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Re: {MPML} Re: 2012 DA14 photometry

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  • Lance Benner
    All, The Goldstone radar observations show a rotation period longer than seven hours. The sequence of images from February 16 spans 7.8 hours, and in that
    Message 1 of 11 , Feb 19, 2013
      All,

      The Goldstone radar observations show a rotation period longer
      than seven hours. The sequence of images from February 16
      spans 7.8 hours, and in that interval the asteroid almost completed
      one full rotation, so the rotation period is probably somewhat
      longer than 8 hours.

      Regards,

      Lance Benner
    • Brian Warner
      Peter, Bruce Gary put together a very nice lightcurve http://brucegary.net/2012DA14/ Paolo Bacci (CC d on this) sent me some data today that I haven t had a
      Message 2 of 11 , Feb 19, 2013
        Peter,

        Bruce Gary put together a very nice lightcurve

        http://brucegary.net/2012DA14/

        Paolo Bacci (CC'd on this) sent me some data today that I haven't had a chance
        to investigate. You're both using the same program it looks like, so perhaps
        you, he, and some others with data can combine your data sets without too much
        trouble. I wasn't able to get observations here, although I did watch some of
        the live webcasts during closest approach.


        Clear Skies,
        Brian D. Warner
        Palmer Divide Observatory

        On 02/19/2013 19:43, pbirtwhistle wrote:
        > Jaime,
        >
        > I produced a partial curve from 3 hours of measures Feb 16 21:10 - 17th 00:11 UT here http://tinyurl.com/a64sxet .
        >
        > Maybe there are enough partial lightcurves from all the DA14 activity when it was bright for a complete optical lightcurve to be put together, covering the ~7 hour solution suggested by the RADAR result?
        >
        > Regards,
        >
        > Peter
        > J95
        >
        > --- In mpml@yahoogroups.com, "Jaime Nomen" <jnomen@...> wrote:
        >>
        >>
        >> Is there any preliminar photometric
        >> lightcurve or estimated rotational period
        >> of 2012 DA14? Along more than 2 hours
        >> of low resolution video streaming, we
        >> didnĀ“t "visually" noticed any apparent variation
        >> of brightness.
        >>
        >> Jaime
        >>
        >
        >
        >
        >
        > ------------------------------------
        >
        > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        >
        > Posts to this list or information found within may be freely used, with the stipulation that MPML and the originating author are cited as the source of the information.Yahoo! Groups Links
        >
        >
        >
        >
        >
      • Brian Warner
        Petr Pravec asked me to forward this message after seeing Bruce Gary s lightcurve ... The asteroid may be tumbling. Well, the unusual shaped lightcurve might
        Message 3 of 11 , Feb 20, 2013
          Petr Pravec asked me to forward this message after seeing Bruce Gary's lightcurve

          >>>>>>>>>>>>>>>>>>
          The asteroid may be tumbling. Well, the unusual shaped lightcurve might be also
          due to shadowing effects on irregular asteroid surface seen at the high solar
          phase angle .... A repeated coverage would be needed to reveal.

          Petr Pravec
          >>>>>>>>>>>>>>>>>>>>>>>>>

          In an off-line message, Leonid Elenin reports a curve very similar to Bruce's
          and a period of 9.48 h.


          Clear Skies,
          Brian D. Warner
          Palmer Divide Observatory

          On 02/20/2013 01:04, Petr Pravec wrote:
          > The asteroid may be tumbling. Well, the unusual shaped lightcurve might be also
          > due to shadowing effects on irregular asteroid surface seen at the high solar
          > phase angle .... A repeated coverage would be needed to reveal.
          >
          > Petr Pravec
        • P. Clay Sherrod
          I thought that the Radar Team reported a period of 7.8 hours. This is a pretty large discrepancy, even if tumbling is considered. Clay _____ Dr. P. Clay
          Message 4 of 11 , Feb 20, 2013
            I thought that the Radar Team reported a period of 7.8 hours.
            This is a pretty large discrepancy, even if tumbling is considered.

