Binary Near-Earth Asteroids

This is a list of characteristics of binary near-Earth asteroids derived from their lightcurve and/or radar observations. The listed values are the best published estimates of the system's parameters as well as unpublished results included with permission of the authors. The list is ordered according to a time of the first official publication of the binary detection, usually in IAU Circulars (even if the first publication may not be mentioned when a more detailed analysis have been published in a later paper.)
This list is created with a primary intention to give an overview of the binary NEAs parameters and to summarize data for statistical analyses of the binary NEA population.

Last updated: 2005 November 7

Object dp
[km]
ds/dp a/dp e Porb
[h]
Pprim
[h]
Aprim
[mag]
Taxon.
Class
Orb.
Type
Observations Further
Apparitions
(until 2010)
References
1994 AW1 1.0 0.49 2.3 <0.05 22.3 2.5193 0.12 L PHA Lc (1994 Jan-Feb) [1]
(35107) 1991 VH 1.2 0.37 2.7 <0.08 32.63 2.6236 0.08 Sk PHA Lc (1997 Feb-Apr)
Lc (2003 Feb)
2008 Aug (D=0.05 AU) [1]
(3671) Dionysus 1.5 0.2 2.5 0.05 27.74 2.7053 0.13 Cb PHA Lc (1997 Apr-Jun) [1]
1996 FG3 1.5 0.31 1.7 0.02 16.15 3.5942 0.08 C PHA, VC Lc (1996 Apr)
Lc (1998 Dec)
2009 Apr-May (V=16,
  D=0.16 AU)
[1]
(5407) 1992 AX 3.9 (0.2) (1.7) (<0.05) (13.520) (2.5488) 0.10 Sk MC Lc (1997 Jan-Feb) 2005 Sep (V=16.5)
2007 Feb (V=15.5)
[1]
(31345) 1998 PG 0.9 (0.3) (1.7) (2.5162) 0.11 Sq Amor Lc (1998 Aug-Oct) [1]
1999 HF1 3.5 0.23 2.0 14.03 2.3192 0.20 X Aten, VC Lc (1999 Apr-May)
Lc (2002 Mar-May)
2005 Apr (V=15)
2008 Apr (V=15.5)
[1], [2]
2000 DP107 0.8R 0.41 ~3.3 0.01 42.2 2.7754 0.18 MP PHA Ra, Lc (2000 Sep-Oct) 2008 Sep (V=15,
  D=0.06 AU)
[1]
2000 UG11 0.23R ≥0.58, 0.4R ~1.8 ~0.12 18.4 (4.44) 0.10 QR PHA Ra, Lc (2000 Oct-Nov) 2008 Nov (V=13,
  D=0.01 AU)
[1]
(66391) 1999 KW4 1.2R 0.35, <0.4R ~2.1 ≤0.03 17.44 2.7650 0.12 S PHA, VC Lc (2000 Jun)
Ra, Lc (2001 Jun)
[1]
1998 ST27 0.8R ~0.13R (~5) (~100) <~3.1 low C PHA, VC Ra (2001 Oct) [3], [4]
(88710) 2001 SL9 0.8 0.28 ~1.8 16.40 2.4004 0.08 Apollo Lc (2001 Oct) [1]
2002 BM26 0.6R ~0.2R (<~5) <~72 ~2.7 PHA Ra (2002 Feb) 2007 Jan (D=0.18 AU) [5]
2002 KK8 0.5R ~0.2R PHA Ra (2002 Jun) [6]
(5381) Sekhmet 1.0R 0.3R ~1.5 (12) (~3) ~0.1 Aten, VC Ra (2003 May) [7], [8]
(66063) 1998 RO1 0.80R 0.48 (1.7) 14.55 2.4925 0.14 Aten, VC Lc (2002 Sep)
Lc, Ra (2003 Sep)
Lc (2004 Sep)
2005 Sep (V=16,
  D=0.11 AU)
2006 Sep (V=17,
  D=0.17 AU)
[1]
2003 SS84 0.12R 0.5R (24) PHA Ra (2003 Oct) [9]
(69230) Hermes 0.6R 0.9R (13.894) (0.06) PHA, VC Ra, Lc (2003 Oct) [1]
1990 OS 0.3R 0.15R 21 hours PHA Ra (2003 Nov) [10]
(65803) Didymos 0.75R 0.22 (1.5) 0.04 11.91 2.2593 0.08 Xk PHA Lc, Ra (2003 Nov-Dec) [1]
(85938) 1999 DJ4 0.35R 0.5, 0.48R (2.0) 17.73 2.5141 0.11 Sq PHA Lc (2004 Feb-Mar)
Ra (2004 Apr)
2009 Jun (D=0.18 AU) [1]
2003 YT1 1.0R 0.18R (2.7) 30R 2.343 0.16 V PHA Ra, Lc (2004 Apr-May) 2009 Oct (V=14.5,
  D=0.12 AU)
[1]
2002 CE26 3.0R ~0.07R ~1.7 ~16R 3.2930 0.06 Apollo Ra, Lc (2004 Aug) [1]
2005 AB 1.0 0.24 ~1.9 17.92 3.3376 0.05 Amor Lc, Ra (2005 Feb) [11], [12], [13]
1994 XD 0.6 ≥0.25 ≥~2 PHA Ra (2005 Jun) [14]
(1862) Apollo 1.2 0.07R >1.3R Q PHA Ra (2005 Nov) [15]
Object dp
[km]
ds/dp a/dp e Porb
[h]
Pprim
[h]
Aprim
[mag]
Taxon.
Class
Orb.
Type
Observations Further
Apparitions
(until 2010)
References

