(357439) 2004 BL86

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(357439) 2004 BL86
Radar images of 2004 BL86 and its moon.gif
Goldstone radar image of (357439) 2004 BL86 and its satellite S/2015 (357439) 1
Discovery[1]
Discovered by LINEAR (704)
Discovery date 30 January 2004
Designations
MPC designation (357439) 2004 BL86
Apollo NEO,
PHA[2]
Orbital characteristics[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0[2]
Observation arc 4084 days (11.18 yr)
Aphelion 2.1069 AU (315.19 Gm)
Perihelion 0.89754 AU (134.270 Gm)
1.50223 AU (224.730 Gm)
Eccentricity 0.40252
1.84 yr (672.52 d)
208.11194°
0° 32m 7.094s / day
Inclination 23.77604°
126.70921°
311.44162°
Known satellites 1[3]
Earth MOID 0.00810452 AU (1,212,419 km)
Jupiter MOID 3.24294 AU (485.137 Gm)
Jupiter Tisserand parameter 4.364
Physical characteristics
Dimensions 325 m (1,066 ft)[3]
2.6205 h (0.10919 d)
V-type asteroid[4]
19.3[2]

(357439) 2004 BL86,[5] provisionally known as 2004 BL86, is a near-Earth asteroid estimated to be about 325 meters (1,066 feet) in diameter.[3] It was discovered on 30 January 2004 by LINEAR.[1] It passed 1,199,600 km (745,400 mi), or 3.1 lunar distances, from Earth on 26 January 2015 at 16:20 UTC.[5][6] During the 2015 approach it was determined to have a satellite.

2015 Earth approach[edit]

On 26–27 January 2015, the asteroid briefly peaked around apparent magnitude 9 and was near the celestial equator.[7] 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.[8] Near closest approach the asteroid was moving about 2.5 degrees per hour (2.5 arcseconds per second).[7][9] The asteroid came to opposition (furthest elongation in the sky from the Sun) on 27 January 2015 at 04:37 UTC.[7] Around 5:00 UTC, the asteroid was near M44 (the Beehive Cluster).[9]

26 January 2015 approach of 3.1 lunar distances was the closest approach of 2004 BL86 for at least the next 200 years.[5][6][10] 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.[11]

Satellite[edit]

A satellite was first detected by ground-based telescopes by Joe Pollock and Petr Pravec.[12] 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 (230 feet) across.[3] The secondary is estimated to orbit at least 500 metres (1,600 ft) from the primary.[13] About 16% of asteroids over 200 metres (660 ft) in diameter are thought to be binaries.[3]

Gallery[edit]

References[edit]

  1. ^ a b "MPEC 2004-B80 : 2004 BL86". IAU Minor Planet Center. 31 January 2004. Retrieved 7 June 2014.  (K04B86L)
  2. ^ a b c d "JPL Small-Body Database Browser: 357439 (2004 BL86)" (last observation: 20 December 2014; arc: 10.89 years). NASA/Jet Propulsion Laboratory. Retrieved 8 April 2016. 
  3. ^ a b c d e Agle, D. C. (26 January 2015). "Asteroid That Flew Past Earth Today Has Moon". NASA. Retrieved 26 January 2015. 
  4. ^ "PSI Scientists Study Surface Composition of Asteroid 2004 BL86 During Close Flyby of Earth". Planetary Science Institute. 27 January 2015. Retrieved 28 January 2015. 
  5. ^ a b c Agle, D. C.; Brown, Dwayne (13 January 2015). "Asteroid to Fly By Earth Safely on January 26 [2015]". NASA. Retrieved 13 January 2015. 
  6. ^ a b "JPL Close-Approach Data: 357439 (2004 BL86)" (last observation: 12 March 2013; arc: 9.11 years). NASA/Jet Propulsion Laboratory. Retrieved 7 June 2014. 
  7. ^ a b c "(357439) 2004BL86 Ephemerides for 25 January 2015 through 29 January 2015". NEODyS. Retrieved 7 June 2014. 
  8. ^ Musgrave, Ian (23 January 2015). "Seeing the Close Flyby of NEO 2004 BL86 26 - 27 January, 2015". Retrieved 28 January 2015. 
  9. ^ a b MacRobert, Alan (22 January 2015). "Mountain-size Asteroid Glides Past Earth". Sky & Telescope. Retrieved 23 January 2015. 
  10. ^ Busch, Michael (7 February 2015). "Final post-flyby update...". Twitter.com. Retrieved 7 February 2015. 
  11. ^ "JPL Close-Approach Data: 2015 TB145" (last observation: 1 November 2015; arc: 22 days). NASA/Jet Propulsion Laboratory. Retrieved 2 December 2015. 
  12. ^ "Image Release: High-Def Radar Images of Near-Earth Asteroid". National Radio Astronomy Observatory. 30 January 2015. Retrieved 30 January 2015. 
  13. ^ Busch, Michael (28 January 2015). "Will require combined analysis...". Twitter.com. Retrieved 7 February 2015. 

External links[edit]