Maffei 1. Maffei 1 is a slightly flattened core type elliptical galaxy. It has a boxy shape and is made mainly of old metal-rich stars. It has a tiny blue nucleus in which stars continue to form. Like all large ellipticals it contains a significant population of globular clusters. Maffei 1 is situated at an estimated distance of 3–4 Mpc from the Milky Way. Maffei 1 lies in the Zone of Avoidance and is heavily obscured by the Milky Way's stars and dust. Discovery[edit] The Italian astronomer Paolo Maffei was one of the pioneers of infrared astronomy.
The galaxy Maffei 1 was discovered on a hyper-sensitized I-N photographic plate exposed on 29 September 1967 with the Schmidt telescope at Asiago Observatory. Due to the its faintness, visual observations of Maffei 1 require a telescope at least 30–35 cm in diameter, high quality sky maps and a very dark sky.[9] Distance[edit] Physical properties[edit] Size and shape[edit] Maffei 1 is the bluish elliptical object near the bottom-right corner.
Nucleus[edit] Messier 32. Picture of the Andromeda Galaxy, showing M32 (above left of centre) The structure and stellar content of M32 is difficult to explain by traditional galaxy formation models. Recent simulations suggest a new scenario in which the strong tidal field of M31 can transform a spiral galaxy into a compact elliptical. As a small spiral galaxy falls into the central parts of M31, most of the outer layers of the smaller spiral are stripped away. The central bulge of the galaxy is much less affected and retains its morphology. Distance measurements[edit] At least two techniques have been used to measure distances to M32. Black Hole[edit] M32 contains a supermassive black hole. Notes[edit] ^ average(755 ± 28, 770 ± 40) = ((755 + 770) / 2) ± ((282 + 402)0.5 / 2) = 763 ± 24 See also[edit] References[edit] External links[edit] Coordinates: 00h 42m 41.8s, +40° 51′ 55″
Messier 33. 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 44 other smaller galaxies. It is one of the most distant permanent objects that can be viewed with the naked eye. Etymology[edit] Visibility[edit] Under exceptionally good viewing conditions with no light pollution, the Triangulum Galaxy can be seen with the naked eye.[12] It is one of the most distant permanent objects that can be viewed without the aid of a telescope.[13][14] Being a diffuse object, its visibility is strongly affected by small amounts of light pollution.
Observation history[edit] It was among the first "spiral nebulae" identified as such by Lord Rosse in 1850. Messier 49. 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 1053 erg (1046 J or 1022 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 × 108 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. To the southwest of the core, the luminous outline of the galaxy can be traced out to a distance of 260 kpc.[5] The only supernova event observed within this galaxy is SN 1969Q,[6] discovered in June 1969.[7] This galaxy has a large collection of globular clusters, estimated at about 5,900.
However, this count is far exceeded by the 13,450 globular clusters orbiting the supergiant elliptical galaxy Messier 87. References[edit] External links[edit] Coordinates: Messier 51a. The Whirlpool Galaxy (also known as Messier 51a, M51a, or NGC 5194) is an interacting[6] grand-design[7] spiral galaxy with a Seyfert 2 active galactic nucleus[8] 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.[9] The galaxy and its companion (NGC 5195) are easily observed by amateur astronomers, and the two galaxies may even be seen with binoculars.[10] 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.
Discovery[edit] The advent of radio astronomy and subsequent radio images of M51 unequivocally demonstrated that the Whirlpool and its companion galaxy are indeed interacting. Visual appearance[edit] Properties[edit] Companion[edit] Messier 59. History[edit] 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] One supernova (1939B) has been recorded in M59; it reached a peak magnitude of 11.9.[5] Characteristics[edit] 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,[6] and counter-rotates with respect of the rest of the galaxy, being bluer.[7] This galaxy also has an inner disk of stars[8][9] and is very rich in globular clusters, with a population of them that has been estimated in around 2200.[10] Virgo Cluster membership[edit] M59 is a member of the Virgo Cluster.
References[edit] Jump up ^ R. External links[edit] Coordinates: 12h 42m 02.3s, +11° 38′ 49″ Messier 105. History[edit] 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] Properties[edit] Messier 105 is known to have a supermassive black hole whose mass is estimated to be between 1.4*108 and 2*108 solar masses.[4] It also contains a few young stars and stellar clusters, suggesting some elliptical galaxies still form new stars, but very slowly.[5] Galaxy group information[edit] References[edit] ^ Jump up to: a b c d e f g h i "NASA/IPAC Extragalactic Database".
External links[edit] Coordinates: 10h 47m 49.6s, +12° 34′ 54″ Milky Way. Stars and gases at a wide range of distances from the Galactic center orbit at approximately 220 kilometers per second. The constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much of the mass of the Milky Way does not emit or absorb electromagnetic radiation. This mass has been given the name “dark matter”.[22] The rotational period is about 240 million years at the position of the Sun.[9] The Galaxy as a whole is moving at a velocity of approximately 600 km per second with respect to extragalactic frames of reference.
The oldest known star in the Galaxy is at least 13.6 billion years old and thus must have formed shortly after the Big Bang.[6] Surrounded by several smaller satellite galaxies, the Milky Way is part of the Local Group of galaxies, which forms a subcomponent of the Virgo Supercluster. Appearance[edit] The Milky Way has a relatively low surface brightness. Size and mass[edit] Schematic illustration showing the galaxy in profile. Alpha Centauri. Location of Alpha Centauri in Centaurus (right-click on starmap to enlarge) From Earth to Alpha Centauri. Alpha Centauri (α Centauri, α Cen; also known as Rigil Kent /ˈraɪdʒəl ˈkɛnt/—see Names) is the brightest star in the southern constellation of Centaurus, and the third brightest star in the night sky.[10][11] The Alpha Centauri system is located 1.34 parsecs or 4.37 light years from the Sun, making it the closest star system to the Solar System.[12] 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 (other than the Sun) seen from Earth after the −1.46 magnitude Sirius and the −0.72 magnitude Canopus.
