
Not all roses are red
of course, but they can still be very pretty. Likewise, the beautiful
Rosette Nebula and other star forming regions are often shown in astronomical images with a predominately red hue, in part because the dominant emission in the nebula is
from hydrogen atoms. Hydrogen's strongest optical emission line, known as H-alpha, is in the red region of the spectrum, but the beauty of an emission nebula need not be appreciated in red light alone.
Other atoms in the nebula are also excited by energetic starlight and produce narrow emission lines as well. In this gorgeous view of the Rosette Nebula, narrowband images are combined to show emission from sulfur atoms in red, hydrogen in blue, and oxygen in green. In fact, the
scheme of mapping these narrow atomic emission lines into broader colors is adopted in many
Hubble images of stellar nurseries. The image spans about 100 light-years in the constellation Monoceros, at the 3,000 light-year
estimated distance of the
Rosette Nebula. To make the Rosette red, just follow
this link or slide your cursor over the image.
from NASA http://ift.tt/2EV0eoC
via
IFTTT