[meteorite-list] 16 Psyche data for epoch 2000

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:28 2004
Message-ID: <3B3F71CD.AC1FC6E_at_lehrer1.rz.uni-karlsruhe.de>

Hello All,

Below is more recent data for asteroid 16 Psyche. For some unknown
reason, the entry for 16 Psyche is missing in the Almanac for 2001,
so I chose last year's data. These parameters would place 16 Psyche
at the edge of main belt IIIa where it borders on the Koronis zone.

... and another passage from Cunningham (p.52);

Employing polarimetry, Dollfus et al. (1979) concluded that M-type
asteroids have a surface texture that is a powder of small metallic
fragments with grain sizes between 20 and 50 microns. It was later
shown by Feierberg et al. (1983) that this powder is mixed with a
significant amount of fine silicate dust, thus ruling out a pure
metallic surface.


Best wishes,

Bernd


Astronomical Almanac for the year 2000, Section G10: Elements
for Epoch 2000, September, Ecliptic and Equinox J2000.0:

Magnitude Parameters: H = 5.90 / G = 0.20
Opposition Date: Dec 06 / Magnitude 9.4
Diameter: 250 km
Inclination: i = 3.092°
Long. of ascending node: 150.434°
Argument of perihelion: w = 229.032°
Mean distance: a = 2.9234 (= the semimajor axis of an elliptic orbit)
Daily motion: n = 0.19718°
Eccentricity: e = 0.1391
Mean anomaly*: M = 26.095°

* M = in undisturbed elliptic motion, the product of the mean
      motion of an orbiting body and the interval of time since
      the body passed pericenter (= the point in an orbit that
      is nearest to the center of force).

Explanations from CUNNINGHAM C.J. (1988) Introduction To Asteroids
(Willmann-Bell Inc., p. 40):

H = absolute magnitude
G = slope parameter
i = angle between the plane of the asteroid's
     orbit and that of the Earth => ecliptic
Long. of ascending node = the angular distance measured eastward in the
                                       plane of the Earth's orbit, from
                                       the vernal equinox to the point
                                       where the asteroid crosses the
                                       ecliptic from south to north.
w = defines how the major axis of the ellipse is oriented in its
    orbital plane by giving the angle between the ascending node
    and the perihelion point, measured in the direction of motion.
e = c/a, where c is the distance from the sun to the center of
    the ellipse and a is the length of the semi-major axis.
Received on Sun 01 Jul 2001 02:54:05 PM PDT