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Damocloids are a class of minor planets such as 5335 Damocles and 1996 PW that have Halley-family or long-period highly eccentric orbits typical of periodic comets such as Halley's Comet, but without showing a cometary coma or tail. David Jewitt defines a damocloid as an object with a Tisserand's parameter relative to Jupiter of 2 or less (TJ ≤ 2),[1] while Akimasa Nakamura defines this group with the following orbital criterion:[2]

  • q < 5.2 AU, a > 8.0 AU, and e > 0.75,
  • or alternatively, i > 90°

However, this definition that does not focus on Jupiter excludes objects such as (127546) 2002 XU93, 2003 WG166, and 2004 DA62.[3]

Using the Tisserand's parameter with respect to Jupiter of 2 or less, there are currently 175 damocloid candidates as of June 2019.[4] Of these objects, 137 have orbital observation arcs greater than 30 days providing reasonably decent orbits.[5][1] Their average radius is eight kilometers assuming an albedo of 0.04. The albedos of four damocloids have been measured, and they are among the darkest objects known in the Solar System. Damocloids are reddish in color, but not as red as many Kuiper-belt objects or centaurs. Other damocloids include: 2013 BL76, 2012 DR30, 2008 KV42, (65407) 2002 RP120, and 20461 Dioretsa.

Retrograde objects such as Halley's Comet and damocloid (343158) 2009 HC82 can have relative velocities to Earth of 81 km/s (290,000 km/h).[6]

Contents

OriginEdit

Damocloids are thought to be nuclei of Halley-type comets that have lost all their volatile materials due to outgassing and become dormant. Such comets probably originate from the Oort cloud. This hypothesis is strengthened by the fact that a number of objects thought to be damocloids (and assigned minor-planet provisional designations) subsequently showed a coma and were confirmed to be comets: C/2001 OG108 (LONEOS), C/2002 CE10 (LINEAR), C/2002 VQ94 (LINEAR), C/2004 HV60 (Spacewatch) and possibly others. Another strong indication of cometary origin is the fact that some damocloids have retrograde orbits, unlike any other minor planets. (Objects with an inclination beyond 90 degrees up to 180 degrees are in a retrograde orbit and orbit in the opposite direction of other objects.)

ListEdit

This is a list of 18 numbered and 139 unnumbered bodies from the JPL SBDB as of June 2019, that meet Akimasa Nakamura's criteria for being classified as a damocloid, that is, either a retrograde orbit, or the following orbital elements: q < 5.2 AU, a > 8.0 AU, and e > 0.75 (also see § top). Tisserand's parameter with respect to Jupiter (TJupiter) is also given. Akimasa Nakamura's criteria and a TJupiter of less than 2 are largely equivalent as only a few listed bodies do not meet the defined TJupiter threshold. Most damocloids are also listed on MPC's list of other unusual minor planets.[7] The orbital data is sourced from JPL numbered and unnumbered element files, and excludes comets and hyperbolic bodies such as ʻOumuamua.

