Galactic Center

[1][2] Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*,[3][4][5] a compact radio source which is almost exactly at the galactic rotational center.

[clarification needed] The Galactic Center is approximately 8 kiloparsecs (26,000 ly) away from Earth[3] in the direction of the constellations Sagittarius, Ophiuchus, and Scorpius, where the Milky Way appears brightest, visually close to the Butterfly Cluster (M6) or the star Shaula, south to the Pipe Nebula.

[6] Harlow Shapley stated in 1918 that the halo of globular clusters surrounding the Milky Way seemed to be centered on the star swarms in the constellation of Sagittarius, but the dark molecular clouds in the area blocked the view for optical astronomy.

[7] In the early 1940s Walter Baade at Mount Wilson Observatory took advantage of wartime blackout conditions in nearby Los Angeles, to conduct a search for the center with the 100-inch (250 cm) Hooker Telescope.

By 1954 they had built an 80-foot (24 m) fixed dish antenna and used it to make a detailed study of an extended, extremely powerful belt of radio emission that was detected in Sagittarius.

[10] In 1958 the International Astronomical Union (IAU) decided to adopt the position of Sagittarius A as the true zero coordinate point for the system of galactic latitude and longitude.

Scientists at the Max Planck Institute for Extraterrestrial Physics in Germany using Chilean telescopes have confirmed the existence of a supermassive black hole at the Galactic Center, on the order of 4.3 million solar masses.

The unusual event may have been caused by the breaking apart of an asteroid falling into the black hole or by the entanglement of magnetic field lines within gas flowing into Sagittarius A*, according to astronomers.

[36] In November 2010, it was announced that two large elliptical lobe structures of energetic plasma, termed bubbles, which emit gamma- and X-rays, were detected astride the Milky Way galaxy's core.

[37] The galaxy's diffuse gamma-ray fog hampered prior observations, but the discovery team led by D. Finkbeiner, building on research by G. Dobler, worked around this problem.

[37] The 2014 Bruno Rossi Prize went to Tracy Slatyer, Douglas Finkbeiner, and Meng Su "for their discovery, in gamma rays, of the large unanticipated Galactic structure called the Fermi bubbles".

Current evidence favors the latter theory, as formation through a large accretion disk is more likely to lead to the observed discrete edge of the young stellar cluster at roughly 0.5 parsec.

They predict that in approximately 200 million years, there will be an episode of starburst in the Galactic Center, with many stars forming rapidly and undergoing supernovae at a hundred times the current rate.

A starchart of the night sky towards the Galactic Center

This pan video gives a closer look at a huge image of the central parts of the Milky Way made by combining thousands of images from ESO's VISTA telescope on Paranal in Chile and compares it with the view in visible light. Because VISTA has a camera sensitive to infrared light, it can see through much of the dust blocking the view in visible light, although many more opaque dust filaments still show up well in this picture.

Animation of a barred galaxy like the Milky Way showing the presence of an X-shaped bulge. The X-shape extends to about one half of the bar radius. It is directly visible when the bar is seen from the side, but when the viewer is close to the long axis of the bar it cannot be seen directly and its presence can only be inferred from the distribution of brightnesses of stars along a given direction.