Neptune anomaly

Jonathan Thornburg -- remove -animal to reply wrote:

I don't recall the reference, but I recall reading a paper in the
Astronomical Journal dated sometime in the 1980s, which concluded
that after due consideration of the error bars in the observations,
there were no unresolved deviations. That is, the authors found that
the modern (very accurately known) orbits of the outer planets did
indeed fit all the observations (including the older ones) to within
reasonable estimates of the observational accuracy.

Perhaps you were remembering this paper:

http://adsabs.harvard.edu/cgi-bin/np...510b 0d825109


Michael Richmond

Michael Richmond wrote:
Perhaps you were remembering this paper:

http://adsabs.harvard.edu/cgi-bin/np...510b 0d825109

Yes indeed -- thanks for finding this reference for me! (And thanks
to NASA and the Harvard-Smithsonian Center for Astrophysics for their
*fantastic* ADS.)

This paper looks like it will be a fun re-read sometime this week...
In the meantime, the abstract already looks very relevant to the original
poster's query about "the apparent differences between Neptune's predicted
and observed orbits":
Title: Planet X - No dynamical evidence in the optical observations
Authors: Standish, E. M.
Journal: Astronomical Journal (ISSN 0004-6256), vol. 105, no. 5, p. 2000-2006.
Publication Date: 05/1993
Abstract:
It is shown that the alleged 'unexplained anomalies in the motion of
Uranus' disappear when one properly accounts for the correct value
of the mass of Neptune and properly adjusts the orbit of Uranus to the
observational data. Also, it is shown that each of the 'irregularities in
the measured positions of Neptune' has a complete explanation within the
framework of the presently known solar system. As a check of certainty, an
actual planetary ephemeris is integrated which well fits the observations
of Uranus. Minor systematic errors do remain in the data, but they are
very small; they are easily explained by a number of uncertainties in the
observations themselves. There is now known to be a mass concentration
of significant size in the outer solar system - 1992 QB1. In comparison
to any of the major planets, though, this object is miniscule. For the
meridian circle observations, there is still no evidence which requires or
even indicates the existence of any planet-sized object; there remains no
need to hypothesize the existence of a tenth planet in the solar system.

ciao,

--
-- "Jonathan Thornburg -- remove -animal to reply"
Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut),
Golm, Germany, "Old Europe" http://www.aei.mpg.de/~jthorn/home.html
"Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral."
-- quote by Freire / poster by Oxfam

In article ,
"Jonathan Thornburg -- remove -animal to reply" writes:
|
| For the
| meridian circle observations, there is still no evidence which requires or
| even indicates the existence of any planet-sized object; there remains no
| need to hypothesize the existence of a tenth planet in the solar system.

I like the precision of his wording!

Given the timescales involved, it obviously isn't possible to be SURE that
there isn't another large planet with an eccentric (possibly non-planar)
orbit that caused some of the remaining oddities, so it is nice to see that
he carefully doesn't exclude the possibility, which making it very clear
that he strongly doubts it ....


Regards,
Nick Maclaren.