Designation a
(AU)
e i
(°)
Orbital criteria and classes q
(AU)
Q
(AU)
Unusual Catalog Refs
Cls Retro TJupiter TJ ≤ 2
5335 Damocles 11.83 0.866 61.7 CEN 1.154  Y 1.58 22.08 unusual LoMP JPL · MPC
(15504) 1999 RG33 9.38 0.774 34.9 CEN 1.950  Y 2.12 16.65 unusual LoMP JPL · MPC
20461 Dioretsa 23.9 0.9 160.4 CEN  Y -1.547  Y 2.4 45.4 unusual LoMP JPL · MPC
(65407) 2002 RP120 53.92 0.954 119 TNO  Y -0.834  Y 2.45 105.39 unusual LoMP JPL · MPC
(154783) 2004 PA44 14.21 0.76 3.3 CEN 2.510 3.41 25.01 unusual LoMP JPL · MPC
(330759) 2008 SO218 8.11 0.564 170.3 CEN  Y -1.391  Y 3.54 12.69 unusual LoMP JPL · MPC
(336756) 2010 NV1 290.08 0.968 140.7 TNO  Y -2.902  Y 9.4 570.76 LoMP JPL · MPC
(342842) 2008 YB3 11.62 0.441 105.1 CEN  Y -0.249  Y 6.5 16.74 LoMP JPL · MPC
(343158) 2009 HC82 2.53 0.807 154.4 NEO  Y 1.317  Y 0.49 4.57 LoMP JPL · MPC
(434620) 2005 VD 6.67 0.252 172.9 CEN  Y -1.396  Y 5 8.35 unusual LoMP JPL · MPC
(459870) 2014 AT28 10.92 0.404 165.6 CEN  Y -2.091  Y 6.51 15.33 LoMP JPL · MPC
(468861) 2013 LU28 180.92 0.952 125.4 TNO  Y -2.065  Y 8.73 353.12 LoMP JPL · MPC
(471325) 2011 KT19 35.6 0.33 110.1 TNO  Y -1.551  Y 23.84 47.35 LoMP JPL · MPC
514107 Kaʻepaokaʻawela 5.14 0.38 163 other  Y -0.746  Y 3.19 7.09 unusual LoMP JPL · MPC
(518151) 2016 FH13 24.53 0.614 93.6 CEN  Y 0.000  Y 9.46 39.6 LoMP JPL · MPC
(523797) 2016 NM56 72.7 0.855 144 TNO  Y -3.063  Y 10.52 134.88 LoMP JPL · MPC
(523800) 2017 KZ31 53.4 0.795 161.7 TNO  Y -3.595  Y 10.96 95.84 LoMP JPL · MPC
(528219) 2008 KV42 41.68 0.493 103.4 TNO  Y -1.016  Y 21.12 62.23 LoMP JPL · MPC
1996 PW 253.36 0.99 30 TNO 1.713  Y 2.49 504.23 unusual JPL · MPC
1997 MD10 26.46 0.942 59.5 CEN 0.965  Y 1.53 51.39 unusual JPL · MPC
1998 QJ1 11.25 0.814 23.6 CEN 2.027 2.09 20.41 unusual JPL · MPC
1998 WU24 15.15 0.906 42.4 CEN 1.412  Y 1.43 28.87 unusual JPL · MPC
1999 LE31 8.13 0.466 151.8 CEN  Y -1.309  Y 4.34 11.91 unusual JPL · MPC
1999 XS35 17.78 0.947 19.4 NEO 1.417  Y 0.95 34.62 JPL · MPC
2000 AB229 52.78 0.956 68.4 TNO 0.786  Y 2.32 103.24 unusual JPL · MPC
2000 DG8 10.76 0.794 129.2 CEN  Y -0.622  Y 2.22 19.31 unusual JPL · MPC
2000 HE46 23.63 0.899 158.5 CEN  Y -1.518  Y 2.39 44.88 unusual JPL · MPC
2000 KP65 90.6 0.963 45.7 TNO 1.620  Y 3.31 177.9 unusual JPL · MPC
2002 RN109 546.7 0.995 58.1 TNO 1.082  Y 2.69 1090.71 unusual JPL · MPC
2003 UY283 33.31 0.895 18.9 TNO 2.289 3.49 63.13 unusual JPL · MPC
2003 WN188 14.4 0.847 26.9 CEN 1.940  Y 2.21 26.59 unusual JPL · MPC
2004 CM111 33.84 0.851 4.7 TNO 2.821 5.03 62.65 unusual JPL · MPC
2004 NN8 98.33 0.976 165.5 TNO  Y -1.779  Y 2.36 194.31 unusual JPL · MPC
2005 HL3 11.28 0.832 35.7 CEN 1.787  Y 1.89 20.67 unusual JPL · MPC
2005 NP82 5.87 0.478 130.5 CEN  Y -0.326  Y 3.07 8.67 unusual JPL · MPC
2005 OE 62.88 0.952 67.5 TNO 0.897  Y 3.03 122.73 unusual JPL · MPC
