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Update on Comet ISON

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  • Nick Howes - FT Project
    Dear group. It seems that C/2012 S1 (ISON) is potentially going to be rather special, and for several reasons. We just updated our blog with a few thoughts and
    Message 1 of 16 , Oct 1, 2012
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      Dear group.

      It seems that C/2012 S1 (ISON) is potentially going to be rather special, and for several reasons.

      We just updated our blog with a few thoughts and some new data on it, and we'll be monitoring this very interesting body with Faulkes continually.

      http://bit.ly/QSjMXJ
      With kind regards,and thanks.

      Nick Howes, Giovanni Sostero and Ernesto Guido
    • terryjlovejoy
      Thank you for posting, very interesting! However what is not clear to be me is why this high near nucleus activity isn t manifested in the total coma
      Message 2 of 16 , Oct 1, 2012
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        Thank you for posting, very interesting! However what is not clear to be me is why this high near nucleus activity isn't manifested in the total coma brightness?

        Terry

        --- In comets-ml@yahoogroups.com, "Nick Howes - FT Project" <howesnickhowes@...> wrote:
        >
        > Dear group.
        >
        > It seems that C/2012 S1 (ISON) is potentially going to be rather special, and for several reasons.
        >
        > We just updated our blog with a few thoughts and some new data on it, and we'll be monitoring this very interesting body with Faulkes continually.
        >
        > http://bit.ly/QSjMXJ
        > With kind regards,and thanks.
        >
        > Nick Howes, Giovanni Sostero and Ernesto Guido
        >
      • Jakub Cerny
        Hi Terry, I think that the problem is when you comparing activity throughout dust filling factor in selected area (ie 16000 km around nucleus) better angular
        Message 3 of 16 , Oct 1, 2012
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          Hi Terry,

          I think that the problem is when you comparing activity throughout dust
          filling factor in selected area (ie 16000 km around nucleus) better
          angular resolution gives you more precise values, therefore smaller one
          will mix larger area and the resulting number will be much smaller. I
          think the main message here is that the real activity of comet looks
          larger now when its compared to another comets in similar distance.
          However I am not sure if this also mean that comet can be brighter in
          maximum or it is only interesting physical fact.

          Best regards!
          Jakub Cerny

          On 10/02/2012 01:17 AM, terryjlovejoy wrote:
          >
          > Thank you for posting, very interesting! However what is not clear to
          > be me is why this high near nucleus activity isn't manifested in the
          > total coma brightness?
          >
          > Terry
          >
          > --- In comets-ml@yahoogroups.com <mailto:comets-ml%40yahoogroups.com>,
          > "Nick Howes - FT Project" <howesnickhowes@...> wrote:
          > >
          > > Dear group.
          > >
          > > It seems that C/2012 S1 (ISON) is potentially going to be rather
          > special, and for several reasons.
          > >
          > > We just updated our blog with a few thoughts and some new data on
          > it, and we'll be monitoring this very interesting body with Faulkes
          > continually.
          > >
          > > http://bit.ly/QSjMXJ
          > > With kind regards,and thanks.
          > >
          > > Nick Howes, Giovanni Sostero and Ernesto Guido
          > >
          >
          >



          [Non-text portions of this message have been removed]
        • Dave Herald
          Thanks for the link to your interesting blog on this comet. I have a question. The image your show – being a stack of 13 x 2min exposures, shows the
          Message 4 of 16 , Oct 2, 2012
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            Thanks for the link to your interesting blog on this comet.

            I have a question. The image your show – being a stack of 13 x 2min exposures, shows the _diameter_ of the comet’s coma as being at most 5.0” (using the scale on the image). That is, the coma is shown for a radius of no more than 3.0 arc secs from the comet’s nucleus.

            Given this, I don’t understand how you can make assertions about activity at greater distances, as would seem to be explicit in your blog statement:
            “This behaviour seems to indicate a steep photometric variation along the coma's profile, with a significant increase of the afrho values close to the central condensation (i.e. within about 6" to 8" of the nucleus), which would not be detected using average amateur telescope, for reasons of resolution and seeing conditions.”

