Denis, You deserve a good reply ... - Quoting your words :
" My imaging may not have not recorded a very faint outer coma , but in the overall description of the condition of this comet I would say that that feature is a minor component of the comet and the major features which I have measured are the substantial ones." I disagree : the outer coma ?is not a minor component : From the ICQ Guide to observing comets ( Daniel Green, 1997 ) :
" ... The ICQ adopted in 1986 the following definition fot total visual magnitude m1 of a comet : the integrated brightness of the comet's entire coma ( but not the tail ) that is visible above the sky background, determined with the smallest possible instrument needed to easily detect the coma ..."
- Regarding the old "Visual vs. CCD" question. I've expressed my opinion in several previous threads. CCD and visual data are ?complementary, not exclusive. We ?( visual observers ) continue a very long observing tradition, adding our data to the historical records.
It would be useful to quote here a highly experienced CCD observer and very good friend, Giovanni Sostero ( unfortunately deceased in 2012 ) : " IMHO most of the times the big troubles with some total cometary magnitude measurements, are not those provided by visual observers ( that are following a long and well documented methodology ) but the CCDs m1 photometry results ( for a number of reasons already discussed here several times ). This makes me more and more convinced that visual observers are still doing a precious work with their m1 estimates, even in these days of widespread hi-tech inviting "options". Then I hope that people like you, J.J., Alan Hale, etc. will not give up yours efforts...".
Many thanks again, Giovanni, for your valued friendship and words ...
Comparison between visual and CCD photometry depends appreciably on the each individual comet spectra ( species present in the coma, production rates, gas to dust ratio, ?... ) and the response of the detector ( human eye, CCD ), among other factors.
In the present "CCD times", some visual observers ( and websites posting observations ) are biased by previously seen CCD images. But as said, we must report a comet's ( or comet-related object, like remnants ) observation data as accurately as we can, from the eyepiece to the paper, based on the correct methodology and personal experience.
As told somewhere, CCD images aren't ALWAYS an evidence against a visual observation, as the C/2010 X1 remnant demonstrate.
- From your words : " ... I admire your abilty to get into the clear dark mountain air to observe comets, and you must derive satisfaction from that ..." My primary motivation is the scientific utility of visual estimates. Quoting Dan Green, "observations of comets by amateurs ( unpaid observers ) are essential to the progress of cometary astronomy ..."
- Another quote from Fred Whipple : "observing comets has broad effects in science, besides giving the observer personal pleasure". I will tell it again, is simple : I try to make the visual observations under the best available conditions. I work hard seeking for the higher and best observing dark sites, specially for comets near perihelion, and trying to observe as much coma diameter as possible, especially for low DC comets, and low altitude over the horizon. As a physicist I must report the estimates exactly as they are.
- Finally, also from a previous ( old ) thread :
It is appropriate to express a "cometary" sorrow, sometimes exposed by myself and frequently by other older fellows : As it seems, the times of the great visual comet observers are coming ( asymptotically ) to an end. We must remember here George Alcock, Bill Bradfield, and other inspiring names. What are the main causes ? Undoubtedly, light pollution has a broad impact on astronomical observations. Is progressively more difficult to observe from a good dark site. But there is another significant concurrent cause : generational relay is decreasing, and the younger people are more favorable to the CCD approach.
At some time in the future, those photons coming from faint distant comets will not be directly observed by human eyes. Only the brightest ones will continue marvelling us over the night sky horizon. Best regards and clear skies, J. J. Gonzalez Suarez ------------------------------------------------------------------------
On Sun, Dec 29, 2024 at 1:24?PM Denis Buczynski via <buczynski8166= [email protected]> wrote:
Hi JJ,
I used the word debate in the context that the apparent magnitude of
this comet is in debate, not your method of observing? or derived
results. I do not want to have an argument about this.I only point out
that the results I have obtained can be repeated and checked again , the
images are in existance. Any one can measure them and see if they get
the same results as myself. My imaging may not have not recorded a very
faint outer coma , but in the overall description of the condition of
this comet I would say that that feature is a minor component of the
comet and the major features which I have measured are the substantial
ones. The astrometry I and others have obtained are meaningful and will
stand the test of time. I admire your abilty to get into the clear dark
mountain air to observe comets, and you must derive satisfaction from
that.? We are both comet observers, just operationally different.
