(this page is part of the Harvard Univesity Astronomy 208 web site)
The Ground Based
View of the Eagle Nebula (image above) reveals "pillar-like"
features which appear to be buried deep within the nebula. The high-resolution
HST view of the
"Pillars"
of M16 shows them to contain strange features on their surfaces. These
features are referred to as "EGGs" or "Evaporating Gaseous
Globules." They are thought to be dense star-forming cores whose environs
have been blasted away by photons and winds from the newly-formed massive
stars in the region. An explanatory
cartoon of this process has been provided at the HST Web Site.
Many views of the Orion
Nebula can be found through the "Web
Nebulae" site. For the best high-resolution composite view, check
out the Orion Nebula
mosaic from HST (shown above), which has a little ground-based data added
in around the edges. The "bright bar" near the lower left of the
image above is also known as Orion
Ridge. This "bar" or "ridge" is actually a relatively
flat region, seen end-on. In other words, it is primarily a column-density
enhancement. This illustration
from National Geographic shows the overall geometry of the Orion Nebula.
Information on the "PROPLYDs" evident in the Orion Nebula mosaic can be found through here.
In 1997, the NICMOS near-IR camera was used to observe the OMC-1 region of Orion, which resulted in this image
:
Perhaps the single most impressive H II region near the Milky Way is the one created by R136, a dense cluster of young hot stars in the center of 30 Doradus (image above) in the Large Magellanic Cloud. The HST images of R136 reveal a higher concentration of early-type stars than any known in the Milky Way.
The very large H II region NGC604 resides in a spiral arm of the Galaxy
M33, and is easily visible in ground-based photographs. The HST
image has the resolution to reveal the cavity carved out by the winds
and photons from the hottest (and youngest) stars at the core of this massive star-forming region.