Celestia Forums

The starnames.dat file has several stars with names separated by colons (e.g. 677:Alpheratz:Sirrah:ALF And:21 And:DEL Peg, which is displayed on Celestia when you enter 'Alpheratz' as [alpha] And A/HIP 677/HD 358/SAO 73765, where [alpha] is greek alpha letter). What does it mean when you have more than one name? Clearly they are alternates, but since Celestia doesn't display all of it, what are the rules?
--Dale--

It's a bug.
They all should be shown.

I wonder if the problem is due to the fact that Alpha Andromeda gets redefined later as the barycenter of a multiple star system.

--Chris

Chris,

I'm sure you're right.

The current methods of setting Star and Barycenter names and parameters are relatively crude, unfortunately: they're pretty much all or nothing.

One needs to be able to specify

"modify star parameters but keep the names unchanged"

"replace star parameters but keep the names unchanged"

"modify star names but keep the parameters unchanged"
and
"replace star names but keep the parameters unchanged"

(Specifying a star's location and classification correctly when one only wants to add some synonyms to its name often can be problematic.)

These would be in addition to the two current options, which are

"replace name and parameters"
and
"replace parameters but keep the names" (which currently happens when only the Hipparcos catalog number is specified; the alternatives I'm describing should work when a name is specified.)

The "modify name" option also is needed for SSC objects, which also need support for alternative names using the colon separator.

However, I have to admit I think that although these improvements would be very welcome, they probably should have lower priority than some of your other ongoing projects

While we're on the subject of modifications and updates, the issue of HIP number collisions also should be dealt with. There should be an option in an SSC/STC to replace the HIP number with something such as '#' and a name such that the program takes the next unused HIP number as its unique id. For fictional add-ons in particular, often the author doesn't care what HIP # his system gets assigned but doesn't want a collision to cause it to be replaced by another add-on with the same number. Of course, this still leaves us with the problem of someone choosing the same system name, but this is probably less likely than number collisions. Or is there a solution to this that I don't know about?

One current "solution" would be to not use HIP numbers in new Addons. Celestia v1.4.0 and subsequent versions let you define Stars by name without requiring a HIP number.

Previously HIP numbers were required, however, and this does not solve the problem of existing Addon collisions.

Guess I missed that fact. This is certainly workable. Perhaps I can do something about collisions of existing add-ons.
--Dale--