2005 SB223 29.43 0.905 91.3 CEN  Y 0.131  Y 2.78 56.09 unusual JPL · MPC
2005 TJ50 9.24 0.589 110.2 CEN  Y -0.183  Y 3.8 14.68 unusual JPL · MPC
2005 VX3 914.86 0.996 112.2 TNO  Y -0.943  Y 4.11 1825.61 unusual JPL · MPC
2006 BZ8 9.6 0.803 165.3 CEN  Y -1.023  Y 1.89 17.31 unusual JPL · MPC
2006 EX52 42.51 0.94 150.1 TNO  Y -1.572  Y 2.56 82.46 unusual JPL · MPC
2006 LM1 37.18 0.9 172.1 TNO  Y -2.166  Y 3.71 70.66 unusual JPL · MPC
2006 RG1 25.4 0.921 133.4 CEN  Y -0.982  Y 2.02 48.78 unusual JPL · MPC
2006 RJ2 9.67 0.762 164.6 CEN  Y -1.165  Y 2.3 17.05 unusual JPL · MPC
2006 SO134 19.51 0.831 4.2 CEN 2.416 3.3 35.73 unusual JPL · MPC
2007 DA61 488 0.995 76.6 TNO 0.479  Y 2.68 973.33 unusual JPL · MPC
2007 VW266 5.44 0.39 108.3 other  Y 0.364  Y 3.32 7.56 unusual JPL · MPC
2008 BN18 30.42 0.914 28.8 TNO 1.888  Y 2.61 58.24 unusual JPL · MPC
2008 SE82 19.31 0.836 17.4 CEN 2.289 3.18 35.45 unusual JPL · MPC
2008 WA95 14.04 0.877 60.1 CEN 1.155  Y 1.72 26.36 unusual JPL · MPC
2009 AU16 23.64 0.918 69.7 CEN 0.806  Y 1.95 45.33 unusual JPL · MPC
2009 DD47 47.98 0.954 107.5 TNO  Y -0.439  Y 2.22 93.73 unusual JPL · MPC
2009 FW23 11.52 0.855 86.6 CEN 0.544  Y 1.67 21.38 unusual JPL · MPC
2009 QY6 12.46 0.834 137.7 CEN  Y -0.844  Y 2.07 22.86 unusual JPL · MPC
2009 YS6 20.15 0.92 147.8 CEN  Y -1.045  Y 1.61 38.69 unusual JPL · MPC
2010 BK118 389.15 0.984 143.9 TNO  Y -2.450  Y 6.09 772.2 JPL · MPC
2010 CG55 31.95 0.91 146.2 TNO  Y -1.545  Y 2.87 61.02 unusual JPL · MPC
2010 EB46 31.45 0.952 156.6 TNO  Y -1.213  Y 1.5 61.4 unusual JPL · MPC
2010 EJ104 21.65 0.901 41.5 CEN 1.568  Y 2.15 41.16 unusual JPL · MPC
2010 EQ169 2.05 0.102 91.6 MBA  Y 2.501 1.84 2.26 JPL · MPC
2010 GW64 63.23 0.941 105.2 TNO  Y -0.537  Y 3.72 122.73 unusual JPL · MPC
2010 GW147 167.17 0.968 99.8 TNO  Y -0.457  Y 5.39 328.95 JPL · MPC
2010 JH124 69.58 0.963 53.4 TNO 1.257  Y 2.6 136.55 unusual JPL · MPC
2010 JC147 14.63 0.763 41.7 CEN 1.974  Y 3.47 25.78 unusual JPL · MPC
2010 LG61 6.84 0.801 123.7 CEN  Y -0.002  Y 1.36 12.32 unusual JPL · MPC
2010 OR1 26.94 0.924 143.9 CEN  Y -1.211  Y 2.04 51.83 unusual JPL · MPC
2010 OM101 26.05 0.919 118.8 CEN  Y -0.652  Y 2.12 49.98 unusual JPL · MPC
2010 PO58 13.14 0.779 121.4 CEN  Y -0.641  Y 2.9 23.38 unusual JPL · MPC
2011 MM4 21.17 0.473 100.5 CEN  Y -0.402  Y 11.16 31.18 JPL · MPC
2011 OR17 267.62 0.988 110.5 TNO  Y -0.744  Y 3.11 532.13 unusual JPL · MPC
2011 SP25 19.55 0.884 109.1 CEN  Y -0.326  Y 2.27 36.83 unusual JPL · MPC
2011 UR402 18.68 0.779 24.6 CEN 2.438 4.12 33.24 unusual JPL · MPC
2011 WS41 38.31 0.946 141.6 TNO  Y -1.248  Y 2.08 74.54 unusual JPL · MPC
2012 HD2 62.83 0.959 146.9 TNO  Y -1.562  Y 2.56 123.11 unusual JPL · MPC
2012 KA51 224.45 0.978 70.7 TNO 0.928  Y 4.91 444 unusual JPL · MPC
2012 TL139 29.95 0.883 160 CEN  Y -1.947  Y 3.52 56.38 unusual JPL · MPC
2012 YO6 6.31 0.478 106.9 CEN  Y 0.262  Y 3.29 9.33 unusual JPL · MPC
