Splendors of the Universe Dr. Harold Alden Williams Montgomery College Planetarium at the Takoma Park/Silver Spring Campus Maryland, United States of America, Planet Earth, Star Sol, in the Milky Way Galaxy an outlying member of the Virgo Supercluster!

Saturday, November 10, 12

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Orion Nebulae Saturday, November 10, 12

M42 is located at a distance of1,344 ± 20 light years[3][6]and is the closest region of massive star formation toEarth.

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Great Orion Nebulae or M42 or NGC1976 Saturday, November 10, 12

http://en.wikipedia.org/wiki/Great_Orion_Nebula The M42 nebula is estimated to be 24 light years across. It has a mass of about 2000 times the mass of the Sun.

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Dust, Blue reflection nebulae, H and He, Red emission nebulae Saturday, November 10, 12

http://en.wikipedia.org/wiki/Reflection_nebula http://en.wikipedia.org/wiki/Emission_nebula

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Horse head nebulae, or Bernard 33, a dark nebulae, within emission nebulae IC434, bright Orion belt star Alnitak Saturday, November 10, 12

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Right ascension 05h 40m 59.0s Declination −02° 27′ 30.0"

Alnitak (Arabic: ‫"ق‬#$%‫ ا‬an-niṭāq‎) is a triple star some 736 light years distant in theconstellation Orion. It is part of Orion's Belt along withAlnilam and Mintaka, and has a Bayer designation ofZeta Orionis. The primary star is a hotblue supergiant with an absolute magnitude of -5.25, and is the brightest class Ostar in the night sky with a visual magnitude of +2.04. It has two bluish 4th magnitude companions, producing a combined magnitude for the trio of +1.72. The stars are members of the Orion OB1association and theCollinder 70 association.

Close up of Horses Head Nebulae Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Horse_head_nebula The nebula was first recorded in 1888 byWilliamina Fleming on photographic plate B2312 taken at the Harvard College Observatory. The Horsehead Nebula is approximately 1500 light years from Earth. It is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which is similar to that of a horse's head when viewed from Earth.[2] She worked as a maid in the home of Professor Edward Charles Pickering. Pickering became frustrated with his male assistants at the Harvard College Observatory and, legend has it, famously declared his maid could do a better job.[1]

Pleiades or the Seven Sisters, M45, Japanese name Subaru

Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Pleiades http://en.wikipedia.org/wiki/Pleiades_in_folklore_and_literature

open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. Formed within the last 100 million years. 128 parsecs or 410 LY away

from us. They are also mentioned four times in the Bible(Job 9:9 and 38:31, as well asAmos 5:8 and Revelation 3:1).Alcyone B7IIIe 2.86mag; Atlas B8III 3.62mag; Electra B6IIIe 3.70mag; Maia B7III 3.86mag; Merope B6IVev 4.17mag; Taygeta B6V 4.29mag; Pleione B8IVpe5.09 (var.)mag

Rosetta Nebula in Monoceros, also called Caldwell 49, a large circular H II region circling some Wolf-Rayet stars Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Rosette_Nebula http://en.wikipedia.org/wiki/Wolf-Rayet_star The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter. The complex has the following NGC designations: ■ NGC 2237 – Part of the nebulous region (Also used to denote whole nebula) ■ NGC 2238 – Part of the nebulous region ■ NGC 2239 – Part of the nebulous region (Discovered by John Herschel) ■ NGC 2244 – The open cluster within the nebula (Discovered by John Flamsteed in 1690) ■ NGC 2246 – Part of the nebulous region The cluster and nebula lie at a distance of some 5,200 light-years from Earth (although estimates of the distance vary considerably, down to 4,900 light-years.[3]) and measure roughly 130 light years in diameter. The radiation from the young stars excite the atoms in the nebula, causing them to emit radiation themselves producing the emission nebula we see. The mass of the nebula is estimated to be around 10,000 solar masses.

Wolf-Rayet stars in the center of the Rosette Nebula Saturday, November 10, 12

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Abstract Art of the Creator Saturday, November 10, 12

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S Monocerotis and NGC 2264 http://en.wikipedia.org/wiki/S_Monocerotis

S Monocerotis, also known as 15 Monocerotis, is a massive variable star system located in the constellation Monoceros.[7] It is a spectroscopic binary system with an orbital period of 25 years.[8] Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[9] It is a type O main sequence dwarf with a stellar classification of O7Ve, and is about 8,500 times as luminous as the Sun, while varying in between magnitude 4.2 and 4.6. The star lies at the base of the Christmas Tree Cluster in NGC 2264. http://en.wikipedia.org/wiki/NGC_2264 NGC 2264 is the designation number of the New General Catalogue that identifies two astronomical objects as a single object: ■ the Cone Nebula, ■ the Christmas Tree Cluster, Two other objects are within this designation but not officially included: ■ Snowflake Cluster,[2][3] ■ and the Fox Fur Nebula.[4] All of the objects are located in the Monoceros constellation and are located about 800 parsecs or 2600 light-years from Earth. NGC 2264 is sometimes referred to as the Christmas Tree Cluster and the Cone Nebula. However, the designation of NGC 2264 in the New General Catalogue refers to both objects and not the cluster alone.

Cone Nebula Saturday, November 10, 12

http://en.wikipedia.org/wiki/Cone_Nebula

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The Cone Nebula is an H II region in the constellation of Monoceros. It was discovered by William Herschel on December 26, 1785, at which time he designated it H V.27. The nebula is located about 830 parsecs or 2,700 lightyears away from Earth. The Cone Nebula forms part of the nebulosity surrounding the Christmas Tree Cluster. The designation of NGC 2264 in the New General Catalogue refers to both objects and not the nebula alone. The diffuse Cone Nebula, so named because of its apparent shape, lies in the southern part of NGC 2264, the northern part being the magnitude-3.9 Christmas Tree Cluster. It is in the northern part of Monoceros, just north of the midpoint of a line from Procyon to Betelgeuse. The cone's shape comes from a dark absorption nebula consisting of cold molecular hydrogen and dust in front of a faint emission nebula containing hydrogen ionized by S Monocerotis, the brightest star of NGC 2264. The faint nebula is approximately seven light-years long (with an apparent length of 10 arcminutes), and is 2,700 light-years away from Earth.

Milky Way in Sagittarius Saturday, November 10, 12

http://en.wikipedia.org/wiki/Sagittarius_(constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is (Unicode U+2650 ♐), a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow. It lies between Ophiuchus to the west and Capricornus to the east.

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M17 and Milky Way Galaxy Saturday, November 10, 12

http://en.wikipedia.org/wiki/Messier_17 The Omega Nebula, also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula[1][2] (catalogued as Messier 17 or M17 and as NGC 6618) is an H II region in the constellation Sagittarius. The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud of interstellar matter of which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses.[3] The total mass of the Omega Nebula is an estimated 800 solar masses.[4] It is considered one of the brightest and most massive star-forming regions of our galaxy.[5] Its local geometry is similar to the Orion Nebula except that it is viewed edge-on rather than face-on.[6]

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Drawing by Trouvelot while at USNO of M17 Saturday, November 10, 12

http://upload.wikimedia.org/wikipedia/commons/5/58/TPSMV8P294_Fig_7.jpg A sketch by Trouvelot in 1875. USN0 26 inch telescope

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Star Cloud in Sagittarius Saturday, November 10, 12

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Baade’s Window in Sagittarius Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Baade%27s_Window Baade's Window is an area of the sky with relatively low amounts of interstellar "dust" along the line of sight from the Earth. This area is considered an observational "window" as the normally obscured Galactic Center of the Milky Way is visible in this direction. It is named for astronomer Walter Baade who first recognized its significance. This area corresponds to one of the brightest visible patches of the Milky Way.

Saturday, November 10, 12

http://upload.wikimedia.org/wikipedia/commons/6/61/ HST_SWEEPS_Galaxy_Location-2006.jpg

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Nebulae in Sagittarius Saturday, November 10, 12

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Dust Cloud NGC6520 Saturday, November 10, 12

http://en.wikipedia.org/wiki/NGC_6520 NGC 6520 is an open cluster in the constellation Sagittarius.

