BINARY AND TERNARY NEAR-EARTH ASTEROIDS DETECTED BY RADAR


http://echo.jpl.nasa.gov/~lance/binary.neas.html
Last update: 2014 July 10

Known binary and ternary NEAs:
  Asteroid          H    Radar detection?
  1862 Apollo      16.2     Yes
  1866 Sisyphus    13.0     Yes              Brightest absolute magnitude among known binaries
  3671 Dionysus    16.3     No
  5143 Heracles    14.0     Yes              Second brightest absolute magnitude
  5381 Sekhmet     16.5     Yes 
  5646 1990 TR     14.3     No
  7088 Ishtar      16.7     No
  7888 1993 UC     15.3     Yes
 31345 1998 PG     17.3     No
 35107 1991 VH     16.9     Yes
 65803 Didymos     18.0     Yes
 66063 1998 RO1    17.9     Yes
 66391 1999 KW4    16.5     Yes
 69230 Hermes      17.5     Yes              Components have comparable sizes
 85938 1999 DJ4    18.5     Yes
 88710 2001 SL9    17.4     No
136617 1994 CC     17.6     Yes              Triple
136993 1998 ST49   17.7     Yes
137170 1999 HF1    14.4     No
138095 2000 DK79   15.8     Yes
153591 2001 SN263  16.9     Yes              Triple
153958 2002 AM31   18.2     Yes
162000 1990 OS     19.3     Yes
164121 2003 YT1    16.1     Yes
175706 1996 FG3    18.0     Yes
185851 2000 DP107  18.1     Yes
276049 2002 CE26   16.8     Yes
285263 1998 QE2    17.1     Yes
311066 2004 DC     18.0     Yes
363027 1998 ST27   19.5     Yes
363067 2000 CO101  19.1     Yes
363599 2004 FG11   21.0     Yes              Third faintest absolute magnitude 
374851 2006 VV2    16.8     Yes
385186 1994 AW1    17.3     No
       1994 CJ1    21.3     Yes              Second faintest absolute magnitue; components have comparable sizes
       1994 XD     19.1     Yes
       2000 UG11   20.3     Yes
       2002 BM26   20.1     Yes
       2002 KK8    20.4     Yes
       2003 SS84   21.8     Yes              Faintest absolute magnitude among known binaries
       2005 AB     17.5     Yes
       2005 NB7    18.8     Yes
       2006 GY2    18.7     Yes
       2007 DT103  19.2     Yes
       2007 LE     19.2     Yes
       2008 BT18   18.2     Yes
       2008 DG17   19.7     Yes
       2013 WT44   19.6     Yes

N = 48

Radar detections: 41/48 = 0.854

Absolute magnitudes were taken from Horizons and may differ from the delta-V lists on this website,
which were taken from the Minor Planet Center lists.

Not included: 162483 2000 PJ5, 2004 RZ164, and 2009 KD5: possible binaries, but unconfirmed.  
None has been observed with radar.


RADAR DETECTIONS IN CHRONOLOGICAL ORDER Radar Detection Discovery Order Asteroid a (AU) e i (deg) H (mag) Q (AU) q (AU) Date Observatory Technique ===== ======== ====== = ======= ======= ====== ====== ==== =========== ========= 0 1866 Sisyphus 1.894 0.539 41.2 13.0 2.914 0.873 Dec 1985 Arecibo Radar 1 185851 2000 DP107 TOO PHA 1.365 0.377 8.7 18.2 1.880 0.850 Sep 2000 Goldstone & Arecibo Radar Aug 2008 Arecibo & Goldstone 2 2000 UG11 TOO PHA 1.934 0.573 8.9 20.4 3.042 0.826 Nov 2000 Arecibo & Goldstone Radar 3 66391 1999 KW4 PHA 0.642 0.688 38.9 16.3 1.084 0.200 May 2001 Goldstone & Arecibo Radar Jun 2002 Arecibo 4 363027 1998 ST27 PHA 0.819 0.530 21.0 19.4 1.253 0.385 Oct 2001 Arecibo Radar Oct 2004 Arecibo 5 2002 BM26 TOO PHA 1.832 0.444 16.2 19.8 2.645 1.019 Feb 2002 Arecibo Radar 6 2002 KK8 TOO PHA 1.967 0.469 24.6 20.5 2.889 1.045 Jun 2002 Arecibo Radar 7 5381 Sekhmet 0.948 0.296 49.0 16.5 1.228 0.667 May 2003 Arecibo Radar 8 66063 1998 RO1 0.991 0.720 22.7 17.9 1.705 0.277 Sep 2003 Arecibo Photometry Sep 2004 Arecibo 9 2003 SS84 TOO PHA 1.932 0.572 5.5 21.7 3.037 0.827 Sep 2003 Arecibo & Goldstone Radar 10 69230 Hermes TOO PHA 1.654 0.624 6.1 17.5 2.686 0.622 Oct 2003 Arecibo & Goldstone Radar 11 162000 1990 OS PHA 1.680 0.463 1.1 20.0 2.458 0.902 Nov 2003 Arecibo Radar (Aug 1990 Goldstone Satellite not detected) 12 65803 Didymos PHA 1.642 0.383 3.4 17.9 2.275 1.013 Nov 2003 Arecibo, Goldstone Photometry, Radar 13 85938 1999 DJ4 PHA 1.851 0.483 9.2 18.4 2.745 0.957 Apr 2004 Arecibo Photometry 14 164121 2003 YT1 TOO PHA 1.110 0.292 44.1 16.2 1.434 0.785 May 2004 Arecibo Radar 15 276049 2002 CE26 2.233 0.559 47.4 16.5 3.481 0.984 Aug 2004 Arecibo Radar Possible triple 16 2005 AB TOO 3.217 0.656 8.2 17.3 5.325 1.107 Feb 2005 Arecibo Photometry 17 1994 XD TOO PHA 2.356 0.730 4.3 19.1 4.076 0.637 Jun 2005 Arecibo Radar 18 1862 Apollo PHA 1.471 0.560 6.4 16.3 2.295 0.647 Oct 2005 Arecibo Radar (Nov 1980 Arecibo Satellite not detected) 19 2006 GY2 TOO PHA 1.853 0.494 30.6 18.7 2.768 0.938 May 2006 Arecibo & Goldstone Radar 20 311066 2004 DC PHA 1.634 0.400 19.4 18.0 2.288 0.981 Jun 2006 Arecibo & Goldstone Radar 21 363599 2006 VV2 TOO PHA 2.388 0.602 23.6 16.6 3.826 0.949 Mar 2007 Goldstone & Arecibo Radar 22 2007 DT103 TOO PHA 2.210 0.574 5.4 19.4 3.480 0.941 Jul 2007 Goldstone Radar 23 153591 2001 SN263 1.987 0.478 6.7 16.9 2.938 1.037 Feb 2008 Arecibo Radar TRIPLE 24 2005 NB7 PHA 2.042 0.516 12.7 18.7 3.096 0.988 Apr 2008 Arecibo & Goldstone Radar 25 2008 BT18 TOO PHA 2.222 0.598 8.1 18.2 3.551 0.894 Jul 2008 Arecibo & Goldstone Radar 26 35107 1991 VH PHA 1.136 0.144 13.9 16.7 1.300 0.973 Jul 