Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Center for Near-Earth Object Studies
JPL Home Earth Solar System Stars & Galaxies Technology
JPL Solar System Dynamics
BODIES ORBITS EPHEMERIDES TOOLS PHYSICAL DATA DISCOVERY FAQ SITE MAP
IMPORTANT: The SSD Announcement email list is now available. Major changes are coming in the near future, including possible hostname and/or URL changes. To be notified of such changes, subscribe to this email list.

Please visit this page for more details.


JPL Small-Body Database Browser
Search: [ help ]  
20428 (1998 WG20)
Classification: Jupiter Trojan          SPK-ID: 2020428
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 22 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1462393671806889 8.0631e-08  
a 5.211465764584315 1.3178e-07 au
q 4.44934430908768 4.5664e-07 au
i 21.03499374795193 8.0435e-06 deg
node 45.39833801021434 1.5909e-05 deg
peri 5.010596061802696 2.6981e-05 deg
M 259.8328065263878 2.7184e-05 deg
tp 2459809.597339332955
(2022-Aug-18.09733933)
0.00035942 TDB
period 4345.485054191239
11.90
0.00016482
4.513e-07
d
yr
n .08284460664587454 3.1423e-09 deg/d
Q 5.97358722008095 1.5105e-07 au
  Orbit Determination Parameters
   # obs. used (total)      893  
   data-arc span      12852 days (35.19 yr)  
   first obs. used      1984-08-21  
   last obs. used      2019-10-29  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .58015  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Nov-07 04:23:14  

Additional Information
 Earth MOID = 3.45975 au 
 Jupiter MOID = .526776 au 
 T_jup = 2.847 
[ 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 11.0   n/a MPO492967  
diameter diameter 27.176 km 3.231 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)  
rotation period rot_per 14.81 h n/a LCDB (Rev. 2019-January); 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 0.095   0.015 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)  

20428 (1998 WG20)          Discovered 1998-Nov-18 by LINEAR at Socorro
Reference: 20010109/Numbers.arcLast Updated: 2004-04-19

Alternate Designations
 1998 WG20 = 1999 YY6 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2020-Jan-19 22:25 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin