Hi Richard,

Oddly, I am currently imaging 29P/S-W1 for Richard's project..

Well, as one of those Americans (only Americans, really?) that still call 29P - SW1 or the full name (or Sony-Walkman 1 as David Levy named it back when Walkmans were a thing), I will simply say - So What.  As long as it is understood and properly designated in formal papers, it is harmless.  Some of us have used the old designation for decades.  The addition of numbers on periodic comets is extremely useful when discoverers have more than one periodic comet.

Most astronomers, professional and amateur, know what comet S-L9 happens to be (Shoemaker-Levy 9).  Without looking it up, I have no idea what its formal designation is.  I would look it up, if I were writing a paper.  Using well-known comet names (with numbers) is not a bad thing unless one is writing a paper.  In a formal paper, both the old and new designations should be given for older comets for clarity.

In my opinion, for current comets, with the exception of those discovered by an actual person, names should be dropped totally from the formal designation.  Who cares what automated discovery device identified the object - there are too many automated discoveries to care about now.  At some point comet names will become just like asteroids in that regard. 

Sorry- The change from AU to au is stupid - someone had too much time on their hands. [No doubt there is a really good reason that someone will explain to me.]

On another subject, but related to change and near and dear to me.  There also has been a change from m1 for total comet magnitude to simply magnitude with the understanding that m2 (nuclear magnitude) is meaningless.  I still use m1.  I have been using it for 50+ years.  Difficult to correct the habit after that long.. However, there is a problem for the ICQ and COBS, both of which will be eliminating m2 - nuclear magnitudes in the near future..  Now a comet's magnitude in the age of CCD is simply the brightness within a certain measurement aperture.  The problem is that in theory the data from Richard's 29P project with tiny measurement apertures could be entered into either archive (after m2 is eliminated) as a 'magnitude.'.  Those data would be mixed with 'total' magnitudes.  One would have to look at the measurement aperture to know that they are not attempts at total magnitudes - not everyone will be that careful, just dumping the archive and plotting all the data..

I wish the IAU had kept m2, but redefined it as 'not total.'  It would allow an archive to maintain both types of data without confusion.  

Sorry for the rant...

Charles (one of those Americans)

ICQ Associate Editor
Dreamweaver Observatory
Fillmore, CA USA

On Monday, November 16, 2020, 12:15:07 PM PST, Richard Miles - rmiles. btee at btinternet. com <baa-comet@simplelists.com> wrote:


Thanks Jonathan for explaining the current nomenclature.
However, U.S. astronomers still often use 29P/Schwassmann-Wachmann 1 or even
29P/S-W1.
It's rather like the change in the abbreviation for the Astronomical Unit
which has changed from AU to au . Not everyone is up to speed as yet !!

Nick A. is right though about the orbit, which on JPL has the most recent
as:
Epoch 2011-Jun-13.0    K192/35 (default)

Richard

----- Original Message -----
From: "Jonathan Shanklin - UKRI BAS" <jdsh@bas.ac.uk>
To: <baa-comet@simplelists.com>
Sent: Monday, November 16, 2020 5:07 PM
Subject: RE: [BAA Comets] Observations of 29P


>I suspect that if you have that designation it is probably for very old
>elements - you need to use some valid for 2020.
>
> The current designation for the comet is 29P/Schwassmann-Wachmann.  Prior
> to the introduction of the scheme numbering periodic comets they were
> referred to as for example Schwassmann-Wachmann 1 and Schwassmann-Wachmann
> 2 (now 31P/ Schwassmann-Wachmann) to distinguish comets with the same
> name.  If we had stuck to the old scheme there would be a large number of
> PanSTARRS comets - I think we are probably up to PanSTARRS 13, which
> instead is numbered 400P/PanSTARRS.
>
> Regards,
>
> BAA Comet Section visual observations co-ordinator
> https://www.ast.cam.ac.uk/~jds/
>
>
>
>
> -----Original Message-----
> From: baa-comet@simplelists.com <baa-comet@simplelists.com> On Behalf Of
> Nick Atkinson
> Sent: 16 November 2020 16:34
> To: baa-comet@simplelists.com
> Subject: Re: [BAA Comets] Observations of 29P
>
> Hi Nick,
>
> Is this the correct one: Comet 29P/Schwassmann-Wachmann 1 [2011]
>
> Nick
>
> On 14/11/2020 14:30, Nick James wrote:
>> Comet 29P/Schwassmann-Wachmann is a fascinating object. It orbits
>> beyond Jupiter and, compared to the comets that we are used to, it has
>> a massive nucleus, over 60km in diameter. It also has frequent outbursts.
>>
>> The section's 29P observation programme is run by Richard Miles and he
>> has recently added a new page to the Comet Section website which you
>> can find here:
>>
>> https://britastro.org/node/24942
>>
>> This page will be frequently updated with observational news. In fact,
>> it currently includes a report of a mini-outburst from yesterday (Nov
>> 13), so it is worth checking back regularly to see the latest news and
>> analysis.
>>
>> Our objective is to observe this comet in a standard way so that
>> Richard can receives estimates with a high degree of consistency
>> between observers. Details of the approach to be adopted are on this
>> web page and they are reproduced in the section observing guide which
>> you can download from here:
>>
>> https://britastro.org/node/6817
>>
>> The comet is now well placed for northern hemisphere observers and we
>> would like to receive your observations. If you have not already done
>> so please consider adding this fascinating comet to your programmes.
>>
>> Many thanks to Richard for running this programme and maintaining the
>> web page.
>>
>> Nick James. Director.
>>
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