Explanation of symbols:

dpDiameter of the primary
ds/dpSecondary-to-primary mean diameter ratio
a/dpMutual orbit semimajor axis to primary diameter ratio
eExcentricity of the mutual orbit
PorbSystem's orbital period
PprimPrimary's rotational period
AprimAmplitude of the primary's lightcurve, containing the mean light from the secondary
Orb. Type:PHA - Potentially Hazardous Asteroid (approaching to 0.05 AU or less to the Earth orbit)
VC - Venus-crosser
MC - Mars-crosser
ObservationsLc - Lightcurve; showing two additive components of different periods, the longer-period one usually shows occultation/eclipse events
Ra - radar
Further Apparitions Listed are apparitions until 2010 in which the asteroid reaches V=17 or less or approaches to the Earth to 0.2 AU or less, providing a favorable opportunity for lightcurve or radar observations, respectively.
RRadar-derived value

Uncertainties of the estimated values:

dpErrors are usually within a few tens percent, and almost certainly within a factor of 2 for all objects.
ds/dpErrors are within a few tens percent unless an unequality sign is given.
a/dpErrors are mostly within a few tens percent. Values in brackets are somewhat more uncertain; see the references.
eErrors are in the last digit (i.e., on the order of a few times 0.01).
PorbErrors are in the last digit (i.e., on the order of a few times 0.01 h in most cases). Uncertainties of the synodic-sidereal differences are a few 0.01 h to a few 0.1 h. For the values in brackets, there is a possible ambiguity; see the references.
PprimErrors are in the last digit (i.e., on the order of several times 0.0001 h in most cases). An uncertainty of the synodic-sidereal difference is on the order of 0.001 h in most cases. The value in the bracket is ambiguous - a half of the value is also possible.
AprimErrors are 0.01-0.02 mag.

References:

[1] Pravec et al. 2005, Icarus, In press.
[2] Pravec, P., L. Sarounova, M. D. Hicks, D. L. Rabinovitz, M. Wolf, P. Scheirich, and Yu. N. Krugly 2002. Two periods of 1999 HF1 - Another binary NEA candidate. Icarus, 158, 276-280
[3] Benner, L. A. M., M. C. Nolan, S. J. Ostro, J. D. Giorgini, and J.-L. Margot 2001. 1998 ST27. IAU Circ. 7730
[4] Abell, P., M. Gaffey, and P. Hardersen 2002. Spectral Rotational Variation and Meteorite Affinities of the Potentially Hazardous Asteroid 1998 ST27. In Asteroids, Comets, Meteors 2002 Conference Abstracts, p. 160
[5] Nolan, M. C., E. S. Howell, C. Magri, B. Beeney, D. B. Campbell, L. A. M. Benner, S. J. Ostro, J. D. Giorgini, and J.-L. Margot 2002. 2002 BM26. IAU Circ. 7824
[6] Nolan, M. C., E. S. Howell, S. J. Ostro, L. A. M. Benner, J. D. Giorgini, J.-L. Margot, and D. B. Campbell 2002. 2002 KK8. IAU Circ. 7921
[7] Nolan, M. C., E. S. Howell, A. S. Rivkin, and C. D. Neish 2003. (5381) Sekhmet. IAU Circ. 8163
[8] P. Pravec et al. 2003. Communication in MPML.
[9] Nolan, M. C., A. A. Hine, E. S. Howell, L. A. M. Benner, and J. D. Giorgini 2003. 2003 SS84. IAU Circ. 8220
[10] Ostro, S. J., M. C. Nolan, L. A. M. Benner, J. D. Giorgini, J. L. Margot, and C. Magri 2003. 1990 OS. IAU Circ. 8237
[11] Reddy, V., R. Dyvig, P. Pravec and P. Kusnir´┐Żk 2005. 2005 AB IAU Circ. 8483
[12] Pravec et al. 2005, in preparation.
[13] Benner, L. A. M. 2005. Communication in MPML. See here.
[14] Benner, L. A. M., Nolan, M. C., Ostro, S. J., Giorgini, J. D., Margot, J. L., Magri, C. 2005. 1994 XD IAU Circ. 8563
[15] Ostro, S. J., Benner, L. A. M., Giorgini, J. D., Nolan, M. C. , Hine, A. A., Howell, E. S., Margot, J. L., Magri, C.,Shepard, M. K. 2005 (1862) APOLLO IAU Circ. 8627

This page is maintained by Petr Pravec and Peter Scheirich, Ondrejov Observatory. Comments can be mailed to ppravec@asu.cas.cz.


Link to the Ondrejov NEO program page.