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!