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
JPL Small-Body Database Browser
Search: [ help ]  
11455 Richardstarr (1981 EN4)
Classification: Main-belt Asteroid          SPK-ID: 2011455
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 34 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04166775123042461 2.2021e-08  
a 3.065654495813729 1.7908e-08 au
q 2.937915566923729 6.8936e-08 au
i 9.878942680354555 9.7331e-07 deg
node 251.7024939123509 1.0408e-05 deg
peri 203.9040623084823 4.0687e-05 deg
M 230.8458133756068 3.8546e-05 deg
tp 2459903.878721850161
(2022-Nov-20.37872185)
0.00021187 TDB
period 1960.573996741296
5.37
1.7179e-05
4.703e-08
d
yr
n .1836196953536884 1.6089e-09 deg/d
Q 3.193393424703728 1.8654e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2382  
   data-arc span      14566 days (39.88 yr)  
   first obs. used      1981-02-02  
   last obs. used      2020-12-20  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .41647  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-12 22:47:07  

Additional Information
 Earth MOID = 1.95679 au 
 Jupiter MOID = 2.01434 au 
 T_jup = 3.208 
[ 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 13.20   n/a E2021B10  
diameter diameter 5.132 km 0.125 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
rotation period rot_per 17.414 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 0.558   0.111 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

11455 Richardstarr           Discovered 1981 Mar. 2 by S. J. Bus at Siding Spring.
Richard Starr (b. 1950) of the Catholic University of America is an expert in planetary X-ray, gamma-ray, and neutron spectroscopy, including their application to asteroid missions.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: MPC batch dated 2017-03-12Last Updated: 2017-04-19

Alternate Designations
 1981 EN4 = 1987 KR1 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2021-May-14 17:57 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin