NGC 1999
| H-alpha image from 17 x 10 min exposures, binned 2:2, SBIG ST10XME/AO8; C9.25 at f/4.8, click on image for full-size. Note that this image is rotated 90 degrees CCW from the Kitt Peak image. |
| Closeup of the reflection nebula NGC 1999 taken by the Hubble Space Telescope. |
About 1500 light years distant and near the large Orion emission nebula (M42), lies the small, but
bright, reflection nebula NGC 1999. This nebula is shown in some detail in the Hubble image shown
below. The dark “T” shape is thought to be a dense gas and dust cloud, seen in silhouette against
the bright blue nebula, and is likely a site of future star formation. Unlike emission nebulae, whose
reddish glow comes from excited atoms of hydrogen gas, reflection nebulae have a bluish cast as
their interstellar dust grains preferentially reflect blue starlight.
I became interested in this area when I saw an image of the emission nebula surrounding NGC1999.
It is a very dim nebula and the grayscale image below is from 17 x 10 minute exposure with the
camera “binned” 2:2 to increase its sensitivity by a factor of four. Binning involves electronically
combining pixels in the camera. The trade off of binning is that the image is smaller (i.e., fewer, but
larger pixels), but the payoff is being able to obtain an image of very dim objects like NGC1999. In
this hydrogen-alpha image, NGC1999 is the small bright spot in the lower center. If you look closely
in the full-sized image, you can see the "T" of the reflection nebula. What is interesting to me is the
complex structure of the emission area. It almost looks volcano-like.
The color image shown below was taken with the 4 meter Mayall telescope at the Kitt Peak National
Observatory. See this link for more information on this interesting image. If you look at the full sized
image you can see many examples of Herbig–Haro objects which are small patches of nebulosity
associated with newly born stars. More info on these "HH" objects can be found in Wikipedia.
bright, reflection nebula NGC 1999. This nebula is shown in some detail in the Hubble image shown
below. The dark “T” shape is thought to be a dense gas and dust cloud, seen in silhouette against
the bright blue nebula, and is likely a site of future star formation. Unlike emission nebulae, whose
reddish glow comes from excited atoms of hydrogen gas, reflection nebulae have a bluish cast as
their interstellar dust grains preferentially reflect blue starlight.
I became interested in this area when I saw an image of the emission nebula surrounding NGC1999.
It is a very dim nebula and the grayscale image below is from 17 x 10 minute exposure with the
camera “binned” 2:2 to increase its sensitivity by a factor of four. Binning involves electronically
combining pixels in the camera. The trade off of binning is that the image is smaller (i.e., fewer, but
larger pixels), but the payoff is being able to obtain an image of very dim objects like NGC1999. In
this hydrogen-alpha image, NGC1999 is the small bright spot in the lower center. If you look closely
in the full-sized image, you can see the "T" of the reflection nebula. What is interesting to me is the
complex structure of the emission area. It almost looks volcano-like.
The color image shown below was taken with the 4 meter Mayall telescope at the Kitt Peak National
Observatory. See this link for more information on this interesting image. If you look at the full sized
image you can see many examples of Herbig–Haro objects which are small patches of nebulosity
associated with newly born stars. More info on these "HH" objects can be found in Wikipedia.
| Image of NGC 1999 from the Kitt Peak National Observatory 4 meter telescope. Click on the image for full size |