On Mon, 23 Jul 2001 14:04:12 -0000
  gianmasi@... wrote:
> feature, maybe connected with what Giovanni reported here
> earlier
> (and I would like to hear his comment about his final
> analysis, announced yesterday): a sort of double jet
> bifurcation?), clearly emerging  from the nucleus.

Hi Gianluca and all,
you can dawnload the picture we made last week-end from
Visnjan Obs. at: http://www.astro.hr/comets/lin2207.jpg
The "bifurcated" tail structure I noticed at that time on
the "raw" images, was actually what it seems a bi-component
tail: one narrow and straight ione tail and a second
component more broad and diffuse, superimposed on the
previous one.  Is the latter a possible dust tail component,
as suggested recently by M. Mattiazzo? Don't know yet. But
on the same night my friends at the
Remanzacco Observatory imaged this comet with V (Johnson)
and R, I (Cousin) filters. Looking at those filtered frames,
I hope that it would be possible to discriminate among the
two different dust/gas components, in any. Let me reduce
also those images.

Kind regards,
Giovanni

Greetings to all and about time we had a comet list!

I've noticed in the past week that the tail of LINEAR 2001 A2 was of higher
surface brightness.
Earth crossed the comets orbit around the 15-16th and any dust in the plane
of the orbit would have been visible ON EDGE, hence more readily observable.
Can anyone confirm that the enhancement was in fact due to the dust element?
ie yellow filtered CCD imaging.
or was the tail made entirely of gas?

Also note that LINEAR is rather dust poor but the dust tail, if it exists,
is also more visible NOW due to the improvement in the orbital geometry of
Earth-Comet. (given that a dust tail lags behind the radius vector by 45
degrees or more and is also more prominent post-perihelion).

Cheers,
Michael Mattiazzo
Wallaroo, South Aust
mmatti@...

Last night, under excellent sky conditions, I managed to image
again this comet, at Bellatrix Astronomical Observatory.

The comet is entering quite dense star fields, making a bit harder an
accurate, deep analysis. But I've been able to isolate an interesting
feature, maybe connected with what Giovanni reported here earlier
(and
I would like to hear his comment about his final analysis, announced
yesterday): a sort of double jet (bifurcation?), clearly emerging
from
the nucleus. It is evident with the Larson-Sekanina rotational
gradient.

As usual, you can have a look at:

http://www.eurolink.it/comets/c2001a2.html

Warmest Regards,
Gianluca

Hi all,
here you my last data and a description of C/2001 A2
(LINEAR):
-I get the firm impression that the comet this evening was
more evident compared to yesterday: the inner part of the
coma shows a clear condensation, and the total magnitude is
a little brighter.
-the tail was almost 50 arcmin long in PA210 deg, i.e.
longer than the previous days. It is rather broad compared
to before, and its final part is very difficult to be traced
due to its faintness.

Please find some data in the ICQ format.

COMET C/2001 A2 (LINEAR) Total magnitude and coma-diameter
estimates:
2001 July 22.89, 6.2, 25' (G. Sostero, Visnjan, Croatia,
7x50 binoculars);

Kind regards,
Giovanni Sostero

Dear Maciej,

> Maik, this morning I tried observed C/2000 SV74. I found
> 13.7 mag diffuse object which semms confirmed 13.2 mag
> observation. But I'm stll not 100% sure due not motion
> confirmation (twilight!). Full raport below.

thanks for your obsrvation. I am right now on business travel
and will return on Wednesday evening. I hope I have then more information.

Regards

Maik
--
_______________________________________________________________________
If they give you ruled paper, write the other way. * Juan Ramon Jimenez
       maik@...            http://www.comethunter.de
       Fachgruppe Kometen             http://www.fg-kometen.de

Hi all,

Maik, this morning I tried observed C/2000 SV74. I found
13.7 mag diffuse object which semms confirmed 13.2 mag
observation. But I'm stll not 100% sure due not motion
confirmation (twilight!). Full raport below.

