==> In this proposal, more time is being requested for WIP.KUIPER_1
In the first cycle, a large programme was approved to investigate the thermal
emission of Kuiper Belt Objects (asteroid-type objects outside the orbit of
Neptune) in the range 60 to 100 microns. This programme was designed to separate
the albedo from the radius of several KBOs and hence provide the first
unambiguous information on the physical properties of this new class of Solar
System object. Unfortunately, this programme has suffered greatly from the
increased noise of the ISOPHOT P3 and C100 detectors. However, there are
indications in the recently acquired auto-analysis data that one object (1993
SC) might have been detected. We propose to use an additional 31318 s of TDT to
confirm our detection of 1993 SC and to acquire additional higher quality
calibration data of our other primary targets (1992 QB1 and 1994 TB). In
addition, we propose to quantify fully the minimum signal to noise ratio
attainable with the experiment by observing the unusual object 1993 HA2 with the
same instrument configuration. This object is also scientifically extremely
interesting because its orbit indicates that it may be in a transitional phase
between KBO and short-period comet. This observation will provide the albedo and
radius of 1993 HA2 and will indicate whether its albedo is compatible with that
of short period comets.