            Similarly, the distance scale of the comet (at 6.4AU) is roughly 1” = 4000km. So your afrho plot is extending out to about 12 arc secs from the nucleus – far far greater than the evident size of the coma on the image. My simplistic interpretation of the image would suggest that anything on the afrho plot for distances greater than 10,000km was noise-related rather than the comet.

            Obviously I’m missing something – and I would appreciate some education on the issue.


            Dave Herald
            Murrumbateman, Australia


            From: Nick Howes - FT Project
            Sent: Tuesday, October 02, 2012 1:38 AM
            To: comets-ml@yahoogroups.com
            Subject: [comets-ml] Update on Comet ISON
            Dear group.

            It seems that C/2012 S1 (ISON) is potentially going to be rather special, and for several reasons.

            We just updated our blog with a few thoughts and some new data on it, and we'll be monitoring this very interesting body with Faulkes continually.

            http://bit.ly/QSjMXJ
            With kind regards,and thanks.

            Nick Howes, Giovanni Sostero and Ernesto Guido



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            [Non-text portions of this message have been removed]
          • howesnickhowes
            Hi Terry Speaking to Giovanni this morning, we re thinking that the key here is about the meaning of the word activity . Our afrho data indicates that in this
            Message 5 of 16 , Oct 2, 2012
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              Hi Terry

              Speaking to Giovanni this morning, we're thinking that the key here is about the meaning of the word "activity". Our afrho data
              indicates that in this comet, the near-nucleus abundance of dust is higher compared to the external parts of the coma (under these circumstances, it's a sort of relative "activity" index within the coma itself). This type of behaviour has been
              observed in a number of comets and its cause might be due to a number of reasons
              (e.g. sublimating grain cloud surrounding the cometary nucleus as is
              suspected in several comets). On the other hand, an indication of a high
              near-nucleus activity that's feeding of dust in the rest of the coma, may be explained by the reported total brightness of C/2012 S1 (which is already
              pretty high, if you consider its current distance from the Sun).

              More study is needed though


              --- In comets-ml@yahoogroups.com, "terryjlovejoy" <terryjlovejoy@...> wrote:
              >
              > Thank you for posting, very interesting! However what is not clear to be me is why this high near nucleus activity isn't manifested in the total coma brightness?
              >
              > Terry
              >
              > --- In comets-ml@yahoogroups.com, "Nick Howes - FT Project" <howesnickhowes@> wrote:
              > >
              > > Dear group.
              > >
              > > It seems that C/2012 S1 (ISON) is potentially going to be rather special, and for several reasons.
              > >
              > > We just updated our blog with a few thoughts and some new data on it, and we'll be monitoring this very interesting body with Faulkes continually.
              > >
              > > http://bit.ly/QSjMXJ
              > > With kind regards,and thanks.
              > >
              > > Nick Howes, Giovanni Sostero and Ernesto Guido
              > >
              >
            • gvnn64@libero.it
              Hi Dave, IMHO the rendition of a JPG picture isn t accurate enough to extrapolate any reliable parameter, included the coma size: depending on the image
              Message 6 of 16 , Oct 2, 2012
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                Hi Dave,
                IMHO the rendition of a JPG picture isn't accurate enough to extrapolate any reliable parameter, included the coma size: depending on the image processing parameters, compression, etc. you can enhance the apparent coma size, or reduce it, depending on what you want to show.

                We do know that, currently, this comet has an actual coma size of about 9"x11": this is reported in IAUC 3238, and actually it's clearly visible Majdanak's stacking (BTW I hope that Artyom or Vitaly will post it soon or later, because it shows pretty well the current shape of the comet).

