1) It would take months or years for a fragment to move that far in front of (or any direction from) the main nucleus.  I saw the fragments from Comet West many months after the break-up (through John Bortle's 12" L) and they were still in a tight little cluster.  The differential velocity between fragments simply isn't that great and we are looking at vast distances between the center of the comet and the edge of the coma.  

2) If it was real, there would be a string of fragments and not just one out there by itself.  I suspect that all the fragments are still very close to the center of light in the coma.

3) Unless you have a meter class instrument, you are not going to be able to resolve the fragments.  Everyone, PLEASE stop looking for things that can not reasonably be at the edge of the coma.  You will find them.  I doubt that they are real, but you will find stuff.  Heaven knows people did a few weeks ago.  And none of it was real.

4) Prior to suggesting fragments, I propose that such reports be ignored unless 1) the observers are using meter class or larger telescopes, 2) they have two nights of observations with astrometry proving the unknown object is connected to the comet, or 3) the observations are with HST!

A separate question - who has assigned letters to the various fragments???  I hope it is the HST folks that clearly had 11 fragments.  I have seen at least one assignment of fragments and their distribution of fragments did not agree with the HST image - a small problem.  So who did the assignment?

Sorry to be straightforward and undiplomatic, but I don't want to get people's hopes up that they are going to image something that isn't really possible.

I will be posting my recent images on FB and probably on the comet images group.

Regards,
Charles

On Saturday, May 2, 2020, 03:35:49 PM PDT, Nick James <ndj@nickdjames.com> wrote:


This comet continues to do interesting things!

My image tonight shows a new fragment 20 arcsec west and 9 arcsec south
of the the main nucleus (component B). The new fragment is around mag
18.8. The residual nucleus, component B, is currently around magnitude
15.2. An image showing the fragment is here:

http://www.nickdjames.com/Comets/2020/2019y4_20200502_2124_ndj.jpg

Has anyone else imaged this?

Nick.



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