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Sagittarius

Sagittarius is a constellation in the southern sky that lies in the direction of the center of the Milky Way galaxy. It is rich in deep-sky objects and is home to Sagittarius A*, the supermassive black hole at the Milky Way’s core.

Source: nasa.gov

APODs including "Sagittarius"

The Galactic Center Radio Arc

21/05/2002

The Galactic Center Radio Arc
Image Credit: NASA Astronomy Picture of the Day

What causes this unusual structure near the center of our Galaxy? The long parallel rays slanting across the top of the above radio image are known collectively as the Galactic Center Radio Arc and jut straight out from the Galactic plane. The Radio Arc is connected to the Galactic center by strange curving filaments known as the Arches. The bright radio structure at the bottom right likely surrounds a black hole at the Galactic center and is known as Sagittarius A*. One origin hypothesis holds that the Radio Arc and the Arches have their geometry because they contain hot plasma flowing along lines of constant magnetic field. Recent images from the Chandra X-ray Observatory appear to show this plasma colliding with a nearby cloud of cold gas.