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Nebulocity in Sagittarius Saturday, November 10, 12

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Reflection & Trifid Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Trifid_Nebula

The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an H II region located in Sagittarius. Its name means 'divided into three lobes'. The object is an unusual combination of an open cluster of stars; an emission nebula (the lower, red portion), a reflection nebula (the upper, blue portion) and a dark nebula (the apparent 'gaps' within the emission nebula that cause the trifid appearance; these are also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers. The Trifid Nebula was the subject of an investigation by astronomers using the Hubble Space Telescope in 1997, using filters that isolate emission from hydrogen atoms, ionized sulfur atoms,

The close-up images show a dense cloud of dust and gas, which is a stellar nursery full of embryonic stars. This cloud is about 8 light years away from the nebula's central star. A stellar jet protrudes from the head of the cloud and is about 0.75 light-years long. The jet's source is a young stellar object deep within the cloud. Jets are the exhaust gasses of star formation. Radiation from the nebula's central star makes the jet glow. and doubly ionized oxygen atom. The images were combined into a false-color composite picture to suggest how the nebula might look to the eye.

The images also showed a finger-like stalk to the right of the jet. It points from the head of the dense cloud directly toward the star that powers the Trifid nebula. This stalk is a prominent example of evaporating gaseous globules, or 'EGGs'. The stalk has survived because its tip is a knot of gas that is dense enough to resist being eaten away by the powerful radiation from the star. In January 2005, NASA's Spitzer Space Telescope discovered 30 embryonic stars and 120 newborn stars not seen in visible light images. It is approximately 5,200 light years away. It is in a magnitude of 6.3.

Trifid Saturday, November 10, 12

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Stars in Center of Trifid Saturday, November 10, 12

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Dust Lane M16, Eagle dark Nebulae Saturday, November 10, 12

http://en.wikipedia.org/wiki/Messier_16

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Bok Globules in IC2944 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/IC_2944

IC 2944, also known as the Running Chicken Nebula or the Lambda Cen Nebula, is an open cluster with an associated emission nebula found in the constellation Centaurus, near the star Lambda Centauri. It features Bok globules, which are frequently a site of active star formation. However, no evidence for star formation has been found in any of the globules in IC 2944.[2] The Hubble Space Telescope image on the right is a close up of a set of Bok globules discovered in IC 2944 by South African astronomer A. David Thackeray in 1950.[3] These globules are now known as Thackeray's Globules. http://en.wikipedia.org/wiki/Bok_globule Bok globules are dark clouds of dense cosmic dust and gas in which star formation sometimes takes place. Bok globules are found within H II regions, and typically have a mass of about 2[1] to 50 solar masses contained within a region about a light year or so across (about 4.5 × 1047 m³, see Orders of magnitude (volume)).[2] They contain molecular hydrogen (H2), carbon oxides and helium, and around 1% (by mass) of silicate dust. Bok globules most commonly result in the formation of double or multiple star systems.

Carina Nebula Saturday, November 10, 12

http://en.wikipedia.org/wiki/Carina_Nebula

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Eta Carina Saturday, November 10, 12

http://en.wikipedia.org/wiki/Eta_Carinae

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Loops NGC3576 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_3576

NGC 3576 is a minor nebula in the Sagittarius arm of the galaxy a few thousand light-years away from the Eta Carinae nebula. Eventually this nebula even received six different classification numbers. Currently, astronomers call the entire nebula NGC 3576. Type Emission

11  11  32.7 [1] Declination -61° 21′ 44″ h

m

s

Physical characteristics Radius 50 lys

[1]

nebula Right ascension Distance 6,000 [2 Constellation Carina

NGC3576 Saturday, November 10, 12

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Eta Carina & Trumpler Saturday, November 10, 12

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Antares & ρ Ophiuchi Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Rho_Ophiuchi_cloud_complex http://en.wikipedia.org/wiki/Antares α Scorpii, α Sco, Alpha Scorpii) is a red supergiant star in the Milky Way galaxy andthe sixteenth brightest star

