Explanation:
These clouds of interstellar dust and gas have blossomed
1,300 light-years away in the fertile
star fields of the constellation Cepheus.
Sometimes called the Iris Nebula and dutifully
cataloged as
NGC 7023,
this is not the only nebula in the
sky to evoke the imagery of flowers.
Surrounding it, obscuring clouds of dust and cold molecular
gas are also present and can suggest other
convoluted and
fantastic shapes.
Within the Iris, dusty nebular material surrounds a hot,
young star.
The dominant color of the brighter reflection nebula is blue,
characteristic
of dust grains reflecting starlight.
Central filaments of the cosmic dust glow with a faint
reddish photoluminesence as some dust grains
effectively
convert the star's invisible
ultraviolet
radiation to visible red light.
Infrared observations
indicate that this nebula may contain
complex carbon molecules known as
PAHs.
At the estimated distance of the Iris Nebula
this
remarkable wide field view is over 30 light-years across.
digg_url = 'http://apod.nasa.gov/apod/ap090610.html'; digg_skin = 'compact';