Best wishes
Denis Buczynski
? ? ? ? ------ Original Message ------
? ? ? ? From: jjgsgp=[email protected]
? ? ? ? To: [email protected]
? ? ? ? Sent: Sunday, December 29th 2024, 01:44
? ? ? ? Subject: Re: [comets-ml] Unusual brightening of comet C/2023 Q1
? Thomas, Denis, Peter, Jakub, all,Some recent further visual data
:C/2023 Q1 (PANSTARRS):2024 Dec. 28.82 UT: m1=11.7 (AQ), Dia.=6', DC=1/,
20 cm SCT (77x).[ Faint, large and very diffuse outer coma, slightly
enhanced through Swan Band filter. Nearby field stars checked in DSS. At
133x : m=13.3 (AQ) for the 1' inner coma diameter. Limiting star
magnitude near comet : 14.5 (AQ). Mountain location, very clear sky.].(
Collada de Aralla, 1500 m, Leon, Spain )And other comments ?:Denis, in
your posts ?in this thread you mention the word "debate". For my part,
by contributing my data I do not want to discuss the photometric
measurements obtained with CCD/CMOS, I only add complementary
information from another perspective ...On the other hand, the mentioned
visual estimates of C/2023 Q1 and 29P cannot be compared, even if they
are now of similar magnitude m1 and apparent diameter : the comae
structure and composition are different, and Q1 is more diffuse.Thomas,
I fully agree with you : "The aperture diameter MUST be taken into
account when comparing data. The second important parameter is the
spectral range covered."But regarding your report ( 2024-12-23.46 UT,
m1=14.1, coma diam. 5'), I obviously disagree when you say "I would be
very much surprised if it would be possible to detect the same amount of
coma size visually".Best regards,J. J. Gonzalez
Suarez---------------------------------------------------------------------------------
? On Sun, Dec 29, 2024 at 12:07?AM Observatory Gr?mme via
<observatorygromme=[email protected]> wrote:
? ? ? ? ?Dear All,
? ? For the moment i measure magnitude 16 using SDSS r' filter.
Uncalibrated images. PhotAp 6.1arcsec
? ? From: [email protected] <[email protected]> on behalf of David
Moore(Ireland) via <davefriend0=[email protected]> Sent:
Saturday, December 28, 2024 2:19 PM To: [email protected]
<[email protected]> Subject: Re: [comets-ml] Unusual brightening of
comet C/2023 Q1 ?
? ?Skyglow?
? ?If coma diameter is 4' that's 45,000 sq "
? ?I think I saw a figure of 21mag per sq arcsec?
? ?So airglow alone would 'add' 11.6mag i.e. a patch of dark sky 4' in
diameter is mag9.4?
? ?Is my maths wrong!?
? ? ?On Saturday 28 December 2024 at 12:05:34 GMT, Thomas Lehmann via
<t.lehmann=[email protected]> wrote:
? ? Hi Denis,? here is a heavily processed image. Pretty ugly though,
but it might serve for illustration purposes.? Something I'd add to my
"total" coma mesurement within 5': the brighness measurement
(statistical) uncertainty is about 0.15mag.? Best wishes Thomas? ?> Am
Sat, 28 Dec 2024 11:43:28 +0000 (GMT) > schrieb "Denis Buczynski via
" <buczynski8166=[email protected]>: > > Hi Thomas, > I
appreciate all you say in this regard. > I would be more convinced that
there was an extensive coma present if I? > could see an image showing
this coma. Whether it be from fast f/2? > telescopes in excellent dark
skies or from anywhere else . It only? > requires someone posting a
current image showing an extensive coma to? > put this "debate " to
rest.We have yet to see one. > Best wishes > Denis Buczynski >? >? >? ?
? ? ------ Original Message ------ >? ? ? ? From:
t.lehmann=[email protected] >? ? ? ? To: jjgsgp=[email protected]
> Cc: [email protected] >? ? ? ? Sent: Saturday, December 28th 2024,
11:17 >? ? ? ? Subject: Re: [comets-ml] Unusual brightening of comet
C/2023 Q1 >? >? >? >? Dear all, >? >? thanks for the numerous
observation reports, especially to Denis's and? > Peter's >?