Helix Nebula Saturday, November 10, 12

Helix Nebula (also known as The Helix, NGC 7293, or Caldwell 63) is a large planetary nebula (PN) located in the constellation Aquarius. http://en.wikipedia.org/wiki/Helix_Nebula

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NGC 6302 Saturday, November 10, 12

http://en.wikipedia.org/wiki/NGC_6302

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NGC 6164 & 6165 Bi-polar emission nebula Saturday, November 10, 12

http://apod.nasa.gov/apod/ap060606.html Bi-polar emission nebula

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Large Magellanic Cloud Saturday, November 10, 12

http://en.wikipedia.org/wiki/Large_Magellanic_Cloud

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Tarantula Nebula Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Tarantula_nebula The Tarantula Nebula (also known as 30 Doradus, or NGC 2070) is an H II region in the Large Magellanic Cloud (LMC)

Vela Supernova Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Vela_Supernova_Remnant The Vela supernova remnant is a supernova remnant in the southern constellation Vela. Its source supernova exploded approximately 11,000-12,300 years ago (and was about 800 light years away). The association of the Vela supernova remnant with the Vela pulsar, made by astronomers at the University of Sydney in 1968,[2] was direct observational proof that supernovae form neutron stars.

Vela Supernova Remanent Saturday, November 10, 12

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M 5 Globular Star Cluster Saturday, November 10, 12

http://en.wikipedia.org/wiki/Messier_5 Messier 5 or M5 (also designated NGC 5904) is a globular cluster in the constellation Serpens.

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Cometary Globule CG4 Saturday, November 10, 12

http://www.noao.edu/image_gallery/html/im1000.html http://apod.nasa.gov/apod/ap060314.html

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Centaurus A Saturday, November 10, 12

http://en.wikipedia.org/wiki/Centaurus_A

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Dust in Centaurus A Saturday, November 10, 12

Unsharp masking http://en.wikipedia.org/wiki/Unsharp_masking

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NGC6822 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_6822 NGC 6822 (also known as Barnard's Galaxy, IC 4895, or Caldwell 57) is a barred irregular galaxy approximately 1.6 million light-years away in the constellation Sagittarius. Part of the Local Group of galaxies, it was discovered by E. E. Barnard in 1881 (hence its name), with a six-inch refractor telescope. It is one of the closer galaxies to the Milky Way. It is similar in structure and composition to the Small Magellanic Cloud.

Leo Dwarf Spheroidal galaxy Saturday, November 10, 12

http://en.wikipedia.org/wiki/Dwarf_galaxy http://en.wikipedia.org/wiki/Leo_I_(dwarf_galaxy) Leo I is a dwarf spheroidal galaxy in the constellation Leo. At about 820,000 light-years distant, it is a member of the Local Group of galaxies and is thought to be one of the most distant satellites of the Milky Way galaxy. It was discovered in 1950

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M 83 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Messier_83 Messier 83 (also known as the Southern Pinwheel Galaxy, M83 or NGC 5236) is a barred spiral galaxy[6] approximately 15 million light-years away in the constellation Hydra. It is one of the closest and brightest barred spiral galaxies in the sky, making it visible with binoculars. Six supernovae (SN 1923A, SN 1945B, SN 1950B, SN 1957D, SN 1968L and SN 1983N) have been observed in M83.

NGC 2997 Saturday, November 10, 12

http://en.wikipedia.org/wiki/NGC_2997 NGC 2997 is a face-on unbarred spiral galaxy about 40 million light-years away in the constellation Antlia.[2] It is the brightest galaxy of the NGC 2997 group of galaxies. NGC 2997 is particularly notable for a nucleus surrounded by a chain of hot giant clouds of ionized hydrogen.

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NGC 253 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_253 The Sculptor Galaxy (also known as the Silver Coin or Silver Dollar Galaxy, NGC 253, or Caldwell 65) is an intermediate spiral galaxy in the constellation Sculptor. The Sculptor Galaxy is a starburst galaxy, which means that it is currently undergoing a period of intense star formation. Using the planetary nebula luminosity function method, an estimate of 10.89 +0.85 −0.38 Mpc) was achieved in 2006.[2] Sculptor

is close enough that the tip of the red giant branch (TRGB) method may also be used to estimate its distance. The estimated distance to Sculptor using this technique in 2004 yielded 12.8 ± 1.2 Mly (3.94 ± 0.37 Mpc).[10][11]A weighted average of the most reliable distance estimates gives a distance of 11.4 ± 0.7 Mly (3.5 ± 0.2 Mpc).[2]

NGC 1365 bared spiral Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_1365 NGC 1365, also known as the Great Barred Spiral

Galaxy,[3] is abarred spiral galaxy about 56 million light-years away in theconstellation Fornax.

