Hi all,
I first tried to spot C/2009 Q4 Boattini on October 21 in my 37cm reflector
but was unable to see it. This Sunday morning Nov. 15 I was surprised to
find the comet easily visible even at modest magnification in the same
telescope. My observation follows:

Nov. 15.3 UT
37cm reflector at 142x, 286x
Coma diameter = ~1'
DC=5, well-condensed
Mag. = ~12.3

Wishing everyone clear skies for Comet Tempel-Tuttle's Leonids tomorrow.
Bob


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

Giovanni is correct, of course.

Ignacio

--- In comets-ml@yahoogroups.com, "gvnn64\@...\.it" <gvnn64@...> wrote:
>
> Dear Ignacio and all.
>
> > I agree with Richard Miles that this is how science works.
>
> Science works on data and experimental facts, and here we have only *one*
observational evidence about a certain occurence.
> Then, anyone can propose nearly any theory to explain such unique event, and
it would be very difficult to accept or refuse it, just relying over one
sporadic observation.
>
> I agree that more observations are needed.
>
> Giovanni
>

Hi all,

I have updated my analysis of the currently observable comets. You can find them
at

http://kometen.fg-vds.de/aktause.htm

Regards,

Andreas


PS: third(!) try, hoping that the link will work now...

Hi all,

I have updated my analysis of the currently observable comets. You can find them
at

http://kometen. fg-vds.de/aktause.htm

Regards,

Andreas


PS: second try, now without the final point incorporated in the link...

Hi all,

I have updated my analysis of the currently observable comets. You can find them
at http://kometen.fg-vds.de/aktause.htm.

Regards,

Andreas

Comet 81P has developed a nice tail on images this morning
  Twitter:  http://twitter.com/cbellh47
Flickr: http://www.flickr.com/photos/cbellh47/
Facebook: http://www.facebook.com/cbellh47

Thank you Dimitry and Charles very much! Those will both work.
Gratefully yours,
Bob

On Sun, Nov 15, 2009 at 1:58 PM, Dimitry Chestnov <chestd@...> wrote:

>
>
> --- In comets-ml@yahoogroups.com <comets-ml%40yahoogroups.com>, Bob King
> <nightsky55@...> wrote:
> >
> > Does anyone have orbital elements for 107P?
>
> Bob,
>
> You can find comet-style orbital elements for 107P with dates of perihelion
> and info about close approaches at Kazuo Kinoshita home page:
>
> http://jcometobs.web.fc2.com/pcmtn/0107p.htm
>
>
>


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

--- In comets-ml@yahoogroups.com, Bob King <nightsky55@...> wrote:
>
> Does anyone have orbital elements for 107P?

Bob,

You can find comet-style orbital elements for 107P with dates of perihelion and
info about close approaches at Kazuo Kinoshita home page:

http://jcometobs.web.fc2.com/pcmtn/0107p.htm

Hi everyone,
Does anyone have orbital elements for 107P? I found an incomplete set online
but none that list the perihelion date and distance for this apparition. I
use MegaStar to plot comets. Seiichi's entry for 107P lists everything but
those details. Thanks for your help.
Best wishes,
Bob


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

Dear Rob McNaught,

> > I heard that P/2009 U4 (McNaught) was discovered in the course of
> > follow-up observations of C/2009 R1.
>
> No, it was found in general surveying.

Thank you for your information.

I read IAUC 9087 again, and I see that you discovered P/2009 U4 on
Oct. 23, and then you found the pre-discovery image of this new comet
in the images of C/2009 R1 on the previous day.

So, it seems to be another case like C/2009 U6 near by 29P and 81P.

Best regards,

--
Seiichi Yoshida
comet@...
http://www.aerith.net/

Dear Rob Matson,

Thank you for your comments. I guess the next return of P/2009 Q1 (Hill)
can prove the linkage of your data in 1996 and 1998.