measurements over longer time span. >? >? I'd like to emphasize that any
brightness measurement MUST be read in >? conjunction to the measurement
aperture used. The aperture diameter? > MUST be >? taken into account
when comparing data. The second important parameter? > is >? the
spectral range covered. The brightening from gaseous outbursts can? > be
>? more prominent in the green filtered images than in unfiltered (or? >
red) images. >? >? About visual estimates. >? My report of 2024-12-23.46
UT, m1=14.1, coma diam. 5' >? is derived from images using a fast f/2.2
scope under excellent skies? > having >? a limited stellar magnitude of
21mag and using heavy smoothing and? > contrast >? enhancement. I would
be very much surprised if it would be possible to? > detect >? the same
amount of coma size visually. It is even harder for me to? > accept that
>? I have missed 90% of the comets coma flux in my measurement - which
> would be >? the case if the magnitude were near ~11.6mag - though I
cannot rule? > out some >? additional outburst has happened recently. >
>? Anyway, I'd like to encourage anyone to continue monitoring the
comet. >? For those doing imaging, it would be nice if you could measure
the? > coma >? additionally using a true aperture diameter of d=15000km
and 30000km? > at the >? comet (and report filter information) so we
would be able to construct? > a >? combined light curve of the inner
coma brightness. >? >? Thanks >? Thomas >? >? >? > Am Sat, 28 Dec 2024
07:54:29 +0100 >? > schrieb "jjgonzalez jjgonzalez via "?? >
<jjgsgp=[email protected]>: >? > >? > Thomas, Denis, Alan, all, >? >
>? > Obviously, I am also interested in the confirmation of the large
and?? > very >? > diffuse gas coma by visual observers from dark skies.
>? > >? > Best regards, >? > >? > J. J. Gonzalez Suarez >? > >? > P.S.:
>? > >? > As complementary information, this is the report of my recent?
> observation >? > of the large dust coma of 29P : >? > >? >
29P/Schwassmann-Wachmann: >? > 2024 Dec. 27.00 UT: m1=11.1, Dia.=4',
DC=2/, 20 cm SCT (77x). >? > ( Cubiellos - Sierra del Aramo, 1510 m,
Asturias, Spain ) >? > >? >?? >
-----------------------------------------------------------------------------------------------------------
>? > >? > >? > On Sat, Dec 28, 2024 at 5:39?AM Alan Hale via
> [email protected]> wrote: >? >?? >? > > Dear Denis,
all, >? > > >? > > >? > > >? > > I¡¯m attaching an image I took of C/2023
Q1 via LCO-Tenerife on?? > December >? > > 26.97 UT (0.35-m Cassegrain,
single 180-second image, unprocessed, >? > > uncropped (dimensions 30x30
arcmin)). I¡¯ve had some trouble?? > getting >? > > measurements from the
image (possible software issues), but would >? > > ¡°guesstimate¡± the
magnitude to be somewhere around 15-15.5. I had?? > not >? > > imaged
the comet previously so I can¡¯t comment about any recent?? >
brightening. >? > > >? > > >? > > >? > > For comparison, I¡¯m also
attaching an image I took of 29P on?? > December >? > > 25.60 UT from
LCO-Haleakala (0.35-m Cassegrain, single 150-second?? > image, >? > >
also unprocessed and uncropped, 30x30 arcmin). About eight hours?? >
before I >? > > took this image I observed the comet visually at m1 =
11.7, 5.5¡¯?? > coma, DC >? > > ~1 (41 cm reflector, 70x). >? > > >? > >
>? > > >? > > >? > > >? > > Sincerely, >? > > >? > > Alan >? > > >? > >
>? > > >? > > Hello all, >? > > >? > > I must admit I am a little
baffled by these reports of a?? > substantial >? > > >? > > increase in
brightness of C/2023 Q1. >? > > >? > > Firstly Thomas? Lehmann reported
an increase in the brightness of?? > this >? > > >? > > comet in
November to mag 14.1 My observations made for astrometry?? > for >? > >
>? > > the months of November and December (10 nights data) show the?? >
comet only >? > > >? > > increasing from mag 17 to mag 16. >? > > >? > >
This is borne out by Peter Carson and Francois Kugel's comments of?? >
their >? > > >? > > own observations and measurements. >? > > >? > > Now
JJ Gonzalez is reporting an observation on the night of Dec 27?? > of >?
> > >? > > this comet with a magnitude of 11.6. >? > > >? > > My last
observation was a day or so earlier on Dec 25 and my?? > Comphot >? > >
>? > > measurement gives a magnitude of 15.73 with a coma diameter of
34?? > arc >? > > >? > > secs. >? > > >? > > I attach my image. >? > >
>? > >? Can someone confirm the apparent +4 mag increase in brightness?