2008 Arecibo & Goldstone Photometry 27 136617 1994 CC PHA 1.638 0.417 4.7 17.7 2.321 0.955 Jun 2009 Goldstone & Arecibo Radar TRIPLE 28 363067 2000 CO101 PHA 1.075 0.090 15.3 19.0 1.172 0.979 Sep 2009 Arecibo Radar 29 175706 1996 FG3 PHA 1.054 0.350 2.0 18.0 1.423 0.685 Nov 2011 Arecibo Photometry 30 5143 Heracles 1.833 0.773 9.1 14.0 3.249 0.417 Dec 2011 Arecibo Radar 31 363599 2004 FG11 PHA 1.589 0.724 3.1 20.9 2.739 0.438 Apr 2012 Arecibo Radar 32 2007 LE PHA 1.839 0.517 29.5 19.2 2.790 0.889 May 2012 Goldstone Radar 33 153958 2002 AM31 PHA 1.704 0.452 4.6 18.2 2.475 0.935 Jul 2012 Arecibo Radar 34 136993 1998 ST49 2.311 0.593 24.5 17.7 3.681 0.939 Oct 2012 Arecibo Radar 35 2008 DG17 1.837 0.449 41.1 19.7 2.664 1.012 Feb 2013 Arecibo Radar 36 7888 1993 UC 2.434 0.664 26.1 15.3 4.053 0.817 Mar 2013 Arecibo Radar 37 285263 1998 QE2 PHA 2.421 0.571 12.9 17.1 3.805 1.039 May 2013 Goldstone Radar 38 138095 2000 DK79 PHA 1.777 0.414 60.7 15.8 2.513 1.040 Nov 2013 Arecibo Radar 39 2013 WT44 TOO PHA 2.259 0.568 12.2 19.6 3.542 0.975 Mar 2014 Goldstone Radar 40 1994 CJ1 PHA 1.489 0.325 2.3 21.3 1.973 1.005 Jun 2014 Arecibo Radar "date" refers to the first radar apparition that showed evidence of a binary. 1990 OS was observed in 1990 but did not show evidence for a secondary until it was observed again in 2003. Similarly, Apollo was observed by radar in 1980 but its satellite was not detected until 2005. Consequently, radar observations that did not yield detections of secondaries are excluded from this list (e.g., 1990 OS at Goldstone in 2003, Apollo at Goldstone in 2005, and 2000 CO101 at Goldstone in 2009). With 2006 GY2, there was a suggestion of a satellite in Goldstone CW data on May 13, but it wasn't obviously a binary until radar imaging at Arecibo on May 15. May 16 Goldstone data also showed two objects. With Didymos, we did not realize that the Goldstone data showed both components until Sep. 2009. 1866 Sisyphus is now listed as a binary based on CW data obtained at Arecibo in December, 1985. The CW signature matches those subsequently seen many times with other binary NEAs. Attempts to detect the secondary with ranging observations in 1985 were unsuccessful. TOO indicates targets-of-opportunity. PHA = "Potentially Hazardous Asteroid" as defined by the Minor Planet Center Binaries and triples discovered by radar that have been targets-of-opportunity: 13/31 = 41.9% Percentage of radar binaries and triples classified as "Potentially Hazardous:" 30/41 = 73.7%
RADAR DETECTIONS ORDERED BY ASTEROID NUMBER AND PROVISIONAL DESIGNATION Asteroid a (AU) e i (deg) H (mag) Q (AU) q (AU) Order Date Observatory ======== ====== = ======= ======= ====== ====== ===== ==== =========== 1862 Apollo 1.471 0.560 6.4 16.3 2.295 0.647 PHA 18 Oct 2005 Arecibo 1866 Sisyphus 1.894 0.539 41.2 13.0 2.914 0.873 0 Dec 1985 Arecibo 5143 Heracles 1.833 0.773 9.1 14.0 3.249 0.417 30 Dec 2011 Arecibo 5381 Sekhmet 0.948 0.296 49.0 16.5 1.228 0.667 7 May 2003 Arecibo 7888 1993 UC 2.434 0.664 26.1 15.3 4.053 0.817 36 Mar 2013 Arecibo & Goldstone 35107 1991 VH 1.136 0.144 13.9 16.7 1.300 0.973 PHA 26 Jul 2008 Arecibo 65803 Didymos 1.642 0.383 3.4 17.9 2.275 1.013 PHA 12 Nov 2003 Arecibo & Goldstone 66063 1998 RO1 0.991 0.720 22.7 17.9 1.705 0.277 8 Sep 2003 Arecibo 66391 1999 KW4 0.642 0.688 38.9 16.3 1.084 0.200 PHA 3 May 2001 Goldstone & Arecibo 69230 Hermes 1.654 0.624 6.1 17.5 2.686 0.622 PHA 10 Oct 2003 Arecibo & Goldstone 85938 1999 DJ4 1.851 0.483 9.2 18.4 2.745 0.957 PHA 12 Apr 2004 Arecibo 136617 1994 CC 1.638 0.417 4.7 17.7 2.321 0.955 PHA 27 Jun 2009 Goldstone & Arecibo 136993 1998 ST49 2.311 0.593 24.5 17.7 3.681 0.939 34 Oct 2012 Arecibo 138095 2000 DK79 1.777 0.414 60.7 15.8 2.513 1.040 PHA 38 Nov 2013 Arecibo 153591 2001 SN263 1.987 0.478 6.7 16.9 2.938 1.037 23 Feb 2008 Arecibo 153958 2002 AM31 1.705 0.452 4.6 18.2 2.475 0.935 PHA 33 Jul 2012 Arecibo & Goldstone 162000 1990 OS 1.680 0.463 1.1 20.0 2.458 0.902 PHA 11 Nov 2003 Arecibo 164121 2003 YT1 1.110 0.292 44.1 16.2 1.434 0.785 PHA 14 May 2004 Arecibo 175706 1996 FG3 1.054 0.350 2.0 18.0 1.423 0.685 PHA 29 Nov 2011 Arecibo & Goldstone 185851 2000 DP107 1.365 0.377 8.7 18.2 1.880 0.850 PHA 1 Sep 2000 Goldstone & Arecibo 276049 2002 CE26 2.233 0.559 47.4 16.5 3.481 0.984 15 Aug 2004 Arecibo 285263 1998 QE2 2.421 0.571 12.9 17.1 3.805 1.039 PHA 37 May 2013 Goldstone & Arecibo 311066 2004 DC 1.634 0.400 19.4 18.0 2.288 0.981 PHA 20 Jun 2006 Arecibo & Goldstone 363027 1998 ST27 0.819 0.530 21.0 19.4 1.253 0.385 PHA 4 Oct 2001 Arecibo 363067 2000 CO101 1.075 0.090 15.3 19.0 1.172 0.979 PHA 28 Sep 2009 Arecibo 363599 2004 FG11 1.589 0.724 3.1 20.9 2.739 0.438 PHA 31 Apr 2012 Arecibo 374851 2006 VV2 2.388 0.602 23.6 16.6 3.826 0.949 PHA 21 Mar 2007 Goldstone & Arecibo 1994 XD 2.356 0.730 4.3 19.1 4.076 0.637 PHA 17 Jun 2005 Arecibo 2000 UG11 1.934 0.573 8.9 20.4 3.042 0.826 PHA 2 Nov 2000 Arecibo & Goldstone 2002 BM26 1.832 0.444 16.2 19.8 2.645 1.019 PHA 5 Feb 2002 Arecibo 2002 KK8 1.967 0.469 24.6 20.5 2.889 1.045 PHA 6 Jun 2002 Arecibo 2003 SS84 1.932 0.572 5.5 21.7 3.037 0.827 PHA 9 Sep 2003 Arecibo & Goldstone 2005 AB 3.217 0.656 8.2 17.3 5.325 1.107 16 Feb 2005 Arecibo 2005 NB7 2.042 0.516 12.7 18.7 3.096 0.988 PHA 24 Apr 2008 Arecibo & Goldstone 2006 GY2 1.853 0.494 30.6 18.7 2.768 0.938 PHA 19 May 2006 Arecibo & Goldstone 2007 DT103 2.210 0.574 5.4 19.5 3.480 0.941 PHA 22 Jul 2007 Goldstone 2007 LE 1.839 0.517 29.5 19.2 2.790 0.889 PHA 32 May 2012 Goldstone & Arecibo 2008 BT18 2.222 0.598 8.1 18.2 3.551 0.894 PHA 25 Jul 2008 Arecibo 2008 DG17 1.837 0.449 41.1 19.7 2.664 1.101 35 Feb 2013 Arecibo 2013 WT44 2.259 0.568 12.2 19.6 3.542 0.975 PHA 39 Mar 2014 Goldstone