Best regards,

> They were reported right away. Brian Marsden and I exchanged a
> number of e-mails on the linkage, and ultimately came to the
> conclusion that the residuals were too high to link BOTH the
> 1996 obs and 1998 obs. The 1996 obs are definitely real, but
> the 1998 obs were right at the noise limit, so could easily
> have been false (or another object). Of course, with only the
> single night from 1996, the linkage (while certainly real)
> could not be proven.  We really needed a second night.
>
> I may revisit the 1998 data to see if anything can be done
> to pull the comet out of the noise, but I suspect it was
> just too dim.
>
> --Rob

--
Seiichi Yoshida
comet@...
http://www.aerith.net/

Hello Francois and all.
this morning 29P measures bring the same result as your observations.
nuclear mag. 13.71 nuclear magn. 10"
coma diameter = 9.6"
multiaperture obs;
COD J47
OBS G. Muler
CATALOGO: USNO A2.0 / CMC-14 - BANDA: R

                                    10x10  20x20  30x30  40x40  50x50  60x60  
RSR   FC   COD
OBJETO        FECHA      HORA        +/-    +/-    +/-    +/-    +/-    +/-    
N  FWHM  CAT
------------  ---------- --------  -----  -----  -----  -----  -----  ----- 
----  ----  ---
29P           12/11/2009 06:29:05  13.71  13.27  13.14  13.02  12.89  12.75 
14.3  16.8  J47
29P           12/11/2009 06:29:05*  0.01   0.01   0.01   0.01   0.04   0.04    
5   3.5  CMC

FoCAs II - 13/10/2009
www.astrosurf.com/cometas-obs
es.groups.yahoo.com/group/Cometas_Obs
--- In comets-ml@yahoogroups.com, francois kugel <fkugel@...> wrote:
>
> Hello,
>
> 29P in outburst again :
>
> Nov. 09.22 mag.16.3 (dia=20")
> Nov. 12.22 mag.13.3 (dia=20")
>
> Francois Kugel
> #A77
>

Hello,

29P in outburst again :

Nov. 09.22 mag.16.3 (dia=20")
Nov. 12.22 mag.13.3 (dia=20")

Francois Kugel
#A77

(4015) Wilson-Harrington was an object of study by the Midcourse Space
Experiment (MSX) mission

Mission images are available in the Planetary Data System MSX Small Bodies
Images data set:

"Kraemer, K., Lisse, C.M., Price, S., Mizuno, D., Walker, R.G., Farnham, T.L.,
and Makinen, T., MSX Small Bodies Images. MSX-C-SPIRIT3-3-MSXSB-V1.0. NASA
Planetary Data System, 2005."

http://www.psi.edu/pds/resource/msxsb.html

in this directory:
http://www.psi.edu/pds/asteroid/MSX_C_SPIRIT3_3_MSXSB_V1_0/data/wilsonh/


There is an on line article about this mission:

MIDCOURSE SPACE EXPERIMENT OBSERVATIONS OF SMALL SOLAR SYSTEM BODIES by KATHLEEN
E. KRAEMER, C. M. LISSE, STEPHAN D. PRICE,D. MIZUNO, R. G. WALKER,T. L.
FARNHAM,5 AND T. MÄKINEN, 2005

http://www.iop.org/EJ/article/1538-3881/130/5/2363/204596.text.html

Figure 15 text gives a summary

MSX images of the asteroid-comet transition object (4015) P/Wilson-Harrington
taken on 1997 January 6 (left) and 10 (right). The target was detected at 8.3 m
on both days, at 14.7 m on January 10, but not at the other wavelengths on
either day. There is no apparent extension of the image due to an extended dust
atmosphere.
http://www.iop.org/EJ/article/1538-3881/130/5/2363/204596.fg15.html

Dear Ignacio and all.

> I agree with Richard Miles that this is how science works.

Science works on data and experimental facts, and here we have only *one*
observational evidence about a certain occurence.
Then, anyone can propose nearly any theory to explain such unique event, and it
would be very difficult to accept or refuse it, just relying over one sporadic
observation.

I agree that more observations are needed.

