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Arecibo and Goldstone Radar Imaging of Contact Binary
Near-Earth Asteroids
L. A. M. Benner, M. C. Nolan, J. L. Margot,
S. J. Ostro, M. K. Shepard, C. Magri,
J. D. Giorgini, and M. W. Busch
Outline
1. Overview of NEAs detected by radar
2. Updated binary NEA statistics
3. 2005 NB7
4. (1139) Atami
5. Smorgasbord of contact binaries
6. Upcoming NEA radar targets
7. Historical note
NEAs Detected by Radar
Binary NEAs: Statistics for Radar TargetsOVERALLDiscovered by radar: 21/33 = 64%Detected by radar 25/33 = 76%
Discovered at Arecibo: 17/33 = 52% (Includes Sisyphus)
Discovered at Goldstone: 4/33 = 12%
Since completion of the upgrade at Arecibo in 1999:Discovered by radar: 20/25 = 80%Detected by radar: 23/25 = 92%Abundance among radar targets: 17%
Arecibo has become the primary technique for discovery and characterization of binary NEAs.
Binary NEAs Detected by Radar
2000 DP107 2000
2000 UG11 2000
1999 KW4 2001, 2002
1998 ST272001, 2004
2002 BM26 2002
2002 KK8 2002
Sekhmet 2003
1998 RO1 2003, 2004
2003 SS84 2003
Hermes 2003
1990 OS 2003 (1990)
Didymos 20031999 DJ4 20042003 YT1 20042002 CE26 20042005 AB 20051994 XD 2005Apollo 2005 (1980)2006 GY2 20062004 DC 20062006 VV2 20072007 DT103 20072001 SN263 20082005 NB7 2008
Sisyphus 1985
2005 NB7
(1139) Atami
Contact Binary Candidates Detected by Radar
2201 Oljato (?) 1983 Jun4769 Castalia 1989 Aug2064 Bacchus 1996 Mar4486 Mithra 2000 Jul-Aug
2000 YF29 2001 Jan2002 FC 2002 Jun2002 NY40 2002 Aug
141593 2002 HK12 2002 Aug52387 1993 OM7 2003 Jan68346 2001 KZ66 2003 Oct11066 Sigurd 2004 Sep
2005 CR37 2005 Feb2004 RF84 2005 Feb2004 XL14 2006 Dec2007 VD12 2007 Nov2007 TU24 2008 Jan-Feb2002 TD66 2008 Feb
4450 Pan 2008 Feb
Not included:3908 Nyx4179 Toutatis25143 Itokawa
Abundance: ~11%among NEAs > 200 min diameter
What can we estimate for each?
Object Shape? ClassOljato No SCastalia AvailableBacchus Available QMithra Maybe 2000 YF29 No S2002 FC No 2002 NY40 Maybe S2002 HK12 Maybe X1993 OM7 No 2001 KZ66 Yes SSigurd Yes S2005 CR37 No C?2004 RF84 No 2004 XL14 Not yet C Returns in December2007 VD12 No S2007 TU24 No S2002 TD66 No SPan No S
(2201) Oljato
(4769) Castalia
(2063) Bacchus
(4486) Mithra
2000 YF29
2000 YF29
2002 FC
2002 NY40Arecibo, Aug. 2002
(141593) 2002 HK12Arecibo, Aug. 2002
Aug. 25Aug. 23
(52387) 1993 OM7Arecibo-Green Bank
2003 Jan 13 2003 Jan 14
(68346) 2001 KZ66Arecibo, Oct. 2003
(11066) Sigurd
(11066) Sigurd
(11066) Sigurd
(3908) Nyx
2005 CR37
2005 CR37
2004 RF84
2004 XL14
2007 VD12
2007 TU24
2007 TU24
(4450) PanArecibo, Feb. 2008
Feb. 13
Feb. 12 Feb. 14
Upcoming Radar Opportunities:55319 1999 JM8 May-June A
2008 BT18 July A, G90403 2003 YE45 July A, G
2005 RC34 July A, G35107 1991 VH August A, G
2000 DP107 September A, G8567 1996 HW1 September A137032 1998 UO1 September A164400 2005 GN59 October A, G85774 1998 UT18 November A
2004 XL14 December A2008 EV5 December A, G2004 LV3 December A
136849 1998 CS1 January A, G
NEA Radar Detection History
40th anniversary of the 1st asteroid radar detection is inJune: 1566 Icarus by Dick Goldstein at Goldstone
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