Asteroids with Satellites Database--Johnston's Archive

(136993) 1998 ST49

compiled by Wm. Robert Johnston
last updated 20 September 2014

--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

orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 2.310275758 AU
orbital period P: 3.511591052 yr
(= 1282.6086320 d)
eccentricity e: 0.593080131
perihelion distance q: 0.940097109 AU
aphelion distance Q: 3.680454407 AU
inclination i: 24.5223528°
argument of perihelion ω: 47.9279902°
ascending node Ω: 18.3656128°
mean anomaly M: 153.7597313°
perihelion passage TP: 2012 Nov 21.184559
Epoch: 2014 May 23
data arc: 1998-2013 (443 obs.)
Earth MOID: 0.0592897 AU
Jupiter Tisserand invariant TJ: 3.228

orbital data, secondary:
semimajor axis as: ?
orbital period Ps: ?
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 17.7 [MPC]
17.81 ± 0.02 [H12a]
slope parameter G: (0.15) [*A]
effective diameter dE: 0.69 ± 0.08 km [*D]
geometric albedo: (0.16 ) [*A]
color index U-B: ?
color index B-V: ?
color index V-R:0.439 ± 0.0011 [H12c]
color index B-R:1.192 ± 0.022 [H12c]
color index V-I:0.806 [H12c]
taxonomic type: Q (SMASSII) [JPL]
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 50 km [*E]

other data, primary:
diameter dp: 0.69 ± 0.08 km [W14c]
rotation period RPp: 2.302 ± 0.001 h [W14c]
amplitude in mag., rotational ΔM: 0.11 [B12e]
pole direction Β, λ: ? , ?

other data, secondary:
diameter ds: 0.08 ± 0.04 km [W14c]
diameter ratio ds/dp: 0.109 ± 0.056 [*D]
component mag. difference ΔM: 4.8 [* D]
rotation period RPs: ?

-- (136993) 1998 ST49 --discovery and notes:

Primary discovered 1998 Sep 29 from Socorro, New Mexico, USA by LINEAR. Permanent number assigned 2006 Dec 05.

Companion discovered 2012 Oct using radar observations. Announced 2012 Oct .

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

© 2012-2013, 2014 by Wm. Robert Johnston.
Last modified 20 September 2014.
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