Giovanni

Hi everyone,

I am happy to see this worthwhile discussion on this most interesting
object, and like the other posters I would encourage physical observation
attempts of all kinds while it is currently well-placed and near Earth.

There is one point I tried to make which, upon re-reading my earlier post,
may not have been as clear as I had thought:

The comet was discovered on photographs taken November 19, 1949. We do not
know, however, what its activity level was prior to that date; it
conceivably could have been active days, perhaps even weeks or months, prior
to that date, and we simply didn't know that since the comet's existence
wasn't yet known. We should probably keep this in mind now, both when
planning observing strategies as well as in formulating explantions for the
activity.

For what it's worth, I made another unsuccessful visual attempt last night.
My sky conditions probably weren't the greatest, but on the other hand I now
have a very clean optical system. Assuming a stellar object, the "comet" is
certainly no brighter than "m1" ~15.3, and probably a few tenths fainter
than that. This is, of course, consistent with the DOU MPECs as well as with
the photometry that has been reported in this forum.


Sincerely,

Alan

I agree with Richard Miles that this is how science works.
So it is fascinating to see so many hypothesis poping up.
In this regard I would like to point out two things:

(1) The activity may have been triggered by a) the thermal
wave penetrating inside the nucleus and activating a deep
layer of ice.  This hypothesis finds support from the
fact that the activity was observed +42 days *after*
perihelion.  Or b) the pole of the comet is pointing to the sun
at +42 days after perihelion.  Then there is no night and
the amount of solar energy received is maximum.

(2) The critical observing period starts next december 4th.
So please try to make an effort to observe from that day
onward.   In a previous posting Clay Sherrod and Alan Hale
suggested that the activity may take place at any time.
They may be correct.  We really do not know.  The pole
position may have shifted, the deep layer may have
been exhausted, etc.   So we should be observing for as long
as possible.

      I am already plotting the secular light curve of this
object in 2009 and I will have it available soon.  Please
let me know of your magnitudes to place them in the plot.
Robert Mason and all, go ahead with your observations.  The
object deserved all our attention.  In the Atlas of Secular
Light Curves this comet has a photometric age of 760 comet
years, so it is a methuselah comet.  The question is if it
is dead or alive.

Kind Regards,

Ignacio
Center for Fundamental Physics,
University of the Andes,
Merida, Venezuela

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
--- In comets-ml@yahoogroups.com, "RICHARD MILES" <rmiles.btee@...> wrote:
>
> Giovanni,
>
> I guess this is how science works, people come forward with options for
> working hypotheses and these are then compared with experimental
> observation.  In this case, I am flagging the possibility that some
> asteroids in comet-like orbits when struck by energetic particles
> originating from a major solar flare will have water molecules ejected from
> otherwise stable hydrated minerals.  It might be a worthwhile exercise to
> test this in an ultrahigh vacuum chamber in the laboratory.  Certainly the
> energy of some particles emitted from the Sun is sufficient to sputter and
> erode the surface on the molecular scale.
>
> If the hypothesis is valid then we would expect other low-albedo asteroidal
> objects in comet-like orbits, which spend only a small fraction of their
> life close to the Sun, to exhibit similar behaviour when exposed to
> highly-energetic particles arising from solar flares.  So, for observers
> like ourselves, we should consider monitoring those few comet-like objects
> as they make their perihelion passage around the time of the next solar
> maximum since one might then discover another 'comet' of this type.  One
> requirement for success is that the object would need to be relatively close
> to the Earth for the emitted material to be detected.  In the case of 107P
> at the time of discovery, it was really quite close at about 0.22 AU.
>
> btw: A definitive study of the case of 107P was published in:
>
> Icarus, Volume 128, Issue 1, July 1997, Pages 114-126
> Analysis of POSS Images of Comet-Asteroid Transition Object 107P/1949 W1
> (Wilson-Harrington)
> Yanga R. Fernández, Lucy A. McFadden, Carey M. Lisse, Eleanor F. Helin and
> Alan B. Chamberlin
> http://adsabs.harvard.edu/abs/1997Icar..128..114F
>
> I have only been able to read the abstract online.  I would imagine that in
> their discussion they would have mooted a similar hypothesis to the one I am
> suggesting.
>
> Cheers,
> Richard
>
> P.S.  It's a pity that the Sun is so inactive at present.
>
> ----- Original Message -----
> From: <gvnn64@...>
> To: "comets-ml" <comets-ml@yahoogroups.com>
> Cc: "comets-ml" <comets-ml@yahoogroups.com>; "mpml" <mpml@egroups.com>
> Sent: Wednesday, November 11, 2009 9:56 AM
> Subject: Re: [comets-ml] Incoming Activity of comet 107P/Wilson-Harrington?
>
>
> > Dear Richard
> > yours is a fascinating working hypothesis (as there are many others).
> > Obviously, without a robust experimental support, I'm afraid it will
> > remain as such.
> > With kind regards,
> > Giovanni
>

