Comet Atlas 2019/Y4 - breaks up

[Mike JW]

Comet Atlas 2019/Y4. (April 12th 2020)

I was given the heads up that Y4 is breaking up. As we know Y4 has been worth a look for awhile as the volatiles and dust were released; making it bright. Apparently in mid March the comet stopped (slowed down?) the release of volatiles and I assume this is the cause of it not getting any brighter. The stresses and strains on the comet (sun’s gravity) appears to have now caused fragmentation, dust pouring off to form the large dust coma. The core no longer has the normal spherical appearance. The fragmented rocky junks are ahead of the core giving it a curved, elongated appearance. Visible in the image are the different zones of brightness. What will happen next?

 

 

[Bill S]

I had a look at this last night and managed to get a snap. Here's a before (when it looked like it could be promising later in the year - in May) followed by an after (the snapshot last night).

 

an last night:

 

 

The Wikipedia page has quite a lot of background information:

https://en.wikipedia.org/wiki/C/2019_Y4_(ATLAS)

and some recent discussion on the BAA forum:

https://britastro.org/node/21397

It's definitely not looking promising!

 

Best regards

 

[Mike JW]

Bill, Great to see your shots and the comparison. Enjoyed the BAA link but much of it way beyond my knowledge.

[Martin Meredith]

Fascinating to see these images -- thanks! There appear to be fragments behind the core too. I took the liberty to compare the two images in order to see what elements are in common. What do you reckon to these? Background stars?

 

 

Mike's (left) is about 30 minutes before Bill's.

There's a great animation here: 

 

Martin

 

Edited April 12, 2020 by Martin Meredith

[stash_old]

39 minutes ago, Martin Meredith said:

Fascinating to see these images -- thanks! There appear to be fragments behind the core too. I took the liberty to compare the two images in order to see what elements are in common. What do you reckon to these? Background stars?

 

 

Mike's (left) is about 30 minutes before Bill's.

There's a great animation here: 

 

Martin

 

Background Stars - I would have thought the fragments would dull very quickly and be very very small IMO 

[Mike JW]

Thanks Martin, Great idea to compare our two shots and the link to the video, adds more drama. Mike

[roelb]

Here are two images with ZWO ASI533MC-Pro on a Evo 8 @ f/4.4

March 28 and April 11

 

[Mike JW]

Last night (15/4/20) I took another look at Y4. Obvious that the core has changed from a curve to a more rounded appearance. Closer inspection suggests three separate brighter chunks. Are there two more behind the bright front three? Comet appeared to be dimmer than a few nights ago. Mike

 

[Bill S]

Yes, Mike. I also looked at it on the evening of 15 April and it's a shadow of its former self. Your pictures show the detail better. Best regards.