﻿<?xml version="1.0" encoding="utf-8"?><rss version="2.0"><channel><title>Advances in Astronomy</title><link>http://www.hindawi.com</link><description>The latest articles from Hindawi Publishing Corporation</description><copyright>&amp;#169; 2008, Hindawi Publishing Corporation. All rights reserved.</copyright><item><title>Effect of Perturbations in Coriolis and Centrifugal Forces on the Nonlinear Stability of Equilibrium Point in Robe&amp;#39;s Restricted Circular Three-Body Problem</title><link>http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/425412</link><description>The effect of perturbations in Coriolis and cetrifugal forces on the nonlinear
stability of the equilibrium point of the Robe&amp;#39;s (1977) restricted circular
three-body problem has been studied when the density parameter K is zero. By applying Kolmogorov-Arnold-Moser (KAM) theory, it has been found
that the equilibrium point is stable for all mass ratios &amp;#x003BC; in the range of
linear stability 8/9+(2/3)((43/25)&amp;#x003F5;1&amp;#x02212;(10/3)&amp;#x003F5;)&amp;lt;&amp;#x003BC;&amp;lt;1, where &amp;#x003F5; and &amp;#x003F5;1 are, respectively, the perturbations in Coriolis and centrifugal forces, except for five mass ratios
&amp;#x003BC;1=0.93711086&amp;#x02212;1.12983217&amp;#x003F5;+1.50202694&amp;#x003F5;1, &amp;#x003BC;2 = 0.9672922&amp;#x02212;0.5542091&amp;#x003F5;+ 1.2443968&amp;#x003F5;1, &amp;#x003BC;3=0.9459503&amp;#x02212;0.70458206&amp;#x003F5;+ 1.28436549&amp;#x003F5;1, &amp;#x003BC;4=0.9660792&amp;#x02212;0.30152273&amp;#x003F5; + 1.11684064&amp;#x003F5;1, &amp;#x003BC;5=0.893981&amp;#x02212;2.37971679&amp;#x003F5; + 1.22385421&amp;#x003F5;1, where the theory is not applicable.</description><Author>P. P. Hallan and Khundrakpam Binod Mangang</Author><copyright>&amp;#169; 2008, Hindawi Publishing Corporation. All rights reserved.</copyright></item><item><title>Solar System Motions and the Cosmological Constant: A New Approach</title><link>http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/268647</link><description>We use the corrections to the Newton-Einstein secular
precessions of the longitudes of perihelia &amp;#x03D6;&amp;#x02D9; of some planets (Mercury, Earth, Mars,
Jupiter, Saturn) of the Solar System, phenomenologically estimated
as solve-for parameters by the Russian astronomer E. V. Pitjeva in a
global fit of almost one century of data with the EPM2004 ephemerides,
in order to put on the test the expression for the perihelion precession
induced by a uniform cosmological constant &amp;#x039B; in the framework of the
Schwarzschild-de Sitter (or Kottler) space-time. We compare such an
extra rate to the estimated corrections to the planetary perihelion precessions
by taking their ratio for different pairs of planets instead of using
one perihelion at a time for each planet separately, as done so far in
literature. The answer is  negative, even by further rescaling by
a factor 10 (and even 100 for Saturn) the errors in the estimated extra
precessions of the perihelia released by Pitjeva. Our conclusions hold
also for any other metric perturbation having the same dependence on
the spatial coordinates, as those induced by other general relativistic
cosmological scenarios and by many modified models of gravity. Currently
ongoing and planned interplanetary spacecraft-based missions
should improve our knowledge of the planets&amp;#39; orbits allowing for more
stringent constraints.</description><Author>Lorenzo Iorio</Author><copyright>&amp;#169; 2008, Hindawi Publishing Corporation. All rights reserved.</copyright></item></channel></rss>