2009 HC82

2009 HC82
Discovery[1]
Discovered by A. Boattini,
E. C. Beshore,
G. J. Garradd,
A. D. Grauer,
R. E. Hill,
R. A. Kowalski,
S. M. Larson,
R. H. McNaught
Catalina Sky Survey (703)
Discovery date 2009-04-29
Designations
MPC designation 2009 HC82
Minor planet
category		 PHA[1]
Apollo[2]
Retrograde orbit
Epoch 2010-Jul-23 (JD 2455400.5)
T_jup = 1.315
Aphelion 4.568 AU (Q)
Perihelion 0.4874 AU (q)
Semi-major axis 2.528 AU (a)
Eccentricity 0.8071
Orbital period 4.02 yr
Mean anomaly 153.72° (M)
Inclination 154.51°
Longitude of ascending node 294.85°
Argument of perihelion 298.42°
Physical characteristics
Dimensions 1.6-3.6 km[2][3]
Apparent magnitude ~20[1]
Absolute magnitude (H) 16.1[2]

2009 HC82, also written as 2009 HC82, was initially listed as a potentially hazardous object.[1] It has a retrograde orbit and makes many close approaches to Earth, Venus, and Mars at a very high relative velocity.

Velocity

2009 HC82 has a retrograde orbit and thus orbits the Sun in the opposite direction of other objects. So close-approaches to this object can have very high relative velocities. As of 2011, this Near-Earth object has the highest relative velocity to the Earth of objects that come within 0.5 AU of the Earth.[4] On 11 November 2024, 2009 HC82 will pass about 0.485 AU (72,600,000 km; 45,100,000 mi) from the Earth, but with a record high relative velocity of about 282,900 km/hr (78.58 km/s).[5] Both Halley's Comet (254,000 km/hr)[6] and 55P/Tempel-Tuttle (252,800 km/hr)[7] have slightly lower relative velocities to the Earth.

On 2 February 2053, 2009 HC82 will pass about 0.08 AU from Venus.[5] On 22 October 2060, it may pass about 0.004 AU (600,000 km; 370,000 mi) from Mars.[5]

The multiple planet crossing and retrograde orbit suggests that this object may be an extinct comet or damocloid asteroid similar to 5335 Damocles, 2008 KV42, and 20461 Dioretsa.[8]

Since the true albedo is unknown and it has an absolute magnitude (H) of 16.1,[2] it is about 1.6 to 3.6 km in diameter.[3]

References

  1. ^ a b c d "MPEC 2009-J04 : 2009 HC82". IAU Minor Planet Center. 2009-05-01. http://www.minorplanetcenter.org/mpec/K09/K09J04.html. Retrieved 2011-02-08. 
  2. ^ a b c d e "JPL Small-Body Database Browser: (2009 HC82)". 2010-04-04 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009HC82. Retrieved 2011-02-08. 
  3. ^ a b "Absolute Magnitude (H)". NASA/JPL. http://neo.jpl.nasa.gov/glossary/h.html. Retrieved 2009-12-06. 
  4. ^ "NEO Close-Approaches (Between 1900 and 2200)". NASA/JPL Near-Earth Object Program. http://neo.jpl.nasa.gov/cgi-bin/neo_ca. Retrieved 2011-02-09.  (sorted by descending relative velocity, dist<0.5AU = "186,491 close-Earth approaches")
  5. ^ a b c "JPL Close-Approach Data: (2009 HC82)". 2010-04-04 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009HC82;cad=1#cad. Retrieved 2011-02-09. 
  6. ^ "JPL Close-Approach Data: 1P/Halley". 1994-01-11 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=1P;cad=1#cad. Retrieved 2011-02-09. 
  7. ^ "JPL Close-Approach Data: 55P/Tempel-Tuttle". 1998-07-05 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=55P;cad=1#cad. Retrieved 2011-02-09. 
  8. ^ Akimasa Nakamura and bas (2009-05-02). "List of Damocloids (Oort cloud asteroids)". Lowell Observatory. ftp://ftp.lowell.edu/pub/bas/damocloid. Retrieved 2011-02-09. 

External links