Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-26T05:21:44.848Z Has data issue: false hasContentIssue false
  • English
  • Français

Observation of small solar system objects with spacewatch

Published online by Cambridge University Press:  25 May 2016

James V. Scotti  and
Robert Jedicke
James V. Scotti
Affiliation:
Lunar and Planetary Laboratory The University of Arizona Tucson, AZ, 85721 USA
Robert Jedicke
Affiliation:
Lunar and Planetary Laboratory The University of Arizona Tucson, AZ, 85721 USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Since beginning an automated full-time survey for Near-Earth objects in September 1990, the Spacewatch project has discovered 95 new Near-Earth asteroids (NEAs), 3 new comets, and 3 new Centaur asteroids. Spacewatch typically identifies about 2000 main-belt asteroids each lunation while covering about 150 square degrees to a limiting magnitude of Vlim ∼ 20.9. We report automatically measured astrometric asteroid detections to the Minor Planet Center where known and multiply detected objects are identified. NEAs and other interesting objects are identified by their angular rates of motion near opposition at the time of discovery and are scheduled for astrometric follow-up on subsequent nights. Objects with exceptionally high rates of motion, called very fast moving objects, have been detected in near real-time by the observer and followed for several hours to several days. These objects are the smallest yet detected outside the Earth's atmosphere. Careful analysis of their discovery rates and orbits have indicated an enhancement of their magnitude-frequency distribution over that anticipated before the Spacewatch survey began – of about a factor of 40 for objects near absolute magnitude H ∼ 29 (Rabinowitz, 1993; 1994). A subset of these small objects which have almost circular orbits and perihelia near the orbit of Earth have been recognized as having significantly different orbits from those of the previously known NEAs (Rabinowitz et al., 1993). Their origin is still under debate, with possible sources including Earth or Lunar impact ejecta, Earth-Sun Trojans, or more complicated secular resonance interactions of NEA orbits with the giant planets combined with stochastic perturbational encounters with the inner planets (Bottke, 1994; N.W. Harris, 1995, personal communication). The large volume of asteroid detections allows magnitude–frequency studies of the detected main-belt asteroids and Jupiter Trojans. New discoveries of Comets and Centaur asteroids (whose orbits cross those of the outer planets) may allow studies of their magnitude–frequency distributions as well.

Type
Part X - Solar System Astrometry
Information
Symposium - International Astronomical Union , Volume 172: Dynamics, Ephemerides and Astrometry of the Solar System , 1996 , pp. 389 - 398
Copyright
Copyright © Kluwer 1996 

References

Bottke, W.F. (1994) Provenance of the Spacewatch Small Earth-Approaching Asteroids, to be published in Proceedings of the Astronomical Society of the Pacific: Inventory of the Solar System Conference, in press.Google Scholar
Bowell, E.L.G., Skiff, B.A., Wasserman, L.H., and Russell, K.S. (1990) Orbital information from Asteroid motion vectors, in Asteroids, Comets, Meteors III, (Lagerkvist, C.-I., Rickman, H., Lindblad, B.A., and Lindgren, M., eds.), pp. 19–24.Google Scholar
Gehrels, T. (1981) Faint Comet Searching, Icarus, 47, pp. 518–522.Google Scholar
Gehrels, T. (1991) Scanning with charge-coupled devices, Space Sci. Rev., 58, pp. 347–375.Google Scholar
Gehrels, T., Marsden, B.G., McMillan, R.S., and Scotti, J.V. (1986) Astrometry with a Scanning CCD, Astron. J., 91, pp. 1242–1243.Google Scholar
Holman, M.J., and Wisdom, J. (1993) Dynamical stability in the outer Solar System and the delivery of short period comets. Astron. J. 105, pp. 1987–1998.CrossRefGoogle Scholar
Jedicke, R. (1995) Detection of Near Earth Asteroids based upon their rates of Motion, submitted to Astron. J..Google Scholar
McMillan, R.S., Scotti, J.V., Frecker, J.E., Gehrels, T., and Perry, M.L. (1986) Use of a scanning CCD to discriminate Asteroid images moving in a field of stars. In Instrumentation in Astronomy VI (Crawford, D. L., Ed.), Proceedings of the SPIE, 627, pp. 151–154.Google Scholar
Rabinowitz, D.L. (1991) Detection of Earth-Approaching Asteroids in near real time.” Astron. J. 101, pp. 1518–1529.Google Scholar
Rabinowitz, D.L. (1993) The size distribution of the Earth-Approaching Asteroids.” Astrophys. J. 407, pp. 412–427.Google Scholar
Rabinowitz, D.L. (1994) The size and shape of the Near-Earth Asteroid Belt.” Icarus 111, pp. 364–377.Google Scholar
Rabinowitz, D.L., Gehrels, T., Scotti, J.V., McMillan, R.S., Perry, M.L., Wisniewski, W., Larson, S.M., Howell, E.S., & Mueller, B.E.A. (1993) Evidence for a Near-Earth Asteroid Belt.” Nature 363, pp. 704–706.Google Scholar
Scotti, J.V. (1994) Computer aided Near Earth Object detection.” In Asteroids, Comets, Meteors 1993 (Milani, A., DiMartino, M., and Cellino, A., Eds.), pp. 17–30. Kluwer.CrossRefGoogle Scholar
Scotti, J.V., Rabinowitz, D.L., and Gehrels, T. (1992) Automated detection of Asteroids in real-time with the Spacewatch Telescope.” In Asteroids, Comets, Meteors 1991 (Bowell, E. and Harris, A., Eds.), pp. 541–544. Lunar and Planetary Institute, Houston.Google Scholar