Hubble's sweet 16
The famous space telescope struts its stuff as another year passes by.
April 26, 2006
There weren't any balloons or cake, as far as we know, but NASA and the European Space Agency celebrated the Hubble Space Telescope's 16th birthday Monday with the release of a spectacular image of starburst galaxy M82, also called the Cigar Galaxy. The image is a mosaic of exposures taken through different color filters and is the sharpest view of the galaxy yet.
M82 was selected for the birthday celebration in part because, "It displays celestial fireworks that seem appropriate for 16 years of great Hubble results," says Jay Gallagher of the University of Wisconsin. Gallagher assisted the Hubble Heritage Team at the Space Telescope Science Institute in designing the observations.
In addition to its beauty, the image contains a great deal of science, and astronomers are eager to analyze the data. "While previous Hubble [images] and other observations have given us insight into many of the details of M82, this series of observations will lay a new foundation for understanding the big picture," Gallagher tells Astronomy.
Stars form at a prodigious rate inside M82 — some 10 times faster than star birth in the Milky Way. In the image, what appear to be fuzzy stars throughout the galaxy are actually star clusters, each containing up to a million stars. Astronomers say these young, massive clusters are youthful equivalents of the ancient globular clusters orbiting the outskirts of the Milky Way and other galaxies.
A close encounter with neighboring galaxy M81 appears to have stoked M82's stellar fires by providing a massive influx of gas, the fuel of star formation. Stellar wind from M82's hot, young stars shoots ionized hydrogen, seen in the image as red plumes, out from the galactic disk. In time, such rapid star formation will strip the Cigar of its gas clouds, and star birth there will subside. By then, many of the massive stars formed in this round of star formation will begin exploding as supernovae, further disrupting the galaxy.
M82 lies 12 million light-years away in Ursa Major the Great Bear.