Characteristics and large bulk density of the C-type main-belt triple asteroid (93) Minerva
Abstract
From a set of adaptive optics (AO) observations collected with the W.M. Keck telescope between August and September 2009, we derived the orbital parameters of the most recently discovered satellites of the large C-type asteroid (93) Minerva. The satellites of Minerva, which are approximately 3 and 4 km in diameter, orbit very close to the primary (∼5 and ∼8 × R_p and ∼1% and ∼2% × R_(Hill)) in a circular manner, sharing common characteristics with most of the triple asteroid systems in the main-belt. Combining these AO observations with lightcurve data collected since 1980 and two stellar occultations in 2010 and 2011, we removed the ambiguity of the pole solution of Minerva's primary and showed that it has an almost regular shape with an equivalent diameter D_(eq) = 154 ± 6 km in agreement with IRAS observations. The surprisingly high bulk density of 1.75 ± 0.30 g/cm3 for this C-type asteroid, suggests that this taxonomic class is composed of asteroids with different compositions, For instance, Minerva could be made of the same material as dry CR, CO, and CV meteorites. We discuss possible scenarios on the origin of the system and conclude that future observations may shine light on the nature and composition of this fifth known triple main-belt asteroid.
Additional Information
© 2013 Elsevier Inc. Received 18 December 2012. Revised 11 February 2013. Accepted 11 February 2013. Available online 5 March 2013. FMA and JEM were supported by NASA Grant NNX11AD62G. Parts of these data were obtained with the W.M. Keck Observatory, which is operated by the California Institute of Technology, the University of California, Berkeley and the National Aeronautics and Space Administration. The work of JD was supported by Grants P209/10/0537 of the Czech Science Foundation and by the Re- search Program MSM0021620860 of the Ministry of Education. We are thankful to H.-Y. Shih and K. Larson for their participation in the photometric observations. Thanks to D. Polishook and G. Consolmagno for their comments which improved significantly the quality of this work. The observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors extend special thanks to those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. Without their generous hospitality, none of the observations presented would have been possible. The authors would like to thank the IOTA group for helping to coordinate and gather observations of the December 24, 2010 stellar occultation especially the observers: R. Peterson, G. Lucas, J. Ray, S. Herchak, J. Menke, W. Thomas, D. Dunham, J. Dunham, B. Jones, S. Conard.Attached Files
Supplemental Material - mmc1.pdf
Supplemental Material - mmc2.pdf
Supplemental Material - mmc3.txt
Files
Additional details
- Eprint ID
- 38874
- Resolver ID
- CaltechAUTHORS:20130610-092309109
- NNX11AD62G
- NASA
- P209/10/0537
- Czech Science Foundation
- MSM0021620860
- Ministry of Education Research Program
- W. M. Keck Foundation
- Created
-
2013-06-10Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field