* Astronomy

Blobrana · L

RE: Asteroid 2013 ND15

Blobrana · L

Asteroid 2013 ND15 - a Venus Trojan - makes its closest approach to Earth today (0.5 AU). pic.twitter.com/HnSqT7RxKn
Ron Baalke (@RonBaalke) July 28, 2015

Blobrana · L

Asteroid 2013 ND15 makes its closest approach to the Earth (0.699 AU) on the 1st February 2015.

Ephemeris

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase     Mag
2015 01 31    20 49 35.9 -16 34 29   0.7005  0.2851     1.2   175.9
2015 02 01    20 41 44.4 -16 50 30   0.6992  0.2905     3.5   168.1
2015 02 02    20 34 06.6 -17 05 53   0.7018  0.2977     6.2   158.9    31.3
2015 02 03    20 26 56.8 -17 20 07   0.7079  0.3067     8.9   150.0    29.2
2015 02 04    20 20 25.6 -17 32 53   0.7169  0.3172    11.5   141.7    28.0
2015 02 05    20 14 39.5 -17 44 03   0.7285  0.3290    13.9   134.0    27.1
2015 02 06    20 09 41.0 -17 53 38   0.7421  0.3418    16.1   126.9    26.5
2015 02 07    20 05 30.3 -18 01 43   0.7571  0.3554    18.1   120.5    26.1
2015 02 08    20 02 05.2 -18 08 26   0.7733  0.3697    19.9   114.6    25.8
2015 02 09    19 59 22.5 -18 13 57   0.7902  0.3844    21.6   109.3    25.6
2015 02 10    19 57 18.3 -18 18 23   0.8075  0.3996    23.1   104.5    25.5
2015 02 11    19 55 48.5 -18 21 52   0.8251  0.4149    24.4   100.2    25.4
2015 02 12    19 54 49.2 -18 24 32   0.8428  0.4304    25.7    96.2    25.3
2015 02 13    19 54 16.8 -18 26 27   0.8604  0.4461    26.8    92.6    25.3
2015 02 14    19 54 07.8 -18 27 42   0.8777  0.4617    27.9    89.4    25.3
2015 02 15    19 54 19.2 -18 28 22   0.8948  0.4773    28.8    86.4    25.3
2015 02 16    19 54 48.4 -18 28 30   0.9115  0.4928    29.7    83.7    25.3
2015 02 17    19 55 33.0 -18 28 08   0.9279  0.5083    30.6    81.3    25.3
2015 02 18    19 56 31.0 -18 27 20   0.9438  0.5236    31.3    79.0    25.3
2015 02 19    19 57 40.5 -18 26 06   0.9593  0.5387    32.1    76.9    25.4
2015 02 20    19 59 00.2 -18 24 29   0.9743  0.5538    32.8    75.0    25.4
2015 02 21    20 00 28.6 -18 22 30   0.9888  0.5686    33.4    73.3    25.4
2015 02 22    20 02 04.5 -18 20 12   1.0029  0.5832    34.0    71.7    25.4
2015 02 23    20 03 47.0 -18 17 34   1.0165  0.5977    34.6    70.2    25.5
2015 02 24    20 05 35.3 -18 14 38   1.0296  0.6119    35.2    68.8    25.5
2015 02 25    20 07 28.5 -18 11 24   1.0422  0.6260    35.8    67.5    25.6
2015 02 26    20 09 25.9 -18 07 55   1.0544  0.6398    36.3    66.4    25.6
2015 02 27    20 11 27.2 -18 04 10   1.0661  0.6535    36.8    65.3    25.6
2015 02 28    20 13 31.6 -18 00 10   1.0774  0.6669    37.3    64.2    25.7

Blobrana · L

Title: Asteroid 2013 ND15: Trojan companion to Venus, PHA to the Earth
Authors: C. de la Fuente Marcos, R. de la Fuente Marcos

Version 2

Venus has three known co-orbitals: (322756) 2001 CK32, 2002 VE68 and 2012 XE133. The first two have absolute magnitudes 18 < H < 21. The third one, significantly smaller at H = 23.4 mag, is a recent discovery that signals the probable presence of many other similar objects: small transient companions to Venus that are also potentially hazardous asteroids (PHAs). Here, we study the dynamical evolution of the recently discovered asteroid 2013 ND15. At H = 24.1 mag, this minor body is yet another small Venus co-orbital and PHA, currently close to the Lagrangian point L4 and following the most eccentric path found so far for objects in this group. Due to its high eccentricity (0.6), its dynamics is different from that of the other three known Venus co-orbitals even if they all are near-Earth objects (NEOs). A Monte Carlo simulation that uses the orbital data and discovery circumstances of the four objects as proxies to estimate the current size of this population, indicates that the number of high-eccentricity, low-inclination Venus co-orbital NEOs may have been greatly underestimated by current models. Three out of four known objects were discovered with solar elongation at perigee greater than 135 degrees even if visibility estimates show that less than 4 per cent of these objects are expected to reach perigee at such large elongations. Nearly 70 per cent of the objects discussed here have elongation at perigee < 90 degrees and 65 per cent are prospective PHAs.