Bibcode
Magnusson, P.; Dahlgren, M.; Barucci, M. A.; Jorda, L.; Binzel, R. P.; Slivan, S. M.; Blanco, C.; Riccioli, D.; Buratti, B. J.; Colas, F.; Berthier, J.; de Angelis, G.; di Martino, M.; Dotto, E.; Drummond, J. D.; Fink, U.; Hicks, M.; Grundy, W.; Wisniewski, W.; Gaftonyuk, N. M.; Geyer, E. H.; Bauer, T.; Hoffmann, M.; Ivanova, V.; Komitov, B.; Donchev, Z.; Denchev, P.; Krugly, Yu. N.; Velichko, F. P.; Chiorny, V. G.; Lupishko, D. F.; Shevchenko, V. G.; Kwiatkowski, T.; Kryszczynska, A.; Lahulla, J. F.; Licandro, J.; Mendez, O.; Mottola, S.; Erikson, A.; Ostro, S. J.; Pravec, P.; Pych, W.; Tholen, D. J.; Whiteley, R.; Wild, W. J.; Wolf, M.; Sarounova, L.
Bibliographical reference
Icarus, Volume 123, Issue 1, pp. 227-244.
Advertised on:
9
1996
Journal
Citations
23
Refereed citations
22
Description
Photometric observations of 1620 Geographos in 1993 and 1994 are
presented and, in combination with previously published data, are used
to derive models of Geographos. We estimate that the sidereal period of
rotation is 0.21763860 +/- 0.00000003 days (5^h13^m23.975^s +/-
0.003^s). The sense of rotation is retrograde. The ecliptic coordinates
of the spin angular velocity vector are estimated to lambda_p = 56 deg
+/- 6 deg and beta_p = -47 deg +/- 4 deg (equinox J2000.0). The
lightcurve amplitudes are well-explained by an ellipsoidal model with
axis ratios a/b = 2.58 +/- 0.16 and b/c = 1.00 +/- 0.15. Models that
have one or both ends more sharply pointed than the ellipsoid improve
the fit to the observations. There are no significant indications of
albedo variegation, but non-geometric scattering effects are tentatively
suggested based on significant rotational color variation.