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Re: {MPML} 2009 KD5

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  • Reiner M. Stoss
    ... Mille grazie, Luca! Let s see if the solution turns out to be true with more follow-up during the next days. I am somewhat sceptical. I think it is too big
    Message 1 of 14 , May 27, 2009
      > http://www.cfa.harvard.edu/mpec/K09/K09K55.html
      >
      > Congratulation Reiner and the LSSS team for this discovery.
      > So there are still objects with H>18 out there? :-)

      Mille grazie, Luca!

      Let's see if the solution turns out to be true with more
      follow-up during the next days. I am somewhat sceptical.

      I think it is too big to have gone unnoticed and the solution
      implies that it was found almost at aphelion, which is also
      very unlikely. I have discussed that with Bill Gray and Tim Spahr
      already and they seem more optimistic than me. Fingers
      crossed that they are right :o)

      The only thing that *really* indicates it could be true:
      It was found on a partially cloudy night where almost all
      images were affected by clouds. And since "Deadly Impact"
      (SL9 story) we know that "big" things get discovered only on
      such cloudy nights ;-)

      R.
    • Juan Antonio Henríquez Santana
      Felicidades Reiner y a todo el OAM :-) Congratulations! Juan A.Henríquez http://atlante.org.es 2009/5/27 Luca Buzzi ... [Non-text
      Message 2 of 14 , May 27, 2009
        Felicidades Reiner y a todo el OAM :-)

        Congratulations!
        Juan A.Henríquez
        http://atlante.org.es
        2009/5/27 Luca Buzzi <luca_buzzi@...>

        >
        >
        > http://www.cfa.harvard.edu/mpec/K09/K09K55.html
        >
        > Congratulation Reiner and the LSSS team for this discovery.
        > So there are still objects with H>18 out there? :-)
        >
        > Regards,
        > Luca Buzzi
        > # 204
        >
        >


        [Non-text portions of this message have been removed]
      • Dave Tholen
        ... The currently available observations are insufficient to rule out Damocloid-type orbits at the two sigma level. At the one sigma level, the aphelion
        Message 3 of 14 , May 27, 2009
          > Let's see if the solution turns out to be true with more
          > follow-up during the next days. I am somewhat sceptical.

          The currently available observations are insufficient to rule
          out Damocloid-type orbits at the two sigma level. At the
          one sigma level, the aphelion distance is probably less than
          Jupiter's distance.
        • Alan W Harris
          ... Just for fun, to illustrate the degree of uncertainty in one-day arcs, compare the initial discovery orbit of 2008 CM with the orbit recently published
          Message 4 of 14 , May 27, 2009
            At 03:42 PM 5/27/2009, Dave Tholen wrote:
            > > Let's see if the solution turns out to be true with more
            > > follow-up during the next days. I am somewhat sceptical.
            >
            >The currently available observations are insufficient to rule
            >out Damocloid-type orbits at the two sigma level. At the
            >one sigma level, the aphelion distance is probably less than
            >Jupiter's distance.

            Just for fun, to illustrate the degree of uncertainty in one-day arcs,
            compare the initial discovery orbit of 2008 CM with the orbit recently
            published based on what must have been a totally independent "re-discovery":

            From MPEC 2008-C12, 2/2/08:
            2008 CM Earth MOID = 0.1317 AU
            Epoch 2007 Oct. 27.0 TT = JDT 2454400.5 MPC
            M 277.69942 (2000.0) P Q
            n 2.67164189 Peri. 331.75901 +0.46021835 +0.88150995
            a 0.5143798 Node 325.34090 -0.77561968 +0.34136769
            e 0.7045807 Incl. 10.69545 -0.43198748 +0.32620288
            P 0.37 H 18.1 G 0.15 U 9

            From MPEC 2009-K50, 5/26/09:
            2008 CM PHA, Earth MOID = 0.0432 AU
            Epoch 2009 June 18.0 TT = JDT 2455000.5 MPC
            M 260.95707 (2000.0) P Q
            n 0.50277727 Peri. 130.59829 +0.49679200 -0.64607352
            a 1.5663385 Node 279.62910 +0.50539761 +0.75816491
            e 0.4084417 Incl. 35.99763 +0.70552886 -0.08817581
            P 1.96 H 17.1 G 0.15 U 2

