2008 BT18

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: 2.21926929 AU
orbital period P: 3.31 y (=1,207.57311 d)
eccentricity e: 0.59698778
perihelion distance q: 0.89439265 AU
aphelion distance Q: 3.54414593 AU
inclination i: 8.14983°
argument of perihelion omega: 139.04028°
ascending node OMEGA: 107.88767°
mean anomaly M: 351.6914718°
perihelion passage TP: 2008-06-10.869876
Epoch: 14 MAY 2008
data arc: 1955-2008 (223 obs.)

orbital data, secondary:
semimajor axis a: >=1.5 km [C1450]
semimajor axis/primary radius a/Rp: (>=5)
orbital period P: (~1 d?)
eccentricity e: ?

other data, primary:
diameter: 600 m [C1450]
absolute magnitude H: 18.207 ± 0.407 [JPL]
18.2 ± 0.2 [B09b]
rotation period: 2.726 ± 0.007 h [B09b]
amplitude delta M: 0.045 ± 0.002 [B09b]
color index B-V: ?
color index V-R: ?
color index R-I: ?
slope parameter G: 0.2 ± 0.1 [B09b]
geometric albedo: (~0.23)
mass: ?
density: ?
type: S; V [R08b]

other data, secondary:
diameter: >200 m [C1450]
diameter ratio Ds/Dp: (>0.3)
component magnitude difference: (<2.4)
rotation period: ?

--2008 BT18--discovery and notes:

Primary discovered 31 January 2008 by the LINEAR program; linked to pre-discovery observations from 14 March 1955.

Companion discovered by L. A. M. Benner, M. C. Nolan, E. S. Howell, C. Magri, J. D. Giorgini, S. J. Ostro, M. Brozovic, M. W. Busch, J. L. Margot, P. A. Taylor, M. K. Shepard, L. M. Carter, and T. M. Becker from radar observations obtained 6-7 July 2008 from Arecibo and Goldstone; reported 29 July 2008.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

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