Hawaii Kuiper Belt Variability Project: An Update

We have been systematically monitoring a large sample of bright Kuiper Beltobjects for possible light variations due to rotational and phase angle effects.Here we report on three objects, 2003 AZ₈₄, (24835) 1995 SM₅₅and (55636) 2002 TX₃₀₀ observed to have measurable rotational lightcurveswith peak-to-peak amplitudes of 0.14 ± 0.03, 0.19 ± 0.05 and 0.08 ± 0.02magnitudes and single-peaked periods of 6.71 ± 0.05, 4.04 ± 0.03 and8.12 ± 0.08 hours, respectively. We observed a further ten objects whichshowed no rotational photometric variation within measurement uncertainties.In addition, we find that the lightcurve of 1995 SM₅₅ may have a variableamplitude. We discuss this peculiar object as well as our observations of the reportedlyvariable Kuiper Belt object (19308) 1996 TO₆₆. Finally, we continue to find the phase functions of the Kuiper Belt objects to be very steep and linear, to firstorder, with a median slope of 0.16 ± 0.01 magnitudes per degree in the phaseangle range 0 to 2 degrees.