(357439) 2004 BL86
Near-Earth asteroid discovered in 2004
From Wikipedia, the free encyclopedia
(357439) 2004 BL86 is a bright sub-kilometer asteroid and binary system, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters (980 ft) in diameter. It was discovered on 30 January 2004 by astronomers of the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico.[3] Its 70-meter (200 ft) moon was discovered during the asteroid's close approach to the Earth in January 2015.[4][5]
| |
| Discovery[1][2] | |
|---|---|
| Discovered by | LINEAR |
| Discovery site | Lincoln Lab's ETS |
| Discovery date | 30 January 2004 |
| Designations | |
| (357439) 2004 BL86 | |
| NEO · PHA · Apollo[1][3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 4,863 d (13.31 yr) |
| Aphelion | 2.1070 AU |
| Perihelion | 0.8974 AU |
| 1.5022 AU | |
| Eccentricity | 0.4026 |
| 673 d (1.84 yr) | |
| 169.27° | |
| 0° 32m 7.08s / day | |
| Inclination | 23.775° |
| 126.69° | |
| 311.45° | |
| Known satellites | 1[4][5] |
| Earth MOID | 0.0092 AU (3.6 LD) |
| Physical characteristics | |
| 0.263±0.026 km[6] 0.290±0.030 km[7] 0.325±0.025 km[5][a] | |
| 2.620±0.001 h[6] 2.6205±0.0003 h[8] 2.637±0.024 h[7] | |
| 0.40[7] 0.40±0.08[6] | |
| V[7][9][10] | |
| 19.05[9] 19.3[1][7] 19.51±0.02[6] | |
2015 Earth approach
On 26 January 2015 at 16:20 UTC, 2004 BL86 passed 1,199,600 km (745,400 mi), or 3.1 lunar distances, from Earth.[11] The asteroid briefly peaked around apparent magnitude 9 and was near the celestial equator.[12] The asteroid was visible in telescopes with objectives of 100 mm (4 in) or larger; high-end binoculars under a dark sky may also have worked.[13] Near closest approach the asteroid was moving about 2.5 degrees per hour (2.5 arcseconds per second).[12][14] The asteroid came to opposition (furthest elongation in the sky from the Sun) on 27 January 2015 at 04:37 UTC.[12] Around 5:00 UTC, the asteroid was near M44 (the Beehive Cluster).[14]
The 26 January 2015 approach of 3.1 lunar distances was the closest approach of 2004 BL86 for at least the next 200 years.[11][15] For comparison, 2015 TB145, about twice the size of 2004 BL86, passed 486,800 km (302,500 mi), or 1.3 lunar distances, from Earth on 31 October 2015.[16]
Satellite
A minor-planet moon orbiting (357439) 2004 BL86 was first detected by ground-based telescopes by Joe Pollock and Petr Pravec.[8][17] Observations by the Goldstone Deep Space Communications Complex and Green Bank Telescope confirmed that it is a binary asteroid with a secondary roughly 70 meters (200 ft) across.[5] The secondary is estimated to orbit at least 500 meters (1,600 ft) from the primary.[4] About 16% of asteroids over 200 meters (660 ft) in diameter are thought to be binaries.[5]
Numbering and naming
This minor planet was numbered on 27 March 2013 (M.P.C. 83151).[18] As of 2020, it has not been named.[3]
Gallery
Animation of 2004 BL86's orbit
Sun · Earth · 2004 BL86
2004 BL86 safely passes Earth on 26 January 2015
Trajectory of 2004 BL86 during Earth close approach
Another gif of 2004 BL86 and its moon.
