NGC 1569

The NGC 1569 is a relatively nearby dwarf irregular galaxy in Camelopardalis. It’s characterized by a large starburst that has formed stars at a rate 100 times greater than that of the Milky Way during the last 100 million years.

The spectrum of NGC 1569 is blueshifted. This means that the galaxy is moving towards the Earth. In contrast, the spectra of most other galaxies are redshifted because of the expansion of the universe.

Image Credit: NASA

A Dwarf Galaxy

NGC 5949 is a dwarf galaxy around 44 million light-years from us. NGC 5949 is a relatively bulky example of a dwarf galaxy with a mass of about one percent of the Milk Way’s. It’s classified as a dwarf because of its relatively small number of constituent stars, but with loosely-bound spiral arms it is also classified as a barred spiral galaxy.

Image Credit: ESA / NASA

A Lonely Dwarf

Wolf – Lundmark – Melotte (WLM) is a lonely dwarf galaxy named for the three astronomers who discovered it. It’s about 3 million light-years from the Milky Way in the constellation Cetus, and it’s one of the most remote members of our local galaxy group. It’s so isolated that it may never have interacted with any other local group galaxy.

Image Credit: ESO

A Dwarf Starburst Galaxy

NGC 1705 is a oddball irregular dwarf galaxy undergoing a starburst. It’s about 17 million light-years from the Earth in the constellation Pictor. Dwarf galaxies were probably the first systems to collapse and start forming stars in the early universe. They represent the building blocks from which more massive objects (such as spiral and elliptical galaxies) were formed through mergers. The remaining dwarf galaxies are thought to be the leftovers of the galaxy-formation process.

Image Credit: NASA

NGC 4214

ngc-4214This is dwarf galaxy NGC 4214 which is forming clusters of new stars from its interstellar gas and dust. The young clusters of new stars are within glowing gas clouds. The gas glows because it is excited by the strong ultraviolet light emitted from the young stars forming in the gravitational collapse of the gas. These hot stars eject stellar winds moving at thousands of km/s which blow bubbles in the gas. Near the center of the galaxy, there is a cluster of hundreds of massive blue stars, each more than 10,000 X brighter than our Sun, and a huge bubble inflated by stellar winds and radiation pressure surrounds the cluster.

Image Credit: NASA / ESA