                On the other hand, you can easily understand where the coma physically ends, directly from the afrho data: on the graph, it's the flex (minimum value of afrho of about 900cm) having a radius of nearly 31,000 km. These 31,000 Km distance from the nucleus, roughly correspond to a radius of about 6" (then not far from the 11" visible in Majdanak's image). The afrho algorithm is very sentitive in this. Any data in the panel further away from these 31,000 Km, is "noise". We didn't cut the graph at the 31,000 Km limit, just to show such flex, so people might realize were the sky background actually starts (obviously in any scientific publication, we will report only meaningful data).

                Hope that this was helpful to clarify the situation.

                Bye,
                Giovanni
              • buzzlyr2001
                I hope someone can confirm this image of C/2012 S1 (ISON). Taken earlier today with FT (North) remotely from the Norman Lockyer Observatory. Image taken
                Message 7 of 16 , Oct 4, 2012
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                  I hope someone can confirm this image of C/2012 S1 (ISON).
                  Taken earlier today with FT (North) remotely from the Norman Lockyer Observatory.
                  Image taken 2012-10-04 at 15:15h UT. 7x120s with R filter. RA 8h 17m 22s Dec +27deg 48m 17s.

                  http://www.davidstrange.org.uk/c2012S1_20121004_nlo2.jpg

                  http://www.davidstrange.org.uk/C2012S1_20121004_nlo4.jpg

                  Congratulations to Artyom and Vitali for finding this comet with so much promise!
                  Reminds me of the Hale-Bopp days!

                  Thanks,
                  David
                • gvnn64@libero.it
                  Hi Denis. ... I m not sure: what do you ask to confirm in your image? Bye, Giovanni
                  Message 8 of 16 , Oct 5, 2012
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                    Hi Denis.

                    > I hope someone can confirm this image of C/2012 S1 (ISON).

                    I'm not sure: what do you ask to confirm in your image?

                    Bye,
                    Giovanni
                  • buzzlyr2001
                    Whether I had correctly identified the comet, there were a few fuzzy objects in the field. Thanks David
                    Message 9 of 16 , Oct 5, 2012
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                      Whether I had correctly identified the comet, there were a few fuzzy objects in the field.
                      Thanks
                      David

                      --- In comets-ml@yahoogroups.com, "gvnn64\@...\.it" <gvnn64@...> wrote:
                      >
                      > Hi Denis.
                      >
                      > > I hope someone can confirm this image of C/2012 S1 (ISON).
                      >
                      > I'm not sure: what do you ask to confirm in your image?
                      >
                      > Bye,
                      > Giovanni
                      >
                    • Richard Miles
                      ... Confirmed with 100% certainty. Now Giovanni et al. can use the FITS images to update the Afrho data. Richard Miles BAA
                      Message 10 of 16 , Oct 5, 2012
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                        David S. wrote:

                        >I hope someone can confirm this image of C/2012 S1 (ISON).
                        > Taken earlier today with FT (North) remotely from the Norman Lockyer
                        > Observatory.
                        > Image taken 2012-10-04 at 15:15h UT. 7x120s with R filter. RA 8h 17m 22s
                        > Dec +27deg 48m 17s.

                        Confirmed with 100% certainty. Now Giovanni et al. can use the FITS images
                        to update the Afrho data.

                        Richard Miles
                        BAA
                      • David Strange
                        Richard, I had a problem accessing the FITS data yesterday. Only 75% of the image was apparent when downloaded. My images were captured jpg s from our FTN
                        Message 11 of 16 , Oct 5, 2012
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                          Richard,

                          I had a problem accessing the FITS data
                          yesterday. Only 75% of the image was apparent when downloaded.
                          My images were captured jpg's from our FTN image
                          archive page. Could you take a look at the FITS data please?
                          Thanks
                          David