Giovanni,

I guess this is how science works, people come forward with options for
working hypotheses and these are then compared with experimental
observation.  In this case, I am flagging the possibility that some
asteroids in comet-like orbits when struck by energetic particles
originating from a major solar flare will have water molecules ejected from
otherwise stable hydrated minerals.  It might be a worthwhile exercise to
test this in an ultrahigh vacuum chamber in the laboratory.  Certainly the
energy of some particles emitted from the Sun is sufficient to sputter and
erode the surface on the molecular scale.

If the hypothesis is valid then we would expect other low-albedo asteroidal
objects in comet-like orbits, which spend only a small fraction of their
life close to the Sun, to exhibit similar behaviour when exposed to
highly-energetic particles arising from solar flares.  So, for observers
like ourselves, we should consider monitoring those few comet-like objects
as they make their perihelion passage around the time of the next solar
maximum since one might then discover another 'comet' of this type.  One
requirement for success is that the object would need to be relatively close
to the Earth for the emitted material to be detected.  In the case of 107P
at the time of discovery, it was really quite close at about 0.22 AU.

btw: A definitive study of the case of 107P was published in:

Icarus, Volume 128, Issue 1, July 1997, Pages 114-126
Analysis of POSS Images of Comet-Asteroid Transition Object 107P/1949 W1
(Wilson-Harrington)
Yanga R. Fernández, Lucy A. McFadden, Carey M. Lisse, Eleanor F. Helin and
Alan B. Chamberlin
http://adsabs.harvard.edu/abs/1997Icar..128..114F

I have only been able to read the abstract online.  I would imagine that in
their discussion they would have mooted a similar hypothesis to the one I am
suggesting.

Cheers,
Richard

P.S.  It's a pity that the Sun is so inactive at present.

----- Original Message -----
From: <gvnn64@...>
To: "comets-ml" <comets-ml@yahoogroups.com>
Cc: "comets-ml" <comets-ml@yahoogroups.com>; "mpml" <mpml@egroups.com>
Sent: Wednesday, November 11, 2009 9:56 AM
Subject: Re: [comets-ml] Incoming Activity of comet 107P/Wilson-Harrington?


> Dear Richard
> yours is a fascinating working hypothesis (as there are many others).
> Obviously, without a robust experimental support, I'm afraid it will
> remain as such.
> With kind regards,
> Giovanni

Dear Richard
yours is a fashinating working hypothesis (as there are many others). Obviously,
without a robust experimental support, I'm afraid it will remain as such.
With kind regards,
Giovanni

Dear Giovanni,

Some meteorites and presumably asteroids contain a significant proportion of
hydrated minerals.  Energetic particles from a solar flare would dissociate
the water of hydration liberating it to form a temporary ion tail.

Following my suggestion, today I checked the database at:
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SOLAR_FLARES/HALPHA_FLARES/earlierdata/op\
t1949
which contains the worldwide H-alpha solar flare records for 1949.

Comet 107P was discovered on an image taken on 1949 November 19.  Turns out
that the second-most active series of solar flares during the entire year
took place on Nov 18-19 !!
(The most active day for flares was on August 5).

