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7645 Pons (1989 AC2)
Classification: Main-belt Asteroid          SPK-ID: 2007645
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.

Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 33 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1599957524967043 2.5598e-08  
a 2.372108873581374 6.6774e-09 au
q 1.992581529348612 6.169e-08 au
i .3921364885735031 2.92e-06 deg
node 247.9073649200348 0.00049884 deg
peri 214.217620036324 0.000499 deg
M 270.9572680799337 1.3732e-05 deg
tp 2459530.562609882424
5.1758e-05 TDB
period 1334.44400228353
n .2697752767324519 1.1391e-09 deg/d
Q 2.751636217814135 7.7458e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2139  
   data-arc span      11703 days (32.04 yr)  
   first obs. used      1989-01-04  
   last obs. used      2021-01-19  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .46621  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 01:38:30  

Additional Information
 Earth MOID = 1.00931 au 
 Jupiter MOID = 2.38704 au 
 T_jup = 3.527 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 14.33   n/a E2021B10  
diameter diameter 4.051 km 0.069 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
rotation period rot_per 35.390 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so.
Published Reference List:
[Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.]
geometric albedo albedo 0.187   0.033 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  

7645 Pons           Discovered 1989 Jan. 4 by A. Mrkos at Klet.
Named in memory of Jean-Louis Pons (1761-1831), whose name appears on 26 different comets and who claimed to discover as many as 37. Initially hired as the doorkeeper of the Marseilles Observatory, he soon showed his proficiency for both constructing and using telescopes, and at the end of his career he was directing observatories in Tuscany. He discovered comet 2P/Encke in both 1805 and 1818, and although it is named for the person who recognized this and other apparitions of it as being one and the same body, Encke himself always referred to it as "Pons' comet". Name suggested by J. Ticha, citation prepared by B. G. Marsden.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 19980411/MPCPages.arcLast Updated: 2009-11-17

[ show close-approach data ]
Alternate Designations
 1989 AC2 = 1991 RO18 
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