Asteroids with Satellites Database--Johnston's Archive

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

compiled by Wm. Robert Johnston
last updated 24 May 2014
under construction--testing upgrades!

--Orbital and physical data--

(See this page for definitions of quantities; source codes in brackets, see this link for full references; *A, *D, and *E indicate assumed, derived, and estimated values, respectively.)

dynamical type, primary: TNO, 1:2 resonance


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 47.675 AU
orbital period P: 329.190 yr (= 120236.8 d)
eccentricity e: 0.369454
perihelion distance q: 30.0614 AU
aphelion distance Q: 65.289 AU
inclination i: 13.50696°
argument of perihelion ω: 131.216°
ascending node Ω: 183.16624°
mean anomaly M: 43.221°
perihelion passage TP: 1974 Nov 13
Epoch: 2014 May 23
data arc: 1982-2010 (83 obs.)
Earth MOID: 29.0631 AU
Jupiter Tisserand invariant TJ: 5.579
Neptune Tisserand invariant TN:2.91 [*D]


orbital data, secondary:
semimajor axis as: 11377 ± 8 km [G14a]
separation/primary radius as/rp:85 [*D]
separation/Hill radius as/rH:0.024 [*D]
orbital period Ps: 130.158 ± 0.005 d [G14a]
eccentricity es: 0.4727 ± 0.0007 [G14a]
inclination is:81.57°± 0.05 [G14a]
ascending node Ωs:47.09°± 0.08 [G14a]
argument of pericenter ωs:114.9°± 0.1 [G14a]
mean anomaly M:280.5°± 0.1 [G14a]
Epoch:2003 Mar 01.5
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 5.8 [MPC]
6.38 [S08a]
slope parameter G: 0.15 [*A]
effective diameter dE: 279.8 ± 29.7/28.6 km [S08b]
geometric albedo: 0.063 ± 0.015/0.012 [S08b]
color index U-B: 0.21 [J07a]
color index B-V: 1.02 [G14a]
color index V-R:0.63± 0.02 [G14a]
color index B-R:1.653 [H02a]
color index V-I:1.3± 0.05 [D07c]
color index R-J:1.71 [D07c]
color index V-J:2.33± 0.06 [D07c]
color index J-H:0.56± 0.04 [D07c]
color index V-H:2.88± 0.08 [H02a]
taxonomic type: ? RR (BBRB) [*B05c]
mass m: 6.87x1018 ± 1.8x1016 kg [G11a]
density ρ: 0.51 ± 0.29/0.14 g/cm3 [S06b]
Hill radius rH: 470000 km [*D]

other data, primary:
diameter dp: 268 ± 28 km [*D]
color index V-I:1.4± 0.04 [B08d]
rotation period RPp: 8.4 ± 0.05 h [S06b]
amplitude in mag., rotational ΔM: ?
pole direction : ? ; ?


other data, secondary:
diameter ds: 81 ± 14 km [*D]
diameter ratio ds/dp: 0.302 ± 0.042 [N08c]
component mag. difference ΔM: 2.69 [G14a]
color index V-I:1.32± 0.05 [B08d]
rotation period RPs: ?

-- (26308) 1998 SM165 and S/2001 (26308) 1 --discovery and notes:

Primary discovered 1998 Sep 16 from Kitt Peak Observatory, Arizona, USA by N. Danzl. . Linked to prediscovery observations from 1982 Oct 12. Permanent number assigned 2001 Jul 05.

Companion discovered 2001 Dec 22 by M. E. Brown and C. A. Trujillo using HST observations from Hubble Space Telescope. Announced 2002 Jan 24 [I7807]. Provisional designation S/2001 (26308) 1.

--Links, more technical:

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--Links to ADS abstracts:


© 2002-2012, 2014 by Wm. Robert Johnston.
Last modified 24 May 2014.
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