Celestia Forums

The entry for Auriga in asterisms.dat contains a reference to a "To Aur", which seems to be an error. What star should go here?

Hello

Yes, the Charioteer is poorly designed. The missing star is Theta Aur. But other stars should also appear in the constellation like that:


Theta and iota Aur are often connected with AlNath (Theta Tau) which belongs to the constellation of the Bull.

Here is my modif to the asterisms.dat

And lastly, the names of the stars Alpha and Beta are Capella and Menkalinan.
You can search and select them by typing their name and Celestia finds them.
But those names never appear in the description at the top left of the screen nor near the star.

Thanks for the info.

Well the reason that the names Capella and Menkalinan are not displayed is because of the binary stars files, which only apply one name to the barycenter (thus removing the proper names from the display). You'll have to talk to Fridger about that.

The IAU has published an 'official' list of constellation charts:
http://www.iau.org/public_press/themes/constellations/

Here's how Auriga looks like according to the IAU chart:

Here's the corresponding definition in asterisms.dat:


And here's how it looks like in Celestia:

Might be worth updating asterisms.dat to those forms, but note that in some constellations there are "more important" lines than others, e.g. in the Ursa Major figure, the asterism variously termed the Plough, the Big Dipper, etc. is drawn in thicker lines than the rest of the Ursa Major constellation... this is not supported under the current syntax.

...well for now I'll just go with the following:

which makes more sense than what's currently there.

ajtribick wrote:...well for now I'll just go with the following:

Code: Select all

"Auriga"
[
[ "Iota Aur" "Epsilon Aur" "Alpha Aur" "Beta Aur" "Theta Aur" ]
]

which makes more sense than what's currently there.

Since I did the asterisms about 6 years ago, what exactly is different between the IAU shape of Auriga and mine in Celestia?? I think the two are pretty similar.

I spent quite a bit of time to design asterisms from many different sources that are relatively simple (to satisfy their very purpose of guiding the eye) and NOT nationally biased. The latter constraint is the most severe one, actually. I also found out that a sensible overall solution to these constraints is quite time consuming...

Fridger

Well the problem was that the line was



The two main problems with that being the reference to the non-existent star "To Aur" and the zero-length line from Eta Aur to Eta Aur... to me this is clearly a bug.

ajtribick wrote:Well the problem was that the line was

Code: Select all

[ "Beta Aur" "To Aur" "Eta Aur" "Eta Aur" "Alpha Aur" "Beta Aur" ]

The two main problems with that being the reference to the non-existent star "To Aur" and the zero-length line from Eta Aur to Eta Aur... to me this is clearly a bug.

Oh, mea culpa. Above, I misread Vincent's post, thinking that his image was as things looked like in Celestia NOW, as compared to the IAU design.

Indeed, this bug was introduced by me May 15. 2002 (unintentionally, via a Perl script ). The idea was actually to do precisely this IAU supported form, as we have also introduced it in XEphem, where I was associated to for 11 years... But Perl did it in it's own way

Anyway, Auriga should be exactly as in the IAU design.

Fridger

t00fri wrote:Oh, mea culpa. Above, I misread Vincent's post, thinking that his image was as things looked like in Celestia NOW, as compared to the IAU design.

Sorry, I wasn't that clear, indeed. I meant here's how it would look like in Celestia with the correct definition from IAU.

t00fri wrote:Anyway, Auriga should be exactly as in the IAU design.

OK, so I'll check in the Auriga definition I posted above.