NGC 7023: The Iris Nebula . ... Credit Copyright: Tony Hallas Explanation: Like delicate cosmic petals, 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 . ... The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. ...