Saturday, October 20, 2007
Friday Galactic Blogging
Dwarf Irregular galaxy I Zwicky 18 is a relatively nearby (59 million light years), notably strange object which was once thought to an extremely young galaxy in our general neighborhood. Hubble imaging has recently shown a much older star population than had previously been seen, and current estimates give its age at about 10 billion years, consonant with estimates of the age og the Milky Way. The bright young stars which seem to dominate its light output may have been created because of the gravitational effect of the nearby companion galaxy, seen here to the upper right.
Click through for the APOD page describing this object.