January 4, 2001: The saying "X" marks the spot holds true in this Hubble telescope image. In this case, X marks the location of Hubble-X, a glowing gas cloud in one of the most active star-forming regions in galaxy NGC 6822. The galaxy lies 1.6 million light-years from Earth in the constellation Sagittarius, one of the Milky Way's closest neighbors. This hotbed of star birth is similar to the fertile regions in the Orion Nebula in our Milky Way Galaxy, but on a vastly greater scale. The intense star birth in Hubble-X occurred about 4 million years ago, a small fraction of the approximate 10-billion-year age of the universe.
The image shows a nearly circular bright cloud at the core of Hubble-X. The cloud's diameter is about 110 light-years and contains many thousands of newly formed stars in a central cluster. The brightest young stars are easily visible in the Hubble picture, where they appear as numerous bright white dots.
Hubble-X is many times brighter and larger than the Orion Nebula, the brightest nearby star formation region in our Milky Way Galaxy. In fact, the tiny cloud just below Hubble-X, barely resolved even by the Hubble telescope, is about the same size and brightness as the Orion Nebula.