where are we on the milky way galaxy
Milky Way The Milky Way is a barred spiral galaxy with a diameter between 100,000[26] and 180,000 light-years (ly).[27] It is estimated to contain 100â€“400 billion stars.[28][29] There are probably at least 100 billion planets in the Milky Way.[30][31] The Solar System is located within the disk, about 26,000 light-years from the Galactic Center, on the inner edge of the Orion Arm, one of the spiral-shaped concentrations of gas and dust. The stars in the innermost 10,000 light-years form a bulge and one or more bars that radiate from the bulge. The galactic center is an intense radio source known as Sagittarius A*, likely a supermassive black hole.
Milky Way Two smaller galaxies and a number of dwarf galaxies in the Local Group orbit the Milky Way. The largest of these is the Large Magellanic Cloud with a diameter of 14,000 light-years. It has a close companion, the Small Magellanic Cloud. The Magellanic Stream is a stream of neutral hydrogen gas extending from these two small galaxies across 100Â° of the sky. The stream is thought to have been dragged from the Magellanic Clouds in tidal interactions with the Milky Way.[176] Some of the dwarf galaxies orbiting the Milky Way are Canis Major Dwarf (the closest), Sagittarius Dwarf Elliptical Galaxy, Ursa Minor Dwarf, Sculptor Dwarf, Sextans Dwarf, Fornax Dwarf, and Leo I Dwarf. The smallest dwarf galaxies of the Milky Way are only 500 light-years in diameter. These include Carina Dwarf, Draco Dwarf, and Leo II Dwarf. There may still be undetected dwarf galaxies that are dynamically bound to the Milky Way, which is supported by the detection of nine new satellites of the Milky Way in a relatively small patch of the night sky in 2015.[177] There are also some dwarf galaxies that have already been absorbed by the Milky Way, such as Omega Centauri.[178]
Hubble sequence Our own Milky Way is generally classed as SBb, making it a barred spiral with well-defined arms. However, this classification is somewhat uncertain since we can only infer how our galaxy would appear to an outside observer.
Supermassive black hole Astronomers are very confident that the Milky Way galaxy has a supermassive black hole at its center, 26,000 light-years from the Solar System, in a region called Sagittarius A*[19] because: