IC 434 and NGC2024

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praesepe
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IC 434 and NGC2024

Post #1by praesepe » 08.04.2003, 02:36

Well, this is my new experiment, the IC434 reflection nebula, and NGC2024 emission nebula, just a test to try to implement to Celestia.
The 3d mesh still needs LOTS of work in order to have it a decent look (the horsehead looks distorted for example) and of course, the object its not properly oriented in space (Zeta Orionis should be in the left, just on top of NGC2024), so RA and DEC parameters for the dsc file would be very apreciated.

Celestia
Image

Hubble
Image
Last edited by praesepe on 08.04.2003, 03:52, edited 1 time in total.
Greets :P

praesepe

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Post #2by billybob884 » 08.04.2003, 03:21

can't see either pic
Mike M.

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Post #3by praesepe » 08.04.2003, 03:53

Damn Netfirms server...:x I've moved the pics to another one and edited the previous post. :)
Greets :P

praesepe

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Post #4by marc » 08.04.2003, 04:18

That looks fantastic, are the stars in the celestia image part of the nebula texture, or are they rendered by celestia?

In other words (did you filter the stars out of the nebula texture?)

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Re: IC 434 and NGC2024

Post #5by selden » 08.04.2003, 04:33

praesepe wrote:the object its not properly oriented in space (Zeta Orionis should be in the left, just on top of NGC2024), so RA and DEC parameters for the dsc file would be very apreciated.


http://www.astropix.com/HTML/B_WINTER/B33_O.HTM has coordinates for most of the components of the Orion Nebula, including IC 434 (RA 5h 41m Dec 2 23' 59" ), NGC 2024 ( RA 5h 41m 54s Dec -1 50' 07") and B33, the Horsehead itself ( RA 5h 40m 49s Dec -2 28' 19")

Does this help?
Selden

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Post #6by praesepe » 08.04.2003, 05:08

marc wrote:That looks fantastic, are the stars in the celestia image part of the nebula texture, or are they rendered by celestia?

In other words (did you filter the stars out of the nebula texture?)

Yes, all stars there are rendered by Celestia, I've carefully edited the original Hubble photograph and removed all stars using Photoshop.

Image

selden wrote:http://www.astropix.com/HTML/B_WINTER/B33_O.HTM has coordinates for most of the components of the Orion Nebula, including IC 434 (RA 5h 41m Dec 2 23' 59" ), NGC 2024 ( RA 5h 41m 54s Dec -1 50' 07") and B33, the Horsehead itself ( RA 5h 40m 49s Dec -2 28' 19")

Does this help?


Sure! lots of thanks! :wink:
Greets :P

praesepe

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Post #7by Rassilon » 08.04.2003, 05:25

beautiful work....wishing I had more time to work with some of you in making the models I would help to decorate Celestia but the billboards should do for now...
I'm trying to teach the cavemen how to play scrabble, its uphill work. The only word they know is Uhh and they dont know how to spell it!

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Post #8by billybob884 » 08.04.2003, 11:36

(referring to first set of pics) It looks like the milkey way is too visible. in hte hubble shot its not visible at all
Mike M.



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Post #9by jgrillo2002 » 08.04.2003, 21:32

here are some pics of the flame nebula which is the one on he bottom left of the first pic ImageImage :)
Heres a special pic of the nebula in infered Image :D :D :D :) :) :o :wink:

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Post #10by selden » 08.04.2003, 22:08

praesepe,

A minor quibble: the blue "star" just below and to the left of Barnard 33 is actually the emission nebula NGC 2023. It's much more extended in some wavelengths. You might want to include it. As best I can tell the other bright blue stars are just overexposed.
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Post #11by praesepe » 09.04.2003, 01:33

Here's an update. I've reworked the texture again in photoshop and improved a little more the 3d mesh. I've also arranged the dsc file so the nebula is now placed in the correctly in Orion (thanks to selden for the data).

Here are some screenshots:
Image
Image
Image
Image

selden wrote:praesepe,

A minor quibble: the blue "star" just below and to the left of Barnard 33 is actually the emission nebula NGC 2023. It's much more extended in some wavelengths. You might want to include it. As best I can tell the other bright blue stars are just overexposed.


