IC 10 is a dwarf irregular galaxy in the constellation Cassiopeia. The galaxy is a member of the local group, which is also our home galaxy, the Milky Way belongs. The term "IC " in the name stands for the index catalog, a late 19th and early 20th century published astronomical catalog of galactic nebulae, star clusters and galaxies. IC 10 is a very young galaxy with highly active star formation, and that of the Earth nearest starburst galaxy.
History of discovery and localization
IC 10 was discovered on October 8, 1887 by the American astronomers Lewis A. Swift, and identified in 1935 as an extragalactic object. Since the galaxy is located just three degrees away from the galactic plane, optical observations are difficult, and it took decades for this object could be located precisely: Already Edwin Hubble suggested that it could be a galaxy group in the Local, of our home galaxy, the Milky Way belongs. However, concrete evidence could be obtained only in 1962, in the form of measurements of the radial velocity of the object, confirmed the Hubble's assumption. Subsequent optical observations of H II regions of the galaxy, confirmed the comparatively short distance of this galaxy of our own.
Only in the year 1996, the membership of the Local Group could be definitively established. But in the course of eleven years of observations a number of variable stars were detected in the galaxy, including so-called Cepheids, which from the period of the brightness changes on the absolute magnitude and so, in comparison with the observed apparent brightness, the suggesting removal. In addition, it was found that IC 10 is a companion galaxy of the Andromeda galaxy.
Since the 1980s, is the question of the nature and number of existing types of stars in this galaxy subject of research. In comparison with other galaxies 10 are formed in IC comparatively many new stars. In addition, this galaxy contains an unexpected number of Wolf -Rayet stars; massive stars in the late phase of stellar evolution. IC 10 is thus the Earth nearest starburst galaxy.
Observations of the non-ionized hydrogen in the Galaxy (HI regions) suggest that IC 10 is still in the making: The galaxy continues to attract gas from the surrounding regions of space to itself ( accretion ); in galaxies inside the stellar wind of active, massive stars has created cavities are formed at the outer limits stars of the next generation. The galaxy appears to be in a star formation phase, which did not start until ten million years ago. More signs of the young age of the galaxy is the absence of traces of supernova explosions.