Astronomy 490†††††††††††††††††††††† †††††††††† Homework #1†††††††††††††††††††††††††††††††††††††† Spring 2007



Due date:†† Monday, Feb 5 at start of class.

Please make a copy of your assignment to refer to during the class discussion.



Journal paper:†† Brown, Trujillo, and Rabinowitz 2005, ApJ Letters, 635, L97


Additional reference:

††††† Basri and Brown 2006, Annual Review of Earth and Planetary Sciences, 34, 193



1.Read the journal paper carefully, more than once.For each section of the paper

†††† (ABSTRACT, INTRODUCTION, DISCOVERY, etc), write down your questions and

††† comments.Try to include at least one question or comment per section.Then write a

†† 1-2 sentence summary of each individual section other than the abstract.



2.Look up the basic orbital characteristics of the planets (Mercury through Pluto):

†††† semi- major axis, eccentricity, orbital inclination.†† In a paragraph or two, compare the

†††† characteristics of 2003 UB313 to those of the known planets (including Pluto).


3.†† Review the properties of ellipses and Keplerís laws.Then compute the orbital period

††††† of 2003 UB313.Show your work.



4.Read as much of the Annual Review article as you can.It will be assigned as the

†† primary paper in the near future.