I rest my case.
Richard Miles

----- Original Message -----
From: <gvnn64@...>
To: "comets-ml" <comets-ml@yahoogroups.com>
Sent: Wednesday, November 11, 2009 8:40 AM
Subject: Re: [comets-ml] Incoming Activity of comet 107P/Wilson-Harrington?


> Dear Richard and all.
>
>>  My
>> interpretation of the bluish ion tail in 1949 was that it was caused by a
>> particularly energetic solar flare which sputtered material off of the
>> asteroids surface and not that it was volatile material finding its way
>> from
>> within the nucleus.
>
> In the few instances where asteroidal object have shown discontinuous
> signs of cometary activity (e.g. the so called "main belt comets"), dust
> and not gases were considered to be responsable of the observed tails. All
> the evidences rules out the presence of ion tails...
>
> Some interesting readings:
> http://adsabs.harvard.edu/abs/2009MNRAS.399L..79P
> http://adsabs.harvard.edu/abs/2009DPS....41.2003J
> http://adsabs.harvard.edu/abs/2009AJ....137.4313J
> ect.
>
> With kind regards,
> Giovanni Sostero

Dear all,

In the case of non-main belt, NEO comets like 107P (apollo) and 162P (amor)
the tails have been found to be of Ionic nature (107P Yanga Fernandez et
al., 162P Seiichi Yoshida).

Intermitent activity was detected in the case of 162P, if observations do
not show activity that wouldn't ensure the object is dead.

Others consider the posibility of ignition triggered by colisions with
meteoroids.

Regards
Juan



On Wed, Nov 11, 2009 at 9:40 AM, gvnn64@... <gvnn64@...> wrote:

>
>
> Dear Richard and all.
>
>
> > My
> > interpretation of the bluish ion tail in 1949 was that it was caused by a
>
> > particularly energetic solar flare which sputtered material off of the
> > asteroids surface and not that it was volatile material finding its way
> from
> > within the nucleus.
>
> In the few instances where asteroidal object have shown discontinuous signs
> of cometary activity (e.g. the so called "main belt comets"), dust and not
> gases were considered to be responsable of the observed tails. All the
> evidences rules out the presence of ion tails...
>
> Some interesting readings:
> http://adsabs.harvard.edu/abs/2009MNRAS.399L..79P
> http://adsabs.harvard.edu/abs/2009DPS....41.2003J
> http://adsabs.harvard.edu/abs/2009AJ....137.4313J
> ect.
>
> With kind regards,
> Giovanni Sostero
>
>
>



--
                Eppur si muove
------------------------------------------------------------
Site http://www.lacanada.es
Nature http://lacanadawx.blogspot.com
Astro http://asteroblog.blogspot.com
Meteors http://cometeors.blogspot.com


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

Dear Richard and all.

>  My
> interpretation of the bluish ion tail in 1949 was that it was caused by a
> particularly energetic solar flare which sputtered material off of the
> asteroids surface and not that it was volatile material finding its way from
> within the nucleus.

In the few instances where asteroidal object have shown discontinuous signs of
cometary activity (e.g. the so called "main belt comets"), dust and not gases
were considered to be responsable of the observed tails. All the evidences rules
out the presence of ion tails...

Some interesting readings:
http://adsabs.harvard.edu/abs/2009MNRAS.399L..79P
http://adsabs.harvard.edu/abs/2009DPS....41.2003J
http://adsabs.harvard.edu/abs/2009AJ....137.4313J
ect.

With kind regards,
Giovanni Sostero

I was tempted to try 107P from SSO (0.61-m, no filter) during this
lunation and stack a bunch of 90-second images. On clear nights,
I routinely get down to magnitude +20.3 using this scope with a
120-second integration time, so I would think it would have no
problem showing cometary activity if present.

