G A L A C T I C C O R E

The central eight degrees of the Milky Way Galaxy; click for additional views of the same region

Image courtesy NASA/Spitzer Space Telescope

A panoramic photographic view of the core of the Milky Way Galaxy, as captured from Earth orbit by the Spitzer Space Telescope. This picture is a mosaic of infrared images of the central 8 degrees of the Milky Way (from 4 to 356 degrees Galactic Longitude). At the heart of this maelstrom of nebulae is Sagittarius A*, the supermassive black hole around which the Galactic Disk is rotating. See the APOD presentation. See more images of the Galactic Core.

Star clusters toward the center of the Milky Way Galaxy; click for additional views of central regions of our Galaxy

Image by A. Schaller; courtesy NASA/ESA/A. Schaller/STScI

Artist's rendering of a view toward the core of the Milky Way Galaxy, showing a massive star cluster located 5.8 kiloparsecs (almost 20,000 light years) away from Earth in the constellation Scutum. This cluster contains 14 red supergiants, each between 8 and 25 times the mass of our Sun, and it emits great bursts of x-rays and gamma rays. For more information, see this news release from the Spitzer Space Telescope team. In general, the central regions of the Milky Way are crowded with massive stars that cause violent storms of radiation.

Image courtesy NASA/Hubble Space Telescope

If we could see the core of the Milky Way from outside, it might resemble an overhead view of the central bulge of NGC 1672. This spiral galaxy in Dorado has a well-developed central bar and two major arms. An analogous spiral structure has been proposed for the Milky Way. The bar of NGC 1672 is more than 6 kiloparsecs (20,000 light years) long, while that of the Milky Way is even longer, at about 8.8 kiloparsecs (28,700 light years); see Benjamin et al. 2005, Astrophysical Journal 630, L149-L152.

All text is copyright Raymond Harris 2006-2008. Image credits appear in the accompanying caption.