English: Diagrams showing the location and characteristics of the Hygiea family of asteroids. Where circles are plotted, their diameter is proportional to the mean diameter of the asteroid.
core family members (shown in red) are those identified by the 1995 Zappala (V. Zappala et al, Icarus Vol. 116, p. 291 (1995)) HCM method analysis. The data set is here.
interlopers (shown in green) were identified either:
by the spectroscopic analysis of Mothé-Diniz (T. Mothé-Diniz et al Rotationally Resolved Spectra of 10 Hygiea and a Spectroscopic Study of the Hygiea Family, Icarus, Vol. 152, p. 117 (2001)),
and also by inspection of the PDS asteroid taxonomy data set for non C,B,or X-type members of the above Zappala 1995 data-set.
additional significant asteroids (shown in orange), that may be members of the family (although probably interlopers).
additional significant non-family asteroids (shown in light blue) in the vicinity, but apparently not members of the family (52 Europa and 159 Aemilia). It is not clear why the latter was not included as a family member by the Zappalà analysis.
numbered asteroids in general (shown as small blue dots), from the AstDys database.
The location of asteroids that are very large and/or explicitly named on the plot is shown by a light cross within the circle.
Asteroid diameters were obtained from two sources:
(thick circles): From the IRAS survey, when available (data set here).
(thin circles): Otherwise, by assuming an albedo of 0.072 (same as 10 Hygiea), and estimating from absolute magnitudes from the AstOrb database herearchive copy at the Wayback Machine.
The diagrams were created by me (Piotr Deuar) using proper element data for 96944 minor planets, which was obtained from the AstDys site. Data was dated March 2005, calculation was by Z. Knezevic and A. Milani.