[Previous] | [Session 2] | [Next]
D. D. Durda, S. A. Stern, D. C. Terrell (SwRI), S. J. Weidenschilling (PSI)
We are conducting a unique, high-altitude observing campaign to search for vulcanoids, a population of small, asteroid-like bodies hypothesized to reside in the dynamically stable region interior to Mercury's orbit (i.e., orbits with aphelia <0.21 AU). This airborne search campaign utilizes our versatile and highly capable SWUIS-A (Southwest Universal Imaging System - Airborne) instrument flown with the flight astronomer (SAS and DDD) to an altitude of 49,000 MSL aboard NASA F/A-18B aircraft in order to obtain darker twilight conditions for near-Sun observing than are possible from the ground. The first observing run was successfully completed at NASA's Dryden Flight Research Center during the March/April 2002 vernal equinox observing opportunity. On each of the three evening flights we recorded image data covering ~250 square degrees of sky centered on the ecliptic from solar elongations of 6-18 deg. Initial reduction of portions of the Mar/Apr 2002 data set demonstrates that we are reliably detecting objects to magnitude V = 9.5 at ~15 degrees solar elongation. This is at least a magnitude fainter than the best previous ground-based searches and comparable to the faintest stars visible in our space-based SOHO LASCO C3 coronagraph vulcanoids search. The SWUIS-A instrument itself is capable of imaging objects as faint as magnitude V = 13, corresponding to vulcanoids less than 10 km across, with a sufficiently dark sky background; we are working to mitigate sky background brightness to reach these deeper magnitude limits for a second F/A-18B observing run during the September 2002 autumnal equinox observing opportunity.
We thank NASA research pilots Rick Searfoss, Dana Purifoy, and Craig Bomben. This research is supported by the NASA Planetary Astronomy program, NASA's Dryden Flight Research Center, and the National Geographic Society.
If the author provided an email address or URL for general inquiries,
it is as follows:
Bulletin of the American Astronomical Society, 34, #3< br> © 2002. The American Astronomical Soceity.