Asteroids with Satellites Database--Johnston's Archive

1999 RM45

compiled by Wm. Robert Johnston
last updated 21 Feb 2021

--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: NEA, Apollo (PHA)


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 1.681249259 AU
orbital period P: 2.179958163 yr
(= 796.2447572 d)
eccentricity e: 0.64414103
perihelion distance q: 0.59828763 AU
aphelion distance Q: 2.764210883 AU
inclination i: 10.888953°
argument of perihelion ω: 88.763528°
ascending node Ω: 162.844309°
mean anomaly M: 213.380034°
perihelion passage TP: 2021 Apr 20.292720
Epoch: 2020 May 31
data arc: 1999-2021 (168 obs.)
Earth MOID: 0.00273761 AU
Jupiter Tisserand invariant TJ: 3.949


orbital data, secondary:
semimajor axis as: 0.29 km [*E]
separation/primary radius as/rp:3.5 [*E]
separation/Hill radius as/rH:0.037 [*D]
orbital period Ps: 0.6852 ± 0.0005 d [P21a]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 19.4 [MPC]
19.27 ± 0.13 [P21a]
slope parameter G: 0.24 [P21a]
effective diameter dE: 0.181 ± 0.057/0.029 km [N18a]
geometric albedo: 0.781 ± 0.325/0.342 [N18a]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 8 km [*E]

other data, primary:
diameter dp: 0.165 ± 0.052/0.027 km [*D]
axial ratios a/b, b/c:1.3, ? [P21a]
rotation period RPp: 3.0697 ± 0.0006 h [P21a]
amplitude in mag., rotational ΔM: 0.07 [P21a]
amplitude in mag., mutual events ΔM:0.2 [P21a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 0.074 ± 0.024/0.013 km [*D]
diameter ratio ds/dp: 0.45 ± 0.02 [P21a]
component mag. difference ΔM: 1.73 ± 0.097 [*D]
rotation period RPs: ?

-- 1999 RM45 --discovery and notes:

Primary discovered 1999 Sep 14 from Lincoln Laboratory ETS, New Mexico, USA by LINEAR Program.

Companion discovered 2020 by P. Pravec, K. Hornoch, P. Farka, and P. Kusnirak using lightcurve observations. Announced 2021 Feb 13 [P21a].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2021 by Wm. Robert Johnston.
Last modified 21 Feb 2021.
Return to Home. Return to Astronomy and Space. Return to Asteroids with Satellites.