IC 434 and NGC2024
With Celestia v1.3.0 when you put a subdirectory within the extras directory, you do *not* have to make any changes to celestia.cfg. Celestia automatically looks through all the subdirectories that it finds in its extras directory. The change to celestia.cfg is only needed if you want to use a directory that is *not* within the extras directory.
added slightly later:
I've updated http://www.lns.cornell.edu/~seb/celestia/addon-intro.html to include several examples of this procedure.
added slightly later:
I've updated http://www.lns.cornell.edu/~seb/celestia/addon-intro.html to include several examples of this procedure.
Selden
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Guest
Oh, I didn't realize that you didn't have to modify the celestia.cfg file for folders in the extras folder. I misread your response in this thread:
http://www.shatters.net/forum/viewtopic.php?t=2062
Thanks for clearing that up Selden.
Anyway, adding those names to the celestia.cfg file did *not* hurt anything!
http://www.shatters.net/forum/viewtopic.php?t=2062
Thanks for clearing that up Selden.
Anyway, adding those names to the celestia.cfg file did *not* hurt anything!
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Guest
bh,
Right Ascension (RA) is measured in Hours, Minutes and Seconds of time:
it corresponds to the Earth turning under the sky, similar to longitude. 0 hours is measured from the position of the sun at the Vernal (spring) Equinox. RA Hours increase toward the East (not West, as I had here before!) on the sky.
Declination is measured in Degrees, Minutes and Seconds of angle: it corresponds to latitude on the Earth's surface: 0 at the equator and 90 at the poles, the North Pole being positive and the Sough Pole negative.
The stars should be put in about the right place if you use the same coordinates as for the Nebula -- although you didn't say which Nebula you want to do this for.
A quibble: bear in mind that Rassilon's Cluster Generator is supposed to be for simulating Globular Clusters. Open Clusters (also known as Galactic Clusters) tend to be much more irregular.
Right Ascension (RA) is measured in Hours, Minutes and Seconds of time:
it corresponds to the Earth turning under the sky, similar to longitude. 0 hours is measured from the position of the sun at the Vernal (spring) Equinox. RA Hours increase toward the East (not West, as I had here before!) on the sky.
Declination is measured in Degrees, Minutes and Seconds of angle: it corresponds to latitude on the Earth's surface: 0 at the equator and 90 at the poles, the North Pole being positive and the Sough Pole negative.
The stars should be put in about the right place if you use the same coordinates as for the Nebula -- although you didn't say which Nebula you want to do this for.
A quibble: bear in mind that Rassilon's Cluster Generator is supposed to be for simulating Globular Clusters. Open Clusters (also known as Galactic Clusters) tend to be much more irregular.
Last edited by selden on 25.04.2003, 14:18, edited 1 time in total.
Selden
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Guest
Does anyone have any accurate settings for star clusters around the NGC2023 and 2024 nebulas for use in the cluster generator?
I have made up my own using the following settings;
NGC2023
Distance 1614 LY : Radius 3 LY : MAG 15 :CORE 2 : 100 STARS
RA 5(hr!?) 42' 7.2"
DEC -2(hr) 19' 48"
HIP 180000
NGC2024
Distance 1605 LY : Radius 15 LY : MAG 12 : CORE 4 : 300 STARS
RA 5(hr) 42' 0"
DEC -1(hr) 42' 0"
HIP 180100
You get some pretty spectacular views by visiting some of the stars inside the nebula!
But as I say they are made up and I would like to be more accurate if possible.
I have made up my own using the following settings;
NGC2023
Distance 1614 LY : Radius 3 LY : MAG 15 :CORE 2 : 100 STARS
RA 5(hr!?) 42' 7.2"
DEC -2(hr) 19' 48"
HIP 180000
NGC2024
Distance 1605 LY : Radius 15 LY : MAG 12 : CORE 4 : 300 STARS
RA 5(hr) 42' 0"
DEC -1(hr) 42' 0"
HIP 180100
You get some pretty spectacular views by visiting some of the stars inside the nebula!
But as I say they are made up and I would like to be more accurate if possible.
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chris
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The units required in STC files are fractional degrees, both for RA and Dec. (I think this was a serious mistake, but it's probably too late now.)
Yes, I agree that this was a mistake. RA for stars should be in fractional hours, just as for objects in DSC files. The hours/minutes/seconds representation I find very cumbersome, however, and I've deliberately avoided using it.
--Chris
Chris,
Although cumbersome, I think it would be greatly appreciated by many if the RA and Dec fields could be persuaded to accept h/m/s and d/m/s, presumably in quoted strings, similar to the way the Epoch can be specified. Many astronomical information sites use that notation and it's all too easy to make mistakes when manually converting from one format to another. After all, that's what computers are for, right? to eliminate some of the numerical drudgery
This certainly isn't a critical problem, just a minor annoyance.
Although cumbersome, I think it would be greatly appreciated by many if the RA and Dec fields could be persuaded to accept h/m/s and d/m/s, presumably in quoted strings, similar to the way the Epoch can be specified. Many astronomical information sites use that notation and it's all too easy to make mistakes when manually converting from one format to another. After all, that's what computers are for, right? to eliminate some of the numerical drudgery
This certainly isn't a critical problem, just a minor annoyance.
Selden