But if the 2-meter Faulkes saw no such activity a week ago, I
wonder if it's even worth trying with less than 1/10th the
aperture area.  --Rob

-----Original Message-----
From: mpml@yahoogroups.com [mailto:mpml@yahoogroups.com] On Behalf Of
RICHARD MILES
Sent: Tuesday, November 10, 2009 2:14 PM
To: comets-ml@yahoogroups.com
Cc: Edward Gomez; mpml@yahoogroups.com
Subject: {MPML} Re: [comets-ml] Incoming Activity of comet
107P/Wilson-Harrington?

Ignacio,

Thanks for alerting the comet community.  I agree that during the next
few weeks it is worth monitoring this asteroid (4105) for activity.  My
interpretation of the bluish ion tail in 1949 was that it was caused by
a particularly energetic solar flare which sputtered material off of the
asteroids surface and not that it was volatile material finding its way
from within the nucleus.  I have already started observations of (4015).
Here's an extract of a report made on November 04:

>> A tracked and stacked set of 6 x 90 sec images taken with the B
>> filter in a dark sky on the 2.0-m Faulkes Telescope South on 2009
>> November 04 at 10:19UT of 'Comet 107P' at a solar elongation of 80
>> deg two weeks past perihelion shows no evidence of cometary activity.

>> Likewise for a single R-filter image.  (R.Miles) <<

Just to illustrate the point that this is a particularly favourable
perihelic return of the 'comet', here are the approx. distances from the
Earth at each of its perihelic returns since first discovered:

Year    Delta
1949  0.20 AU
1954  1.8 AU
1958  1.8 AU
1962  0.5 AU
1966  1.1 AU
1971  2.0 AU
1975  1.3 AU
1979  0.15 AU
1984  1.7 AU
1988  1.8 AU
1992  0.50 AU
1997  1.2 AU
2001  2.0 AU
2005  1.1 AU
2009  0.38 AU

BTW:  Concerning its brightness, I think you are over-estimating this.
My photometry using 7 CMC-14 reference stars on Nov 4 10:09 UT gave
R=17.01 +/- 0.05.  The V magnitude predicted by JPL Horizons for this
epoch is 16.71 and that it will be brightest at V=16.37 on November 27.

Richard Miles
British Astronomical Association

Ignacio,

Thanks for alerting the comet community.  I agree that during the next few
weeks it is worth monitoring this asteroid (4105) for activity.  My
interpretation of the bluish ion tail in 1949 was that it was caused by a
particularly energetic solar flare which sputtered material off of the
asteroids surface and not that it was volatile material finding its way from
within the nucleus.  I have already started observations of (4015).  Here's
an extract of a report made on November 04:

>> A tracked and stacked set of 6 x 90 sec images taken with the B filter in
>> a dark sky on the 2.0-m Faulkes Telescope South on 2009 November 04 at
>> 10:19UT of 'Comet 107P' at a solar elongation of 80 deg two weeks past
>> perihelion shows no evidence of cometary activity.  Likewise for a single
>> R-filter image.  (R.Miles) <<

Just to illustrate the point that this is a particularly favourable
perihelic return of the 'comet', here are the approx. distances from the
Earth at each of its perihelic returns since first discovered:

Year    Delta
1949  0.20 AU
1954  1.8 AU
1958  1.8 AU
1962  0.5 AU
1966  1.1 AU
1971  2.0 AU
1975  1.3 AU
1979  0.15 AU
1984  1.7 AU
1988  1.8 AU
1992  0.50 AU
1997  1.2 AU
2001  2.0 AU
2005  1.1 AU
2009  0.38 AU

BTW:  Concerning its brightness, I think you are over-estimating this.  My
photometry using 7 CMC-14 reference stars on Nov 4 10:09 UT gave R=17.01 +/-
0.05.  The V magnitude predicted by JPL Horizons for this epoch is 16.71 and
that it will be brightest at V=16.37 on November 27.

Richard Miles
British Astronomical Association

----- Original Message -----
From: "iferrinv" <ferrin@...>
To: <comets-ml@yahoogroups.com>
Sent: Tuesday, November 10, 2009 6:25 PM
Subject: [comets-ml] Incoming Activity of comet 107P/Wilson-Harrington?


