Maffei << mah FAY ee >> galaxies, often called Maffei 1 and Maffei 2, are two large star systems. They probably once belonged to the Local Group, the group of galaxies that includes our own Milky Way galaxy. Gravitational interactions among galaxies likely expelled the Maffei galaxies from the Local Group. The Maffei galaxies are less than 12 million light-years from Earth. A light-year is the distance that light travels in a year. It equals about 5.88 trillion miles (9.46 trillion kilometers).
Each of the Maffei galaxies measures from 50,000 to 100,000 light-years in diameter. Maffei 1, the brighter of the two systems, may consist of as many as 100 billion stars. Maffei 2 has only about 10 billion stars. Astronomers classify Maffei 1 as an elliptical galaxy because of its oval shape. Maffei 2 resembles a flattened coil and is classified as a spiral galaxy.
The Maffei galaxies remained unknown until 1968 because they are hidden by dense clouds of cosmic dust and gas in Earth’s galaxy. They were discovered that year by the Italian astronomer Paolo Maffei, for whom they were named. Maffei photographed the galaxies through a telescope by using film sensitive to infrared rays, the invisible heat rays given off by the galaxies. Infrared rays, unlike light rays, can penetrate dust clouds. In 1971, astronomers at several California observatories determined the approximate size and shape of the Maffei galaxies.