            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: "Brian Warner" <Brian@...>
            To: "MPML" <mpml@yahoogroups.com>
            Sent: Wednesday, February 20, 2013 7:30 AM
            Subject: {MPML} 2012 DA14 photometry


            > Petr Pravec asked me to forward this message after seeing Bruce Gary's
            > lightcurve
            >
            > >>>>>>>>>>>>>>>>>>
            > The asteroid may be tumbling. Well, the unusual shaped lightcurve might be
            > also
            > due to shadowing effects on irregular asteroid surface seen at the high solar
            > phase angle .... A repeated coverage would be needed to reveal.
            >
            > Petr Pravec
            > >>>>>>>>>>>>>>>>>>>>>>>>>
            >
            > In an off-line message, Leonid Elenin reports a curve very similar to Bruce's
            > and a period of 9.48 h.
            >
            >
            > Clear Skies,
            > Brian D. Warner
            > Palmer Divide Observatory
            >
            > On 02/20/2013 01:04, Petr Pravec wrote:
            >> The asteroid may be tumbling. Well, the unusual shaped lightcurve might be
            >> also
            >> due to shadowing effects on irregular asteroid surface seen at the high solar
            >> phase angle .... A repeated coverage would be needed to reveal.
            >>
            >> Petr Pravec
            >
            >
            > ------------------------------------
            >
            > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            >
            > Posts to this list or information found within may be freely used, with the
            > stipulation that MPML and the originating author are cited as the source of
            > the information.Yahoo! Groups Links
            >
            >
            >
          • Brian Warner
            Actually, that was a rough approximation based on the images covering approximately 8 hours and covering about a full revolution. Lance Benner has said
            Message 5 of 11 , Feb 20, 2013
              Actually, that was a rough approximation based on the images covering
              'approximately' 8 hours and covering 'about a full revolution.' Lance Benner has
              said elsewhere that the radar data and 9.5 h period a consistent. It will take
              time to get a concise period from the radar data. I believe they have been
              getting additional data the past few nights, which will improve their estimates.


              Clear Skies,
              Brian D. Warner
              Palmer Divide Observatory

              On 02/20/2013 06:31, P. Clay Sherrod wrote:
              > I thought that the Radar Team reported a period of 7.8 hours.
              > This is a pretty large discrepancy, even if tumbling is considered.
              >
              > 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: "Brian Warner" <Brian@...>
              > To: "MPML" <mpml@yahoogroups.com>
              > Sent: Wednesday, February 20, 2013 7:30 AM
              > Subject: {MPML} 2012 DA14 photometry
              >
              >
              >> Petr Pravec asked me to forward this message after seeing Bruce Gary's lightcurve
              >>
              >> >>>>>>>>>>>>>>>>>>
              >> The asteroid may be tumbling. Well, the unusual shaped lightcurve might be also
              >> due to shadowing effects on irregular asteroid surface seen at the high solar
              >> phase angle .... A repeated coverage would be needed to reveal.
              >>
              >> Petr Pravec
              >> >>>>>>>>>>>>>>>>>>>>>>>>>
              >>
              >> In an off-line message, Leonid Elenin reports a curve very similar to Bruce's
              >> and a period of 9.48 h.
              >>
              >>
              >> Clear Skies,
              >> Brian D. Warner
              >> Palmer Divide Observatory
              >>
              >> On 02/20/2013 01:04, Petr Pravec wrote:
              >>> The asteroid may be tumbling. Well, the unusual shaped lightcurve might be also
              >>> due to shadowing effects on irregular asteroid surface seen at the high solar
              >>> phase angle .... A repeated coverage would be needed to reveal.
              >>>
              >>> Petr Pravec
              >>
              >>
              >> ------------------------------------
              >>
              >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
              >>
              >> Posts to this list or information found within may be freely used, with the
              >> stipulation that MPML and the originating author are cited as the source of
              >> the information.Yahoo! Groups Links
              >>
              >>
              >>
              >
              >
              >
            • P. Clay Sherrod
              And this shows the real value of ground based optical studies; kudos to those who are keeping up with this. Clay _____ Dr. P. Clay Sherrod Arkansas Sky
              Message 6 of 11 , Feb 20, 2013
                And this shows the real value of ground based optical studies; kudos to those
                who are keeping up with this.

                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: "Brian Warner" <brian@...>
                To: "P. Clay Sherrod" <drclay@...>
                Cc: "MPML" <mpml@yahoogroups.com>
                Sent: Wednesday, February 20, 2013 7:38 AM
                Subject: Re: {MPML} 2012 DA14 photometry


                > Actually, that was a rough approximation based on the images covering
                > 'approximately' 8 hours and covering 'about a full revolution.' Lance Benner
                > has said elsewhere that the radar data and 9.5 h period a consistent. It will
                > take time to get a concise period from the radar data. I believe they have
                > been getting additional data the past few nights, which will improve their
                > estimates.
                >
                >
                > Clear Skies,
                > Brian D. Warner
                > Palmer Divide Observatory
                >
                > On 02/20/2013 06:31, P. Clay Sherrod wrote:
                >> I thought that the Radar Team reported a period of 7.8 hours.
                >> This is a pretty large discrepancy, even if tumbling is considered.
                >>
                >> 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: "Brian Warner"
                >> <Brian@...>
                >> To: "MPML" <mpml@yahoogroups.com>
                >> Sent: Wednesday, February 20, 2013 7:30 AM
                >> Subject: {MPML} 2012 DA14 photometry
                >>
                >>
                >>> Petr Pravec asked me to forward this message after seeing Bruce Gary's
                >>> lightcurve
                >>>
                >>> >>>>>>>>>>>>>>>>>>
                >>> The asteroid may be tumbling. Well, the unusual shaped lightcurve might be
                >>> also
                >>> due to shadowing effects on irregular asteroid surface seen at the high
                >>> solar
                >>> phase angle .... A repeated coverage would be needed to reveal.
                >>>
                >>> Petr Pravec
                >>> >>>>>>>>>>>>>>>>>>>>>>>>>
                >>>
                >>> In an off-line message, Leonid Elenin reports a curve very similar to
                >>> Bruce's
                >>> and a period of 9.48 h.
                >>>
                >>>
                >>> Clear Skies,
                >>> Brian D. Warner
                >>> Palmer Divide Observatory
                >>>
                >>> On 02/20/2013 01:04, Petr Pravec wrote:
                >>>> The asteroid may be tumbling. Well, the unusual shaped lightcurve might be
                >>>> also
                >>>> due to shadowing effects on irregular asteroid surface seen at the high
                >>>> solar
                >>>> phase angle .... A repeated coverage would be needed to reveal.
                >>>>
                >>>> Petr Pravec
                >>>
                >>>
                >>> ------------------------------------
                >>>
                >>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                >>>
                >>> Posts to this list or information found within may be freely used, with the
                >>> stipulation that MPML and the originating author are cited as the source of
                >>> the information.Yahoo! Groups Links
                >>>
                >>>
                >>>
                >>
                >>
                >>
              • Lance Benner
                Hi Everyone, I concur with what Brian Warner wrote about the radar observations. The Goldstone imaging sequence on Feb. 16 covered 7.8 hours, and during that
                Message 7 of 11 , Feb 20, 2013
                  Hi Everyone,

                  I concur with what Brian Warner wrote about the radar observations.

                  The Goldstone imaging sequence on Feb. 16 covered 7.8 hours, and during that
                  interval, 2012 DA14 _almost_ completed one rotation. This is based
                  on visual inspection of features in the images, so it's very preliminary and
                  we know that we'll be able to obtain a more precise estimate
                  from shape modeling in concert with photometry.
                  The obvious implication is that the rotation period is somewhat more
                  than about 8 hours.

                  The Feb. radar images are available at:
                  http://www.jpl.nasa.gov/news/news.php?release=2013-063

                  and

                  http://echo.jpl.nasa.gov/asteroids/2012DA14/2012DA14_planning.html

                  Regards,

                  Lance
                • skyweek
                  During the first day of the PDC - all webcast live on http://www.livestream.com/pdc2013 - the contributions of amateur astronomers in the NEO field were hailed
                  Message 8 of 11 , Apr 15, 2013
                    During the first day of the PDC - all webcast live on
                    http://www.livestream.com/pdc2013 - the contributions of amateur
                    astronomers in the NEO field were hailed numerous times already (although
                    their role in discovery plummets beyond a certain H, as Tim Spahr pointed
                    out). Here is - if attachments are allowed on this list which I will find
                    out immediately - a screenshot from the talk on follow-up observations by
                    Eileen Ryan in which Peter Birtwhistle's work is admired.

                    Dan

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