(85938) 1999 DJ4

compiled by Wm. Robert Johnston
last updated 6 December 2009

Orbital elements and other data (Assumed or derived values in parenthesis, my estimates in italics and parenthesis. Source identifications in brackets, see this link for sources):

orbital data, primary (osculating elements) [JPL]:
semimajor axis a: 1.85238300985206 AU
orbital period P: 2.5212 y (=920.9 d)
eccentricity e: 0.483274007213759
perihelion distance q: 0.957174449786172 AU
aphelion distance Q: 2.74759157 AU
inclination i: 9.15349995835191°
argument of perihelion omega: 197.510290867754°
ascending node OMEGA: 20.0189409770589°
mean anomaly M: 108.636496030252°
perihelion passage TP: 2004-04-27.1132376
Epoch: 30 JAN 2005
data arc: 1999-2004 (543 obs.)

orbital data, secondary:
semimajor axis a: (1.5 km?)
semimajor axis/primary radius a/Rp: (4?)
orbital period P: 17.72 ± 0.01 h [OOe]
eccentricity e: ?

other data, primary:
diameter: (~0.6 km?)
absolute magnitude H: 18.49 [JPL]
rotation period: 2.514 ± 0.001 h [OOe]
amplitude delta M: 0.10 [OOe]
color index B-V: ?
color index V-R: ?
color index R-I: ?
slope parameter G: (0.15) assumed
geometric albedo: (0.20) assumed
mass: ?
density: ?
type: ?

other data, secondary:
diameter: (~0.3 km?)
diameter ratio Ds/Dp: 0.5 ± 0.15 [OOe]
component magnitude difference: ?
rotation period: ?

--(85938) 1999 DJ4--discovery and notes:

Primary discovered 24 February 1999 by the LINEAR Program from Lincoln Laboratory ETS, Socorro, New Mexico, USA.

Companion discovered from lightcurve observations 21 February-28 March 2004 from Ondrejov Observatory, Elginfield Observatory, Ontario, and Tenagra II by Petr Pravec, Peter Kusnirak, Lenka Sarounova, Peter Brown, Nicole Kaiser, Gianluca Masi, and Franco Mallia. Radar observations from Arecibo Observatory in April 2004 confirmed the existence of the companion.

See more information and links at Asteroid/Comet Connection Catchall Catalog page

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2004-2008, 2009 by Wm. Robert Johnston.
Last modified 6 December 2009.
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