Image courtesy T. A. Rector/UAA, H. Schweiker/WIYN, and NOAO/NSF
Spring flowers are blooming—even in space. This recently released picture shows NGC 7023, also called the Iris nebula for its floral appearance, as seen from Kitt Peak National Observatory in Arizona.
The cosmic flower is actually what’s known as a reflection nebula. The interstellar cloud of dust and gas glows not because its material is being heated, but because it’s reflecting light from nearby stars.
Lying about 500 million light-years away in the constellation of Sculptor, the cartwheel shape of this galaxy is the result of a violent galactic collision. A smaller galaxy has passed right through a large disc galaxy and produced shock waves that swept up gas and dust — much like the ripples produced when a stone is dropped into a lake — and sparked regions of intense star formation (appearing blue). The outermost ring of the galaxy, which is 1.5 times the size of our Milky Way, marks the shock wave’s leading edge. This object is one of the most dramatic examples of the small class of ring galaxies.