Journal Article

1998 SM165: A Large Kuiper Belt Object with an Irregular Shape

Consolmagno, G., Rettig, T. W., Romanishin, W., Botthof, B., Tegler, S. C.

2001

Overview

The recent discovery of an ancient reservoir of icy bodies at and beyond the orbit of Neptune-the Kuiper belt-has opened a new frontier in astronomy. Measurements of the physical and chemical nature of Kuiper belt objects (KBOs) can constrain our ideas of the processes of planet formation and evolution. Our 1.8-m Vatican Advanced Technology Telescope and charge-coupled device camera observations of the KBO 1998 SM165indicate its brightness periodically varies by 0.56 magnitudes over a 4-h interval. If we assume a uniform albedo of 0.04, which is typical of values found in the literature for a handful of KBOs, and an \"equator-on\" aspect, we find 1998 SM165has axes of length 600 × 360 km. If our assumptions are correct, such dimensions put 1998 SM165among the largest elongated objects known in our solar system. Perhaps long ago, two nearly spherical KBOs of comparable size coalesced to form a compound object, or perhaps 1998 SM165is the residual core of a catastrophic fragmentation of a larger precursor.

• Publisher: National Academy of Sciences,National Acad Sciences,The National Academy of Sciences
• Subject: Albedo / Astronomical magnitude / Astronomical objects / Astronomy / Astrophysics / Faint stars / Kuiper belt objects / Light curves / Neptune / Physical Sciences / Solar systems / Stars / Telescopes