Photometry and models of selected main belt asteroids. VIII. Lowpole asteroids
Abstract
Context. The set of more than 100 asteroids, for which spin parameters have been modelled using an amplitude, magnitude or epoch methods, showed a pronounced gap in the distribution of the asteroid spin axes. These spin axes are rarely aligned with the ecliptic plane.
Aims: The number of asteroids with known spin parameters should be increased to allow for statistical investigations.
Methods: We gathered extensive photometric datasets on four selected mainbelt asteroids to model their spin and shape parameters using the lightcurve inversion method. Our only criterion of selection was their observability for small telescopes.
Results: All four of the modelled asteroids happened to have rotational poles that lie close to the ecliptic plane (periods and J2000 north pole coordinates): (94) Aurora  P = 7.226191 h, λ_{p1} = 58°, β_{p1} = + 16°; λ_{p2} = 242°, β_{p2} = + 4°; (174) Phaedra  P = 5.750249 h, λ_{p} = 265°, β_{p} = + 5°; (679) Pax  P = 8.456016 h, λ_{p1} = 42°, β_{p1} = 5°; λ_{p2} = 220°, β_{p2} = + 32° (pole 2 preferred after comparison with AOresolved observations); (714) Ulula  P = 6.998376 h, λ_{p1} = 42°, β_{p1} = 9°; λ_{p2} = 227°, β_{p2} = 14°.
Conclusions: This work suggests that asteroid spin axes do not avoid the ecliptic plane, contrary to what the classical modelling suggested.
Composite lightcurves (Figs. 126), and aspect data (Table 1) are only available in electronic form at http://www.aanda.orgPhotometric data are only available in electronic form at the CDS via anonymous ftp to cdsarc.ustrasbg.fr (130.79.128.5) or via http://cdsarc.ustrasbg.fr/vizbin/qcat?J/A+A/529/A107
 Publication:

Astronomy and Astrophysics
 Pub Date:
 May 2011
 DOI:
 10.1051/00046361/201015365
 Bibcode:
 2011A&A...529A.107M
 Keywords:

 techniques: photometric;
 minor planets;
 asteroids: general