CONFIRMED BINARY NEAS _NOT_ OBSERVED BY RADAR 3671 Dionysus 5646 1990 TR 7088 Ishtar 31345 1998 PG 88710 2001 SL9 137170 1999 HF1 385186 1994 AW1
BINARY AND TERNARY NEAS RANKED BY ABSOLUTE MAGNITUDE Spectral Dprimary Asteroid H Class (km) 1866 Sisyphus 1972 XA 13.0 S ~8 RADAR DISCOVERY 5143 Heracles 1991 VL 14.0 0 RADAR DISCOVERY 137170 1999 HF1 14.4 X 7888 1993 UC 15.3 U RADAR DISCOVERY 138095 2000 DK79 15.8 RADAR DISCOVERY 164121 2003 YT1 16.1 V 1.0 RADAR DISCOVERY 1862 Apollo 1932 HA 16.2 Q 1.5 RADAR DISCOVERY 3671 Dionysus 1984 KD 16.3 C 5381 Sekhmet 1991 JY 16.5 V 1.0 RADAR DISCOVERY 66391 1999 KW4 16.5 S 1.5 RADAR DISCOVERY 7088 Ishtar 1992 AA 16.7 276049 2002 CE26 16.8 C 3.5 RADAR DISCOVERY 374851 2006 VV2 16.8 S 1.8 RADAR DISCOVERY 35107 1991 VH 16.9 S RADAR 153591 2001 SN263 16.9 B RADAR DISCOVERY 285263 1998 QE2 17.1 C 3 RADAR DISCOVERY 385186 1994 AW1 17.3 S 31345 1998 PG 17.3 Q 88710 2001 SL9 17.4 Q 69230 Hermes 1937 UB 17.5 S 0.6 RADAR DISCOVERY 2005 AB 17.5 C RADAR 136617 1994 CC 17.6 Q 0.7 RADAR DISCOVERY 136993 1998 ST49 17.7 RADAR DISCOVERY 66063 1998 RO1 17.9 S 0.6 RADAR 65803 Didymos 1996 GT 18.0 S 0.8 RADAR 311066 2004 DC 18.0 0.3 RADAR DISCOVERY 185851 2000 DP107 18.1 X 0.8 RADAR DISCOVERY 153958 2002 AM31 18.2 SqV RADAR DISCOVERY 175706 1996 FG3 18.2 C 1.8 RADAR 2008 BT18 18.2 S RADAR 85938 1999 DJ4 18.5 Q 0.42 RADAR 2006 GY2 18.7 0.45 RADAR DISCOVERY 2005 NB7 18.8 S 0.5 RADAR DISCOVERY 363067 2000 CO101 19.1 Xk 0.7 RADAR DISCOVERY 1994 XD 19.1 0.6 RADAR DISCOVERY 2007 DT103 19.2 S ~0.3 RADAR DISCOVERY 2007 LE 19.2 C ~0.45 RADAR DISCOVERY 162000 1990 OS 19.3 0.3 RADAR DISCOVERY 363027 1998 ST27 19.5 C 0.8 RADAR DISCOVERY 2013 WT44 19.6 dark ~0.9 RADAR DISCOVERY 2008 DG17 19.7 RADAR DISCOVERY 2002 BM26 20.1 P 0.6 RADAR DISCOVERY 2000 UG11 20.3 S 0.23 RADAR DISCOVERY 2002 KK8 20.4 0.5 RADAR DISCOVERY 363599 2004 FG11 21.0 RADAR DISCOVERY 1994 CJ1 21.3 RADAR DISCOVERY 2003 SS84 21.8 0.12 RADAR DISCOVERY Here C includes C and B types and S includes S and Q types Note: absolute magnitudes are taken from Horizons. Values may differ by up to a few tenths of a magnitude from those listed on the Minor Planet Center's websites. Dprimary = diameter of the primary, as estimated from radar observations and/or shape modeling.
Spectral classes (all binaries and triples, not just radar detections): C XXXXX XXX E M P X S XXXXX XXXXX XXXXX XXX V XXX X XXX ? XXXXX XXXXX XX Abundance of Radar Binaries and Ternaries by Absolute Magnitude: ...This needs to be updated... (2013 Nov 18, not updated since Nov. 2012) Fraction of Radar Radar radar Fraction of H range NEAs binaries detections known binaries ------- ----- -------- ---------- -------------- H < 13.0 2 0 0.00 None known 13.0 <= H < 14.0 3 1 0.33 1/1 = 1.00 14.0 <= H < 15.0 8 0 0.00 0/1 = 0.00 15.0 <= H < 16.0 15 0 0.00 None known 16.0 <= H < 17.0 29 9 0.31 9/11 = 0.82 17.0 <= H < 18.0 41 3 0.073 3/6 = 0.50 18.0 <= H < 19.0 36 8 0.22 8/9 = 0.89 19.0 <= H < 20.0 37 5 0.14 5/5 = 1.00 20.0 <= H < 21.0 34 3 0.088 3/3 = 1.00 21.0 <= H < 22.0 20 1 0.050 1/1 = 1.00 22.0 <= H 47 0 0.00 None known
DELTA-V RANKINGS ================ Delta-v rankings for all NEA binaries and ternaries observed with radar and photometry. Not included; 2004 RZ164, a possible binary reported by Kwiatkowski et al., Astron. Astrophys. 462, 341-344 (2007) 2000 PJ5, a possible binary reported by Polishook and Brosch, Icarus 194, 111-124 (2008) 2009 KD5, a possible binary reported by Foster et al. Bull. Am. Astron. Soc. 42, 1055 (2010) [abstract] Number of NEAs in the MPC database = 11116 (2014 July 7) RADAR BINARY = Binary or ternary observed by radar, but not necessarily discovered by radar BINARY = Binary observed photometrically but not (yet) by radar SPACECRAFT RENDEZVOUS --------------------- DELTA-V (ASTEROID)/ PROVISIONAL DELTA-V DELTA-V FOR RANK PERCENTILE ASTEROID NAME DESIGNATION (KM/S) THE MOON MARS H (mag) a (AU) e i (deg) ==== ========== ============= =========== ======= ======== ==== ======= ====== === ====== 254 97.72 1994 CJ1 4.698 0.783 0.746 21.4 1.489 0.325 2.3 RADAR BINARY 617 94.45 (65803) Didymos 1996 GT 5.098 0.850 0.809 18.0 1.644 0.384 3.4 RADAR BINARY 967 91.30 (136617) 1994 CC 5.379 0.896 0.854 17.7 1.638 0.417 4.7 RADAR BINARY 1356 87.80 (153958) 2002 AM31 5.627 0.938 0.893 18.3 1.703 0.452 4.6 RADAR BINARY 1433 87.11 (162000) 1990 OS 5.674 0.946 0.901 19.3 1.678 0.462 1.1 RADAR BINARY 1982 82.17 (153591) 2001 SN263 5.963 0.994 0.947 16.9 1.987 0.478 6.7 