These add-ons for Celestia v1.3.0 (or later) display a montage of six images
of the Eagle Nebula and its associated galactic cluster, M16. They also include
an STC file defining 74 of the stars in the cluster. (Some of these star
definitions specify star names, which requires Celestia v1.3.1pre3 or later.)
While m16-v2
contains transparent images, the images included in
m16-v3
are opaque.
Archive: m16-v2.zip (the "-v3" archive contains the same filenames but replaces "-v2" with "-v3") Length Date Time Name -------- ---- ---- ---- 9227 07-01-03 22:21 m16-v2/m16-alignment.html 11189 07-01-03 07:52 m16-v2/m16-cluster.stc 7698 07-03-03 12:33 m16-v2/m16-v2-readme.html 3431 07-01-03 22:15 m16-v2/m16-v2.dsc 8283 07-02-03 21:18 m16-v2/m16-v2a.jpeg 7903 07-02-03 21:18 m16-v2/m16-v2b.jpeg 7633 07-03-03 00:41 m16-v2/m16-v3a.jpeg 10324 07-03-03 00:53 m16-v2/m16-v3b.jpeg 0 07-02-03 20:09 m16-v2/models/ 0 07-02-03 20:09 m16-v2/textures/ 704 06-30-03 22:36 m16-v2/models/04086.3ds 708 06-28-03 09:45 m16-v2/models/1995-44-a.3ds 704 06-28-03 11:56 m16-v2/models/eagle.3ds 707 06-27-03 06:38 m16-v2/models/m16atlas.3ds 708 06-28-03 10:41 m16-v2/models/m16c1_eso.3ds 710 06-25-03 07:45 m16-v2/models/phot-37a-01.3ds 0 07-02-03 20:09 m16-v2/textures/medres/ 5592560 06-30-03 22:34 m16-v2/textures/medres/04086.dds 5592560 07-01-03 20:57 m16-v2/textures/medres/1995-44-a.dds 1398256 06-29-03 17:43 m16-v2/textures/medres/eagle.dds 1398256 06-27-03 07:06 m16-v2/textures/medres/m16atlas.dds 1398256 06-28-03 11:45 m16-v2/textures/medres/m16c1_eso.dds 5592560 06-28-03 10:50 m16-v2/textures/medres/phot-37a-01.dds -------- ------- 21042377 23 files
The easiest way to install these add-ons is just to expand the .ZIP archive into Celestia's extras directory. Zip will automatically create the subdirectory m16-v2 or m16-v3 and its contents.
These archives were updated on 6 July '03 with improved coordinates for the
M16 cluster members in the file m16-cluster.stc
. Errors were
reduced from about 1 second of arc in Right Ascension (1/15 second of time) to
better than 1/10 second of arc (1/150 second of time). The improved coordinates
were obtained by using a more accurate routine to precess from B1950 to J2000,
the Starlink subroutine fk425.f. See http://star-www.rl.ac.uk/.
![]() The Eagle Nebula and M16: full view |
![]() The Eagle Nebula and M16: closeup |
![]() Eagle Nebula with opaque cold gasses |
![]() The Pillars behind the gas |
|
(2Kx2K) | A false-color image of the Eagle Nebula, from NOAO |
|
(1Kx1K) | An infra-red mosaic of stars in the Nebula, from 2MASS |
|
(2Kx2K) | The famous picture of the "Pillars of Creation," from NASA |
|
(2Kx2K) | A high resolution infra-red mosaic of stars, from ESO |
|
(1Kx1K) | A closeup IR image of the top of Pillar #1, from ESO |
|
(1Kx1K) | A picture showing the cold nebulosities (-100 degrees Centigrade) that fill the Nebular region, from ESA's ISO. |
In m16-v2
, all but the backdrop, 04086.dds, incorporate alpha
channels which let you see though them to the images behind. In
m16-v3
, the alpha channels of all of the images eliminate only the
black borders.
Borders were added around the smaller images instead of scaling them up to a size needed by Celestia. This should limit the damage done to the resolution to that inflicted by your graphics hardware. However, two of the images, "04086" and "phot", were scaled down from much larger versions available on the Web.
Hopefully soon Celestia will allow selecting among Nebula textures as it does among alternate planetary surface textures. In the meantime, you can edit m16-v2.dsc and comment out the Mesh declarations of those "billboards" you'd like to ignore.
This add-on has several limitations which may be corrected in a future version.
Selden Ball
July 2003
Grant Hutchison provided a spreadsheet calculator which greatly improved the alignment of the images.
The original images were obtained by the research groups credited below.
If you don't tell me that something's missing, unclear or wrong, I can't improve it.