NEO Science Requirements

This 60-second image of NEO 2000QW7 shows how quickly NEO's move across the sky. The telescope, imager, and control system requirements must take this and other NEO characteristics into account.

There is no such thing as a "general purpose" telescope; each is optimized for a specific purpose. The purpose of the Project ASTEROID telescope will be defined by a Science Advisory Committee (SAC) composed of scientists representing all the partners to the project. Winer Observatory will use the telescope to study NEO characteristics and to track previously discovered NEOs with uncertain orbits. Some of these objects move rapidly on the sky with respect to the "fixed" stars, with large errors from the time of discovery until we seek to refine their orbits. Consequently, the telescope may have a large area of sky to cover to find the object being sought.

Most target NEO's will be faint, usually in the range of magnitude 19 to 22 in V-band for those being detected now, and down to R~25 once the new PanSTARRS telescope reaches its full potential. Calculations show that to reach V~22 for NEO follow-up, a telescope with an aperture of at least one meter is needed. Winer Observatory has a 1.5-m mirror blank in its possession and the blank is ideally suited to this purpose. By way of comparison, the PanSTARRS project proposes to use four 1.8-meter aperture telescopes to reach R~25 with 60-second exposures using Orthogonal Transfer CCD's at a site in Hawai'i with exceptional seeing. Our modeling shows that the 1.5-m telescope should be capable of imaging most NEO's likely to be on our target list for the next several decades, though the 2.5-m option would fainter limiting magnitudes faster.

NEO positions on the sky the night after initial discovery often have large errors, sometimes tens of arc minutes to a degree or more. These errors grow with each night the NEO remains unobserved after discovery (due to clouds, position in the sky, equipment failures, or other reasons). Since the telescope will be used for NEO astrometric follow-up most of the time, the primary instrument to be used on the telescope will be a large-format imager, and the telescope will be designed for wide-field imaging, to minimize the number of images that must be acquired to find each target object.