RADAR BINARY 1996 82.04 (185851) 2000 DP107 5.969 0.995 0.947 18.2 1.365 0.377 8.7 RADAR BINARY 2147 80.69 (85938) 1999 DJ4 6.032 1.005 0.958 18.6 1.853 0.483 9.1 RADAR BINARY 3058 72.49 (35107) 1991 VH 6.364 1.061 1.010 16.8 1.137 0.144 13.9 RADAR BINARY 3118 71.95 2007 DT103 6.383 1.064 1.013 19.2 2.206 0.576 5.5 RADAR BINARY 3526 68.28 2005 NB7 6.507 1.085 1.033 18.7 2.044 0.517 12.7 RADAR BINARY 3875 65.14 (175706) 1996 FG3 6.609 1.102 1.049 18.4 1.054 0.350 2.0 RADAR BINARY 3970 64.29 2003 SS84 6.635 1.106 1.053 21.8 1.930 0.571 5.5 RADAR BINARY 4045 63.61 (31345) 1998 PG 6.656 1.109 1.056 17.3 2.015 0.392 6.5 BINARY 4130 62.85 (7088) Ishtar 1992 AA 6.684 1.114 1.061 16.7 1.981 0.391 8.3 BINARY 4203 62.19 2008 BT18 6.705 1.117 1.064 18.3 2.223 0.593 8.1 RADAR BINARY 4347 60.89 2002 BM26 6.743 1.124 1.070 20.1 1.832 0.444 16.2 RADAR BINARY 4398 60.44 2013 WT44 6.757 1.126 1.073 19.3 2.260 0.568 12.2 RADAR BINARY 4405 60.37 (3671) Dionysus 1984 KD 6.759 1.126 1.073 16.4 2.198 0.542 13.6 BINARY 4671 57.98 (5646) 1990 TR 6.837 1.139 1.085 15.2 2.142 0.437 7.9 BINARY 4796 56.85 2000 UG11 6.877 1.146 1.092 20.4 1.928 0.573 8.9 RADAR BINARY 5260 52.68 (285263) 1998 QE2 7.031 1.172 1.116 17.3 2.423 0.571 12.9 RADAR BINARY 5585 49.76 (311066) 2004 DC 7.140 1.190 1.133 18.1 1.634 0.399 19.4 RADAR BINARY 5775 48.05 (363067) 2000 CO101 7.218 1.203 1.146 19.1 1.076 0.090 15.3 RADAR BINARY 6290 43.41 2005 AB 7.466 1.244 1.185 17.5 3.217 0.655 8.2 RADAR BINARY 6300 43.32 (1862) Apollo 1932 HA 7.471 1.245 1.186 16.2 1.470 0.560 6.4 RADAR BINARY 6869 38.21 (69230) Hermes 1937 UB 7.777 1.296 1.234 17.5 1.655 0.624 6.1 RADAR BINARY 7268 34.62 1994 XD 8.059 1.343 1.279 19.1 2.347 0.733 4.3 RADAR BINARY 7771 30.09 2002 KK8 8.477 1.413 1.346 21.0 1.953 0.466 24.5 RADAR BINARY 7967 28.33 (374851) 2006 VV2 8.641 1.440 1.372 16.8 2.386 0.605 23.7 RADAR BINARY 8069 27.41 (136993) 1998 ST49 8.746 1.458 1.388 17.7 2.310 0.593 24.5 RADAR BINARY 8521 23.34 (363599) 2004 FG11 9.181 1.530 1.457 21.0 1.588 0.724 3.1 RADAR BINARY 8650 22.18 (88710) 2001 SL9 9.322 1.554 1.480 17.6 1.061 0.270 21.9 BINARY 8875 20.16 (7888) 1993 UC 9.584 1.597 1.521 15.1 2.436 0.664 26.1 RADAR BINARY 8888 20.04 (5143) Heracles 1991 VL 9.592 1.599 1.522 13.8 1.834 0.772 9.0 RADAR BINARY 9040 18.68 2007 LE 9.797 1.633 1.555 19.7 1.839 0.517 29.5 RADAR BINARY 9097 18.16 2006 GY2 9.879 1.647 1.568 18.8 1.858 0.496 30.6 RADAR BINARY 9340 15.98 (385186) 1994 AW1 10.252 1.709 1.627 17.5 1.105 0.075 24.1 BINARY 10301 7.33 2008 DG17 12.629 2.105 2.005 19.7 1.838 0.449 41.1 RADAR BINARY 10361 6.79 (1866) Sisyphus 1972 XA 12.829 2.138 2.036 12.4 1.894 0.538 41.2 RADAR BINARY 10376 6.66 (363027) 1998 ST27 12.905 2.151 2.048 19.5 0.819 0.530 21.1 RADAR BINARY 10409 6.36 (137170) 1999 HF1 13.032 2.172 2.069 14.5 0.819 0.462 25.7 BINARY 10612 4.53 (276049) 2002 CE26 14.081 2.347 2.235 16.8 2.234 0.559 47.3 RADAR BINARY 10900 1.94 (164121) 2003 YT1 16.470 2.745 2.614 16.2 1.110 0.292 44.1 RADAR BINARY 11019 0.87 (5381) Sekhmet 1991 JY 18.892 3.149 2.999 16.5 0.947 0.296 49.0 RADAR BINARY 11037 0.71 (138095) 2000 DK79 19.292 3.215 3.062 16.0 1.777 0.414 60.7 RADAR BINARY 11040 0.68 (66063) 1998 RO1 19.402 3.234 3.080 18.1 0.991 0.720 22.7 RADAR BINARY 11088 0.25 (66391) 1999 KW4 21.300 3.550 3.381 16.5 0.642 0.688 38.9 RADAR BINARY SPACECRAFT FLYBY ---------------- Provisional Delta-v H a e i Rank Percentile Asteroid number and name Designation (km/s) (mag) (AU) (deg) ==== ========== ======================== =========== ======= ===== ===== ===== ===== 366 96.71 (175706) 1996 FG3 4.020 18.4 1.054 0.350 2.0 RADAR BINARY 1223 89.00 (35107) 1991 VH 4.499 16.8 1.137 0.144 13.9 RADAR BINARY 1257 88.69 (363067) 2000 CO101 4.514 19.1 1.076 0.090 15.3 RADAR BINARY 1561 85.96 1994 CJ1 4.649 21.4 1.489 0.325 2.3 RADAR BINARY 1847 83.38 (185851) 2000 DP107 4.774 18.2 1.365 0.377 8.7 RADAR BINARY 2329 79.05 (65803) Didymos 1996 GT 4.998 18.0 1.644 0.384 3.4 RADAR BINARY 2540 77.15 (136617) 1994 CC 5.080 17.7 1.638 0.417 4.7 RADAR BINARY 2644 76.21 (1862) Apollo 1932 HA 5.113 16.2 1.470 0.560 6.4 RADAR BINARY 2712 75.60 (162000) 1990 OS 5.144 19.3 1.678 0.462 1.1 RADAR BINARY 2929 73.65 (153958) 2002 AM31 5.228 18.3 1.703 0.452 4.6 RADAR BINARY 3434 69.11 (88710) 2001 SL9 5.400 17.6 1.061 0.270 21.9 BINARY 3544 68.12 (363599) 2004 FG11 5.436 21.0 1.588 0.724 3.1 RADAR BINARY 3685 66.85 (69230) Hermes 1937 UB 5.481 17.5 1.655 0.624 6.1 RADAR BINARY 3851 65.36 (385186) 1994 AW1 5.526 17.5 1.105 0.075 24.1 BINARY 4110 63.03 (31345) 1998 PG 5.600 17.3 2.015 0.392 6.5 BINARY 4265 61.63 (7088) Ishtar 1992 AA 5.643 16.7 1.981 0.391 8.3 BINARY 4411 60.32 (85938) 1999 DJ4 5.681 18.6 1.853 0.483 9.1 RADAR BINARY 4553 59.04 (153591) 2001 SN263 5.719 16.9 1.987 0.478 6.7 RADAR BINARY 4662 58.06 2003 SS84 5.748 21.8 1.930 0.571 5.5 RADAR BINARY 5283 52.47 (5646) 1990 TR 5.887 15.2 2.142 0.437 7.9 BINARY 5375 51.65 2000 UG11 5.906 20.4 1.928 0.573 8.9 RADAR BINARY 6125 44.90 2007 DT103 6.071 19.2 2.206 0.576 5.5 RADAR BINARY 6150 44.67 (5143) Heracles 1991 VL 6.075 13.8 1.834 0.772 9.0 RADAR