Asteroids with Satellites Database--Johnston's Archive

(1798) Watts

compiled by Wm. Robert Johnston
last updated 27 May 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: main belt asteroid

orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 2.1989352556 AU
orbital period P: 3.260758714 yr
(= 1191.0146141 d)
eccentricity e: 0.121958748
perihelion distance q: 1.930755864 AU
aphelion distance Q: 2.4671146469 AU
inclination i: 6.1938386°
argument of perihelion ω: 3.868178°
ascending node Ω: 44.271723°
mean anomaly M: 76.104061°
perihelion passage TP: 2016 Jun 09.219310
Epoch: 2017 Feb 16
data arc: 1934-2017 (1513 obs.)
Earth MOID: 0.940922 AU
Jupiter Tisserand invariant TJ: 3.649

orbital data, secondary:
semimajor axis as: 15 km [*E]
orbital period Ps: 1.123 ± 0.0004 d [P17e]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 13 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 6.63 ± 0.19 km [M11b]
geometric albedo: 0.294 ± 0.053 [M11b]
color index U-B: ?
color index B-V: ?
taxonomic type: S (SMASSII) [JPL]
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 1000 km [*E]

other data, primary:
diameter dp: 6.43 ± 0.19 km [*D]
rotation period RPp: 3.506 ± 0.0004 h [P17e]
amplitude in mag., rotational ΔM: 0.06 [P17e]
amplitude in mag., mutual events ΔM:0.085 ±0.025 [P17e]
pole direction Β, λ: ? , ?

other data, secondary:
diameter ds: 1.61 ± 0.14 km [*D]
diameter ratio ds/dp: 0.25 ± 0.02 [P17e]
component mag. difference ΔM: 3.01 ± 0.17 [*D]
rotation period RPs: ?

-- (1798) Watts --discovery and notes:

Primary discovered 1949 Apr 04 from Brooklyn, Indiana, USA by Indiana Asteroid Program. Alternate designation(s): 1949 GC, 1934 VS, 1937 RL, 1970 YB, 1973 UD6. Linked to prediscovery observations from 1934 Nov 15. Permanent number assigned -.

Named for Chester B. Watts (1889-1971) [MPC003508].

Companion discovered 2017 Jan 31 by D. Pray, P. Pravec, H. Kucakova, J. Vrastil, K. Hornoch, P. Kusnirak, W. Cooney, J. Gross, D. Terrell, B. Flanagan, B. Pellerin, J. Oey using lightcurve observations from Sugarloaf Mountain Observatory, South Deerfield, MA; Ondrejov Observatory; Blue Mountain Observatory; Sonoita Research Observatory, Madrona Peak Observatory. Announced 2017 Mar 19 [P17e].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

© 2017, 2019 by Wm. Robert Johnston.
Last modified 27 May 2019.
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