On Saturday 28 December 2024 at 12:05:34 GMT, Thomas Lehmann via groups.io <t.lehmann@...> 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 groups.io" <buczynski8166@...>:
>
> 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@...
>? ? ? ? To: jjgsgp@...
> 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 groups.io"?
> <jjgsgp@...>:
>? >
>? > 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 groups.io
> [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@...
>? > >
>? > >? ? ? ? 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?
> groups.io
>? > >
>? > > <jdsh@...> 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 –?
> 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 groups.io 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@.... 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 groups.io <t.lehmann@...> 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
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
>? > >
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