(26308) 1998 SM165 and S/2001 (26308) 1

compiled by Wm. Robert Johnston
last updated 3 November 2012

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: 47.4109781076965 AU
orbital period P: 326.4574 y (=119241 d)
eccentricity e: 0.368467617927425
perihelion distance q: 29.9415679407442 AU
aphelion distance Q: 64.88038827 AU
inclination i: 13.5248864922825°
argument of perihelion omega: 130.505296058762°
ascending node OMEGA: 183.174348684175°
mean anomaly M: 33.5526525666883°
perihelion passage TP: 1974-08-27.7480978
Epoch: 30 JAN 2005
data arc: 1982-2002 (60 obs.)

orbital data, secondary:
semimajor axis a: 11,377 ± 8 km [G12a]
semimajor axis/primary radius a/Rp: (79)
orbital period P: 130.158 ± 0.005 d [G12a]
eccentricity e: 0.4727 ± 0.007 [G12a]
inclination to ecliptic i: 81.57° ± 0.05° [G12a]
ascending node OMEGA: 47.09° ± 0.08° [G12a]
longitude of periapsis: 114.9° 0.1± ° [G12a]
mean longitude at epoch: 280.5° ± 0.1° [G12a]
Epoch: JD 2452700 [G12a]

other data, primary:
diameter: 287 ± 36 km [S06b]
absolute magnitude H: 5.8 [JPL]
rotation period: 8.40 ± 0.05 h [S06b]
amplitude delta M: ?
color index B-V: 0.966 ± 0.091 [H02a]
color index V-R: 0.687 ± 0.079 [H02a]
color index V-I: 1.29 ± 0.07 [B05c]
color index V-J: 2.37 ± 0.01 [B05c]
color index V-H: 2.88 ± 0.08 [B05c]
slope parameter G: (0.15) [a]
geometric albedo: 0.07 ± 0.02 [S06b]
mass (system): (6.78 ± 0.24)x1018 kg [M04b]
density: 0.52 +0.29/-0.14 g/cm3 [S06b]
BBFB type: RR [B05c]

other data, secondary:
diameter: 96 ± 12 km [S06b]
diameter ratio Ds/Dp: (0.33 ± 0.02) [M05b]
component magnitude difference: (2.4) [M05b]
rotation period: ?

--(26308) 1998 SM165--discovery and notes:

Primary discovered 16 September 1998 from Steward Observatory, Kitt Peak-Spacewatch, Arizona, USA, by N. Danzl. Linked to prediscovery observations from 1982.

Companion discovered 22 December 2001 by M. E. Brown and C. A. Trujillo in Hubble Space Telescope images; announced 24 January 2002.

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

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2003-2006, 2012 by Wm. Robert Johnston.
Last modified 3 November 2012.
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