Hello all:
107P/Wilson-Harrington is a comet-asteroid transition object that
exhibited activity on one single night in 1949, and has remained
inactive since.  The activity was recorded in two Palomar Observatory
plates.  The red plate did not show activity, while the blue plate
exhibited a faint tail.  This prompted Yanga Fernandez et al. to
conclude that the comet had an ion tail.   The interesting thing
is that the activity took place 41 days after perihelion.   Well,
the comet has just passed perihelion and 41 days will take place
next December 4th, 3 WEEKS FROM NOW!  The present email is to
alert you of the possibility of a new outburst of this object
next month, and to request your help in securing observations to
confirm or deny its activity.  The comet was recovered by Sostero
et al. last year.  Currently is at magnitude 14-15 and will be
magnitude 13-14 in December so it is within reach of small
telescopes in the morning sky just before sunrise. If the
comet does not show activity then we can declare it dead, and
by itself this is an important result.  So please make an effort
to make CCD observations of this object in V, R or without filter,
and let me know about your work sending me an email at
ferrin@....    You can see the light curve of this object in
the "Atlas of Secular Light Curves of Comets",

http://arxiv.org/ftp/arxiv/papers/0909/0909.3498.pdf

Additional information and the call for observations will be
posted in my web site

http://webdelprofesor.ula.ve/ciencias/ferrin

Clear skies to all.

Ignacio Ferrín,
Center for Fundamental Physics,
University of the Andes,
Mérida, Venezuela

Dear Ignacio, and all,

It is good to have a timely reminder that this object is now in prime
viewing position for detecting possible activity. It is nearest Earth (0.379
AU) on November 19; this is the closest it has been to Earth since 1979
(when it was re-discovered by Helin et al.) and the closest approach it
makes until 2039. Unfortunately, this is not as close an approach as one
might like, but we have to work with what nature gives us.

I don't believe there is anything magical about the "41 days" -- if it is
going to exhibit activity, it could theoretically do so at any time. (For
that matter, we don't know whether or not it was active prior to its
discovery in 1949.) It has not exhibited any activity (that we know of,
anyway) at any subsequent return (at least, since 1979) so that in itself
gets rid of any significance behind any particular timeframe with respect to
perihelion. Incidentally, the red plate in 1949 does show the tail; it's
very faint (and on the DSS image you have to enhance the contrast -- but it
is there); the tail is obvious on the blue image.

107P is now in the evening sky, around 20h 50m, -11d, elongation 84 degrees.
The recent CCD magnitudes that have been published on the DOU MPECs are
indicating a magnitude of 16 to 17. Visually, I have so far been unable to
detect it (fainter than mag ~15.2); I've just cleaned my optical system and
am waiting for a very clear night to try it again.


Sincerely,

Alan

This is an excellent reminder, but I hesitate to agree that if we do not see
activity this
December that we "can declare it dead."  With its past, there is always
potential for some
outgassing without warning nor without specifics to position or orientation. 
Without a
doubt it is an unusual object and we are not at all certain of the nature of its
makeup,
be it cometary or asteroidal.

Thanks for posting this; a very good target with some potential.

Clay
_____
Dr. P. Clay Sherrod
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West
http://www.arksky.org/

----- Original Message -----
From: "iferrinv" <ferrin@...>
To: <comets-ml@yahoogroups.com>
Sent: Tuesday, November 10, 2009 12:25 PM
Subject: [comets-ml] Incoming Activity of comet 107P/Wilson-Harrington?