            *******************************************************************
            Alan W. Harris
            Senior Research Scientist
            Space Science Institute
            4603 Orange Knoll Ave. Phone: 818-790-8291
            La Canada, CA 91011-3364 email: awharris@...
            *******************************************************************
          • Reiner M. Stoss
            ... Usually the solutions in the discovery MPECs are pretty close to reality, I think. However sometimes such things happen, mostly because objects get MPEC d
            Message 5 of 14 , May 27, 2009
              > Just for fun, to illustrate the degree of uncertainty in one-day arcs,
              > compare the initial discovery orbit of 2008 CM with the orbit recently
              > published based on what must have been a totally independent "re-discovery":

              Usually the solutions in the discovery MPECs are pretty close
              to reality, I think. However sometimes such things happen,
              mostly because objects get MPEC'd pretty early (I guess to
              keep NEOCP as empty as possible and direct observers to
              the more urgent objects).

              Here is another recent example (was an amateur discovery
              and unfortunately got linked away):

              From MPEC 2009-K42, Issued 2009 May 24, 23:04 UT:
              -----
              2009 KG3 PHA, Earth MOID = 0.0155 AU
              Epoch 2009 June 18.0 TT = JDT 2455000.5 MPC
              M 347.14054 (2000.0) P Q
              n 0.21134100 Peri. 270.45453 +0.97972175 +0.11299212
              a 2.7913452 Node 83.06399 -0.03571662 +0.91107961
              e 0.7819982 Incl. 9.59502 -0.19715378 +0.39644258
              P 4.66 H 19.4 G 0.15 U 9
              Residuals in seconds of arc
              090524 H36 0.3+ 0.4- 090524 G96 0.0 0.3- 090524 611 0.0 0.6-
              090524 H36 0.2- 0.2- 090524 G96 0.2+ 0.3- 090524 611 0.1+ 0.0
              -----

              From MPEC 2009-K43, Issued 2009 May 25, 05:08 UT:
              -----
              Orbital elements:
              2004 LC2 = 2009 KG3 PHA, Earth MOID = 0.0269 AU
              Epoch 2009 June 18.0 TT = JDT 2455000.5 MPC
              M 326.73742 (2000.0) P Q
              n 0.38699881 Peri. 290.35410 +0.94906500 -0.25181351
              a 1.8649318 Node 84.60541 +0.30925459 +0.85952080
              e 0.7345564 Incl. 10.96589 -0.06030937 +0.44476280
              P 2.55 H 18.7 G 0.15 U 4
              Residuals in seconds of arc
              040611 704 0.0 0.0 040612 704 0.1+ 0.1- 040614 379 0.1+ 0.6+
              040611 704 0.2- 0.0 040612 704 0.3- 0.0 040615 926 0.3- 0.2-
              040611 704 0.1+ 0.1+ 040612 704 0.0 0.1+ 040615 926 0.1- 0.3-
              040611 704 0.1- 0.2+ 040612 704 0.5- 0.3- 040615 926 0.1- 0.1-
              040611 704 0.0 0.1+ 040612 704 0.0 0.7- 040616 938 1.2+ 0.7-
              040612 620 0.1- 0.2+ 040612 704 0.1- 0.1+ 040616 938 0.1+ 0.8-
              040612 620 0.1+ 0.1+ 040612 704 0.3- 0.0 040616 938 0.1+ 0.0
              040612 620 0.1+ 0.2+ 040612 926 0.3- 0.0 040616 938 0.4+ 0.6+
              040612 J87 0.3+ 0.1+ 040612 926 0.2- 0.1+ 040616 938 0.2+ 0.1-
              040612 J87 0.4+ 0.1+ 040612 926 0.2+ 0.1- 040616 938 0.2- 0.1-
              040612 J87 0.4+ 0.0 040612 474 0.3+ 0.0 040618 H41 0.2- 0.4-
              040612 J87 0.3+ 0.1- 040612 474 0.4+ 0.1- 040618 H41 0.6+ 0.3-
              040612 J87 1.3+ 0.2- 040612 E12 0.2- 0.4- 040618 H41 0.5+ 0.1-
              040612 J95 0.1+ 0.0 040612 E12 0.1+ 0.8- 040618 H41 0.6- 0.0
              040612 J95 1.0- 0.5+ 040612 E12 0.2+ 0.2- 040618 H41 0.7- 0.6+
              040612 J95 0.2- 0.2+ 040612 E12 0.5+ 1.5- 040618 H41 0.6- 0.3-
              040612 941 1.0+ 0.2+ 040612 474 0.1+ 0.1- 040618 H41 0.2- 0.1+
              040612 941 0.6+ 0.2+ 040612 474 0.2+ 0.1- 040618 H41 0.6+ 0.4+
              040612 941 0.4+ 0.1+ 040612 474 0.1+ 0.1- 090524 H36 1.0- 0.1-
              040612 941 0.2+ 0.4+ 040613 H41 0.7+ 0.4+ 090524 H36 0.8+ 0.2-
              040612 G90 1.1+ 0.1+ 040613 H41 (2.6- 0.3-) 090524 H36 0.9- 0.3-
              040612 H06 0.3- 0.1+ 040613 H41 0.6- 0.2- 090524 H36 0.3+ 0.3-
              040612 H06 0.2- 0.1+ 040613 H41 0.0 0.2- 090524 H36 0.4+ 0.6-
              040612 H06 0.0 0.0 040613 H41 0.1- 0.5+ 090524 H36 0.3- 0.3-
              040612 G90 1.4+ 0.0 040613 H41 0.2+ 0.1- 090524 G96 0.3- 0.1+
              040612 G90 1.4+ 0.1- 040613 H41 0.0 0.1+ 090524 G96 0.3- 0.1+
              040612 651 0.2- 0.2- 040613 H41 0.4- 0.1+ 090524 611 0.5+ 0.2-
              040612 651 0.1- 0.3- 040613 H41 1.9- 0.9+ 090524 B04 0.2+ 0.1-
              040612 651 0.0 0.0 040613 926 0.1- 0.1+ 090524 611 0.2- 0.4+
              040612 704 0.3- 0.3- 040613 926 0.4- 0.2+ 090524 B04 0.4+ 0.4+
              040612 704 0.2- 0.1+ 040613 926 0.2+ 0.0 090524 B04 0.2+ 0.3+
              040612 704 0.0 0.1- 040614 379 0.7+ 0.7+
              -----

