Galaxial Limits?

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Jamstraz
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Galaxial Limits?

Post #1by Jamstraz » 18.03.2005, 16:41

I'm limited to being in the Milky Way right? I tried to define a star over a million light years out...although I could navigate towards it, it said it was like 400000x brighter than the sun, and didn't even show when I got there.
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selden
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Post #2by selden » 18.03.2005, 18:56

Celestia cannot reliably draw stars and planets more than 16K light years from the sun. They tend to flicker and have other problems.

Nebulas and galaxies work OK, though.

Please read the "Preliminary User's FAQ" that's at the top of the Celestia Users Forum. Q/A #12 at
http://www.shatters.net/forum/viewtopic.php?p=16526&highlight=#16526

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Selden

danielj
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Post #3by danielj » 18.03.2005, 19:14

So,the planets in 47 Tucanae and maybe even in M4 can??t be displayed correctly?M4 and 47 Tucanae(NGC 104) are from Selden.

selden wrote:Celestia cannot reliably draw stars and planets more than 16K light years from the sun. They tend to flicker and have other problems.

Nebulas and galaxies work OK, though.

Please read the "Preliminary User's FAQ" that's at the top of the Celestia Users Forum. Q/A #12 at
http://www.shatters.net/forum/viewtopic.php?p=16526&highlight=#16526

.

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selden
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Post #4by selden » 18.03.2005, 19:38

Daniel,

47 Tucanae is 28.4 KLY away, so defining individual stars and their planets won't work reliably. There have been many searches for planets in that cluster, though, and they have all failed.

However, M4 is only about 7000 LY away. Defining stars in it should work fine. At least one planet seems to be located in the cluster, too, orbiting PSR B1620-26.
Selden

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Cham M
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Post #5by Cham » 18.03.2005, 20:14

Selden,

47 Tucanae is 13370 LY (unless there's something wrong in my Celestia installation). I placed a lot of stars, black holes and pulsars there, and they all work fine, as the distance is well below the 16kLY limit.
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selden
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Post #6by selden » 18.03.2005, 20:27

Cham,

I found the distance that I quoted when I did a quick Web search a few minutes ago. Obviously I should have verified it with other sources.
:oops:

SEDS claims 13.4 KLY and 14.7 KLY on different pages, either of which certainly would be close enough. 2MASS places it at about 15 KLY from us (also close enough; and also the distance quoted on HubbleSite) and 23.8 KLY from the Galactic center. Maybe the page I glanced at was specifying the latter distance.

So both of the clusters that Daniel mentioned are indeed close enough to draw stars and planets in.

p.s.
Other close globulars are NGC 6397 at about 7.2 KLY, M22 at about 10 KLY and M10 at 14 KLY. NGC 6541 may be about 15 KLY.
Selden


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