Hello all:
107P/Wilson-Harrington is a comet-asteroid transition object that
exhibited activity on one single night in 1949, and has remained
inactive since.  The activity was recorded in two Palomar Observatory
plates.  The red plate did not show activity, while the blue plate
exhibited a faint tail.  This prompted Yanga Fernandez et al. to
conclude that the comet had an ion tail.   The interesting thing
is that the activity took place 41 days after perihelion.   Well,
the comet has just passed perihelion and 41 days will take place
next December 4th, 3 WEEKS FROM NOW!  The present email is to
alert you of the possibility of a new outburst of this object
next month, and to request your help in securing observations to
confirm or deny its activity.  The comet was recovered by Sostero
et al. last year.  Currently is at magnitude 14-15 and will be
magnitude 13-14 in December so it is within reach of small
telescopes in the morning sky just before sunrise. If the
comet does not show activity then we can declare it dead, and
by itself this is an important result.  So please make an effort
to make CCD observations of this object in V, R or without filter,
and let me know about your work sending me an email at
ferrin@....    You can see the light curve of this object in
the "Atlas of Secular Light Curves of Comets",

http://arxiv.org/ftp/arxiv/papers/0909/0909.3498.pdf

Additional information and the call for observations will be
posted in my web site

http://webdelprofesor.ula.ve/ciencias/ferrin

Clear skies to all.

Ignacio Ferrín,
Center for Fundamental Physics,
University of the Andes,
Mérida, Venezuela
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++





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Hello all:
107P/Wilson-Harrington is a comet-asteroid transition object that
exhibited activity on one single night in 1949, and has remained
inactive since.  The activity was recorded in two Palomar Observatory
plates.  The red plate did not show activity, while the blue plate
exhibited a faint tail.  This prompted Yanga Fernandez et al. to
conclude that the comet had an ion tail.   The interesting thing
is that the activity took place 41 days after perihelion.   Well,
the comet has just passed perihelion and 41 days will take place
next December 4th, 3 WEEKS FROM NOW!  The present email is to
alert you of the possibility of a new outburst of this object
next month, and to request your help in securing observations to
confirm or deny its activity.  The comet was recovered by Sostero
et al. last year.  Currently is at magnitude 14-15 and will be
magnitude 13-14 in December so it is within reach of small
telescopes in the morning sky just before sunrise. If the
comet does not show activity then we can declare it dead, and
by itself this is an important result.  So please make an effort
to make CCD observations of this object in V, R or without filter,
and let me know about your work sending me an email at
ferrin@....    You can see the light curve of this object in
the "Atlas of Secular Light Curves of Comets",

http://arxiv.org/ftp/arxiv/papers/0909/0909.3498.pdf

Additional information and the call for observations will be
posted in my web site

http://webdelprofesor.ula.ve/ciencias/ferrin

Clear skies to all.

Ignacio Ferrín,
Center for Fundamental Physics,
University of the Andes,
Mérida, Venezuela
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

On Sun, 8 Nov 2009, Seiichi Yoshida wrote:

> I heard that P/2009 U4 (McNaught) was discovered in the course of
> follow-up observations of C/2009 R1.

No, it was found in general surveying.

Cheers, Rob

Hello,

P/2009 Q4 (Boattini) seem to be brighter than expected (mag. previ : 16.1)

      PK09Q040  C2009 11 08.21384 08 22 06.49 +04 06 53.7          14.2 N     
I10
      PK09Q040  C2009 11 08.22118 08 22 07.94 +04 06 54.9          14.6 N     
I10
      PK09Q040  C2009 11 09.21847 08 25 12.21 +04 02 02.0          14.4 N     
A77
      PK09Q040  C2009 11 09.22003 08 25 12.46 +04 02 01.6          14.4 N     
A77
      PK09Q040  C2009 11 09.22158 08 25 12.75 +04 02 01.2          14.4 N     
A77

Francois Kugel #A77

Hi Seiichi,

> Maybe the precovery observations in 1996 and 1998 you found
> have not been reported to the IAU/CBAT yet?

They were reported right away. Brian Marsden and I exchanged a
number of e-mails on the linkage, and ultimately came to the
conclusion that the residuals were too high to link BOTH the
1996 obs and 1998 obs. The 1996 obs are definitely real, but
the 1998 obs were right at the noise limit, so could easily
have been false (or another object). Of course, with only the
single night from 1996, the linkage (while certainly real)
could not be proven.  We really needed a second night.

I may revisit the 1998 data to see if anything can be done
to pull the comet out of the noise, but I suspect it was
just too dim.

--Rob


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