Best regards,
Maciej

C/2000 SV74
Jul. 22.03, 13.7, 1'.0 (M. Reszelski, Szamotuly, Poland, 0.41-m reflactor);

IIIYYYYMnL YYYY MM DD.DD eM/mm.m:r AAA.ATF/xxxx /dd.ddnDC /t.ttmANG ICQ
XX*OBSxx
    2000SV742001 07 22.03  S 13.7 AC 40.8L 5 262   1.0  2/           ICQ XX
RES

Comment:
C/2000 SV74
Jul. 22.03: Diffuse object at correct position. Due twilight motion not
observed. [RES]

Hi all,
Here you my observations of last night: the comet seems to
be faded by almost 0.5 magnitudes in two days. A tail 0.7
degrees long in PA 210 deg is still visible. I also imaged
this object by means of a CCD, and I get the firm impression
of a kind of “bifurcation” in the tail. But I
will inform you better later on about this possible feature,
when I will detrend the data.

Kind regards,
Giovanni




COMET C/2001 A2 (LINEAR) Total magnitude and coma-diameter
estimates:

2001 July 22.05, 6.4, 20' (G. Sostero, Visnjan, Croatia,
7x50 binoculars);

Hello all:
This it is the history of my measures. All measures are with USNO SA2.0 with
red stars.
Lx200 12" f:6,3  st9E.   The measures are ccd nuclear. In this moment the
comet has a small cola.
There are more measures in the web Dr. Mark Kidger:
http://www.iac.es/galeria/mrk/recent_obs.html

COMET 2000 WM1
CK00W01M C2001 06 16.12742 02 54 06.82 +46 13 37.0    16.1 T   170
CK00W01M C2001 06 16.12742 02 54 06.82 +46 13 37.0    16.1 T   170
CK00W01M C2001 06 22.05839 03 02 13.91 +46 31 12.5    16.0 T   170
CK00W01M C2001 06 22.06469 03 02 14.74 +46 31 13.4    16.0 T   170
CK00W01M C2001 06 22.06716 03 02 14.86 +46 31 14.2    16.1 T   170
CK00W01M C2001 06 22.07979 03 02 15.88 +46 31 17.2    16.0 T   170
CK00W01M C2001 06 22.08234 03 02 16.13 +46 31 17.4   16.1 T    170
CK00W01M C2001 06 22.08484 03 02 16.28 +46 31 17.9   16.0 T    170
CK00W01M C2001 06 22.08976 03 02 16.68 +46 31 19.0   16.0 T    170
CK00W01M C2001 06 24.12682 03 05 04.47 +46 37 28.4   15.9 T    170
CK00W01M C2001 06 24.13063 03 05 04.74 +46 37 29.3   16.0 T    170
CK00W01M C2001 06 29.04675 03 11 49.70 +46 52 29.8   16.1 N   170
CK00W01M C2001 06 29.04913 03 11 49.99 +46 52 30.3   16.2 N    170
CK00W01M C2001 06 29.05593 03 11 50.42 +46 52 31.4   16.1 N    170
CK00W01M C2001 06 29.05837 03 11 50.61 +46 52 31.8    16.1 N   170
CK00W01M C2001 06 29.07385 03 11 51.94 +46 52 34.6    16.1 N   170
CK00W01M C2001 07 01.08675 03 14 37.89 +46 58 47.0    15.9 N    170
CK00W01M C2001 07 01.09837 03 14 38.89 +46 58 49.5    15.9 N   170
CK00W01M C2001 07 11.01933 03 28 15.66 +47 29 40.4    15.9 N   170
CK00W01M C2001 07 11.02354 03 28 16.05 +47 29 41.8    15.8 N   170
CK00W01M C2001 07 11.02718 03 28 16.28 +47 29 42.3    15.8 N   170
CK00W01M C2001 07 13.06308 03 31 03.57 +47 36 04.3    16.0 N   170
CK00W01M C2001 07 13.06560 03 31 03.67 +47 36 05.1    16.0 N   170
CK00W01M C2001 07 13.07100 03 31 04.24 +47 36 06.3    15.9 N   170
CK00W01M C2001 07 13.07606 03 31 04.64 +47 36 07.1    15.9 N   170
CK00W01M C2001 07 20.99255 03 41 51.43 +48 00 56.1   15.76N   170
CK00W01M  C2001 07 20.99580 03 41 51.74 +48 00 57.9  15.74N   170

See you soon.