                          At 09:16 05/10/2012, you wrote:
                          >
                          >
                          >David S. wrote:
                          >
                          > >I hope someone can confirm this image of C/2012 S1 (ISON).
                          > > Taken earlier today with FT (North) remotely from the Norman Lockyer
                          > > Observatory.
                          > > Image taken 2012-10-04 at 15:15h UT. 7x120s with R filter. RA 8h 17m 22s
                          > > Dec +27deg 48m 17s.
                          >
                          >Confirmed with 100% certainty. Now Giovanni et al. can use the FITS images
                          >to update the Afrho data.
                          >
                          >Richard Miles
                          >BAA
                          >
                          >
                        • howesnickhowes
                          David and Richard Yes, it was ISON and nice job. The data and our own data has helped with the Afrho update, which we ll be posting on the blog soon. What
                          Message 12 of 16 , Oct 5, 2012
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                            David and Richard

                            Yes, it was ISON and nice job. The data and our own data has helped with the Afrho update, which we'll be posting on the blog soon.

                            What we're seeing is a well developed and elongated coma measuring nearly 6"x9" (PA 280). The Afrho coming in at 1530 +/- 150 cm, and total Magnitude as R=17.7

                            We have more time on it today, along with other projects ongoing, but thank you for your observations.

                            Nick Howes, Giovanni Sostero and Ernesto Guido

                            --- In comets-ml@yahoogroups.com, David Strange <dg.strange@...> wrote:
                            >
                            > Richard,
                            >
                            > I had a problem accessing the FITS data
                            > yesterday. Only 75% of the image was apparent when downloaded.
                            > My images were captured jpg's from our FTN image
                            > archive page. Could you take a look at the FITS data please?
                            > Thanks
                            > David
                            >
                            > At 09:16 05/10/2012, you wrote:
                            > >
                            > >
                            > >David S. wrote:
                            > >
                            > > >I hope someone can confirm this image of C/2012 S1 (ISON).
                            > > > Taken earlier today with FT (North) remotely from the Norman Lockyer
                            > > > Observatory.
                            > > > Image taken 2012-10-04 at 15:15h UT. 7x120s with R filter. RA 8h 17m 22s
                            > > > Dec +27deg 48m 17s.
                            > >
                            > >Confirmed with 100% certainty. Now Giovanni et al. can use the FITS images
                            > >to update the Afrho data.
                            > >
                            > >Richard Miles
                            > >BAA
                            > >
                            > >
                            >
                          • Nick Howes - FT Project
                            The bupdate is now live too http://bit.ly/VDtmlD best regards Nick, Ernesto, Giovanni
                            Message 13 of 16 , Oct 5, 2012
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                              The bupdate is now live too

                              http://bit.ly/VDtmlD

                              best regards

                              Nick, Ernesto, Giovanni



                              --- In comets-ml@yahoogroups.com, "howesnickhowes" <howesnickhowes@...> wrote:
                              >
                              > David and Richard
                              >
                              > Yes, it was ISON and nice job. The data and our own data has helped with the Afrho update, which we'll be posting on the blog soon.
                              >
                              > What we're seeing is a well developed and elongated coma measuring nearly 6"x9" (PA 280). The Afrho coming in at 1530 +/- 150 cm, and total Magnitude as R=17.7
                              >
                              > We have more time on it today, along with other projects ongoing, but thank you for your observations.
                              >
                              > Nick Howes, Giovanni Sostero and Ernesto Guido
                              >
                              > --- In comets-ml@yahoogroups.com, David Strange <dg.strange@> wrote:
                              > >
                              > > Richard,
                              > >
                              > > I had a problem accessing the FITS data
                              > > yesterday. Only 75% of the image was apparent when downloaded.
                              > > My images were captured jpg's from our FTN image
                              > > archive page. Could you take a look at the FITS data please?
                              > > Thanks
                              > > David
                              > >
                              > > At 09:16 05/10/2012, you wrote:
                              > > >
                              > > >
                              > > >David S. wrote:
                              > > >
                              > > > >I hope someone can confirm this image of C/2012 S1 (ISON).
                              > > > > Taken earlier today with FT (North) remotely from the Norman Lockyer
                              > > > > Observatory.
                              > > > > Image taken 2012-10-04 at 15:15h UT. 7x120s with R filter. RA 8h 17m 22s
                              > > > > Dec +27deg 48m 17s.
                              > > >
                              > > >Confirmed with 100% certainty. Now Giovanni et al. can use the FITS images
                              > > >to update the Afrho data.
                              > > >
                              > > >Richard Miles
                              > > >BAA
                              > > >
                              > > >
                              > >
                              >
                            • howesnickhowes
                              Sorry that should have read Blog update (iphone)
                              Message 14 of 16 , Oct 5, 2012
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                                Sorry that should have read Blog update (iphone)