BINARY 6458 41.90 2002 BM26 6.152 20.1 1.832 0.444 16.2 RADAR BINARY 6460 41.89 (311066) 2004 DC 6.153 18.1 1.634 0.399 19.4 RADAR BINARY 6696 39.76 2005 NB7 6.217 18.7 2.044 0.517 12.7 RADAR BINARY 6742 39.35 2008 BT18 6.226 18.3 2.223 0.593 8.1 RADAR BINARY 7356 33.83 1994 XD 6.389 19.1 2.347 0.733 4.3 RADAR BINARY 7687 30.85 2013 WT44 6.488 19.3 2.260 0.568 12.2 RADAR BINARY 7714 30.60 (3671) Dionysus 1984 KD 6.498 16.4 2.198 0.542 13.6 BINARY 8266 25.64 (285263) 1998 QE2 6.704 17.3 2.423 0.571 12.9 RADAR BINARY 8639 22.28 (137170) 1999 HF1 6.886 14.5 0.819 0.462 25.7 BINARY 8938 19.59 2005 AB 7.099 17.5 3.217 0.655 8.2 RADAR BINARY 9057 18.52 (363027) 1998 ST27 7.180 19.5 0.819 0.530 21.1 RADAR BINARY 9247 16.81 2002 KK8 7.333 21.0 1.953 0.466 24.5 RADAR BINARY 9752 12.27 (66391) 1999 KW4 7.877 16.5 0.642 0.688 38.9 RADAR BINARY 9757 12.23 (374851) 2006 VV2 7.882 16.8 2.386 0.605 23.7 RADAR BINARY 9772 12.09 (136993) 1998 ST49 7.904 17.7 2.310 0.593 24.5 RADAR BINARY 9871 11.20 2007 LE 8.017 19.7 1.839 0.517 29.5 RADAR BINARY 10004 10.00 2006 GY2 8.185 18.8 1.858 0.496 30.6 RADAR BINARY 10109 9.06 (7888) 1993 UC 8.337 15.1 2.436 0.664 26.1 RADAR BINARY 10466 5.85 (164121) 2003 YT1 9.168 16.2 1.110 0.292 44.1 RADAR BINARY 10681 3.91 2008 DG17 9.962 19.7 1.838 0.449 41.1 RADAR BINARY 10738 3.40 (1866) Sisyphus 1972 XA 10.188 12.4 1.894 0.538 41.2 RADAR BINARY 10837 2.51 (5381) Sekhmet 1991 JY 10.775 16.5 0.947 0.296 49.0 RADAR BINARY 10940 1.58 (276049) 2002 CE26 11.804 16.8 2.234 0.559 47.3 RADAR BINARY 11052 0.58 (138095) 2000 DK79 13.949 16.0 1.777 0.414 60.7 RADAR BINARY 11114 0.02 (66063) 1998 RO1 18.576 18.1 0.991 0.720 22.7 RADAR BINARY TISSERAND PARAMETER RANKINGS FOR BINARIES Tisserand Parameter is computed from T = aj/a + 2.0*cos(i)*sqrt((a/aj)*(1.0 - e*e)) where aj is the semimajor axis of Jupiter, a is the semimajor axis of an asteroid, i is the asteroid's inclination, and e is the asteroid's eccentricity. In general, most Jupiter-family (short period) comets have T < 3.0 and ~90% of numbered asteroids with a < 3.3 AU have T > 3. PROVISIONAL TISSERAND RANK PERCENTILE ASTEROID NAME DESIGNATION PARAMETER H (mag) a (AU) e i (deg) Q (AU) q (AU) ==== ========== ============= =========== ========= ======= ====== = ======= ====== ====== 247 97.78 2005 AB 2.793 17.5 3.217 0.655 8.2 5.324 1.110 RADAR BINARY 947 91.48 (7888) 1993 UC 3.055 15.1 2.436 0.664 26.1 4.054 0.818 RADAR BINARY 1001 90.99 (276049) 2002 CE26 3.066 16.8 2.234 0.559 47.3 3.483 0.985 RADAR BINARY 1317 88.15 1994 XD 3.128 19.1 2.347 0.733 4.3 4.067 0.627 RADAR BINARY 1526 86.27 (374851) 2006 VV2 3.168 16.8 2.386 0.605 23.7 3.830 0.942 RADAR BINARY 1889 83.01 (136993) 1998 ST49 3.229 17.7 2.310 0.593 24.5 3.680 0.940 RADAR BINARY 1948 82.48 (285263) 1998 QE2 3.239 17.3 2.423 0.571 12.9 3.807 1.039 RADAR BINARY 2635 76.30 2013 WT44 3.362 19.3 2.260 0.568 12.2 3.544 0.976 RADAR BINARY 2754 75.22 2008 BT18 3.383 18.3 2.223 0.593 8.1 3.541 0.905 RADAR BINARY 2969 73.29 2007 DT103 3.418 19.2 2.206 0.576 5.5 3.477 0.935 RADAR BINARY 3022 72.81 (3671) Dionysus 1984 KD 3.429 16.4 2.198 0.542 13.6 3.389 1.007 BINARY 3149 71.67 (138095) 2000 DK79 3.448 16.0 1.777 0.414 60.7 2.513 1.041 RADAR BINARY 3520 68.33 (1866) Sisyphus 1972 XA 3.512 12.4 1.894 0.538 41.2 2.913 0.875 RADAR BINARY 3864 65.24 (5646) 1990 TR 3.572 15.2 2.142 0.437 7.9 3.078 1.206 BINARY 3941 64.55 (5143) Heracles 1991 VL 3.582 13.8 1.834 0.772 9.0 3.250 0.418 RADAR BINARY 3995 64.06 2005 NB7 3.592 18.7 2.044 0.517 12.7 3.101 0.987 RADAR BINARY 4226 61.98 2008 DG17 3.631 19.7 1.838 0.449 41.1 2.663 1.013 RADAR BINARY 4316 61.17 2002 KK8 3.650 21.0 1.953 0.466 24.5 2.863 1.043 RADAR BINARY 4497 59.54 2000 UG11 3.684 20.4 1.928 0.573 8.9 3.033 0.823 RADAR BINARY 4537 59.18 2003 SS84 3.691 21.8 1.930 0.571 5.5 3.032 0.828 RADAR BINARY 4551 59.06 2006 GY2 3.693 18.8 1.858 0.496 30.6 2.780 0.936 RADAR BINARY 4566 58.92 (153591) 2001 SN263 3.697 16.9 1.987 0.478 6.7 2.937 1.037 RADAR BINARY 4636 58.29 2007 LE 3.715 19.7 1.839 0.517 29.5 2.790 0.888 RADAR BINARY 4656 58.11 (31345) 1998 PG 3.720 17.3 2.015 0.392 6.5 2.805 1.225 BINARY 4775 57.04 (7088) Ishtar 1992 AA 3.750 16.7 1.981 0.391 8.3 2.756 1.206 BINARY 5113 54.00 (85938) 1999 DJ4 3.840 18.6 1.853 0.483 9.1 2.748 0.958 RADAR BINARY 5210 53.13 2002 BM26 3.861 20.1 1.832 0.444 16.2 2.645 1.019 RADAR BINARY 5859 47.29 (69230) Hermes 1937 UB 4.020 17.5 1.655 0.624 6.1 2.688 0.622 RADAR BINARY 5919 46.75 (363599) 2004 FG11 4.037 21.0 1.588 0.724 3.1 2.738 0.438 RADAR BINARY 6071 45.39 (153958) 2002 AM31 4.072 18.3 1.703 0.452 4.6 2.473 0.933 RADAR BINARY 6183 44.38 (162000) 1990 OS 4.108 19.3 1.678 0.462 1.1 2.453 0.903 RADAR BINARY 6344 42.93 (311066) 2004 DC 4.153 18.1 1.634 0.399 19.4 2.286 0.982 RADAR BINARY 6479 41.71 (136617) 1994 CC 4.193 17.7 1.638 0.417 4.7 2.321 0.955 RADAR BINARY 6499 41.53 (65803) Didymos 1996 GT 4.201 18.0 1.644 0.384 3.4 2.275 1.013 RADAR BINARY 7185 35.36 (1862) Apollo 1932 HA 4.414 16.2 1.470 0.560 6.4 2.293 0.647 RADAR BINARY 7458 32.91 1994 CJ1 4.505 21.4 1.489 0.325 2.3 1.973 1.005 RADAR BINARY 