Celestia Forums

Hi, I've gotten a user name and visited this site just to ask a question.
I was trying to find the Orion Nebula in relation to the Constellation, both
in real life, and in the game. I found a site online that explained the Nebula as being the middle star of Orion's Sword, the smaller three star set within the Constellation, below Orion's Belt. I have been looking at the Constellation, last night, in the sky and also on the game, and noticed that the only three star lineup that could be the 'sword of Orion' in the Constellation, has a star in the middle on the game. So now the big question; is there a patch or mod that'll actually make the Nebula appear instead of a fake star, or am I completely off the charts looking at the wrong 'sword of Orion' in the game? Thanks for your time, if anyone answers!

Lamb4Dreme wrote:both
in real life, and in the game. ....... in the sky and also on the game, and ..... a star in the middle on the game. ....... in the game?

To see the Orion nebula, you'll have to download and install an addon from the Motherlode. Currently, there is no nebulae installed by default in the game... er ... I mean Celestia

O well ! ...

Also, there are no fake stars included with Celestia. You're probably seeing one of the members of the Trapezium, a cluster of stars in the center of M42

I wish someone could get their hands on that 3d Orion Nebula that was used in planetariums and conver it to a mesh we could use. Any of you "real" astrophysicists have some connections?

http://vis.sdsc.edu/research/orion.html

I tried.

The astronomers who originally created it have retired and can't be contacted. The copyright is currently held by the Hayden Planetarium and the model is used in some of their presentations. They're very reluctant to make it publicly available.

That's a shame, you would think Mr. DeGrasse Tyson would be into this kind of thing. Maybe I will try contacting him... I thought of trying to reconstruct the main floor mesh at one time, but my 3d skills aren't all that developed. Bummer.

If you know the right person to contact, then you may be more successful than I was. Good luck!

The video is very nice.

But do we have those stars in Celestia ? I'm unable to find them.

No, not all of the stars of the Triangulum are in Celestia. Only some of them were measured by Hipparcos.

However, Grant Hutchison created an Addon that includes the one that's missing from the Triangulum itself.

http://www.lepp.cornell.edu/~seb/celest ... ezium.html

Of course, there are hundreds of other stars in the entire cluster.

Thanks Selden,

but this surprises me a lot. So there is currently no Orion stars available for Celestia ? Yet, this is a very interesting part of the universe, and nothing available for Celestia ? This can't be !

Cham,

Three of the four primary stars of the Trapezium, a cluster of stars also known as Theta Orionis, which are in the center of the Orion Nebula, M42, had their parallax measured by Hipparcos and are included in Celestia's stars.dat. They are
Tet1 Ori A = HIP 26220
Tet1 Ori C = HIP 26221
Tet1 Ori D = HIP 26224

The one that Hipparcos didn't measure directly, Tet1 Ori B, is in Grant's Addon.

For some unknown reason, only one of those stars is included in Pascal's 1 and 2 million star versions of stars.dat.

This is very strange to me. The Orion nebula is so popular and spectacular, we should have more of it in Celestia.

This 3D model video is really stimulating. We should try do do something like this for Celestia.

It may be a very good time to add more stars from this cluster to our database. However, my own technical and astronomical skills are very limited to do it myself. I'll try to do something, but my results should not be trusted.

Is it possible to update the default stars.dat with the Tet1 Ori B star?

stars.dat in v1.4.0 is strictly the Hipparcos catalog translated for use with Celestia.

revised.stc in v1.4.0 contains corrected values when stars' Hipparcos values are known to be incorrect.

Other star catalogs can be provided as Addons.

I guess that would be a more sensible approach

selden wrote:stars.dat in v1.4.0 is strictly the Hipparcos catalog translated for use with Celestia.

revised.stc in v1.4.0 contains corrected values when stars' Hipparcos values are known to be incorrect.

Other star catalogs can be provided as Addons.

You could do a orionnebula.stc for those that load the addon.

Is this this nebula you are talking about?



Where is it located exactly or has it got an NGC catalog number?

Boux,

The Orion Nebula is also known as M42 and NGC 1976.

I don't recognize the nebula that you show, although it looks like it might be a very small portion of the center of the nebula. The 3D model used by the Hayden Planetarium is based on an image of M42 that covers a larger area on the sky.

Here's one image of the central portion, My understanding is that the Hayden model is based on one similar to this.

.
The dark area absorption nebula in the upper left is the "roof" of the "cave" in the 3D model, while the bright stripe in the lower left is a "cliff".

selden wrote:Boux,
The Orion Nebula is also known as M42 and NGC 1976.
I don't recognize the nebula that you show, although it looks like it might be a very small portion of the center of the nebula. The 3D model used by the Hayden Planetarium is based on an image of M42 that covers a larger area on the sky.

OK, thanks, Selden
Actually, it is a small portion of it.
It happens that I was working on it.
I am trying to put 4 layers spaced 0, 3, 2, 1 light years in deepness with the first 3 layers as increasingly narrow windows on the 4th one, with different color saturation and transparencies. This to give some 3d feeling to it.

Hello

I have two problems with Orion nebula :

1) With Celestia 1.4pre6, Tet1 Ori A, B, C, D stars are closer than on Celestia-FT1.2.

So with Celestia 1.4pre6 my model seems to be ok



But not in Celestia FT1.2 where TET1 Ori A is 2,07 Kpc away ...

Only Grant Hutchison's description of TET1 Ori B remain inside my model.
What's wrong ?

2) I am not satisfied with the side view of my model


Does somebody have an idea on the structure of this nebula seen on the side view (if i can say there is a side ) ?

Thanks
jll