2012 YE8 9.37 0.592 136.1 CEN  Y -1.003  Y 3.83 14.92 unusual JPL · MPC
2013 BN27 66.39 0.976 101.8 TNO  Y -0.238  Y 1.57 131.22 unusual JPL · MPC
2013 BL76 966.43 0.991 98.6 TNO  Y -0.529  Y 8.35 1924.5 JPL · MPC
2013 HS150 26.15 0.894 96.5 CEN  Y -0.027  Y 2.78 49.52 unusual JPL · MPC
2013 JD4 12.11 0.865 73 CEN 0.877  Y 1.63 22.59 unusual JPL · MPC
2013 LA2 7.51 0.594 175.2 CEN  Y -1.233  Y 3.05 11.97 unusual JPL · MPC
2013 LD16 80.96 0.968 154.7 TNO  Y -1.713  Y 2.55 159.37 unusual JPL · MPC
2013 LG29 16.99 0.791 15.4 CEN 2.438 3.55 30.43 unusual JPL · MPC
2013 NS11 12.63 0.787 130.3 CEN  Y -0.832  Y 2.69 22.56 unusual JPL · MPC
2013 YG48 8.19 0.752 61.3 CEN 1.430  Y 2.03 14.34 unusual JPL · MPC
2014 CW14 27.7 0.846 170.7 CEN  Y -2.244  Y 4.28 51.13 unusual JPL · MPC
2014 JJ57 6.99 0.293 95.9 CEN  Y 0.515  Y 4.95 9.04 unusual JPL · MPC
2014 MH55 27.54 0.838 91.5 CEN  Y 0.124  Y 4.45 50.63 unusual JPL · MPC
2014 PP69 21.33 0.942 93.7 NEO  Y 0.157  Y 1.25 41.42 JPL · MPC
2014 SQ339 28.52 0.903 128.5 CEN  Y -1.073  Y 2.78 54.26 unusual JPL · MPC
2014 UV114 6.36 0.385 170.5 CEN  Y -1.195  Y 3.91 8.81 unusual JPL · MPC
2014 XS3 73.56 0.956 101.4 TNO  Y -0.366  Y 3.25 143.86 unusual JPL · MPC
2015 AO44 22.11 0.836 139.9 CEN  Y -1.495  Y 3.62 40.6 unusual JPL · MPC
2015 BH311 9.17 0.729 94.5 CEN  Y 0.424  Y 2.49 15.85 unusual JPL · MPC
2015 FK37 196.82 0.975 156.1 TNO  Y -2.481  Y 4.96 388.69 unusual JPL · MPC
2015 RK245 80.62 0.966 91.6 TNO  Y 0.007  Y 2.76 158.49 unusual JPL · MPC
2015 RE277 20.23 0.764 1.6 CEN 2.799 4.77 35.69 unusual JPL · MPC
2015 RL277 34.59 0.85 3.1 TNO 2.862 5.19 63.99 unusual JPL · MPC
2015 TN178 54.65 0.956 91.1 TNO  Y 0.059  Y 2.38 106.92 unusual JPL · MPC
2015 TS350 140.72 0.964 58.1 TNO 1.497  Y 5.05 276.39 JPL · MPC
2015 XN63 19.91 0.932 19.7 CEN 1.601  Y 1.36 38.45 unusual JPL · MPC
2015 XX351 14.58 0.854 159.1 CEN  Y -1.269  Y 2.13 27.03 unusual JPL · MPC
2015 XR384 36.95 0.903 157.5 TNO  Y -1.971  Y 3.57 70.34 unusual JPL · MPC
2015 YY18 19.46 0.831 118.2 CEN  Y -0.751  Y 3.29 35.63 unusual JPL · MPC
2016 CO264 48.39 0.938 129.8 TNO  Y -1.250  Y 3.02 93.76 unusual JPL · MPC
2016 DF2 5.58 0.415 166.8 CEN  Y -0.904  Y 3.27 7.9 unusual JPL · MPC
2016 EJ203 67.77 0.96 171 TNO  Y -1.928  Y 2.73 132.81 unusual JPL · MPC
2016 JK24 13.07 0.661 152.3 CEN  Y -1.709  Y 4.43 21.71 unusual JPL · MPC
2016 LS 13.32 0.607 114.3 CEN  Y -0.658  Y 5.24 21.41 JPL · MPC
2016 PN66 31.24 0.907 105.1 TNO  Y -0.371  Y 2.9 59.57 unusual JPL · MPC
2016 PO66 49.66 0.996 53.1 NEO 0.442  Y 0.21 99.12 JPL · MPC
2016 TK2 9.18 0.551 92.3 CEN  Y 0.477  Y 4.12 14.24 unusual JPL · MPC
2016 TP93 7.47 0.56 138.3 CEN  Y -0.787  Y 3.29 11.65 unusual JPL · MPC
2016 US109 36.14 0.949 87.2 TNO 0.226  Y 1.86 70.43 unusual JPL · MPC
2016 VY17 11.17 0.851 148.5 CEN  Y -0.846  Y 1.66 20.67 unusual JPL · MPC