8181 26.40 (185851) 2000 DP107 4.749 18.2 1.365 0.377 8.7 1.880 0.850 RADAR BINARY 9398 15.46 (164121) 2003 YT1 5.322 16.2 1.110 0.292 44.1 1.434 0.786 RADAR BINARY 9620 13.46 (35107) 1991 VH 5.474 16.8 1.137 0.144 13.9 1.301 0.973 RADAR BINARY 9729 12.48 (385186) 1994 AW1 5.547 17.5 1.105 0.075 24.1 1.188 1.022 BINARY 9946 10.53 (363067) 2000 CO101 5.709 19.1 1.076 0.090 15.3 1.173 0.979 RADAR BINARY 9949 10.50 (88710) 2001 SL9 5.710 17.6 1.061 0.270 21.9 1.347 0.775 BINARY 10027 9.80 (175706) 1996 FG3 5.779 18.4 1.054 0.350 2.0 1.423 0.685 RADAR BINARY 10058 9.52 (66063) 1998 RO1 5.809 18.1 0.991 0.720 22.7 1.705 0.277 RADAR BINARY 10274 7.57 (5381) Sekhmet 1991 JY 6.028 16.5 0.947 0.296 49.0 1.227 0.667 RADAR BINARY 10907 1.88 (363027) 1998 ST27 6.980 19.5 0.819 0.530 21.1 1.253 0.385 RADAR BINARY 10910 1.85 (137170) 1999 HF1 6.987 14.5 0.819 0.462 25.7 1.197 0.441 BINARY 11105 0.10 (66391) 1999 KW4 8.501 16.5 0.642 0.688 38.9 1.084 0.200 RADAR BINARY
Since completion of the upgrade At Arecibo (Jan. 1999): NEA binaries and ternaries with H < 22.0 (diameters > ~200 meters) detected by radar: 40/295 = 13.6% This does not include 2003 SS84, which is probably < 200 m in diameter. NEA ternaries with H < 22 detected by radar: 2/295 = 0.7% Note: the tabulations below include 1866 Sisyphus but do NOT include: 2004 RZ164, a possible binary reported by Kwiatkowski et al. (2007), or 2000 PJ5, a possible binary reported by Polishook and Brosch (2008). Percentage of all NEA binaries and ternaries discovered by radar: 35/48 = 72.9% (includes Sisyphus) Percentage of all NEA binaries and ternaries discovered photometrically: 13/48 = 27.1% Percentage of all NEA binaries and ternaries detected by radar: 41/48 = 85.4% (includes Sisyphus) Percentage of all NEA binaries and ternaries detected photometrically: 19/48 = 39.6% (Lightcurves of 1998 ST27, Hermes, 2003 YT1, 2002 CE26, Apollo, Sisyphus, and 2000 CO101 do not show evidence for secondaries. The secondaries are probably too small. The lightcurve of 1994 CJ1 hasn't shown evidence for mutual events either.) Percentage of all NEA binaries and ternaries discovered at Arecibo: 27/48 = 56.3% (includes Sisyphus) Percentage of all NEA binaries and ternaries discovered at Goldstone: 8/48 = 16.7% Percentage of all NEA radar binaries and ternaries detected at Arecibo: 39/41 = 95.1% (includes Sisyphus) Percentage of all NEA radar binaries and ternaries detected at Goldstone: 17/41 = 41.5% Percentage of all NEA binaries and ternaries since January 1999 discovered by radar: 35/41 = 85.4% Percentage of all NEA binaries and ternaries since January 1999 detected by radar: 39/41 = 95.1% Percentage of NEA radar binaries and ternaries that are "Potentially Hazardous:" 30/41 = 73.2% Percentage of NEA binaries and ternaries discovered by radar (including Sisyphus) that were targets-of-opportunity: 14/35 = 40.0% Ternaries: Percentage of NEA ternaries discovered by radar: 2/2 = 100% Percentage of NEA multiple systems detected by radar that are ternaries: 2/40 = 5.0% This is probably an underestimate due to low SNRs for many of the binary radar detections. This does not include 2002 CE26, a candidate ternary system. Photometry of 1999 KW4 in 1999 showed tentative evidence of mutual events, but the binary status of that object was not discovered until radar observations at Goldstone in 2001. 1998 RO1, Didymos, and 1999 DJ4, were strongly suspected of being binaries based on lightcurves prior to observations by radar. Photometry of 2006 VV2 suggested a binary in mid-March 2007 but not at the level required for an IAU Circular by the Binary Asteroid Photometric Survey. Its binary status became clear on March 27, 2007 based on observations at Goldstone. 1990 OS was first detected by radar in 1990 but was unrecognized as a binary system until November, 2003. 1862 Apollo was first detected by radar in 1980 but was unrecognized as a binary system until November, 2005. August, 2007 update: 1866 Sisyphus was suspected of being a binary in December, 1985 based on a narrow spike in CW data that did not move in frequency with the asteroid's 2.4 hour rotation period. Similar echo power spectra were not seen again with any asteroid until September, 2000 when 2000 DP107 was recognized as a binary based on both CW spectra and delay-Doppler imaging. Due to the narrow spikes observed in most known binaries, we now classify Sisyphus as a binary system. With an estimated diameter of about 8 km, Sisyphus is by far the largest binary NEA known. For additional lists of binary NEAs, their discovery history, and estimated physical properties, see Petr Pravec's website at: http://www.asu.cas.cz/~asteroid/binneas.htm#1 [THAT WEBSITE IS NOW OUTDATED]