                                --- In comets-ml@yahoogroups.com, "Nick Howes - FT Project" <howesnickhowes@...> wrote:
                                >
                                > The bupdate is now live too
                                >
                                > http://bit.ly/VDtmlD
                                >
                                > best regards
                                >
                                > Nick, Ernesto, Giovanni
                                >
                                >
                                >
                                > --- In comets-ml@yahoogroups.com, "howesnickhowes" <howesnickhowes@> wrote:
                                > >
                                > > David and Richard
                                > >
                                > > Yes, it was ISON and nice job. The data and our own data has helped with the Afrho update, which we'll be posting on the blog soon.
                                > >
                                > > What we're seeing is a well developed and elongated coma measuring nearly 6"x9" (PA 280). The Afrho coming in at 1530 +/- 150 cm, and total Magnitude as R=17.7
                                > >
                                > > We have more time on it today, along with other projects ongoing, but thank you for your observations.
                                > >
                                > > Nick Howes, Giovanni Sostero and Ernesto Guido
                                > >
                                > > --- In comets-ml@yahoogroups.com, David Strange <dg.strange@> wrote:
                                > > >
                                > > > Richard,
                                > > >
                                > > > I had a problem accessing the FITS data
                                > > > yesterday. Only 75% of the image was apparent when downloaded.
                                > > > My images were captured jpg's from our FTN image
                                > > > archive page. Could you take a look at the FITS data please?
                                > > > Thanks
                                > > > David
                                > > >
                                > > > At 09:16 05/10/2012, you wrote:
                                > > > >
                                > > > >
                                > > > >David S. wrote:
                                > > > >
                                > > > > >I hope someone can confirm this image of C/2012 S1 (ISON).
                                > > > > > Taken earlier today with FT (North) remotely from the Norman Lockyer
                                > > > > > Observatory.
                                > > > > > Image taken 2012-10-04 at 15:15h UT. 7x120s with R filter. RA 8h 17m 22s
                                > > > > > Dec +27deg 48m 17s.
                                > > > >
                                > > > >Confirmed with 100% certainty. Now Giovanni et al. can use the FITS images
                                > > > >to update the Afrho data.
                                > > > >
                                > > > >Richard Miles
                                > > > >BAA
                                > > > >
                                > > > >
                                > > >
                                > >
                                >
                              • Adam
                                I make animation of comet track from SOHO LASCO C3 and C2 http://www.youtube.com/watch?v=ZVHiAKrBeQU&hd=1 Adam
                                Message 15 of 16 , Oct 9, 2012
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                                  I make animation of comet track from SOHO LASCO C3 and C2
                                  http://www.youtube.com/watch?v=ZVHiAKrBeQU&hd=1

                                  Adam
                                • Adam
                                  And the track in PNG image http://picupload.pl/vi-OMhtdA.png
                                  Message 16 of 16 , Oct 9, 2012
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                                    And the track in PNG image
                                    http://picupload.pl/vi-OMhtdA.png

                                    --- In comets-ml@yahoogroups.com, "Adam" <limax7@...> wrote:
                                    >
                                    > I make animation of comet track from SOHO LASCO C3 and C2
                                    > http://www.youtube.com/watch?v=ZVHiAKrBeQU&hd=1
                                    >
                                    > Adam
                                    >
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