2016 WS1 14.42 0.882 53 CEN 1.305  Y 1.7 27.15 unusual JPL · MPC
2016 YB13 5.46 0.408 139.7 other  Y -0.475  Y 3.24 7.69 unusual JPL · MPC
2017 AX13 28.59 0.883 137.2 CEN  Y -1.434  Y 3.35 53.83 unusual JPL · MPC
2017 BD86 5.5 0.475 159.2 CEN  Y -0.746  Y 2.89 8.11 unusual JPL · MPC
2017 CW32 192.52 0.985 152.4 TNO  Y -1.856  Y 2.96 382.08 unusual JPL · MPC
2017 EE 17.92 0.884 73.9 CEN 0.772  Y 2.08 33.76 JPL · MPC
2017 EM4 33.39 0.921 83.4 TNO 0.382  Y 2.65 64.13 unusual JPL · MPC
2017 GD8 43.28 0.947 74.9 TNO 0.601  Y 2.28 84.28 unusual JPL · MPC
2017 JB6 32.47 0.883 160.9 TNO  Y -2.058  Y 3.81 61.13 unusual JPL · MPC
2017 MZ4 66.39 0.952 65.8 TNO 0.973  Y 3.18 129.59 unusual JPL · MPC
2017 MB7 3043.15 0.999 55.7 TNO 1.476  Y 4.46 6081.84 unusual JPL · MPC
2017 NM2 14.66 0.624 101.3 CEN  Y -0.158  Y 5.51 23.81 JPL · MPC
2017 OX68 58.97 0.971 94.7 TNO  Y -0.046  Y 1.74 116.21 unusual JPL · MPC
2017 PY24 17.36 0.924 71.8 CEN 0.736  Y 1.31 33.41 unusual JPL · MPC
2017 QO33 34.64 0.858 148.8 TNO  Y -2.121  Y 4.93 64.35 unusual JPL · MPC
2017 RR2 17.21 0.849 88.6 CEN 0.350  Y 2.61 31.82 unusual JPL · MPC
2017 SV13 9.67 0.792 113.2 CEN  Y -0.118  Y 2.01 17.32 unusual JPL · MPC
2017 SN33 271.64 0.993 152 TNO  Y -1.465  Y 1.84 541.43 unusual JPL · MPC
2017 UW51 134.55 0.977 144.2 TNO  Y -1.731  Y 3.13 265.97 unusual JPL · MPC
2017 UX51 30.11 0.747 90.5 TNO  Y 0.144  Y 7.61 52.61 JPL · MPC
2017 UR52 380.39 0.997 108.2 NEO  Y -0.418  Y 1.24 759.54 JPL · MPC
2017 YL2 8.97 0.768 27.8 CEN 2.069 2.08 15.85 unusual JPL · MPC
2018 AS18 12.99 0.872 63 CEN 1.102  Y 1.66 24.33 unusual JPL · MPC
2018 DE4 32.52 0.927 81.3 TNO 0.443  Y 2.39 62.64 unusual JPL · MPC
2018 DF4 100.02 0.984 68.2 TNO 0.632  Y 1.6 198.44 unusual JPL · MPC
2018 DO4 25.85 0.907 160.5 CEN  Y -1.569  Y 2.41 49.3 unusual JPL · MPC
2018 KH3 94.51 0.961 46.9 TNO 1.670  Y 3.7 185.32 unusual JPL · MPC
2018 MP8 353.35 0.989 68.3 TNO 0.909  Y 3.83 702.88 unusual JPL · MPC
2018 PL28 19.55 0.863 74.2 CEN 0.801  Y 2.69 36.41 unusual JPL · MPC
2018 SQ13 158.5 0.981 91 TNO  Y -0.003  Y 2.97 314.02 unusual JPL · MPC
2018 TL6 8.22 0.79 170.9 CEN  Y -0.888  Y 1.72 14.72 unusual JPL · MPC
2018 V3 121.69 0.989 165 TNO  Y -1.339  Y 1.34 242.05 JPL · MPC
2018 WB1 7.86 0.716 152.1 CEN  Y -0.853  Y 2.23 13.48 unusual JPL · MPC
2019 CR 14.51 0.595 160.3 CEN  Y -2.168  Y 5.87 23.15 JPL · MPC
2019 EJ3 64.72 0.983 139.7 NEO  Y -0.897  Y 1.08 128.36 JPL · MPC
2019 G2 613.74 0.996 159.2 TNO  Y -1.745  Y 2.29 1225.18 JPL · MPC
2019 G3 17.27 0.835 156.8 CEN  Y -1.543  Y 2.85 31.68 JPL · MPC
2019 G4 96.26 0.939 138.3 TNO  Y -2.152  Y 5.85 186.66 JPL · MPC
2019 HC4 8.86 0.559 134.3 CEN  Y -0.924  Y 3.91 13.81 unusual JPL · MPC
Designation a
(AU)
e i
(°)
Orbital criteria and classes q
(AU)
Q
(AU)
Unusual Catalog Refs
Cls Retro TJupiter TJ ≤ 2

