13th October 06 - UPDATES and NEW PAGES
The warm weather has arrived at last, so back to some new
Web Pages! I have added significant updates to the Solar System
pages, totalling some 20 NEW Pages!. This is mainly with the
introduction of the minor bodies, like asteroids and the
unobservable Trans-Neptunian Objects. Since the changes in
the number of planets by the I.A.U. has reduced from nine to
eight, and that the sub-catergory of dwarf planets
now it official, I have added new information for these
objects - especially troublesome Eris, Ceres
and now Pluto. A page entitled Dwarf Planets
is available for you to read - especially if you are just
as confused as I was before writing the article itself.
You will also find among these new pages general info on
Asteroid or Minor Planets, and detailed pages on the first
TEN Asteroids; namely; (1) Ceres, (2) Pallas, (3) Juno,
(4)Vesta, (5) Astraea, (6) Hebe, (7) Iris, (8) Flora,
(9) Metis and (10) Metis. All these have ephemerides between
2006 and 2015, though the last three are between 2006 and
2012. There are problems with determining the orbits beyond
a few years because of the perturbations of these small bodies
by the major planets, however, the positions should be exact
enough for amateur uses.
Readers should also be aware that the Pluto Page needs
an update after the removal of its planetary status. I will be
doing this in the next few days.
In addition, the next update sometime next week will include
the new update of the Southern Cross series (at last)
and the final corrections and improvements to some of the
missing pages found on the MAC Site.
ENJOY! (Any comments welcomed)
29th April 06 - UPDATES and NEW PAGES
Significant update to pages. Many files are smaller and now
faster to load. Small update were made to the Pluto, Venus and
Moon Pages. Uranus Page has new information, though needs text
updates in afew places and some new tables. Neptune Pages updated
to latest information. Extension of Neptunian Rings and Moons,
with the Ephemeris now between 2006-2015. (like Uranus and Pluto)
Large change to Parramatta Observatory Article, now includes an
introduction and images and recent information. Another will follow
soon, containing information on Parramatta itself.
NEW articles on the Early History of Australian Astronomy (1789-1820)
tells something about prior to Parramatta Observatory. Another NEW
article on the William Dawes observatory added.
Observational article added to General Articles, on the Dynameter
to measure eyepiece focal length. Thanks to Tom Teague for the
addition ideas and additional text.
05th March 06 - UPDATE : PLUTO SECTION has now been
greatly extended and now includes more detail and the
corrected ephemeris. Pluto is a difficult object to correctly
position and is problematic to calculate. I have modified
my data calculations using JPL’s
HORIZON
Web-Interface Page for the planet, in line with the
NASA’s NEW HORIZON Mission launched only this year on the
voyage to Pluto that arrives in 2015. The calculations are
geocentric positioned and differ slightly for the 2005 parameters
used in the earlier version. All the new positional data is based
for the period between the 20th Jan 1962 to 28th February 2006,
whose best predictions are made for 21st May 2006.
In all the presented data is the best of several sources, but is
still based on several unknowns which will not be solved - at least
until 2015! The tables are accurate enough for most amateur
purposes, but it is highly recommended to use the HORIZON Site
if further accuracy is required.
The Pluto page also has has new updated information on Charon
and the crrent information on the two new fainter moons
discovered in December 2005. (This is likely to become out-of-date
as new information comes to hand, but it is more updated than
other planetary pages I have seen. So much is changing lately,
it is hard to keep up! A similar problem is also with the
moons of Saturn, which have been recently been reobserved
by the Cassini spacecraft.
29th Feb - CORRECTION : VENUS EPHEMERIS
FILES. I recieved a kind email from David Bohlender
on the 23rd February 2006 advising me of errors with the
Venus Ephemerides. This was that none of the declinations
between 2005 and 2010 having negative declination! I
immmediately corrected this. The reason was due to a problem
when transferring the final Excel spreadsheet data into text.
(The spreadsheet was in fact correct.) It just goes to show
how simiple errors can occur or be unnoticed. Thanks David
for pointing this out!
(NO ADS!)