FUTURE EARTH APPROACHES WITHIN 0.1 AU THROUGH 2099 FOR BINARY OR TERNARY NEAs This table also includes apparitions sufficiently close to yield detections for some objects even if Delta > 0.1 AU. Date Distance (AU) 1862 Apollo 2021 Dec 0.242 2023 May 0.213 2046 Nov 0.035 2048 May 0.050 2080 Nov 0.098 2082 May 0.033 1866 Sisyphus NONE Approaches within 0.51 AU in Dec. 2011 but the secondary is probably too small to detect photometrically. Sisyphus radar opportunities: 2032 Nov 0.470 Weak CW target: daily SNR ~15 2045 Nov 0.304 Coarse resolution imaging opportunity: daily SNR ~100 2058 Nov 0.154 Good imaging opportunity: daily SNR > 1000 2071 Nov 0.116 Good imaging opportunity: daily SNR > 1000 3671 Dionysus 2085 Jun 0.028 5143 Heracles 2039 Jul 0.058 5381 Sekhmet 2014 May 0.310 Weak CW target 2015 May 0.227 CW and coarse ranging 2026 May 0.261 CW and coarse ranging 5646 1990 TR NONE...but makes regular approaches within 0.07 AU of Ceres 7088 Ishtar NONE 7888 1993 UC 2055 Mar 0.082 31345 1998 PG NONE 35107 1991 VH 2020 Feb 0.307 Weak CW target 2025 Aug 0.078 2026 Jan 0.292 Weak CW target 2048 Aug 0.090 2065 Aug 0.045 2088 Aug 0.045 65803 Didymos 2022 Oct 0.071 2062 Oct 0.050 66063 1998 RO1 2076 Sep 0.098 66391 1999 KW4 2016 May 0.265 Weak CW target 2017 May 0.167 coarse imaging target 2018 May 0.078 2019 May 0.035 2020 Jun 0.180 CW and ranging 2036 May 0.016 2053 May 0.068 2054 May 0.046 2071 May 0.018 2088 May 0.087 2089 May 0.024 69230 Hermes 2040 Apr 0.028 2057 Apr 0.027 2069 Oct 0.086 2086 Oct 0.024 85938 1999 DJ4 2057 Mar 0.085 2062 May 0.087 88710 2001 SL9 2014 Apr 0.226 CW target 2026 Apr 0.202 CW & ranging target 136617 1994 CC 2032 Aug 0.111 Coarse-resolution imaging target 2053 Jul 0.073 2074 Jun 0.017 2095 Jun 0.034 136993 1998 ST49 ...None... 137170 1999 HF1 ...None... 138095 2000 DK79 2058 Nov 0.065 153591 2001 SN263 2022 Feb 0.101 153958 2002 AM31 2032 Jul 0.034 2052 Aug 0.070 2072 Sep 0.071 2092 Oct 0.086 162000 1990 OS 2027 Aug 0.131 2040 Sep 0.082 2053 Nov 0.020 2077 Oct 0.086 162483 2000 PJ5 2018 Jul 0.194 Possible binary; Polishook & Brosch 2008 2027 Jul 0.183 This object does not approach within 0.1 AU until at least 2100. 2049 Jul 0.176 2071 Jul 0.182 2080 Jul 0.196 2093 Jul 0.198) 164121 2003 YT1 2016 Oct 0.035 2018 May 0.260 CW and ranging 2023 Nov 0.059 2025 May 0.337 Weak CW 2066 Apr 0.068 2073 Apr 0.011 2085 Nov 0.040 175706 1996 FG3 2022 May 0.078 2024 Nov 0.180 2035 May 0.106 2037 Nov 0.129 2048 May 0.175 2050 Nov 0.057 2063 Nov 0.062 2086 Apr 0.057 2099 May 0.066 186851 2000 DP107 2016 Aug 0.179 CW and ranging 2067 Sep 0.042 2075 Sep 0.046 276049 2002 CE26 2014 Sep 0.131 Imaging 2024 Sep 0.201 CW and ranging 311066 2004 DC 2077 Jun 0.027 285263 1998 QE2 NONE 363027 1998 ST27 2021 Oct 0.189 Weak CW target 2024 Oct 0.024 2027 Oct 0.155 CW and ranging 2047 Oct 0.075 2050 Oct 0.092 2073 Oct 0.034 2096 Oct 0.044 363067 2000 CO101 2028 Sep 0.061 2057 Sep 0.025 2096 Sep 0.031 363599 2004 FG11 2014 Apr 0.053 2016 Apr 0.050 2018 Apr 0.049 2020 Apr 0.049 2022 Apr 0.049 2024 Apr 0.052 2026 Apr 0.057 2028 Apr 0.064 2030 Apr 0.079 2032 Apr 0.098 2094 Apr 0.092 2096 Apr 0.052 374851 2006 VV2 2092 Mar 0.134 2129 Mar 0.166 2140 Apr 0.118 2177 Mar 0.032 385186 1994 AW1 2015 Jul 0.065 2022 Jul 0.112 2023 Jan 0.255 Weak CW 2058 Jul 0.065 2094 Jul 0.083 1994 CJ1 2065 Apr 0.094 2134 Jul 0.094 1994 XD 2023 Jun 0.021 2041 Jun 0.015 2000 UG11 2067 Nov 0.081 2067 Nov 0.087 2002 BM26 2069 Jan 0.094 2002 KK8 2054 Jun 0.074 2003 SS84 2020 Feb 0.100 2054 Oct 0.047 (2004 RZ164 2074 Dec 0.053 Possible binary; Kwiatkowski et al. 2007) 2005 AB NONE 2005 NB7 2046 Apr 0.029 2006 GY2 2044 May 0.029 2007 DT103 2089 Jul 0.066 2007 LE 2017 May 0.082 2008 BT18 2072 Feb 0.018 2008 DG17 2018 Feb 0.1002 2008 DG17 also makes close approaches within 0.15 AU of 15 Eunomia and 88 Thisbe 2013 WT44 2014 Mar 0.033 2031 Mar 0.067 2048 Mar 0.149 2133 Mar 0.020 2150 Mar 0.062 2167 Apr 0.106
Binary and Triple NEAs observed by radar: What can we estimate for each? Primary Spectral Object Orbit? Density? Shape? Class PI 1862 Apollo No No Maybe Q Benner 1866 Sisyphus No No No S Benner/Margot 5381 Sekhmet Maybe Maybe Maybe V Nolan 7888 1993 UC Maybe Maybe Maybe Brozovic 35107 1991 VH Yes Yes Yes S Margot In preparation 65803 Didymos Yes Yes Yes M Benner In preparation 66063 1998 RO1 Yes Yes Yes S Benner 66391 1999 KW4 Yes Yes Yes S Ostro/Benner PUBLISHED (2001 data) 69230 Hermes Yes Yes Yes S Margot In preparation 89538 1999 DJ4 Maybe Maybe Yes Q Benner In preparation 136617 1994 CC Yes Yes Yes ? Brozovic PUBLISHED 136993 1998 ST49 Maybe Maybe Yes Brozovic 138095 2000 DK79 Naidu 153591 2001 SN263 Yes Yes Yes P Nolan In preparation 153958 2002 AM31 Yes Yes Yes SqV Taylor In preparation 162000 1990 OS Yes Yes Yes ? Benner 164121 2003 YT1 Yes Yes Yes V Nolan 175706 1996 FG3 Yes Yes Yes C Benner 185851 2000 DP107 Yes Yes Yes X Margot PUBLISHED (2000 data); 2008 data in preparation 285263 1998 QE2 Yes Yes Yes C Springmann In preparation 311066 2004 DC Yes Yes Yes ? Taylor In preparation 363027 1998 ST27 Yes Yes:Not unique Yes C Benner In preparation 363067 2000 CO101 Not yet Not yet Yes Xk Benner In preparation 363599 2004 FG11 Maybe Maybe Yes Taylor? 374851 2006 VV2 Yes Yes Yes S Benner/Nolan/Black/Busch In preparation 1994 CJ1 No No No Springmann 1994 XD No No No ? Benner 2000 UG11 Yes Yes Yes S Nolan/Benner In preparation 2002 BM26 P Nolan 2002 CE26 Yes Yes Yes C Shepard PUBLISHED 2002 KK8 ? Nolan 2003 SS84 Maybe Maybe Yes ? Nolan/Benner 2005 AB No No No C Benner 2005 NB7 Maybe Maybe Maybe S Shepard 2006 GY2 Yes Yes Yes ? Nolan/Benner 2007 DT103 No No No S Benner 2007 LE Maybe Maybe Maybe Brozovic 2008 BT18 No No Yes E Benner 2008 DG17 No No No Taylor 2013 WT44 Maybe Maybe Maybe dark Benner PI Number L. A. M. Benner 15 M. Brozovic 3 J. L. Margot 3 M. C. Nolan 8 S. J. Ostro 1 M. K. Shepard 2 A. Springmann 2 P. A. Taylor 4 S. P. Naidu 1