> or of >? > > >? > > mine, Peter Carson's and Francois Kugel's
observation results? >? > > >? > > >? > > >? > > Comets eh! >? > > >? >
>? Happy NY >? > > >? > > Denis Buczynski >? > > >? > > BAA Comet
Section >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > >? ? ? ?
------ Original Message ------ >? > > >? > >? ? ? ? From:
jjgsgp=[email protected] >? > > >? > >? ? ? ? To: [email protected]
>? > > >? > >? ? ? ? Sent: Friday, December 27th 2024, 23:52 >? > > >? >
>? ? ? ? Subject: Re: [comets-ml] Unusual brightening of comet?? >
C/2023 Q1 >? > > >? > > >? > > >? > > >? > > >? > >? Thomas, all,After
reading your email sent to the list yesterday,?? > I >? > > >? > > have
arranged an observing session for tonight. This is the report >? > > >?
> > :C/2023 Q1 (PANSTARRS):2024 Dec. 27.81 UT: m1=11.6, Dia.=6',?? >
DC=1/, 20 >? > > >? > > cm SCT (77x).[ From dark mountain skies the
comet appears visually?? > much >? > > >? > > brighter than expected,
showing a faint, large and very diffuse?? > outer >? > > >? > > coma.
Nearby field stars checked in DSS. Limiting star magnitude?? > near >? >
> >? > > comet : 14.2 (AQ).].( Cubiellos - Sierra del Aramo, 1510 m,?? >
Asturias, >? > > >? > > Spain ). All the best from the Cantabrian
Mountains,J. J. Gonzalez >? > > >? > > >? > >?? >
Suarez--------------------------------------------------------------------------------------------------------------------------
>? > > >? > > >? > > >? > > >? > > >? > >? On Fri, Dec 27, 2024 at
5:28?PM Shanklin, Jonathan D. via?? > >? > > >? > >
<jdsh=[email protected]> wrote: >? > > >? > >? ? ? ? ? My entry for
the comet for The Astronomer magazine?? > covering >? > > >? > >
observations to the end of November and giving the behaviour for >? > >
>? > > November was: >? > > >? > >? ? 2023 Q1 (PANSTARRS) observations
cover: -144 to -16 days, 2.6 ¨C?? > 3.0 >? > > >? > > au >? > > >? > >? ?
At 17.5, steady (Carson, Pappa) >? > > >? > > >? > > >? > >? ? Which
does suggest that the brightness seen in December is >? > > >? > >
unexpected. >? > > >? > > >? > > >? > >? ? I won¡¯t start putting the TA
column for the next issue together?? > until >? > > >? > > around
January 4. >? > > >? > > >? > > >? > > >? > > >? > >? ? Regards, >? > >
>? > > >? > > >? > >? ? Jonathan Shanklin >? > > >? > >? ? BAA Comet
Section visual observations co-ordinator >? > > >? > >? ?
>? > > >? > > >? > > >? > > >? > > >?
> > >? > > >? > > >? > > >? > >? ? ? From: [email protected]
<[email protected]> On Behalf Of?? > Peter >? > > >? > > Carson via
Sent: Friday, December 27, 2024 3:37 PM To: >? > > >? > >
[email protected] Subject: [comets-ml] Unusual brightening of?? >
comet >? > > >? > > C/2023 Q1 >? > > >? > > >? > > >? > > >? > > >? > >
>? > > >? > >? ? ? ? You don't often get email from >? > > >? > >
petercarson100=[email protected]. Learn why this is important >? > >
>? > > >? > > >? > > >? > > >? > > >? > > >? > >? ? Hello Thomas, >? > >
>? > > >? > > >? > >? ? Here are my observations from summer to now.
Unfortunately, I?? > made >? > > >? > > no observations in October and
early November, so although the?? > comet has >? > > >? > > brightened,
it is not? clear if the brightening occurred over a?? > short or >? > >
>? > > long period. >? > > >? > > >? > > >? > > >? > > >? > > >? > > >?
> >? ? All the best >? > > >? > > >? > > >? > >? ? Peter >? > > >? > >
>? > > >? > > >? > > >? > > >? > > >? > >? ? Type Comet Obs? ? ? ? ? ? ?
