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21479 Marymartha (1998 HN124)
Classification: Main-belt Asteroid          SPK-ID: 2021479
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

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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 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 40 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2003609379284762 2.5641e-08  
a 2.174904384766881 6.4093e-09 au
q 1.739138502330233 5.6792e-08 au
i 4.830959042858849 3.0364e-06 deg
node 142.3657322747552 4.4366e-05 deg
peri 166.0662979353491 4.5958e-05 deg
M 18.74025618982082 1.4364e-05 deg
tp 2459335.513781837969
4.6601e-05 TDB
period 1171.544204942964
n .307286740424384 1.3583e-09 deg/d
Q 2.610670267203529 7.6935e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2259  
   data-arc span      16419 days (44.95 yr)  
   first obs. used      1976-08-26  
   last obs. used      2021-08-09  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .45038  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-24 22:42:49  

Additional Information
 Earth MOID = .72444 au 
 Jupiter MOID = 2.64782 au 
 T_jup = 3.655 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 14.32   n/a E2020-QM5  
diameter diameter 3.660 km 0.266 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
rotation period rot_per 5.3183 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:
[Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.]
geometric albedo albedo 0.331   0.032 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  

21479 Marymartha           Discovered 1998 Apr. 23 by the Lincoln Laboratory Near-Earth Asteroid Research Team at Socorro.
Mary Martha Ferrari Douglas (b. 1988) was awarded first place and Best in Category in the 2006 Intel International Science and Engineering Fair for her behavioral and social sciences team project. She received the EU Contest for Young Scientists Award. She attends the Manhasset High School, Manhasset, New York, U.S.A.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20060711/MPCPages.arcLast Updated: 2006-07-17

Alternate Designations
 1998 HN124 = 1976 QS1 = 1991 ER5 = 2000 AP74 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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