              R.
            • Bill J Gray
              Dave Tholen wrote: ...The currently available observations are insufficient to rule out Damocloid-type orbits at the two sigma level. At the one sigma level,
              Message 6 of 14 , May 27, 2009
                Dave Tholen wrote:

                "...The currently available observations are insufficient
                to rule out Damocloid-type orbits at the two sigma level. At
                the one sigma level, the aphelion distance is probably less than
                Jupiter's distance."

                Example orbits follow, determined by setting constraints on
                the semimajor axis and then solving for the best-fitting orbit,
                then doing the same thing with the constraint e=1 (parabolic
                orbit). They have RMS errors higher than the nominal orbit's
                .421 arcseconds, but are still well within reason. (I can
                also believe the nominal orbit, which doesn't put the object
                very close to opposition in the survey era.)

                -- Bill

                2009 KD5
                Perihelion 2009 Aug 15.421212 TT; Constraint: a=4
                Epoch 2009 May 27.0 TT = JDT 2454978.5 Earth MOID: 0.1382
                M 350.09202 (2000.0) P Q
                n 0.12320095 Peri. 240.61023 0.93245096 0.02223129
                a 3.99999999 Node 115.99090 0.05522209 0.97760814
                e 0.7623521 Incl. 23.65237 -0.35705142 0.20925604
                P 8.00 H 16.5 G 0.15 q 0.95059145 Q 7.04940854
                From 14 observations 2009 May 26-27; RMS error 0.510 arcseconds

                2009 KD5
                Perihelion 2009 Aug 12.114306 TT; Constraint: a=8
                Epoch 2009 May 27.0 TT = JDT 2454978.5 Earth MOID: 0.1532 Ju: 0.5024
                M 356.64104 (2000.0) P Q
                n 0.04355811 Peri. 236.34586 0.92881502 0.06630162
                a 7.99999999 Node 117.35740 0.00435533 0.98184030
                e 0.8774402 Incl. 24.23449 -0.37051812 0.17774619
                P 22.63 H 16.4 G 0.15 q 0.98047762 Q 15.0195223
                From 14 observations 2009 May 26-27; RMS error 0.523 arcseconds

                2009 KD5
                Perihelion 2009 Aug 9.312695 TT; Constraint: e=1
                Epoch 2009 May 27.0 TT = JDT 2454978.5 Earth MOID: 0.1684 Ju: 0.0137
                q 1.00902891 (2000.0) Sa: 0.8504
                H 16.2 G 0.15 Peri. 232.79918 0.92493186 0.10045454
                Node 118.63376 -0.03634404 0.98340195
                e 1.0 Incl. 24.68975 -0.37839154 0.15109429
                From 14 observations 2009 May 26-27; RMS error 0.533 arcseconds
              • Paulo Holvorcem
                Hi Alan, ... 2008 CM had an observed arc of about 2 months when it was recovered at E12 on 2009 May 25 (and also at D21, at nearly the same time --
                Message 7 of 14 , May 27, 2009
                  Hi Alan,