? ? ? ? ? date Meth >? > > >? > > Mag Refcat Inst T App Inst F Inst P
Coma User Location >? > > >? > > >? > > >? > >? ? CCD C/2023 Q1
22/12/2024 >? > > >? > > 21:11 Z 15.6 GG C 31.5 8 1260 0.80' CAR06 PGC
>? > > >? > > Observatory Z10, Fregenal de la sierra, Spain >? > > >? >
> >? > > >? > >? ? CCD C/2023 Q1 10/12/2024 >? > > >? > > 03:18 Z 15.9
GG C 31.5 8 1200 0.80' CAR06 PGC >? > > >? > > Observatory Z10, Fregenal
de la sierra, Spain >? > > >? > > >? > > >? > >? ? CCD C/2023 Q1
27/11/2024 >? > > >? > > 02:43 Z 16.1 GG C 31.5 8 1200 0.80' CAR06 PGC
>? > > >? > > Observatory Z10, Fregenal de la sierra, Spain >? > > >? >
> >? > > >? > >? ? CCD C/2023 Q1 04/09/2024 >? > > >? > > 01:48 Z 17.5
GG C 31.5 8 1200 0.40' CAR06 PGC >? > > >? > > Observatory Z10, Fregenal
de la sierra, Spain >? > > >? > > >? > > >? > >? ? CCD C/2023 Q1
16/08/2024 >? > > >? > > 03:21 Z 17.1 GG C 31.5 8 960 0.40' CAR06 PGC >?
> > >? > > Observatory Z10, Fregenal de la sierra, Spain >? > > >? > >
>? > > >? > >? ? CCD C/2023 Q1 05/08/2024 >? > > >? > > 02:33 Z 17.4 GG
C 31.5 8 960 0.40' CAR06 PGC >? > > >? > > Observatory Z10, Fregenal de
la sierra, Spain >? > > >? > > >? > > >? > >? ? CCD C/2023 Q1 16/07/2024
>? > > >? > > 02:52 Z 17.5 GG C 31.5 8 1080 0.40' CAR06 PGC >? > > >? >
> Observatory Z10, Fregenal de la sierra, Spain >? > > >? > > >? > > >?
> >? ? CCD C/2023 Q1 10/07/2024 >? > > >? > > 02:39 Z 17.5 GG C 31.5 8
1200 0.40' CAR06 PGC >? > > >? > > Observatory Z10, Fregenal de la
sierra, Spain >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >?
> > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > >? ?
From: [email protected] <[email protected]> on behalf of?? > Thomas
>? > > >? > > Lehmann via <t.lehmann=[email protected]>
Sent: 26 >? > > >? > > December 2024 22:19 To: [email protected]
<[email protected]> >? > > >? > > Subject: [comets-ml] Unusual
brightening of comet C/2023 Q1 >? > > >? > > >? > > >? > > >? > > >? > >
>? > > >? > >? ? ? According to observations by S. Fritsche and myself
the?? > comet >? > > >? > > C/2023 Q1 has started a sudden brightening
in November.?? > Unfortunately >? > > >? > > our observations are very
sparse due to the bad weather during the?? > last >? > > >? > > two
months. Our data suggest a brightening by 1-2 mag between?? > October >?
> > >? > > 26th and November 30th.? Latest measurement (green channel):
>? > > >? > > 2024-12-23.46 UT, m1=14.1, coma diam. 5'? A more thorough?
> investigation >? > > >? > > by using small aperture measurements is on
the way.? Thanks to?? > all >? > > >? > > contributors for sharing
results and ideas/thoughts to this list.?? > Merry >? > > >? > >
Christmas and best wishes to all of you, Thomas >? > > >? > > >? > > >?
> > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? >
>? ? ? This email and any attachments are intended solely for the?? >
use of >? > > >? > > the named recipients. If you are not the intended
recipient you?? > must not >? > > >? > > use, disclose, copy or
distribute this email or any of its?? > attachments >? > > >? > > and
should notify the sender immediately and delete? this email?? > from >?
> > >? > > your system. UK Research and Innovation (UKRI) has taken
every >? > > >? > > reasonable precaution to minimise risk of this email
or any?? > attachments >? > > >? > > containing viruses or malware but
the recipient should carry out?? > its own >? > > >? > > virus and
malware checks before? opening the attachments. UKRI?? > does not >? > >
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> > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? >
> >? > > >? > > >? > > >? > > >? > > >? > > >? > > >? > >?? >? > >? > >?
> >? > >? >?? >? >? >?? >? >? >? >? >? >? >? >? >? >
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