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Maximum distance for stars in Celestia
http://forum.celestialmatters.org/viewtopic.php?f=9&t=620
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Author:  Cham [ Sat, 25-01-14, 3:54 GMT ]
Post subject:  Maximum distance for stars in Celestia

Guys, could you remind me the maximum distance a star could be defined and shown in Celestia ?

I thought that it was 10 millions LY (which covers the whole local group of galaxies), but I was able to define and visit some stars inside the M81 large spiral galaxy, which is located at about 12 MLY from the Milky Way !

I'm now very tempted to populate that galaxy (and several other spirals) with tons of stars, like what I have done for M31, M33, NGC 300 and NGC 404.

Author:  t00fri [ Sat, 25-01-14, 12:06 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

Cham wrote:
I'm now very tempted to populate that galaxy (and several other spirals) with tons of stars,

For your info: Since quite a while, in .Sci all 10000+ galaxies have a star halo strictly incorporating the measured extension, luminosity function and color composition. For a detailed discussion see

viewtopic.php?f=11&t=544
viewforum.php?f=11

As an illustration, here is e.g. M 101 in head-on and sideways view:

[Click on images + browser fullscreen by all means!]
Attachment:
m101_halo.jpg
m101_halo.jpg [ 85.35 KiB | Viewed 5783 times ]

The pink spots are compact H_II regions (starforming)
Attachment:
m101_sideways.jpg
m101_sideways.jpg [ 100.12 KiB | Viewed 5783 times ]


We don't have any normal stars in the arms, though. There we concentrate on massive stars, compact H_II regions and pulsars.

Fridger

Author:  Cham [ Sat, 25-01-14, 14:04 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

Very nice Fridger.

Is there a test built that I could try, for OS X ? You need beta testers.

Author:  t00fri [ Sat, 25-01-14, 14:14 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

Cham wrote:
Very nice Fridger.

Is there a test built that I could try, for OS X ?

Sorry, not yet. Since DW is currently very busy with writing his Master thesis, we are behind schedule of making the dev code public.
Quote:
You need beta testers.

Nevertheless in the .Sci dev team, we are 3 (self critical) testers ;-). Christophe and DW both use MACs as you know. I am testing Linux and Windows, besides coding. Christophe is our very valuable graphics expert.

Fridger

Author:  Cham [ Sat, 25-01-14, 14:50 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

I placed 40000 stars and a solar system inside the whole M81 galaxy, and apparently all of them are there, while they are located at 12 millions LY from Sol. I'm wondering what is the true distance limit for stars in Celestia.

Two views from inside M81 :
Attachment:
M81a.jpg
M81a.jpg [ 174.18 KiB | Viewed 5778 times ]

Attachment:
M81b.jpg
M81b.jpg [ 166 KiB | Viewed 5778 times ]

Author:  Cham [ Sat, 25-01-14, 15:48 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

Sadly, stars aren't showing inside M101, located at 24 MLY from Sol.

The M101 stars and planets could be found in Celestia, and the markers are even showing them at the proper location, but the objects cannot be seen. :(

I'm still amazed that the objects could be seen in M81.

Author:  t00fri [ Sat, 25-01-14, 17:21 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

Cham wrote:
Sadly, stars aren't showing inside M101, located at 24 MLY from Sol.

Not sure whether you are talking about Celestia or about .Sci? Note .Sci is a lot different from Celestia, meanwhile, after > 4 years of coding.
Quote:
The M101 stars and planets could be found in Celestia, and the markers are even showing them at the proper location, but the objects cannot be seen. :(

I'm still amazed that the objects could be seen in M81.


In any case I can enter AND draw stars at any place near M 101 and the locations are correct. It's a long time ago that I looked at Celestia in this respect. No reason to do so for us. :°

After ChrisL changed the type for the star locations from Float to Double long time ago, there was no sharp drawing limit anymore in Celestia. Yet, eventually the drawing becomes inaccurate at sufficiently large distances if no precautions are taken to prevent extinction errors.

Fridger

Author:  Cham [ Sat, 25-01-14, 17:26 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

t00fri wrote:
Not sure whether you are talking about Celestia or about .Sci? Note .Sci is a lot different from Celestia, meanwhile, after > 4 years of coding.


Fridger, you should know that I'm talking about Celestia, since you never released any "Sci" version that we could try, especially for OS X. I don't have any "Sci" version.

Author:  t00fri [ Sat, 25-01-14, 21:10 GMT ]
Post subject:  Re: Maximum distance for stars in Celestia

Cham wrote:
t00fri wrote:
Not sure whether you are talking about Celestia or about .Sci? Note .Sci is a lot different from Celestia, meanwhile, after > 4 years of coding.


Fridger, you should know that I'm talking about Celestia, since you never released any "Sci" version that we could try, especially for OS X. I don't have any "Sci" version.


Right you are ...

F.

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