Asteroids with Satellites Database--Johnston's Archive

(31345) 1998 PG

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: NEA, Amor


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 2.014955130 AU
orbital period P: 2.860264998 yr (= 1044.7117910 d)
eccentricity e: 0.391553520
perihelion distance q: 1.225992357 AU
aphelion distance Q: 2.803917903 AU
inclination i: 6.4942996°
argument of perihelion ω: 155.955286°
ascending node Ω: 222.793932°
mean anomaly M: 162.183243°
perihelion passage TP: 2013 Feb 06.34792
Epoch: 2014 May 23
data arc: 1978-2014 (684 obs.)
Earth MOID: 0.232775 AU
Jupiter Tisserand invariant TJ: 3.72


orbital data, secondary:
binary dynamical type:A [*VO]
semimajor axis as: 1.4 km [*E]
separation/primary radius as/rp:3.1 [*E]
separation/Hill radius as/rH:0.016 [*E]
orbital period Ps: 0.5835 ± 0.00004 d [P06b]
eccentricity es: ?
normalized ang. mom. αL: 1.2 [*VO]

other data, system (combined):
absolute mag. H: 17.3 [MPC]
17.64 ± 0.14 [P00a]
slope parameter G: 0.15 [*A]
effective diameter dE: 0.94 ± 0.21 km [*D]
geometric albedo: 0.18 [P06b]
color index U-B: ?
color index B-V: 0.81 [P00a]
color index V-R:0.44± 0.01 [P00a]
color index B-R:1.25 [P00a]
color index V-I:0.76 [P00a]
taxonomic type: Sq (SMASSII) [JPL]
mass m: ?
density ρ: 1.6 g/cm3 [*A]
Hill radius rH: 87 km [*E]

other data, primary:
diameter dp: 0.9 ± 0.2 km [P06b]
rotation period RPp: 2.51620 ± 0.00003 h [P00a]
amplitude in mag., rotational ΔM: 0.11 [*MPb]
pole direction : ? ; ?


other data, secondary:
diameter ds: 0.27 km [*D]
diameter ratio ds/dp: 0.3 [P06b]
component mag. difference ΔM: 2.6 [*D]
rotation period RPs: ?

-- (31345) 1998 PG --discovery and notes:

Primary discovered 1998 Aug 03 from Anderson Mesa Station, Arizona, USA by LONEOS. . Linked to prediscovery observations from 1978 Oct 07. Permanent number assigned 2001 Nov 30.

Companion discovered 1998 Aug 29 using LC observations. Announced 1998.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2001-2005, 2014 by Wm. Robert Johnston.
Last modified 24 May 2014.
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