Published peer-reviewed papers on radar observations: Margot, J. L., M. C. Nolan, L. A. M. Benner, S.J. Ostro, R. F. Jurgens, J. D. Giorgini, M. A. Slade, and D. B. Campbell. Binary asteroids in the near-Earth object population. Science 296, 1445-1448. (2002). Shepard, M. K., J. Schlieder, B. Estes, C. Magri, M. C. Nolan, J.-L. Margot, S. J. Bus, E. L. Volquardsen, A. Rivkin, L. A. M. Benner, J. D. Giorgini, S. J. Ostro, and M. W. Busch. Radar, optical, and thermal observations of the binary near-Earth asteroid 2002 CE26. Icarus 184, 198-210 (2006). Ostro, S. J., J.-L. Margot, L. A. M. Benner, J. D. Giorgini, D. J. Scheeres, E. G. Fahnestock, S. B. Broschart, J. Bellerose, M. C. Nolan, C. Magri, P. Pravec, P. Scheirich, R. Rose, R. F. Jurgens, E. M. de Jong, and S. Suzuki. Radar imaging of binary near-Earth asteroid (66391) 1999 KW4. Science 314, 1276-1280 (DOI: 10.1126/science.1133622) (2006). Scheeres, D. J., E. G. Fahnestock, S. J. Ostro, J. L. Margot, L. A. M. Benner, S. B Broschart, J. Bellerose, J. D. Giorgini, M. C. Nolan, C. Magri, P. Pravec, P. Scheirich, R. Rose, R. F. Jurgens, E. M. de Jong, and S. Suzuki. Dynamical configuration of binary near-Earth asteroid (66391) 1999 KW4. Science 314, 1280-1283 (2006) Brozovic, M., L. A. M. Benner, M. C. Nolan, E. S. Howell, P. A. Taylor, C. Magri,, D. J. Scheeres, J. D. Giorgini, J. T. Pollock, P. Pravec, A. Galad, M. W. Busch, J. L. Margot, M. K. Shepard, D. E. Reichart, K. M. Ivarsen, J. B. Haislip, A. P. LaCluyze, J. Jao, M. A. Slade, K. J. Lawrence, and M. D. Hicks. Radar observations and physical modeling of triple near-Earth asteroid (136617) 1994 CC. Icarus 216, 241-256. Reviews of radar observations of binaries: Ostro, S. J., R. S. Hudson, L. A. M. Benner, J. D. Giorgini, C. Magri, J. L. Margot, and M. C. Nolan. Asteroid radar astronomy. In Asteroids III (W. F. Bottke, A. Cellino, P. Paolicchi, and R. P. Binzel, Eds.), Univ. of Arizona Press, Tucson, pp. 151-168. (2002) Merline, W. J., S. J. Weidenschilling, D. D. Durda, J. L. Margot, P. Pravec, and A. D. Storrs. Asteroids do have satellites. In Asteroids III (W. F. Bottke, A. Cellino, P. Paolicchi, and R. P. Binzel, Eds.), Univ. of Arizona Press, Tucson, pp. 289-312. (2002)
NEA Binary and Ternary systems with at least one companion that rotates more rapidly than its orbital period: 7/40 = 17.5% 35107 1991 VH 136617 1994 CC Outer satellite only 153591 2001 SN263 Outer satellite only 162000 1990 OS 164121 2003 YT1 363027 1998 ST27 2004 DC
CANDIDATE CONTACT BINARY NEAR-EARTH ASTEROIDS OBSERVED BY RADAR Arranged in order of increasing rotation period to the extent that it's known Last update: 2014 July 9 Approximate Rotation Asteroid H diameter (km) Period (h) Radar reference 4769 Castalia 16.9 1.0 4.0 Ostro et al. 1990, Hudson and Ostro 1994 275677 2000 RS11 19.1 ~0.5 4.4 unpublished 242643 2005 NZ6 17.4 2.3 ~5 unpublished 388188 2006 DP14 18.9 ~0.3 5.8 unpublished 68346 2001 KZ66 16.7 1.0 ~6 unpublished 2005 CR37 18.9 1.0 6.5 Benner et al. 2006 137126 1999 CF9 18.0 <1 6.7 unpublished 2007 VD12 20.0 0.5 7.4 unpublished 2002 AY1 20.8 ~0.2 ~8 unpublished 11066 Sigurd 15.2 3.0 8.5 Busch et al., in prep. 8567 1996 HW1 15.3 2.0 8.8 unpublished 179806 2002 TD66 20.2 0.3 9.5 unpublished 348306 2005 AY28 21.5 ~0.2 6-10 unpublished 2013 JR28 21.6 ~0.1 >10 unpublished 2000 YF29 20.3 0.5 <12 unpublished 25143 Itokawa 19.2 0.33 12.1 Ostro et al. 2004, 2005 2002 HK12 18.1 0.6 12.7 unpublished 2063 Bacchus 17.2 0.6 15.1 Benner et al. 1999 192642 1999 RD32 16.3 ~5 17.1 unpublished 152664 1998 FW4 19.7 ~0.3 ~18 unpublished 2002 NY40 19.0 ~0.4 20.0 unpublished 2014 HQ124 18.9 ~0.4 ~20 unpublished 398188 2010 LE15 19.5 0.44 ~20 unpublished Diameter from Mainzer et al. 2011 2003 UV11 19.5 ~0.4 ~24? Busch et al., submitted 2004 XL14 21.2 0.4 ~24 unpublished 2012 QG42 20.9 ~0.2 ~24 unpublished 52387 1993 OM7 17.8 1.0 >26 unpublished 2008 SV11 18.4 0.8 32.4 unpublished 2007 TU24 20.3 0.3 ~1-2 days unpublished 4450 Pan 17.1 1.0 2-3 days unpublished 144411 2003 EW9 16.6 1.1 49.9 unpublished 4486 Mithra 15.6 1.6 67.5 Brozovic et al. 2010 4179 Toutatis 15.3 2.4 5.4, 7.4 d Hudson et al. 1995, 2003 2002 FC 18.9 0.7 days unpublished 2004 RF84 18.4 2.4 weeks unpublished Fastest rotator: Castalia Slowest rotator: possibly 2004 RF84. The bandwidth is so narrow that it's hard to tell. Largest: 1999 RD32 ~5 km Smallest: 2013 JR28 ~0.1 km Toutatis and Itokawa are now included although they not considered contact binaries as defined in Benner et al. 2006. With the relaxed definition of a "contact binary," there could be other objects observed by radar that aren't on this list yet.

Lance Benner