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See alsoEdit

ReferencesEdit

  1. ^ a b David Jewitt (August 2013). "The DAMOCLOIDS". UCLA, Department of Earth and Space Sciences. Retrieved 14 February 2014. (2013 list / 2011 list / 2010 list)
  2. ^ Akimasa Nakamura and bas (2 May 2009). "List of Damocloids (Oort cloud asteroids)". Lowell Observatory. Retrieved 15 February 2017.
  3. ^ Jewitt, David (2005). "A first look at the Damocloids" (PDF). The Astronomical Journal. 129 (1): 530–538. Bibcode:2005AJ....129..530J. doi:10.1086/426328. Retrieved 13 February 2011.
  4. ^ "JPL Small-Body Database Search Engine: asteroids and T-Jupiter <= 2". JPL Solar System Dynamics. Retrieved 1 June 2019. Search parameters used: Limited by object type/group: Asteroids and T-Jupiter <= 2
  5. ^ "JPL Small-Body Database Search Engine: asteroids and T-Jupiter <= 2 and data-arc span > 30 (d)". JPL Solar System Dynamics. Retrieved 1 June 2019.
  6. ^ "NEO Close-Approaches (Between 1900 and 2200)". NASA/JPL Near-Earth Object Program. Retrieved 22 June 2012. (sorted by descending relative velocity, dist<0.5AU = "215,221 close-Earth approaches")
  7. ^ "List Of Other Unusual Objects". Minor Planet Center. Retrieved 1 June 2019.

External linksEdit