Asteroids with Satellites Database--Johnston's Archive

2004 MU8

compiled by Wm. Robert Johnston
last updated 17 August 2019

--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, Cubewano


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 45.127 AU
orbital period P: 303.16 yr
(= 110728.3 d)
eccentricity e: 0.07491
perihelion distance q: 41.747 AU
aphelion distance Q: 48.508 AU
inclination i: 3.57263°
argument of perihelion ω: 335.5°
ascending node Ω: 109.71791°
mean anomaly M: 226.06°
perihelion passage TP: 2132 Feb 09.7
Epoch: 2019 Apr 27
data arc: 2004-2013 (23 obs.)
Earth MOID: 40.7634 AU
Jupiter Tisserand invariant TJ: 5.977


orbital data, secondary:
semimajor axis as: 5840 ± 80 km (separation) [G19c]
separation/primary radius as/rp:89 [*E]
separation/Hill radius as/rH:0.012 [*E]
orbital period Ps: 89 d [*E]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 7 [MPC]
6.4 ± 0.5 [G19c]
slope parameter G: (0.15) [*A]
effective diameter dE: 175 km [*E]
geometric albedo: (0.09 ) [*A]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1 g/cm3) [*A]
Hill radius rH: 470000 km [*E]

other data, primary:
diameter dp: 131 km [*E]
rotation period RPp: >2.5 h [T19b]
amplitude in mag., rotational ΔM: 0.48 [T19b]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 116 km [*E]
diameter ratio ds/dp: 0.89 [*D]
component mag. difference ΔM: 0.26 [G19c]
rotation period RPs: ?

-- 2004 MU8 --discovery and notes:

Primary discovered 2004 Jun 24 from Mauna Kea Observatory, Hawaii, USA by B. Gladman.

Companion discovered 2019 Jun 28 using Hubble Space Telescope observations. Announced 2019 Aug [G19c].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2019 by Wm. Robert Johnston.
Last modified 17 August 2019.
Return to Home. Return to Astronomy and Space. Return to Asteroids with Satellites.