Hi All,

It appears that A10iMHA, an object currently on the PCCP discoverd by ATLAS, is another fragment of C/1988 A1 (Liller).
From the observations reported sofar on the PCCP I calculated (using FIND_ORB) the following parabolic elements:

T = 2020 Mar 15.51188
q   0.84058950      (2000.0)            P               Q
M(T) 13.0  K 10.0  Peri.   57.27035     +0.33758334     -0.79908501     
                   Node    31.26916     +0.12494162     -0.48580533     
e   1.0            Incl.   73.42637     +0.93296681     +0.35419812     
From 16 observations 2019 Dec. 16-18; mean residual 0".61

MPC 13459 gives for C/1988 A1 (Liller) the following elements:

T = 1988 Mar 31.11442
q = 0.8413332          Peri.   57.38762
                                    Node 31.51540
e = 0.9965647          incl.    73.32240

The similarity is striking, even considering the short arc for A10iMHA.
So we are probably seeing the fourth member of this comet group that broke up during an earlier (the previous?) apparition.

best regards,
    Reinder

Reinder,

It appears that A10iMHA, an object currently on the PCCP discoverd by ATLAS, is another fragment of C/1988 A1 (Liller).
From the observations reported sofar on the PCCP I calculated (using FIND_ORB) the following parabolic elements:

well spotted! I fully agree with yourt assessment.

Kind regards

Maik
--
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http://cobs.si

Hi Folks,

To be precise, this is not a fragment of 1988a1, but a member of the same family of comets,
arising from a breakup of a larger comet about 3000+ years ago.
Note that 1988a1 Liller appears to be the primary component, which reached 5th magnitude.
with succeeding members intrinsically fainter.
C/1996 Q1 Tabur , then C/2015 F3 SWAN.
This latest member seems to be faint intrinsically (about 13.5) and may struggle to survive perihelion.
It could reach 12th mag, then again it might outburst and show up brighter.

Cheers,
Michael Mattiazzo

Hi Folks,

To be precise, this is not a fragment of 1988a1, but a member of the same family of comets,
arising from a breakup of a larger comet about 3000+ years ago.
Note that 1988a1 Liller appears to be the primary component, which reached 5th magnitude.
with succeeding members intrinsically fainter.
 C/1996 Q1 Tabur , then C/2015 F3 SWAN.
This latest member seems to be faint intrinsically (about 13.5) and may struggle to survive perihelion.
It could reach 12th mag, then again it might outburst and show up brighter.

Cheers,
Michael Mattiazzo

Hi Michael (and list),

You are right of course, I was a bit sloppy in my wording, but from the rest of my original message (clipped in your reply), it was obvious that I meant another member of the C/1988 A1 group.
I too am wondering what the fate of this small comet will be.
C/1996 Q1 (Tabur) desintegrated around the time of perihelion, but surprisingly C/2015 F3 (SWAN) seems to have survived, at least until 2-3 months past perihelion.
Let's hope that A10iMHA will surprise us (in a positive way)!

best regards,
Reinder

This is an image taken one hour ago in Namibia

 

https://www.facebook.com/photo.php?fbid=2403402079786850&set=gm.1025962667574195&type=3&theater&ifg=1

 

regards

 

Gerald

 

Hi Gerald,

I get a message that this page is not available.
Normally I can see Facebook messages, although I am not a member.
Can you repost it?
I am very curious to see what this new member of the C/1988 A1 group looks like...

Best regards,
Reinder

Based on the most recent orbit solutions, it's starting to look like assigning A10iMHA to the Liller group may have been a bit premature...

q: 0.707 +/- 0.035 AU (off by about 3.5 sigma from ~0.84 AU)

e: 0.892 +/- 0.023 (off by about 4.5 sigma from ~0.996)

I: 70.78 +/- 0.80 deg (off by about 3.3 sigma from ~73.35 deg)

node: 35.1 +/- 1.1 deg (off by about 3 sigma from ~31.5 deg)

peri: 67.7 +/- 2.7 deg (off by about 3.8 sigma from ~57.4 deg)

the eccentricity difference appears to be the most damning. The above orbit solution has a residual of about 0.62 arcseconds, while force-fitting an eccentricity of 0.996 brings the mean residuals up to 0.76 arcseconds.

I wouldn't say for sure whether or not it might have an orbit in the Liller group, but it's starting to look less likely.

~Sam

On Friday, December 20, 2019, 8:23:59 AM MST, Gerald Rhemann <gerald.rhemann@...> wrote:

Hi Reinder,

 

Done – I forwarded the data to MPC

 

Best regards

 

Gerald

 

Von: comets-ml@groups.io [mailto:comets-ml@groups.io] Im Auftrag von reinder j bouma via Groups.Io
Gesendet: Donnerstag, 19. Dezember 2019 16:09
An: comets-ml@groups.io
Betreff: Re: [comets-ml] A10iMHA, another fragment of C/1988 A1?

 

 

Hi Gerald,

 

Thanks for the new link. That is a very nice image!

I can easily spot a 1-1.5' coma, and it must certainly be in the magnitude 15-16 range.

But that is a crude estimate. It is not easy to compare an extented diffuse object to star trails.

 

Is it possible for you to get astrometry from your images?

Sofar the PCCP lists only 18 observations over a 2.2 day arc. It would not hurt to get a few more.

 

best regards,

Reinder

 

Hi Reinder,

 

That is strange. But I have uploaded the image to my website:

 

http://www.astrostudio.at/3_Faint%20Comets.php?img=images/3_Faint%20Comets/226_A10iMHA.jpg

 

best regards

 

Gerald

 

Von: comets-ml@groups.io [mailto:comets-ml@groups.io] Im Auftrag von reinder j bouma via Groups.Io
Gesendet: Donnerstag, 19. Dezember 2019 10:57
An: comets-ml@groups.io
Betreff: Re: [comets-ml] A10iMHA, another fragment of C/1988 A1?

 

Op 18-12-2019 om 23:08 schreef Gerald Rhemann:

This is an image taken one hour ago in Namibia

 

https://www.facebook.com/photo.php?fbid=2403402079786850&set=gm.1025962667574195&type=3&theater&ifg=1

 

regards

 

Gerald

 

 

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