It is the name of newly discovered black hole toward the centre of Milky Way galaxy. It was discovered by NASA’s Swift satellite which detected a rising tide of high-energy X-rays from a source toward the center of our Milky Way galaxy. It is named after the coordinates of its position in the sky. The nova is located a few degrees from the center of our galaxy toward the constellation Sagittarius
An X-ray nova is a transitory X-ray source that appears suddenly, reaches its emission peak in a few days and then fades out over a period of months. The outburst occurs when a torrent of stored gas suddenly rushes toward one of the most compact objects known, either a neutron star or a black hole.