                  Alan W Harris wrote:
                  > Just for fun, to illustrate the degree of uncertainty in one-day arcs,
                  > compare the initial discovery orbit of 2008 CM with the orbit recently
                  > published based on what must have been a totally independent "re-discovery":

                  2008 CM had an observed arc of about 2 months when it was recovered
                  at E12 on 2009 May 25 (and also at D21, at nearly the same time -- observations
                  should appear on tomorrow's DOU MPEC). It was an easy recovery
                  due to the small ephemeris uncertainty, not an independent rediscovery.
                  The orbit changed very little with the addition of the 2009 observations:

                  Orbital elements:
                  2008 CM
                  Perihelion 2008 Jan 16.112827 TT
                  Epoch 2008 Apr 6.0 TT = JDT 2454562.5 Find_Orb
                  M 40.66684 (2000.0) P Q
                  n 0.50276014 Peri. 130.63110 0.49641599 -0.64632800
                  a 1.5663740 Node 279.62800 0.50580863 0.75789899
                  e 0.4085470 Incl. 36.00025 0.70549896 -0.08859587
                  P 1.96 /716.03d H 17.0 G 0.15 q 0.9264365
                  From 69 observations 2008 Feb. 2-Apr. 6; RMS error 0.652 arcseconds

                  Orbital elements:
                  2008 CM
                  Perihelion 2008 Jan 16.113063 TT
                  Epoch 2008 Apr 6.0 TT = JDT 2454562.5 Find_Orb
                  M 40.66938 (2000.0) P Q
                  n 0.50279300 Peri. 130.63141 0.49640722 -0.64634214
                  a 1.5663058 Node 279.62870 0.50582112 0.75788659
                  e 0.4085222 Incl. 35.99974 0.70549617 -0.08859883
                  P 1.96 /715.99d H 17.0 G 0.15 q 0.9264350
                  From 74 observations 2008 Feb. 2-2009 May 26; RMS error 0.696 arcseconds

                  The big change in elements you mentioned occurred during the days or weeks
                  after discovery.

                  Paulo
                • Dave Tholen
                  ... The MPEC solution puts the mean anomaly at 289 deg on the standard epoch of June 18. Backing up 23 days to the discovery date of May 26, given a mean
                  Message 8 of 14 , May 27, 2009
                    > I think it is too big to have gone unnoticed and the solution
                    > implies that it was found almost at aphelion, which is also
                    > very unlikely.

                    The MPEC solution puts the mean anomaly at 289 deg on the
                    standard epoch of June 18. Backing up 23 days to the
                    discovery date of May 26, given a mean daily motion of
                    0.79 deg per day, puts the mean anomaly at 271 deg as of
                    discovery. That puts it marginally closer to perihelion
                    than to aphelion.
                  • Bill J Gray
                    Hello all, I just visited MPCOBS and got the latest data for 2009 KD5, which lists three new observations from (D21) and six from (J75). With these data, one
                    Message 9 of 14 , May 28, 2009
                      Hello all,

                      I just visited MPCOBS and got the latest data for 2009 KD5,
                      which lists three new observations from (D21) and six from (J75).
                      With these data, one gets an orbit with P=1.06. As a result,
                      the object doesn't line up with us all that often. It hasn't
                      been at an elongation greater than 90 degrees since early
                      1996. Obviously, this is still not a completely defined
                      solution, but it gives an idea as to why it hasn't turned up
                      before now.

                      -- Bill
                    • Dave Tholen
                      ... All it took was one position from code D21 to eliminate all the high eccentricity orbital solutions. ... Sort of like 2000 SG344. Its synodic period is
                      Message 10 of 14 , May 28, 2009
                        > I just visited MPCOBS and got the latest data for 2009 KD5,
                        > which lists three new observations from (D21) and six from (J75).

                        All it took was one position from code D21 to eliminate all the
                        high eccentricity orbital solutions.

                        > With these data, one gets an orbit with P=1.06. As a result,
                        > the object doesn't line up with us all that often. It hasn't
                        > been at an elongation greater than 90 degrees since early
                        > 1996.

                        Sort of like 2000 SG344. Its synodic period is around 30 years,
                        therefore it hides from opposition surveys for a VERY long time.
                        Apophis spent or will spend something like 90 percent of the
                        20 years centered on discovery at elongations of less than 90 deg.
                        That's been part of my justification for doing a survey at
                        elongations of less than 90 deg.