Oops! I just thought it was a star. I'll add it in the next update, thanks!
Greets :P

praesepe

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Horsehead

Post #12by ogg » 09.04.2003, 05:13

I seem to remember my old copy of sky3d rendering the horsehead as a dark 'dust nebula' object many light years in front of the bright nebula: the horsehead effect being an artifact of the line-up of the dark and bright nebulas as seen from earth. It looked kinda hokey... but what's the truth of that matter here? are all the features we see in this nebula from earth part of the same object, or is it two objects? anyone know?
I might be mistaken about this... I'll see if I can dig it up again. Not that this really matters; the thing looks fantastic!!!
___________

ogg
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Post #13by marc » 09.04.2003, 08:29

Again very nice work, cant wait to get the addon.

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Post #14by selden » 09.04.2003, 17:11

Ogg,

Yes, they're at different distances, although the distances aren't known very accurately. The only precise measurement that I've found so far is for the star that's illuminating NGC 2023. That star is already in Celestia as HD 37903 / HIP 26816 at a distance of 1538 ly. It's "obviously" either in front of, or in the closest fringes of, the absorption nebula that includes the Horsehead Nebula. 1600 ly seems to be a reasonable estimate for the distance to the nebular complex.
Selden

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Re: IC 434 and NGC2024

Post #15by selden » 10.04.2003, 17:59

praesepe,

Where did you get your "Hubble" picture of the nebula?
Can you provide a URL? I haven't been able to find it.

The Hubble telescope itself can't take pictures that are so wide; they had a lot of trouble getting a mosaic of just the Horsehead. See http://heritage.stsci.edu/2001/12/supplemental.html
Selden

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Post #16by praesepe » 10.04.2003, 21:12

selden wrote:praesepe,

Where did you get your "Hubble" picture of the nebula?
Can you provide a URL? I haven't been able to find it.

The Hubble telescope itself can't take pictures that are so wide; they had a lot of trouble getting a mosaic of just the Horsehead. See http://heritage.stsci.edu/2001/12/supplemental.html


selden,

i've got all the information from http://www.seds.org/billa/twn/b33x.html and also the original pic wich I modified in order to use for Celestia.

Here's also a new update, with some work on the east region (the original picture had a cut off) and with the emission nebula NGC2023 added.

Image
Greets :P

praesepe

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Post #17by selden » 10.04.2003, 21:29

Thanks!

(I'm guessing that you haven't put the nebula in exactly the right place yet. There are a few strange stars in the image :) )

But it's looking quite good!
Selden

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Post #18by praesepe » 11.04.2003, 01:15

selden wrote:(I'm guessing that you haven't put the nebula in exactly the right place yet. There are a few strange stars in the image )


Ummm may be I've done something wrong in the conversion of dec and ra coordinates, for now, the dsc setting I'm using are these:

Code: Select all

Nebula "IC434"
{
   Mesh "IC434neb.3ds"
   Radius 5
   RA 5.673
   Dec -1.95
   Distance 1500
}


And here's a pic of the current orientation:

Image
Greets :P

praesepe

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Post #19by selden » 11.04.2003, 02:09

Praesepe,

The problem is its orientation: the long dimension should be north-south, not east-west.

I've created a billboard of the Horshead Nebula region which can be seen at http://www.lns.cornell.edu/~seb/celestia/billboard.html#5.0

I think you can get the orientation and size right if you can use the original picture with stars. Then you can turn up the limiting magnitude in Celestia and align its stars with those in the texture. That's what I did for the "billboard" picture.

Another minor quibble: the distance to the lower part of the absorption nebula is probably slightly more than 1500 ly. The distance to the star in the middle of the emission nebula was measured by Hipparcos. It is in Celestia's database as HD 37903 / HIP 26816 at a distance of 1538 ly. Since we can see it, the emission nebula must be in front of the absorption nebula that forms the Horsehead. Of course, B33 could be closer to us than the eastern parts of the nebula.


(added later)
Here's the DSC that I used:

Code: Select all

#Horsehead Nebula in Orion
#
# the "billboard" picture used with this definition is derived from
#a photograph of the Horsehead Nebula Region taken by Walter Koprolin,
# Austria, Europe: http://www.astro.univie.ac.at/~koprolin/
#
Nebula "Barnard 33" {
    Mesh     "b33.3ds"
        Axis [ -0.625476 0.339879 -0.702326 ]
        Angle 128.818
    Distance   1600
    RA          5.69
    Dec        -2.35
    Radius     40.3


(added still later)
here's a picture of the billboard with constellation lines
Image
As usual, this links to a much larger picture.
Selden

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praesepe
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Post #20by praesepe » 11.04.2003, 04:34

selden,

Looks like I got strongly confused when orientating the model :o

I've done the appropiate corrections and checked some data that was wrong (i.e. radius).

Now it looks like this:

Image
Greets :P

praesepe


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