Pepe Manteca
Web personal de COMETAS, ASTEROIDES
http://www.geocities.com/p_manteca

----- Original Message -----
From: "Maciej Reszelski" <macres@...>
To: <comets-ml@yahoogroups.com>
Sent: Saturday, July 21, 2001 11:11 AM
Subject: Re: [comets-ml] presentation


> >     CK00W01M  C2001 07 20.99255 03 41 51.43 +48 00 56.1          15.76N
> 170
> >     CK00W01M  C2001 07 20.99580 03 41 51.74 +48 00 57.9          15.74N
> 170
>
> Dear Pepe,
>
> It is a nuclear magnitude right? Very bright. It suggest that WM1 is much
> brighter
> than in ephemeris...
>
> Best regards,
> Maciej
>
>
> To unsubscribe from this group, send an email to:
> comets-ml-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

>     CK00W01M  C2001 07 20.99255 03 41 51.43 +48 00 56.1          15.76N
170
>     CK00W01M  C2001 07 20.99580 03 41 51.74 +48 00 57.9          15.74N
170

Dear Pepe,

It is a nuclear magnitude right? Very bright. It suggest that WM1 is much
brighter
than in ephemeris...

Best regards,
Maciej

Hello from Spain:

My name is Jose Manteca and I live in Begues near Barcelona. I am amateur
astronomer and I like very much the comets.
I am moderator of comet List in language spanish  with Mark Kidger (IAC) and
Rafael Ferrando.
Here is: http://es.groups.yahoo.com/group/Cometas_Obs I hope mutual
collaboration among the two lists.

I am very happy of being integrated to the list Comets-ml and  I want many
messages and a lot of information for all.
I read 2000 WM1 is 13,8.

I captured tonight this comet and this is the measures in Nucleu:

     CK00W01M  C2001 07 20.99255 03 41 51.43 +48 00 56.1          15.76N      170
     CK00W01M  C2001 07 20.99580 03 41 51.74 +48 00 57.9          15.74N      170


Kind regards.


Pepe Manteca
Web personal de COMETAS, ASTEROIDES
http://www.geocities.com/p_manteca



[Non-text portions of this message have been removed]

Hi,
you can download the three files at:
http://www.astro.hr/comets

-LRGB.jpg is a Johnson V, Cousin R and I tricolor of C/2001
A2 (LINEAR) made on July 14.1 with a 0.3m f/2.8 baker camera
+ Hi-Sis 24 CCD

-comet.jpg is a drawing of the same comet I made on July
19.92 through a 7x50 binocular

-rays.jpg are two frames taken on the night og July 14-15,
2001 by means of a C8 + SBIG ST6V, showing some interesting
features ("tail folding rays"?!) on C/2001 A2 (LINEAR)

Regards,
Giovanni Sostero

P.S. if the sky will clear out, I'm ready to image C/2000
WM1 (LINEAR) in order to confirm the sudden brightness
increase that was suggested by one observer

I think it's better if you just upload the files to your own server,
instead of the Yahoo Groups page.

-joshua








----------
>From: "Maik Meyer" <maik@...>
>To: <comets-ml@yahoogroups.com>
>Subject: Re: [comets-ml] Presentation & data
>Date: Fri, Jul 20, 2001, 4:37 AM
>

>Dear Giovanni (and all),
>
>> [Non-text portions of this message have been removed]
>
>the settings for this group are that attachments are not
>permitted. But you have the possibility to upload any file
>in the files section of this group
>
>http://groups.yahoo.com/group/comets-ml/files/
>
>Regards
>
>Maik
>--
>If they give you ruled paper, write the other way.  * Juan Ramon Jimenez
>________________________________________________________________________
>       maik@...          http://www.comethunter.de
>       German Comet Section         http://www.fg-kometen.de
>              http://groups.yahoo.com/group/comets-ml
>
>
>
>To unsubscribe from this group, send an email to:
>comets-ml-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

Oops,
sorry for the inconvenience! I will upload the file as for
your suggestion.