                        > Obviously, this is still not a completely defined solution,
                        > but it gives an idea as to why it hasn't turned up before now.

                        Actually, the new observations really firmed up the solution.
                        Topocentric distance at the time of discovery is now constrained
                        to fall between 0.393 and 0.416 AU, and the semimajor axis appears
                        to be between 1.028 and 1.055 AU. That is based on the assumption
                        that the astrometric accuracy is 0.3 arcsec, which all but two of
                        the observations satisfy. If that turns out to be optimistic,
                        then open up the limits some.
                      • Dave Tholen
                        Oh, and I forgot to mention that my updated orbit solution puts the mean anomaly at the time of discovery at 246 deg, so it was closer to aphelion than
                        Message 11 of 14 , May 28, 2009
                          Oh, and I forgot to mention that my updated orbit solution puts the mean
                          anomaly at the time of discovery at 246 deg, so it was closer to aphelion
                          than perihelion when found. The absolute magnitude is 18.3 now, so a bit
                          smaller than a kilometer.
                        • Reiner M. Stoss
                          Bill, Dave, all, ... Another set that should be in today s DOU in a couple of hours: NET UCAC-2 K09K05D C2009 05 29.09729 21 09 03.192-01 41 36.08
                          Message 12 of 14 , May 28, 2009
                            Bill, Dave, all,

                            > I just visited MPCOBS and got the latest data for 2009 KD5,
                            > which lists three new observations from (D21) and six from (J75).

                            Another set that should be in today's DOU in a couple of hours:

                            NET UCAC-2
                            K09K05D C2009 05 29.09729 21 09 03.192-01 41 36.08 18.3 V J75
                            K09K05D C2009 05 29.11081 21 09 05.801-01 41 35.75 18.4 V J75
                            K09K05D C2009 05 29.12319 21 09 08.183-01 41 35.71 18.6 V J75

                            Not sure if double-solutions can be completely excluded
                            meanwhile. Here is what FindOrb returns:

                            2009 KD5
                            Perihelion 2009 Sep 25.524864 TT = 12:35:48 (JD 2455100.024864)
                            Epoch 2009 May 28.0 TT = JDT 2454979.5 Earth MOID: 0.0479
                            M 248.31982 (2000.0) P Q
                            n 0.92661519 Peri. 294.96568 0.74903863 -0.62387485
                            a 1.04200492 Node 104.44376 0.65993010 0.67280972
                            e 0.2590066 Incl. 13.31241 0.05859505 0.39762701
                            P 1.06/388.50d H 18.3 G 0.15 q 0.77211876 Q 1.31189108
                            From 26 observations 2009 May 26-29; RMS error 0.424 arcseconds

                            > With these data, one gets an orbit with P=1.06. As a result,
                            > the object doesn't line up with us all that often. It hasn't
                            > been at an elongation greater than 90 degrees since early
                            > 1996. Obviously, this is still not a completely defined

                            I think with some luck it could show up on some old DSS plates.
                            Once the arc is 2-3 weeks long, it makes sense to start a search.

                            R.
                          • microplanet333
                            Yes Reiner, One should never give up of observing! :-) Bill
                            Message 13 of 14 , May 31, 2009
                              Yes Reiner,

                              One should never give up of observing! :-)

                              Bill

                              --- In mpml@yahoogroups.com, "Reiner M. Stoss" <rstoss@...> wrote:
                              >
                              > > http://www.cfa.harvard.edu/mpec/K09/K09K55.html
                              > >
                              > > Congratulation Reiner and the LSSS team for this discovery.
                              > > So there are still objects with H>18 out there? :-)
                              >
                              > Mille grazie, Luca!
                              >
                              > Let's see if the solution turns out to be true with more
                              > follow-up during the next days. I am somewhat sceptical.
                              >
                              > I think it is too big to have gone unnoticed and the solution
                              > implies that it was found almost at aphelion, which is also
                              > very unlikely. I have discussed that with Bill Gray and Tim Spahr
                              > already and they seem more optimistic than me. Fingers
                              > crossed that they are right :o)
                              >
                              > The only thing that *really* indicates it could be true:
                              > It was found on a partially cloudy night where almost all
                              > images were affected by clouds. And since "Deadly Impact"
                              > (SL9 story) we know that "big" things get discovered only on
                              > such cloudy nights ;-)
                              >
                              > R.
                              >
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