Comet Halley XYZ file for Celestia

What is it?

This is an "XYZ" file for Comet Halley for Celestia - it allows Celestia to plot the position of the Comet for any date between 261BC and 2380AD.

Downloading

Download halleyxyz.zip and unzip it into your Celestia installation.

Numerical Integration

The XYZ file presented here is the output of three numerical integrations performed with Solex. The three integrations and the Solex SLX files are -

• 859/12/20 to 2380/01/25 (2035160.5 to 2590360.5)
  -2449400.5
  8.0 -0.0000055 5.5 0.0 1P-Halley
  0.9671429084623043 162.2626905791606 111.3324851045177
  58.42008097656843 0.0 0.0 0.5859781115169086 2446467.395317051
  2.696464E-10 1.554613E-10 0.0 0.1113
• 799/12/15 to 869/12/07 (2013240.5 to 2038800.5)
  -2027000.5
  8.0 -0.0000055 5.5 0.0 1P-Halley
  0.96778458 163.445800 100.113622
  44.951780 0.0 0.0 0.58238434 2026830.77
  0.046e-9 0.01548e-9 0.0 0.1113
• -261/12/20 to 809/12/20 (1626080.5 to 2016880.5)
  -1998800.5
  8.0 -0.0000055 5.5 0.0 1P-Halley
  0.9678591 163.43647 100.00432
  44.70509 0.0 0.0 0.5819144 1998788.20084
  2.696464E-10 1.554613E-10 0.0 0.1113

In the resulting XYZ file, there is a smooth transition between the result of the first and second integrations between 859/12/20 and 869/12/07. And there is a smooth transition between the result of the second and third integrations between 799/12/15 and 809/12/20.

Wikipedia authors please note that this web page is probably an invalid source of information for Wikipedia, as I believe it violates the "no original research" rule of Wikipedia. I previously used the information here as a source for Wikipedia - apologies.

Results, and accuracy

The resulting osculating elements for each of the returns of Comet Halley (TDT / J2000.0) within the period are contained in the table below. Note that some of the perihelion times are up to a week or more off from some of the elements given in scientific papers about the motion of this comet, though those papers tend not to completely agree with each other either! I would estimate that I'm quite accurate for the 1986 return, that I'm correct to well within a day between the 17th and 24th century, I'm maybe a day off by 1000 AD, about a week or so off by the time of Christ, and maybe a month off in the year -239 (240 BC), depending on which scientific paper I compare myself against (one paper gives -239 Mar 22.5 for the 240 BC perihelion, another gives -239 May 24.4).