(69230) Hermes

compiled by Wm. Robert Johnston
last updated 1 September 2005

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: 1.65493322531459 AU
orbital period P: 2.129 y (=777.6 d)
eccentricity e: 0.624032840749488
perihelion distance q: 0.622200543470814 AU
aphelion distance Q: 2.68766591 AU
inclination i: 6.06800927112482°
argument of perihelion omega: 92.4021883542106°
ascending node OMEGA: 34.5124596889444°
mean anomaly M: 186.987685274742°
perihelion passage TP: 2006-02-07.7176897
Epoch: 30 JAN 2005
data arc: 1937-2003 (717 obs.)

orbital data, secondary:
semimajor axis a: (1.0 km?) [I8227]
semimajor axis/primary radius a/Rp: (2.5)
orbital period P: 13.892 ± 0.006 h [I8233]
eccentricity e: ?

other data, primary:
diameter: 0.4 km [I8227]
absolute magnitude H: 17.55 ± 0.10 [I8233]
rotation period: 13.892 ± 0.006 h? [I8233]
amplitude delta M: ?
color index B-V: ?
color index V-R: ?
color index R-I: ?
slope parameter G: (0.15) [a]
geometric albedo: ?
mass: ?
density: ?
type: ?

other data, secondary:
diameter: 0.4 km [I8227]
diameter ratio Ds/Dp: 1.0 [I8227]
component magnitude difference: (0.0)
rotation period: 13.892 ± 0.006 h? [I8233]

--(69230) Hermes--discovery and notes:

Primary discovered 28 October 1937 by K. Reinmuth from Heidelberg-Konigstuhl. Alternate designation 1937 UB.

Companion discovered from radar observations made 18-20 October 2003 by J. L. Margot, M. C. Nolan, V. Negron, A. A. Hine, D. B. Campbell, E. S. Howell, L. A. M. Benner, S. J. Ostro, J. D. Giorgini, and B. G. Marsden from Arecibo Observatory.

Hermes passed only 741,000 km from the Earth on 30 October 1937. Discovered and only briefly observed during this close approach, it was lost until 2003. On 26 April 1942 it made an unobserved close approach, passing 634,000 km from the Earth and 366,000 km from the Moon. Recovery in October 2003 just preceded a close approach of 7,157,000 km on 4 November 2003.

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

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2002-2004, 2005 by Wm. Robert Johnston.
Last modified 1 September 2005.
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