NGC 7023: The Iris
Nebula
From NASA’s Astronomy Picture of the
Day
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, NGC
7023 is not the only nebula in the sky to evoke the imagery of flowers, though.
Still, this deep
telescopic view shows off the Iris Nebula's range of colors and
symmetries in impressive detail. 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 dusty clouds 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.
The pretty blue petals of the Iris Nebula span about six light-years.