Its 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. Sun. Mercury. Mercury is gravitationally locked and rotates in a way that is unique in the Solar System. As seen relative to the fixed stars, it rotates exactly three times for every two revolutions[b] it makes around its orbit.[13] As seen from the Sun, in a frame of reference that rotates with the orbital motion, it appears to rotate only once every two Mercurian years.
An observer on Mercury would therefore see only one day every two years. Because Mercury's orbit lies within Earth's orbit (as does Venus's), it can appear in Earth's sky in the morning or the evening, but not in the middle of the night. Also, like Venus and the Moon, it displays a complete range of phases as it moves around its orbit relative to Earth. Internal structure Internal structure of Mercury: 1. Mercury's density can be used to infer details of its inner structure.
Mercury's core has a higher iron content than that of any other major planet in the Solar System, and several theories have been proposed to explain this. Plains. Venus. Venus is a terrestrial planet and is sometimes called Earth's "sister planet" because of their similar size, gravity, and bulk composition (Venus is both the closest planet to Earth and the planet closest in size to Earth). However, it has also been shown to be very different from Earth in other respects. It has the densest atmosphere of the four terrestrial planets, consisting of more than 96% carbon dioxide.
The atmospheric pressure at the planet's surface is 92 times that of Earth's. With a mean surface temperature of 735 K (462 °C; 863 °F), Venus is by far the hottest planet in the Solar System. It has no carbon cycle to lock carbon back into rocks and surface features, nor does it seem to have any organic life to absorb it in biomass. Physical characteristics Venus is one of the four terrestrial planets in the Solar System, meaning that, like Earth, it is a rocky body. Geography The longitudes of physical features on Venus are expressed relative to its prime meridian. Earth.
Earth is the third planet from the Sun. It is the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the world or the Blue Planet.[23] Earth formed approximately 4.54 billion years ago, and life appeared on its surface within its first billion years.[24] Earth's biosphere then significantly altered the atmospheric and other basic physical conditions, which enabled the proliferation of organisms as well as the formation of the ozone layer, which together with Earth's magnetic field blocked harmful solar radiation, and permitted formerly ocean-confined life to move safely to land.[25] The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist.
Name and etymology In general English usage, the name earth can be capitalized or spelled in lowercase interchangeably, either when used absolutely or prefixed with "the" (i.e. Heat. Moon. The Moon is in synchronous rotation with Earth, always showing the same face with its near side marked by dark volcanic maria that fill between the bright ancient crustal highlands and the prominent impact craters. It is the second-brightest regularly visible celestial object in Earth's sky (after the Sun), as measured by illuminance on the surface of Earth. Although it can appear a very bright white, its surface is actually dark, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its regular cycle of phases have, since ancient times, made the Moon an important cultural influence on language, calendars, art, and mythology.
The Moon's gravitational influence produces the ocean tides and the slight lengthening of the day. The Moon is thought to have formed nearly 4.5 billion years ago, not long after Earth. As of November 2014[update], the Moon is the only celestial body other than Earth on which humans have set foot. Name and etymology. Mars. Animation of Mars' rotation from the vantage of an observer who moves south, then north, to hover over both poles, showing the planet's major topographic features. Mars is currently host to five functioning spacecraft: three in orbit – the Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter – and two on the surface – Mars Exploration Rover Opportunity and the Mars Science Laboratory Curiosity. Defunct spacecraft on the surface include MER-A Spirit and several other inert landers and rovers such as the Phoenix lander, which completed its mission in 2008.
Observations by the Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars.[25] In 2013, NASA's Curiosity rover discovered that Mars' soil contains between 1.5% and 3% water by mass (about two pints of water per cubic foot or 33 liters per cubic meter, albeit attached to other compounds and thus not freely accessible).[26] Physical characteristics Size comparison of Earth and Mars. Soil. Deimos. Deimos was discovered by Asaph Hall, Sr. at the United States Naval Observatory in Washington, D.C on 12 August 1877, at about 07:48 UTC (given in contemporary sources as "11 August 14:40" Washington mean time, using an astronomical convention of beginning a day at noon, so 12 hours must be added to get the actual local mean time).[9][10][11][12] Hall also discovered Phobos on 18 August 1877, at about 09:14 GMT, after deliberately searching for Martian moons.
It has an escape velocity of 5.6 m/s[3] and apparent magnitude of 12.45.[4] Only two geological features on Deimos have been given names. The craters Swift and Voltaire are named after writers who speculated on the existence of two Martian moons before Phobos and Deimos were discovered.[16] Deimos's orbit is nearly circular and is close to Mars's equatorial plane. Unlike Phobos, which orbits so fast that it actually rises in the west and sets in the east, Deimos rises in the east and sets in the west.
. ^ Jump up to: a b "Apsis". Phobos. Asteriod Belt. Jupiter. Themisto. Carpo. Io. Ganymede. Callisto. Europa. Pasiphaë. Sinope. Callirrhoe. Megaclite. Autonoe. Eurydome. Sponde. Carme Group. Carme (moon) Taygete (moon) Eukelade (moon) S/2003 J 5. Chaldene (moon) Isonoe (moon) Kalyke (moon) Erinome (moon) Aitne (moon) S/2003 J 10. S/2003 J 9. Pasithee (moon) Kale (moon) Ananke Group. Himalia Group. Saturn. Titan. Uranus. Neptune. Pluto.