NGC 300 Saturday, November 10, 12

http://en.wikipedia.org/wiki/NGC_300 NGC 300 (also known as Caldwell 70) is a spiral galaxy in the constellationSculptor. It is one of the closest galaxies to the Local Group, and probably lies between us and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group.[2] It is inclined at an angle of 42° when viewed from earth and shares many characteristics of the Triangulum Galaxy.[4]

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Messier 100 or NGC 4321 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_4321 Messier 100 (also known as NGC 4321) is an example of a grand design spiral galaxy[4] located within the southern part of constellation Coma Berenices. It is one of the brightest and largest galaxies in the Virgo cluster, approximately 55 million light-years[3] distant from Earth and has a diameter of 160,000 light years. It was discovered by Pierre Méchain on March 15, 1781 and was subsequently entered in Messier’s catalogue of nebulae and star clusters[5] after Charles Messier[6] made observations of his own on April 13, 1781. The galaxy was one of the first spirals[6] discovered, and was listed as 1 of 14 spiral nebulae by Lord William Parsons of Rosse in 1850. Two satellite galaxies[7][8] named NGC 4323 -connected with M100 by a bridge of luminous matter- and NGC 4328 are present within this galaxy.

M100 with dwarf galaxy companions Saturday, November 10, 12

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M 65 & NGC 3623 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_3623 Messier 65 (also known as NGC 3623) is an intermediate spiral galaxy about 35 million light-years away in the constellation Leo. It was discovered by Charles Messier in 1780. M65, M66, and NGC 3628 comprise the famous Leo Triplet, a small group of galaxies.

M 66 or NGC 3627 Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_3627 Messier 66 (also known as NGC 3627) is an intermediate spiral galaxy about 36 million light-years away in the constellation Leo. It was discovered by Charles Messier in 1780. M66 is about 95 thousand light-years across[3] with striking dust lanes and bright star clusters along sweeping spiral arms.[4] M66 is part of the famous Leo Triplet, a small group of galaxies that also includes M65 and NGC 3628.

NGC 3628 edge on Spiral Saturday, November 10, 12

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http://en.wikipedia.org/wiki/NGC_3628 NGC 3628 is an unbarred spiral galaxy about 35 million lightyears away in the constellation Leo. It was discovered by William Herschel in 1784. It has an approximately 300,000 light-years long tidal tail. NGC 3628 along with M65 and M66 form the famous Leo Triplet, a small group of galaxies. Its most conspicuous feature is the broad and obscuring band of dust located along the outer edge of its spiral arms, effectively transecting the galaxy to our view.

NGC 1313 Star Burst galaxy Saturday, November 10, 12

http://en.wikipedia.org/wiki/NGC_1313 NGC 1313 (also known as Topsy Turvy Galaxy) is an barred spiral galaxy discovered by the Scottish astronomer James Dunlop on 27 September 1826. It has a strikingly uneven shape and its axis of rotation is not exactly in its centre[2]. In the vicinity of NGC 1313 there is another galaxy called NGC 1309. NGC 1309 was the site of supernova SN 1987k.

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NGC 1586 Seyfert galaxy Saturday, November 10, 12

http://en.wikipedia.org/wiki/Seyfert_Galaxy http://dso-browser.com/dso/info/NGC/1586

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NGC 4038 & 4039 Antennae galaxies Saturday, November 10, 12

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http://en.wikipedia.org/wiki/Antennae_galaxies The Antennae Galaxies (also known as NGC 4038/ NGC 4039 or Caldwell 60/61) are a pair of interacting galaxies in the constellation Corvus. They are currently going through a phase of starburst. They were discovered by William Herschel in 1785.[3] NGC 4038 is located at RA 12h 01m 53.0s, Dec −18° 52′ 10″; and NGC 4039 at RA 12h 01m 53.6s, Dec −18° 53′ 11″.

