(139775) 2001 QG298

Asteroids with Satellites Database--Johnston's Archive

(139775) 2001 QG298

compiled by Wm. Robert Johnston
last updated 16 November 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: TNO, plutino
orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 39.3003 AU
orbital period P: 246.373389495723 yr
(= 89989.4 d)
eccentricity e: 0.19179
perihelion distance q: 31.76273 AU
aphelion distance Q: 46.8378 AU
inclination i: 6.49771°
argument of perihelion ω: 209.686°
ascending node Ω: 162.59564°
mean anomaly M: 5.5239°
perihelion passage T_P: 2011 Feb 27
Epoch: 2014 Dec 09
data arc: 2001-2010 (73 obs.)
Earth MOID: 30.7648 AU
Jupiter Tisserand invariant T_J: 5.492

Neptune Tisserand invariant T_N: 2.99473287931401 [*D]

orbital data, secondary:

semimajor axis a_s: 172 km [T04a]
separation/primary radius a_s/r_p: 2.55 [*D]
separation/Hill radius a_s/r_H: 0.00060 [*D]
orbital period P_s: 0.573933 ± 0.000017 d [S04a]
eccentricity e_s: ?
normalized ang. mom. α_L: ?

other data, system (combined):

absolute mag. H: 7.2 [MPC]
slope parameter G: (0.15) [*A]
effective diameter d_E: 179 km [*D]
geometric albedo: 0.1 [T04a]
color index U-B: ?
color index B-V: 1 [S04a]
color index V-R: 0.6 ± 0.02 [S04a]
color index B-R: 1.6 [S04a]
taxonomic type: ?
mass m: 1.34x10¹⁸ kg [*D]
density ρ: 0.56 ± 0.02 g/cm³[D15a]
Hill radius r_H: 290000 km [*D]
other data, primary:

diameter d_p: 135 km [*D]
dimensions : 164 x 130 x 116km [T04a]
rotation period RP_p: 13.7744 ± 0.0004 h [S04a]
amplitude in mag., rotational ΔM: 1.14 ± 0.04 [S04a]
pole direction Β, λ: 110 ± 4° , -18 ± 17° [D15a]

other data, secondary:

diameter d_s: 117 km [*D]
dimensions : 168 x 160 x 150km [T04a]
diameter ratio d_s/d_p: 0.867 [*D]
component mag. difference ΔM: 0.3 [*D]
rotation period RP_s: ?

-- (139775) 2001 QG298 --discovery and notes:

Primary discovered 2001 Aug 19 from Cerro Tololo Observatory, La Serena, Chile by M. W. Buie. Permanent number assigned 2006 Dec 05.

Companion discovered 2003 Sep 12 using lightcurve observations. Announced 2004 Feb 12.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

Lacerda, P. 2011, EPSC-DPS Joint Meeting 2011 A Change in the Lightcurve of Contact Binary 2001 QG298
Lacerda, Pedro 2011, The Astronomical Journal A Change in the Light Curve of Kuiper Belt Contact Binary (139775) 2001 QG298
Gnat, Orly & Sari, Re'em 2010, The Astrophysical Journal Equilibrium Configurations of Synchronous Binaries: Numerical Solutions and Application to Kuiper Belt Binary 2001 QG298
Lacerda, Pedro & Jewitt, David C. 2007, The Astronomical Journal Densities of Solar System Objects from Their Rotational Light Curves
Lacerda, Pedro & Jewitt, D. 2006, Bulletin of the American Astronomical Society Densities from Lightcurves
Takahashi, Shigeru & Ip, Wing-Huen 2004, Publications of the Astronomical Society of Japan A Shape-and-Density Model of the Putative Binary EKBO 2001 QG298
Sheppard, S. S. & Jewitt, D. 2004, Bulletin of the American Astronomical Society A Contact Binary in the Kuiper Belt?
Sheppard, Scott S. & Jewitt, David 2004, The Astronomical Journal Extreme Kuiper Belt Object 2001 QG298 and the Fraction of Contact Binaries
Sheppard, S. S., Fernandez, Y. R., & Marsden, B. G. 2002, Minor Planet Electronic Circulars 2001 QG298

© 2004-2009, 2014 by Wm. Robert Johnston.
Last modified 16 November 2014.
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