Local GroupThe Local Group is the galaxy group that includes the Milky Way, where Earth is located. It consists of two collections of galaxies in a "dumbbell" shape; the Milky Way and its satellite galaxies form one lobe, and the Andromeda Galaxy and its satellite galaxies constitute the other.
Andromeda GalaxyBarred spiral galaxy in the Local GroupThe Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a D25 isophotal diameter of about 46.56 kiloparsecs (152,000 light-years) and is approximately 765 kpc (2.5 million light-years) from Earth.
Dwarf galaxyA dwarf galaxy is a small galaxy composed of about 1,000 up to several billion stars, as compared to the Milky Way's 100–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is sometimes classified as a dwarf galaxy; others consider it a full-fledged galaxy. Dwarf galaxies' formation and activity are thought to be heavily influenced by interactions with larger galaxies.
Andromeda XVIIIAndromeda XVIII, discovered in 2008, is a dwarf spheroidal galaxy (has no rings, low luminosity, much dark matter, little gas or dust), which is a satellite of the Andromeda Galaxy (M31). It is one of the 14 known dwarf galaxies orbiting M31. It is relatively isolated, being about 1.8 million light-years (579 kpc) away. However, for an isolated dwarf galaxy it is also unusually quiescent.
Andromeda XIAndromeda XI (And 11) is a dwarf spheroidal galaxy about 2.6 millionlight-years away from the Sun in the constellationAndromeda. Discovered in 2006, And XI is a satellite galaxy of the Andromeda Galaxy (M31).
Satellite galaxyA satellite galaxy is a smaller companion galaxy that travels on bound orbits within the gravitational potential of a more massive and luminous host galaxy (also known as the primary galaxy). Satellite galaxies and their constituents are bound to their host galaxy, in the same way that planets within the Solar System are gravitationally bound to the Sun. While most satellite galaxies are dwarf galaxies, satellite galaxies of large galaxy clusters can be much more massive.
Canada–France–Hawaii TelescopeThe Canada–France–Hawaii Telescope (CFHT French: Télescope Canada–France–Hawaï) is a 3.58 metres (11.7 ft) optical/infrared telescope located near the summit of Mauna Kea on the Big Island of Hawaiʻi at an altitude of 4,204 m (13,793 ft), within the Maunakea Observatories. The telescope has a Prime Focus/Cassegrain configuration, and has been in operation since 1979.
RadiusIn classical geometry, a radius (pl.: radii or radiuses) of a circle or sphere is any of the line segments from its center to its perimeter (circle) or surface (sphere), and, in more modern usage, it is also their length. The radius of a regular polygon is the line segment or distance from its center to any of its vertices. The name comes from the Latinradius, meaning ray but also the spoke of a chariot wheel.
ParsecThe parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to 3.26 light-years or 206,265 astronomical units (au), i.e., 30.9 trillionkilometres (19.2 trillion miles). The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 au subtends an angle of one arcsecond (1/3600 of a degree).
Antlia IIAntlia II (Ant II) is a low-surface-brightnessdwarfsatellitegalaxy of the Milky Way at a galactic latitude of 11.2°. It spans 1.26° in the sky just southeast of Epsilon Antliae. The galaxy is similar in size to the Large Magellanic Cloud, despite being 1/10,000 as bright. Antlia II has the lowest surface brightness of any galaxy discovered and is ~ 100 times more diffuse than any known ultra diffuse galaxy.
Milky WayGalaxy containing the Solar SystemArtist's impression of the structure of the Milky Way based on data from the European Space Agency's Gaia telescope, including the location of the spiral arms, bar, and bulgeThe Milky Way or Milky Way Galaxy, or simply the Galaxy, is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are so far away that they cannot be individually distinguished by the naked eye.*As an Amazon Associate I earn from qualifying purchases.