NGC 55 - String of Pearls Galaxy

At a distance of 6 million light years from us lies this spectacular galaxy, NGC 55 also known as The String of Pearls Galaxy. It resides in a relatively nearby gathering of galaxies, the Sculptor Group, which is located about 6 million light years from us.

This image captures huge filaments, loops and "bubbles" of ionized hydrogen gas thousands of light years across. These structures probably result from material blown outward by many generations of massive stars in galaxy. NGC 55 is an irregular galaxy that has hints of spiral structure; it is similar to the Large Magellanic Cloud, a companion to the Milky Way that is visible in the southern sky.

Astronomers theorize that the tangled protrusions from NGC 55 resulted from disruptions caused by a class of hot, rapidly evolving stars within the galaxy. These stars, which have at least ten times the mass of the sun, shine brilliantly and eject material in powerful stellar winds. When such massive stars exhaust their nuclear fuel, they undergo cataclysmic detonations--supernova explosions--which blast away the star's outer layers. The combination of stellar winds and supernova explosions sculpts the interstellar hydrogen gas into the bubbles and filaments seen in this image.

An additional feature I was able to capture in this image is the large center halo. It is highly active in star forming regions and dust lanes. How stars form in the galactic halo, away from traditional regions of star formation remains an enigma. Different scenarios have been proposed including ejection of stars or clusters from the disk as a consequence of supernovae or gravitational encounters.