Asteroids with Satellites Database--Johnston's Archive

(41) Daphne and Peneius

compiled by Wm. Robert Johnston
last updated 15 September 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: 2.760712646 AU
orbital period P: 4.587119026 yr
(= 1675.4452240 d)
eccentricity e: 0.275135943
perihelion distance q: 2.001141370 AU
aphelion distance Q: 3.520283922 AU
inclination i: 15.7935451°
argument of perihelion ω: 46.013284°
ascending node Ω: 178.0862160°
mean anomaly M: 107.3100150°
perihelion passage TP: 2013 Jan 08.57763
Epoch: 2008 Mar 10
data arc: 1866-2013 (1498 obs.)
Earth MOID: 1.02755 AU
Jupiter Tisserand invariant TJ: 3.232

orbital data, secondary:
semimajor axis as: 443 km (separation) [C08a]
separation/primary radius as/rp:5.1 [*E]
separation/Hill radius as/rH:0.015 [*D]
orbital period Ps: 1.1 d [C08b]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 7.12 [MPC]
slope parameter G: 0.10 [JPL]
effective diameter dE: 174 ± 11.7 km [T04c]
geometric albedo: 0.083 ± 0.012 [T04c]
color index U-B: 0.363 [JPL]
color index B-V: 0.726 [JPL]
taxonomic type: Ch (SMASSII) [JPL]
C (Tholen) [JPL]
mass m: 6.31x1018 ± 1.1x1017 kg [C12a]
density ρ: 1.95 ± 0.15 g/cm3[C08b]
Hill radius rH: 31000 km [*D]

other data, primary:
diameter dp: 174 ± 11.7 km [T04c]
axial ratios a/b, b/c:1.37, 1.00 [D95a]
rotation period RPp: 5.9879856 ± 0.0000007 h [D95a]
amplitude in mag., rotational ΔM: ?
pole direction Β, λ: 163 ± 5° , 31 ± 8° [D95a]

other data, secondary:
diameter ds: <2 km [C08a]
diameter ratio ds/dp: 0.011 [*D]
component mag. difference ΔM: 10 [I8930]
rotation period RPs: ?

-- (41) Daphne and S/2008 (41) 1 --discovery and notes:

Primary discovered 1856 May 22 from Paris, France by H. Goldschmidt. Alternate designation(s): 1949 TG. Permanent number assigned 1856.

Named 1856 for the Greek mythological daughter of Terra.

Companion discovered 2008 Mar 28 by A. R. Conrad, W. J. Merline, J. D. Drummond, P. M. Tamblyn, C. Dumas, B. X. Carry, R. D. Campbell, R. W. Goodrich, W. M. Owen, and C. R. Chapman using adaptive optics telescope observations from W. M. Keck II Telescope, Mauna Kea, Hawaii, USA. Announced 2008 Mar 31 [C08a]. Provisional designation S/2008 (41) 1. Permanent designation I Peneius assigned 2019 Mar 06.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

© 2008-2014, 2019 by Wm. Robert Johnston.
Last modified 15 September 2019.
Return to Home. Return to Astronomy and Space. Return to Asteroids with Satellites.