Get flash to fully experience Pearltrees
Maffei 1 is a giant elliptical galaxy in the constellation Cassiopeia . Once believed to be a member of the Local Group of galaxies, it is now known to belong to its own group, the IC 342/Maffei Group . It was named after Paolo Maffei , who discovered it and the neighboring Maffei 2 in 1967 via their infrared emissions.
Picture of the Andromeda Galaxy, showing M32 (above left of centre) Messier 32 (also known as NGC 221 and Le Gentil ) is a dwarf elliptical galaxy about 2.65 million light-years away in the constellation Andromeda . M32 is a satellite galaxy of the famous Andromeda Galaxy (M31) and was discovered by Le Gentil in 1749.
The Triangulum Galaxy is a spiral galaxy approximately 3 million light years (ly) from Earth in the constellation Triangulum . It is catalogued as Messier 33 or NGC 598 , and is sometimes informally referred to as the Pinwheel Galaxy , a nickname it shares with Messier 101 . The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, which includes the Milky Way , the Andromeda Galaxy and about 30 other smaller galaxies. It is one of the most distant permanent objects that can be viewed with the naked eye . [ edit ] Etymology
Messier 49 (also known as M 49 or NGC 4472 ) is an elliptical galaxy located about 49 million light-years away in the equatorial constellation of Virgo . This galaxy was discovered by French astronomer Charles Messier on February 19, 1771. Messier 49 is positioned 4.1° west-southwest of the star Epsilon Virginis . [ 2 ] As an elliptical galaxy, Messier 49 has the physical form of a radio galaxy , but it only has the radio emission of a normal galaxy. From the detected radio emission, the core region is emitting roughly 10 53 erg (10 46 J or 10 22 YJ) of energy. [ 3 ] The nucleus of this galaxy is emitting X-rays, suggests the likely presence of a supermassive black hole with an estimated mass of 5.65 × 10 8 solar masses , or 565 million times the mass of the Sun. [ 4 ] X-ray emissions shows a structure to the north of Messier 49 that resembles a bow shock .
The Whirlpool Galaxy (also known as Messier 51a , M51a , or NGC 5194 ) is an interacting [ 6 ] grand-design [ 7 ] spiral galaxy in the constellation Canes Venatici . Recently it was estimated to be 23 ± 4 million light-years from the Milky Way Galaxy , [ 3 ] but different methods yield distances between 15 and 35 million ly. Messier 51 is one of the best known galaxies in the sky. [ 8 ] The galaxy and its companion ( NGC 5195 ) are easily observed by amateur astronomers , and the two galaxies may even be seen with binoculars . [ 9 ] The Whirlpool Galaxy is also a popular target for professional astronomers, who study it to further understand galaxy structure (particularly structure associated with the spiral arms ) and galaxy interactions. [ edit ] Discovery What was later known as the Whirlpool Galaxy was discovered [ 10 ] on October 13, 1773 by Charles Messier , and is designated as M51 . Its companion galaxy, NGC 5195 , was discovered in 1781 by Pierre Méchain .
Messier 59 (also known as M59 or NGC 4621 ) is an elliptical galaxy in the constellation Virgo . [ edit ] History Messier 59 and the nearby elliptical galaxy Messier 60 were both discovered by Johann Gottfried Koehler in April 1779 during observations of a comet in the same part of the sky. [ 4 ] Charles Messier listed both in the Messier Catalogue about three days after Koehler's discovery. [ 4 ] [ edit ] Characteristics Messier 59's core contains a supermassive black hole , with a mass that has been estimated to be 270 million times the mass of the Sun , [ 5 ] and counter-rotates with respect of the rest of the galaxy, being bluer. [ 6 ] This galaxy also has an inner disk of stars [ 7 ] [ 8 ] and is very rich in globular clusters , with a population of them that has been estimated in around 2200. [ 9 ] [ edit ] Virgo Cluster membership
Messier 105 (also known as M105 and NGC 3379 ) is an elliptical galaxy in the constellation Leo . [ edit ] History Messier 105 was discovered by Pierre Méchain on 24 March 1781, just a few days after he discovered the nearby galaxies Messier 95 and Messier 96 . [ 3 ] This galaxy is one of several that were not originally included in the original Messier Catalogue compiled by Charles Messier . Messier 105 was included in the catalog only when Helen S. Hogg found a letter by Méchain describing Messier 105 and when the object described by Méchain was identified as a galaxy previously named NGC 3379. [ 3 ]
The Milky Way is the galaxy that contains our Solar System . [ 11 ] [ 12 ] [ 13 ] [ nb 1 ] This name derives from its appearance as a dim "milky" glowing band arching across the night sky, in which the naked eye cannot distinguish individual stars.
Location of Alpha Centauri in Centaurus Alpha Centauri ( α Centauri , α Cen; also known as Rigel Kent / ˈ r aɪ dʒ əl ˈ k ɛ n t / —see Names ) is the brightest star in the southern constellation of Centaurus and is currently inside the G-cloud . [ 10 ] [ 11 ] Although it appears to the unaided eye as a single object, Alpha Centauri is actually a binary star system (designated Alpha Centauri AB or α Cen AB ) whose combined visual magnitude of −0.27 makes it the third-brightest star in the night sky after the −1.46 magnitude Sirius and the −0.72 magnitude Canopus . Its individual component stars are named Alpha Centauri A (α Cen A), with 110% of the mass and 151.9% the luminosity of the Sun , and Alpha Centauri B (α Cen B), at 90.7% of the Sun's mass and 44.5% of its luminosity. During the pair's 79.91-year orbit about a common center, the distance between them varies from about that between Pluto and the Sun to that between Saturn and the Sun.
The Sun is the star at the center of the Solar System . It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields . [ 12 ] [ 13 ] It has a diameter of about 1,392,684 km, [ 5 ] about 109 times that of Earth , and its mass (about 2 × 10 30 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. [ 14 ] Chemically, about three quarters of the Sun's mass consists of hydrogen , while the rest is mostly helium .
Mercury is the innermost planet in the Solar System , named after the Roman god Mercury , the messenger to the gods. It is the smallest of the eight planets in the Solar System. [ a ] It orbits the Sun once in about 88 Earth days. Since is has almost no atmosphere to retain heat, Mercury's surface experiences the greatest temperature variation of all the planets, ranging from 100 K (−173 °C; −280 °F) at night to 700 K (427 °C; 800 °F) during the day.
Venus is the second planet from the Sun , orbiting it every 224.7 Earth days. [ 11 ] The planet is named after the Roman goddess of love and beauty.
Earth is the third planet from the Sun , and the densest and fifth-largest of the eight planets in the Solar System .
Red and orange tinted Moon, as seen from Earth during a lunar eclipse, where the Earth comes between the Moon and Sun The Moon is the only natural satellite of the Earth , [ d ] [ 7 ] and the fifth largest satellite in the Solar System . It is the largest natural satellite of a planet in the Solar System relative to the size of its primary , [ e ] having 27% the diameter and 60% the density of Earth, resulting in 1 ⁄ 81 its mass .
Animation of Mars's rotation from the vantage of an observer who moves south, then north, to hover over both poles, showing the planet's major topographic features.