Before going to NGC 1569 dwarf galaxy let us fist know what is dwarf galaxy,
Dwarf Galaxy
These are small galaxies composed of billions of stars, but it is small when compared to our milky way galaxy (200-400 billion stars).
Dwarf Galaxy
These are small galaxies composed of billions of stars, but it is small when compared to our milky way galaxy (200-400 billion stars).
 |
| Eg: UGC 9128 is a dwarf irregular galaxy |
Formation of dwarf galaxies
Current theory states that most galaxies, including dwarf galaxies, form in association with dark matter or out of gas containing metals. However, NASA's Galaxy Evolution Explorer space probe identified new dwarf galaxies forming out of gases lacking metals. These galaxies were located in the Leo Ring, a cloud of hydrogen and helium around two massive galaxies in the constellation Leo.
Conversely, dwarf galaxies because of their small size have been observed to be pulled toward and ripped by neighboring spiral galaxies till they ultimately merge.
There are many dwarf galaxies in the Local Group: these small galaxies frequently orbit around larger galaxies (Satellites of) , such as the Milky Way, the Andromeda Galaxy and the Triangulum Galaxy.
NGC 1569
NGC 1569 is a dwarf irregular galaxy in constellation Camelopardalis. While this faint galaxy is not a popular amateur astronomy target, it is well studied by professional astronomers, who are interested in the history of star formation within the galaxy. The galaxy is relatively nearby.
Consequently, the Hubble Space Telescope can easily resolve the stars within the galaxy. The distance to the galaxy was previously believed to be only 2.4 Mpc (7.8 Mly). However, in 2008 scientists studying images from Hubble calculated the galaxy's distance at nearly 11 million light-years away, about 4 million light-years farther than previous thought and making it a member of the IC 342 group of galaxies.
The entire core of NGC 1569 is 5000 light years wide,The galaxy, called NGC 1569, sparkles with the light from millions of newly formed young stars. NGC 1569 is pumping out stars at a rate that is 100 times faster than the rate observed in our Milky Way Galaxy. This frenzied pace has been almost continuous for the past 100 million years.
The core's centerpiece is a grouping of three giant star clusters, each containing more than a million stars. (Two of the clusters are so close they appear as one grouping.) The clusters reside in a large, central cavity. The gas in the cavity has been blown out by the multitude of massive, young stars that already exploded as supernovae. These explosions also triggered a violent flow of gas and particles that is sculpting giant gaseous structures. The sculpted structure at lower right is about 3,700 light-years long.
 |
| Center of NGC 1569 as imaged by the Hubble Space Telescope. |
Huge bubbles of gas, such as the two at left, appear like floating islands. The largest bubble is about 378 light-years wide and the smallest 119 light-years wide. They are being illuminated by the radiation from the bright, young stars within them. Some of those stars are peeking through their gaseous cocoons.
The biggest and brightest objects surrounding the core are stars scattered throughout our Milky Way Galaxy. In contrast, the thousands of tiny white dots in the image are stars in the halo of NGC 1569. The galaxy is 11 million light-years from Earth as told above.