Celestia

Dear all:
Yesterday, I submitted a couple of minor updates to the CVS tree 
(starnames.dat, stars.txt, stars.dat).
With those, I think I've pretty much reached the end of any useful and 
interesting contributions I can make to Celestia ... and, over the holiday 
season, I've also become more involved in some other, long-neglected 
projects of my own.
So this is just a note to wish you all farewell, and to give you my 
heartfelt best wishes for the future of Celestia - it's a fine project, and 
it's been both immense fun and thoroughly educational for me to be involved 
in it. And, of course, it's also been great knowing you all.

With best wishes,

Grant

Chris,

below I attach some unanswered mail to you from almost a month ago: It 
concerned the relatively urgent assignment of default values  for 
binary  orbit parameters  in case  that  the respective data  were 
missing in the  original catalogs.  I want people to be able to notice 
that the data were missing by employing '?' in the orbit file.

Also  in a second mail I addressed the urgent need of  a binary browser 
extension of Celestia's star browser such that  people will  be able to 
/locate/ those  orbiting marvels  into  which  you and others have spent 
a lot of work already ;-)

Since  there was no response whatsoever, my binary star efforts 
stagnated throughout  the holiday season  and I turned to fiddleing with 
my computers instead...

Bye Fridger

> Chris,
>
> it would be great and relatively urgent (weekend ahead!), if Celestia 
> was (trivially) adapted to assign sensible default values for /all/ 
> (non-orbit related) entries in the binary orbit stc, in case a ? is 
> encountered by the parser.
>
> For spectral classes, it is already incorporated. In case of a ? in 
> the apparent magnitude slot, the respective star is NOT rendered at 
> all. So that's bad. Similarly in case of missing mass values, a 
> sensible default would be great. (e.g. m_A=m_B = 1 (solar mass units))
>
> The actual values for the defaults are not so crucial for now. It's 
> just so that I can mark clearly with a ? /all/ entries in my stc files 
> that are actually missing. At present, I have to put /concrete 
> numbers/ there and no-one can see that the respective parameter is in 
> fact /unknown/!
>
> A somewhat less random procedure for assigning default values would be 
> to compute and use the respective /averages/ over the catalog values...
> Since binary catalogues are typically for certain classes of multiple 
> systems: e.g. visual, spectroscopic..., using averages over a given 
> catalog might give  "guesstimate" values that are not entirely 
> nonsensical.
>
> Bye Fridger 


> Chris,
>
> ...and just in case you could find an empty coding slot ;-): it would 
> be most useful in general and especially now for /testing/ binary 
> orbits, if you could adapt the GOTO command (G key) for binaries 
> slightly as follows:
>
> 1) the final distance to the binary system is /computed/ from the 
> orbit size such that the components /always/ fit onto the screen! 
> (using the semi-major half axis or better of course, a more accurate 
> estimate)
>
> 2) the orientation matches the /viewing direction from earth/ with 
> /standardized/ orientation of north like in all (professional) orbit 
> plots for binaries, like illustrated here for dra_26:
>
> http://www.shatters.net/~t00fri/images/dra_26.gif
>
> Then (amateur) astronomers would be most happy and developers could 
> directly check the positions in Celestia against such standard 
> plots...After a glance at  Celestia one then could proceed to the 
> backyard and look for that binary in the telescope ;-) ...It would 
> also be most useful to display the distance of the components in 
> arc-secs in such an earth-oriented view.
>
> Bye Fridger
>