what is the hubble classification of the milky way galaxy
SBb or SBc
title: Hubble sequence text: identified by appending two lower-case letters to the main galaxy type (for example, Sbc for a galaxy that is intermediate between an Sb and an Sc). Our own Milky Way is generally classed as SBb or SBc, making it a barred spiral with well-defined arms. Examples of regular spiral galaxies: M31 (Andromeda Galaxy), M74, M81, M104 (Sombrero Galaxy), M51a (Whirlpool Galaxy), NGC 300, NGC 772. Examples of barred spiral galaxies: M91, M95, NGC 1097, NGC 1300, NGC1672, NGC 2536, NGC 2903. Galaxies that do not fit into the Hubble sequence, because they have no regular structure (either disk-like or ellipsoidal), title: Milky Way text: that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with a diameter between 150,000 and 200,000 light-years (ly). It is estimated to contain 100–400 billion stars and more than 100 billion planets. The Solar System is located at a radius of 26,490 (± 100) light-years from the Galactic Center, on the inner edge of the Orion Arm, one of the spiral-shaped concentrations title: Milky Way text: of these estimated planets may be orbiting Sun-like stars. The nearest such planet may be 4.2 light-years away, according to a 2016 study. Such Earth-sized planets may be more numerous than gas giants. Besides exoplanets, "exocomets", comets beyond the Solar System, have also been detected and may be common in the Milky Way. The Milky Way consists of a bar-shaped core region surrounded by a disk of gas, dust and stars. The mass distribution within the Milky Way closely resembles the type Sbc in the Hubble classification, which represents spiral galaxies with relatively loosely wound arms. Astronomers first began to title: Milky Way text: 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. There are also some dwarf galaxies that have already been title: Galaxy text: Galaxy A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. The word galaxy is derived from the Greek "" (), literally "milky", a reference to the Milky Way. Galaxies range in size from dwarfs with just a few hundred million () stars to giants with one hundred trillion () stars, each orbiting its galaxy's center of mass. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many galaxies are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*,