Regards,
Giovanni

Dear Giovanni (and all),

> [Non-text portions of this message have been removed]

the settings for this group are that attachments are not
permitted. But you have the possibility to upload any file
in the files section of this group

http://groups.yahoo.com/group/comets-ml/files/

Regards

Maik
--
If they give you ruled paper, write the other way.  * Juan Ramon Jimenez
________________________________________________________________________
        maik@...          http://www.comethunter.de
        German Comet Section         http://www.fg-kometen.de
               http://groups.yahoo.com/group/comets-ml

Hi all,
my name is Giovanni Sostero, and I'm an Italian amateur
astronomer very interested on comets.
I'm going to send you my visual estimate of yesterday night
and a drawing of the
C/2001 A2 (LINEAR) I made the same night under the very dark
sky of Istria (Croatia).

Please, find also a LRGB (VRI) tricolor CCD image of the
same comet, taken on July 14.0 2001
(Baker camera D= 0.3m f/2.8 + Hi-Sis 24 CCD + Johnson V,
Cousin R and I filters)
and a b/w image showing some suspected structures in the
coma (tail folding rays?!)
taken with a Celestron 8 and SBIG ST6V CCD on July 17.9.

Kind regards,
Giovanni Sostero

COMET C/2001 A2 (LINEAR)
      Total magnitude and coma-diameter estimates:
2001
July 19.92, 5.9, 15' (G. Sostero, Visnjan, Croatia, 7x50
binoculars);


[Non-text portions of this message have been removed]

>
SOHO's 341. Komet wurde von S. Hönig in LASCO/C3-Echtzeitaufnahmen erkannt.
C/2001 O1 (SOHO) ist ein Mitglied der Kreutz-Gruppe.
<

Congrats to Sebastian

Best reagrds,
MJ

As some of you might know, I am working on volume two of Cometography
at this time. Most of the editing it complete, but I have holes
scattered about the manuscript that I can not fill, despite numerous
trips to libraries and the assistance of interlibrary loan.

I am really interested in finding a person or persons that might be
able to provide some help. I ran into similar problems with volume
one and received assistance from a couple of people who I
acknowledged in the book.

As an example, two problems are as follows:

Comet C/1823 Y1: Some sources, like J. G. Galle's Cometenbahnen, S.
K. Vsekhsvyatskij's Physical Characteristics of Comets, and Brian G.
Marsden's earlier editions of the Catalogue of Cometary Orbits,
mention that this comet was first seen on December 23/24, 1823, but
do not provide adequate references. J. Holetschek does not mention
this in his work and I have found no reference to such observations
in contemporary journals like Astronomische Nachrichten, Berliner
Astronomisches Jahrbuch, and Correspondance astronomique. Does anyone
have any information on this?

Comet 2P/Encke: This is easier. The library I access for the
Correspondance astronomique is missing a few volumes. I need Valz'
recovery observations and positions for comet Encke's 1825 apparition
that were published in that journal.


I have other areas I need information on and I would be happy to
share them with anyone willing to offer their time.

Sincerely,
Gary
--
Gary W. Kronk

http://cometography.com
http://comets.amsmeteors.org

Hi,

I received additional observations from the same observer who confirmed his
first reports that these comets are at about 13 and 13.8 mag, respectively.
The full set of observations can be found at
http://www.fg-kometen.de/obsakte.html . Visual confirming observations by
other observers are in need.

Maik
--
If they give you ruled paper, write the other way.  * Juan Ramon Jimenez
________________________________________________________________________
        maik@...          http://www.comethunter.de
        German Comet Section         http://www.fg-kometen.de
             http://groups.yahoo.com/group/comets-ml

> And yes, keep a close eye to this comet!

Dear Gianluca and Maik,

Last night comed seem faded mre rapidly. Is it a hint of nucleus
fragmentation? Nucleus looks unsharped, very diffuse.

Also C/1999 T1 (McNaught-Hartley) appears to be still active. I estimated
it at 13.6 last night.

Best regards,
Maciej

Maik>
> it was my first look at your images and have to admit that I am
quite
> impressed. I wonder if the rotation period of the nucleus could be
> determined using such events which are quite frequent with this
comet.


To me, those features appear not strongly connected to the nucleus, as
they seem, in the evolved images, to stay always in the same position.
  Apparently, they experienced only an increasing curvature.

And yes, keep a close eye to this comet!

