2001-2002 Colloquium Series
NAU Liberal Arts (Bldg 18, Rm 135), Thursday, 31 January 2002, 4:00 PM
(Refreshments at 3:45 PM)
OUT PAST NEPTUNE: EXPLORING A NEWLY DISCOVERED REGION OF THE SOLAR SYSTEM
William Romanishin , University of Oklahoma.
Abstract
A half century ago, astronomers Kuiper and Edgeworth independently
hypothesized the existence of a class of objects orbiting the Sun
beyond Neptune, in and beyond the region traversed by Pluto. After
much observational effort with large telescopes, the first such object
was found in 1992, when Dave Jewitt and Jane Luu found 1992 QB1, the
first object known (besides Pluto+Charon) to be orbiting past Neptune.
There are now over 400 such objects known. For the past 5 years, Steve
Tegler (of Northern Arizona University) and I have used large
telescopes to study the colors and lightcurves of these very faint
newly found members of the Solar System. In this talk, I will first
give a brief introduction to the history and current status of
knowledge of the Kuiper Belt. I will then discuss the work we have
been doing on the colors and lightcurves of Kuiper Belt objects,
covering both the technical details of the measurements of these faint
objects and the scientific results we have obtained. We have found
that the Kuiper Belt objects have a bimodal color distribution, with
one group showing colors similar to reflected sunlight, and the other
group redder than any other minor bodies in the Solar System. We have
found that objects in circular orbits beyond 40 AU are all red. At
present, we do not know why there are two classes of Kuiper Belt
objects.
Local Host: Steve Tegler, (928) 523-9382.