ABOUT THIS IMAGE:

To celebrate the 100 Hours of Astronomy, ESO is sharing two stunning images of unusual galaxies, both belonging to the Sculptor group of galaxies. The images, obtained at two of ESO's observatories at La Silla and Paranal in Chile, illustrate the beauty of astronomy.

As part of the International Year of Astronomy 2009 Cornerstone project, 100 Hours of Astronomy, the ambitious "Around the World in 80 Telescopes" event is a unique live webcast over 24 hours, following night and day around the globe to some of the most advanced observatories on and off the planet. To provide a long-lasting memory of this amazing world tour, observatories worldwide are revealing wonderful, and previously unseen, astronomical images. For its part, ESO is releasing outstanding pictures of two galaxies, observed with telescopes at the La Silla and Paranal observatories.

The first of these depicts the irregular galaxy NGC 55, a member of the prominent Sculptor group of galaxies in the southern constellation of Sculptor. The galaxy is about 70,000 light-years across, that is, a little bit smaller than our own Milky Way. NGC 55 actually resembles more our galactic neighbor, the Large Magellanic Cloud (LMC), although the LMC is seen face-on, while NGC 55 is edge-on.

By studying about 20 planetary nebulae in this image, a team of astronomers found that NGC 55 is located about 7.5 million light-years away. They also found that the galaxy might be forming a bound pair with the gorgeous spiral galaxy NGC 300. Planetary nebulae are the final blooming of Sun-like stars before their retirement as white dwarfs.

This striking image of NGC 55, obtained with the Wide Field Imager on the 2.2-meter MPG/ESO telescope at La Silla, is dusted with a flurry of reddish nebulae, created by young, hot massive stars. Some of the more extended ones are not unlike those seen in the LMC, such as the Tarantula Nebula. The quality of the image is clearly demonstrated by the remarkable number of background galaxies seen, as well as the huge numbers of individual stars that can be counted within NGC 55.

From Wikipedia:

NGC 55, also occasionally referred to as The Whale Galaxy, is a Magellanic type barred spiral galaxy located about 6.5 million light-years away in the constellation Sculptor. Along with its neighbor NGC 300, it is one of the closest galaxies to the Local Group, probably lying between the Milky Way and the Sculptor Group.

NGC 55 and the spiral galaxy NGC 300 have traditionally been identified as members of the Sculptor Group, a nearby group of galaxies in the constellation of the same name. However, recent distance measurements indicate that the two galaxies actually lie in the foreground.

It is likely that NGC 55 and NGC 300 form a gravitationally bound pair.