Gianluca,
Bellatrix Astronomical Observatory

Gianluca,

> finally, I posted a couple of images from th night between July 13 and
> 14. These frames now give a better idea about the appearence and
> following evolution of the "T" structure I reported here on July 13.

it was my first look at your images and have to admit that I am quite
impressed. I wonder if the rotation period of the nucleus could be
determined using such events which are quite frequent with this comet.

The T-like structure shows that this comet is still very active and I
definitely think that it holds still some surprises for us in the coming
weeks. Although - on the other side - I am also astonished about the
stamina of this comet. Outbursts, break-offs, but no surrender.

Hmm, even after 80 observed comets I am still surprised. ;)

Maik
--
If they give you ruled paper, write the other way.  * Juan Ramon Jimenez
________________________________________________________________________
        maik@...          http://www.comethunter.de
        German Comet Section         http://www.fg-kometen.de
             http://groups.yahoo.com/group/comets-ml

Dear All,
finally, I posted a couple of images from th night between July 13 and
14. These frames now give a better idea about the appearence and
following evolution of the "T" structure I reported here on July 13.

The new image, with the complete image set, can be seen at this
temporary address (some server problems make impossible for me to update
the usual site, hopefully coming back very soon):

http://www.matosti.it/astro/c2001a2.html

Regards,
Gianluca

--
***********************************************************************
* Gianluca Masi                           "Two things fill the soul   *
* Via Madonna de Loco, 47               with awe and reverence [...]: *
* 03023 Ceccano (FR)                     the starry sky above me and  *
* ITALY                                    the moral law within me"   *
* e-mail: gianmasi@...                                     *
* web:  http://www.eurolink.it/comets/                  I. Kant       *
* Minor Planet Center Obs. Code: 470 - Ceccano                        *
* Center for Backyard Astrophysics - Italy                            *
* VSNET Collaboration Team member                                     *
* CCD-astrometry-photometry@egroup mailing-list moderator             *
***********************************************************************

> I just found an observation of A.Nakamura from July 03. He puts 2000
> WM1 at 16.3 mag with 0.6 reflector + CCD. So in my opinion that
> observation would be 1.5mag too bright.

Dear Sebastian,

I predict two resons:

-Comet is still in rising phase
-CCD observations are about 1.5-2.5 fainter than visual. For example
if I correct remeber P/Klemola (at last return) have CCD m1 values at 16.5
but I, Martin Lehky and Kamil Hornoch estimated it at about 13.7.
>July  3.78, 16.3*, 0'.35 (A. Nakamura, Kuma, Ehime, Japan, 0.60-m reflector
+ CCD);
>June 27.05, 15.9, 0'.3 (G. Sostero, 0.3-m Baker-Schmidt + CCD + Johnson V
filter);

So I feel it is possible. But confirmation is need. In my place now, coming
front clouds...

Best regards,
Maciej

Maik,

I just found an observation of A.Nakamura from July 03. He puts 2000
WM1 at 16.3 mag with 0.6 reflector + CCD. So in my opinion that
observation would be 1.5mag too bright.

I wondered if that observer really identified th comet but I saw his
observation with a DC of 2/. That should make the comet easy to
identify.

Regards, Sebastian

---------------------------------
Sebastian Hoenig
Jahnstr. 38
69221 Dossenheim
Germany
email: sfhoenig@...
website: http://members.aol.com/sfhoenig

>
> If somebody is able to have a look at both comet visually and try to
> confirm this or not I would like to know about.

OK Maik,

Both comets is very palaced for now for me, but I try maybe
tonight. Now is clear...

Best regards,
Maciej

sorry this :

>Both comets is very palaced for now for me, but I try maybe

should be :

Both comets is very bad palaced for now for me, but I try maybe

Best regards,
Maciej

Hi,

I have just received an observation report af a member of of our German
comet section reporting comet C/2001 WM1 (LINEAR) as bright as 13.8 mag, DC
2-3, Dia 0.9'. He also reports comet C/2000 SV74 (LINEAR) as bright as 13.2
mag, DC 3-4, Dia 1.0'. Both observations were done visually with an 54cm L
at 180x and 150x by an observer who has often reported extremely bright
magnitudes over the last years. The latest observations I know of is a CCD
detection by R. Ligustri at about C 15.7 mag on July 14.93 for WM1 and one
of January 2001 for SV74 which just emerges from the sun's glare.

