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Searching satellites of asteroid Itokawa by imaging observation with Hayabusa spacecraft

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Abstract

We carried out a search for satellites around Itokawa, the target asteroid of the Japanese Hayabusa mission. An imaging instrument, AMICA, on the spacecraft was used to take four images of Itokawa and its vicinity on September 1, 2005. The distance of the spacecraft from Itokawa was approximately 1,700 km, somewhat longer than the original plan (1,000 km) due to the mission schedule. The field-of-view of AMICA corresponded to 170 km × 170 km around Itokawa. Since the Hill sphere of Itokawa was estimated to be 33 km at the time of the observations, the images completely covered the detectable area of satellites. However, we cannot find the motion of Itokawa satellites between the four images, because the observation period was set to 2 hr due to the mission schedule and the region where satellites would be observable was only within 8 km of Itokawa, which is inside the extensive glare of Itokawa on the images. In addition, high-energy protons produced by a huge solar flare impacted the spacecraft during the observations, and hence the four images suffered from many random spots. Comparing the positions of the spots with catalogued stars, we managed to identify stellar images. No evidence of satellites was found. Additionally, we evaluated the 1-m detection limit of the images from the limiting magnitude of 9.5. The absence of satellites of Itokawa is consistent with past optical and radar observations as well as other results by the Hayabusa spacecraft.

References

  1. Belton, M. J. S. et al., The Discovery and Orbit of 1993 (243)1 Dactyl, Icarus, 120, 185–199, 1996.

  2. Bowell, E. et al., Application of Photometric Models to Asteroids, in Asteroids II, edited by Binzel, R. P., T. Gehrels, and M. S. Matthews, 993 pp, Univ. of Arizona Press, Tucson, 1989.

  3. Britt, D. T., D. Yeomans, K. Housen, and G. Consolmagno, Asteroids III, edited by Bottke Jr., W. F., A. Cellino, P. Paolicchi, and R. P. Binzel, 785 pp, Univ. of Arizona Press, Tucson, 2002.

  4. Chapman, C. R. et al., Discovery and physical properties of Dactyl, a satellite of asteroid 243 Ida, Nature, 374, 783–785, 1995.

  5. Fujiwara, A. et al., The Rubble-Pile Asteroid Itokawa as Observed by Hayabusa, Science, 312, 1330–1334, 2006.

  6. Hamilton, D. P. and J. A. Burns, Orbital Stability Zones about Asteroids, Icarus, 92, 118–131, 1991.

  7. Jedicke, R., J. Larsen, and T. Spahr, Asteroids III, edited by Bottke Jr., W. F., A. Cellino, P. Paolicchi, and R. P. Binzel, 785 pp, Univ. of Arizona Press, Tucson, 2002.

  8. Lederer, S. M. et al., Physical characteristics of Hayabusa target Asteroid 25143 Itokawa, Icarus, 173, 153–165, 2005.

  9. Melosh, H. J. and J. A. Stansberry, Doublet Craters and the Tidal Disruption of Binary Asteroids, Icarus, 94, 171–179, 1991.

  10. Merline, W. J., S. J. Weidenschilling, D. D. Durda, J.-L. Margot, P. Pravec, and A. D. Storrs, Asteroids III, edited by Bottke Jr., W. F., A. Cellino, P. Paolicchi, and R. P. Binzel, 785 pp, Univ. of Arizona Press, Tucson, 2002.

  11. Ostro, S. J. et al., Radar observations of asteroid 25143 Itokawa (1998 SF36), Meteoritics & Planetary Sci., 39, 407–424, 2004.

  12. Pravec, P. et al., Photometric survey of binary near Earth asteroids, Icarus, 181, 63–93, 2006.

  13. Saito, J. et al., Detailed Images of Asteroid 25143 Itokawa from Hayabusa, Science, 312, 1341–1344, 2006.

  14. Scheeres, D. J. et al., The Dynamical Environment About Asteroid 25143 Itokawa: Target of the Hayabusa Mission, AIAA/AAS Astrodynamics Specialist Conf. and Exhibit, AIAA 2004-4864, 1–12, 2004.

  15. Williams, G. V., 1998 SF36, Minor Planet Electronic Circular, MPEC 1998-S45, 1998.

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Correspondence to Tetsuharu Fuse.

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Fuse, T., Yoshida, F., Tholen, D. et al. Searching satellites of asteroid Itokawa by imaging observation with Hayabusa spacecraft. Earth Planet Sp 60, 33–37 (2008) doi:10.1186/BF03352759

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Key words

  • Asteroid
  • satellite
  • space mission