Saturday, November 10, 12

Virgo Cluster

http://en.wikipedia.org/wiki/Virgo_cluster

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The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ±

0.1 Mpc)[2] away in the constellation Virgo. Comprising approximately 1300 (and possibly up to 2000) member galaxies,[3] the cluster forms the heart of the larger Virgo Supercluster, of which the Local Group is an outlying member. It is estimated that its mass is 1.2×1015 M☉ out to 8 degrees of the cluster's center or a radius of about 2.2 Mpc.[4] Many of the brighter galaxies in this cluster, including the giant elliptical galaxy Messier 87, were discovered in the late 1770s and early 1780s and subsequently included in Charles Messier's catalogue of non-cometary fuzzy objects. Described by Messier as nebulae without stars, their true nature was not recognized until the 1920s.[5] The cluster subtends a maximum arc of approximately 8 degrees centered in the constellation Virgo. Many of the member galaxies of the cluster are visible with a small telescope. Its brightest member is the elliptical galaxy Messier 49, located in one subunit of the cluster.

Messier 87 Giant Elliptical galaxy Saturday, November 10, 12

http://en.wikipedia.org/wiki/Messier_87

Messier 87 (also known as M87, Virgo A or NGC 4486) is a supergiant elliptical galaxy. It was discovered in 1781 by the French astronomer Charles Messier, who cataloged it as a nebulous feature. The second brightest galaxy within the northern Virgo Cluster, it is located about 16.4 million parsecs (53.5 million light-years) from Earth.[3][5] Unlike a disk-shaped spiral galaxy, Messier 87 has no distinctive dust lanes and it has an almost featureless, ellipsoidal shape that diminishes in luminosity with distance from the center. At the core is a supermassive black hole, which forms the primary component of an active galactic nucleus. This object is a strong source of multiwavelength radiation, particularly radio waves. A jet of energetic plasma originates at the core and extends outward at least 1,500 parsecs (5,000 light-years).[6] The stars in this galaxy form about one sixth of Messier 87's mass. They have a nearly spherically symmetric distribution, while the density of stars decreases with increasing distance from the core. The galactic envelope extends out to a radius of about 150 kpc (490 kly), where it has been truncated—possibly by an encounter with another galaxy. Between the stars is a diffuse interstellar medium of gas that has been chemically enriched by elements emitted from evolved stars. Any dust formed within the galaxy is destroyed within 46 million years by the X-ray emission from the core, although optical filaments of dust have been observed. Orbiting the galaxy is an abnormally large population of about 12,000 globular clusters, compared to 150-200 globular clusters orbiting the Milky Way. As one of the most massive[7] giant elliptical galaxies near Earth and one of the brightest radio sources in the sky, Messier 87 is a popular target for both amateur astronomy observations and professional astronomy study.

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Saturday, November 10, 12

M87 Jet

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The relativistic jet of matter emerging from the core extends at least 1.5 kpc (5 kly) from the nucleus of Messier 87 and is made up of matter ejected from the galaxy by a supermassive black hole. This jet is highly collimated, appearing constrained to an angle of about 16° within 2 pc (6.5 ly) of the core and an angle of 6–7° at a distance of 12 pc (39 ly). It is surrounded by a lower velocity, non-relativistic component. There is evidence of a counter jet, but this feature remains unseen from the Earth due to relativistic beaming.[60][61] The jet is precessing, causing the outflow to form a helical pattern out to a distance of 1.6 pc (5.2 ly).[47] Lobes of matter from the jet extend out to a distance of 77 kpc (250 kly).[62] In pictures taken by the Hubble Space Telescope in 1999, the motion of Messier 87's jet was measured at four to six times the speed of light. This motion may be an optical illusion caused by the relativistic velocity of the jet, and not true superluminal motion. However, detection of such motion supports the theory that quasars, BL Lac objects and radio galaxies may all be the same phenomenon, known as active galaxies, viewed from different perspectives.[63][64]