For WM1 I had the feeling that this comet brightened slower than expected
so this observation would be a surprise. The same counts for SV74 since it
should nominally be as bright as 15 mag.

If somebody is able to have a look at both comet visually and try to
confirm this or not I would like to know about.

Regards

Maik
--

Wenn man Dir liniertes Papier gibt, schreibe quer ueber die Zeilen.
If they give you ruled paper, write the other way.  * Juan Ramon Jimenez
________________________________________________________________________
        maik@...          http://www.comethunter.de
   Homepage der Fachgruppe Kometen:  http://www.fg-kometen.de

Dear Comet Lovers,
to me the comet appeared definitely and clearly brighter early on July
13, about 0.5, 0.6 magnitudes more than 24-hours earlier. Also, I
think that was a correlation between that outbusrt and the development
of the "T" structure I reported on july 13, which quite rapidly
evolved in a bow-like structure.

A detailed analysis of theimages I've been so lucky to grab are at

http://www.eurolink.it/comets/c2001a2.html

Regards,
Gianluca


--- In comets-ml@y..., Maik Meyer <maik@c...> wrote:
> Hi,
>
> I was just wondering if the latest outburst of comet C/2001 A2
(LINEAR) was a real
> event or just the effect of weather (the moon just went out of sight
the first time
> for Central Europe) and/or internet (bias by published observation).
Maybe it is even
> a mix of all three effects.
>
> I believe there was an outburst (but with a quite small amplitude,
maybe about 1 mag)
> but we may never find out since the published observations right now
tend to split
> into two groups - no outburst and outburst.
>
> Unfortunately bias is a thing we will never eliminate and such
bright and big comets
> are hard to estimate. Unfortunately we can also not just go out and
observe without
> prior selected comparison stars since there is the danger of picking
up variables or
> red stars which are not suitable.
>
> What do you think?
>
> Regards
>
> Maik
> --
>
> Wenn man Dir liniertes Papier gibt, schreibe quer ueber die Zeilen.
> If they give you ruled paper, write the other way.  * Juan Ramon
Jimenez
>
______________________________________________________________________
__
>        maik@c...          http://www.comethunter.de
>   Homepage der Fachgruppe Kometen:  http://www.fg-kometen.de

I believe the C/2001 A2 experienced an outburst sometime after July
12.4, but agree with Maik that it was not a strong one. With large,
diffuse comets I try to look at individual observers and the
instruments used to observe. In tough situations I will also fall
back to looking exclusively at experienced observers. An outburst of
1 to 1.5 magnitude is not out of the question on this occasion. In
addition, several observers reported a strong condensation appeared
late on the 12th, which subsequently faded and became more diffuse
during the next couple of days. I first saw the condensation with
20x80 binoculars on the 13th and I have seen some CCD images which
also display it. Outbursts are frequently accompanied by an increase
in the DC and/or appearance of a star-like condensation.

Gary W. Kronk

http://cometography.com
http://comets.amsmeteors.org
--
Gary W. Kronk

http://cometography.com
http://comets.amsmeteors.org

Hi,

I was just wondering if the latest outburst of comet C/2001 A2 (LINEAR) was a
real
event or just the effect of weather (the moon just went out of sight the first
time
for Central Europe) and/or internet (bias by published observation). Maybe it is
even
a mix of all three effects.

I believe there was an outburst (but with a quite small amplitude, maybe about 1
mag)
but we may never find out since the published observations right now tend to
split
into two groups - no outburst and outburst.

Unfortunately bias is a thing we will never eliminate and such bright and big
comets
are hard to estimate. Unfortunately we can also not just go out and observe
without
prior selected comparison stars since there is the danger of picking up
variables or
red stars which are not suitable.

What do you think?

Regards

Maik
--

Wenn man Dir liniertes Papier gibt, schreibe quer ueber die Zeilen.
If they give you ruled paper, write the other way.  * Juan Ramon Jimenez
________________________________________________________________________
        maik@...          http://www.comethunter.de
   Homepage der Fachgruppe Kometen:  http://www.fg-kometen.de