New nearest star to the sun

[Hamiltonian]

The sun has a new nearest neighbour in 1.5pre3 (may be earlier too I never looked). A tiny binary called KSI Sco A and B, at 4.16 ly.
Problem seems to be in visualbins.stc

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Barycenter "KSI Sco"
{
RA       241.092450
Dec       92.529645
Distance   4.160160
}

That declination is a bit nonstandard, too.

And is it possible to standardise the usage for Greek letters?
Visualbins uses "KSI", but Celestia converts "XI" to the Greek letter, not "KSI". Visualbins uses the three letter abbreviation "PI." but Celestia recognises and converts "PI" (no dot), so we have stars Celestia calls ?€. Cen A and ?€. Cen B.
It seems like visualbins is using this code and the rest of Celestia isn't.

[t00fri]

Thanks,

here the PERL extraction script was confused, apparently, when merging the revisions with the HIP stars. That star (HIP 78727) is missing in HIP and in the revision we got

RA 241.09245
Dec -11.372945
Distance 92.529645
SpectralType "F6IV"
AppMag 4.16016

So apparently Distance -> Dec as well as AppMag -> Distance

Will be fixed.

Bye Fridger

[t00fri]

It was a pretty nasty little bug in my PERL script, where the HIP stars were merged with the correction file revised.stc:

In the regular expression that is to pick out the declinaton entry (Dec),

Code: Select all

if(/Dec\b\s+([-\d.]+)/){$c2 = $1; next;}


the - sign before \d was missing, whence negative declinations were skipped. That's what happened, yet luckily it affected only one star.

Bye Fridger

[Hamiltonian]

Thanks!

Any thoughts on resolving the situation with regard to Greek letter names?

[t00fri]

Thanks!

Any thoughts on resolving the situation with regard to Greek letter names?

As you suspected, I had adopted the 3 letter standard that is canonically used in many publications. I will discuss this issue with the other developers. It's no problem to tell PERL any convention we like.

The generated .stc data files are never touched by hand, of course. Otherwise we would loose the concise documentation feature (via the PERL script) relative to the published raw orbit data.

Bye Fridger

[Hamiltonian]

OK good.
Another difference in spelling to look out for is KHI / CHI.