Sunday, September 21, 2008

The Messier Astronomical Object Catalog

The Messier catalog was compiled by French astronomer Charles Messier (1730-1817). The original motivation behind the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets.

He compiled the list of 110 objects ranging from M1 to M110. Objects in the list were Galaxies, Nebulae and Star Clusters. The first catalog containing objects M1 to M45 was published in 1774. The final 'now historic' version containing all 110 objects (M1 to M110) was released in 1781.

Because Messier lived and did his astronomical work in France, (in the Northern Hemisphere), the list he compiled contains only objects from the north celestial pole to a celestial latitude of about –35°. Many impressive Southern objects, such as the Large and Small Megallenic Clouds are excluded from the list because Messier did not observe them from his northern latitude location.

Messier objects are visible with binoculars or small telescopes (under favorable conditions) and are popular viewing objects for amateur astronomers.

In early spring, astronomers sometimes gather for "Messier marathons", when all of the objects can be viewed over a single night.

Following is a list of all 110 Messier objects and a description of each.

M1 The Crab Nebula supernova remnant in Taurus

M2 globular cluster in Aquarius

M3 globular cluster in Canes Venatici

M4 globular cluster in Scorpius

M5 globular cluster in Serpens Caput

M6 The Butterfly Cluster open cluster in Scorpius

M7 Ptolemy's Cluster open cluster in Scorpius

M8 The Lagoon Nebula (starforming nebula) in Sagittarius.

M9 globular cluster in Ophiuchus

M10 globular cluster in Ophiuchus

M11 The Wild Duck Cluster open cluster in Scutum

M12 globular cluster in Ophiuchus

M13 Great Hercules Globular Cluster globular cluster in Hercules

M14 globular cluster in Ophiuchus

M15 globular cluster in Pegasus

M16 Eagle or Star Queen Nebula starforming nebula in Serpens Cauda

M17 The Omega or Swan or Horseshoe or Lobster Nebula starforming nebula in Sagittarius

M18 open cluster in Sagittarius

M19 globular cluster in Ophiuchus

M20 The Trifid Nebula starforming nebula in Sagittarius is the star cluster region at upper right of center.

M21 open cluster in Sagittarius

M22 globular cluster in Sagittarius

M23 open cluster in Sagittarius

M24 Milky Way Patch star cloud (center) with open cluster NGC 6603 in Sagittarius

M25 open cluster in Sagittarius

M26 open cluster in Scutum

M27 The Dumbbell Nebula planetary nebula (lower-right) in Vulpecula

M28 globular cluster in Sagittarius

M29 open cluster in Cygnus

M30 globular cluster in Capricornus

M31, The Andromeda Galaxy is the brightest galaxy visible from Earth and is an easy naked-eye and binocular target for star gazers. M31 has two close neighbors, M32 and M110, both of which are much smaller and will eventually be absorbed by M31. This Grand Galaxy lies 2,900 light years (ly) from Earth and is due to collide with our galaxy, The Milky Way in about 1-Billion years. M31 was referred to as the "little cloud" to famous Persian astronomer Al-Sufi who depicted the object in his Book of Fixed Stars in 905AD.

M32 (at center, M31 is lower-right) is a companion galaxy of M31 and will eventually be absorbed by its huge neighbor.

M33 the Triangulum Galaxy (also the Pinwheel) is a spiral galaxy that is a companion of its much larger neighbor, the Andromeda Galaxy. M33 is 3,000 ly from Earth and is moving toward our solar system at a rate of 240 km/s. Don't worry though, at that rate it will take a billion years or so to get here.

M34 is an open star cluster in the constellation Perseus. It consists of about 100 stars and lies about 1,400 ly away from Earth. The object is naked-eye visible under dark sky conditions and can be seen any evening in the Fall, Winter and early Spring.

M35 is an impressive open star cluster that lies in the constellation Gemini. The cluster consists of several hundred stars, many of which are brighter than magnitude 13. M35 covers an area larger than the Moon, is 24 lyacross and is about 2,800 ly from Earth.

M36 is one of three bright open clusters in the constellation Auriga. M37 and M38 are the other clusters. From our perspective M36 measures 14 ly across and is 4,100 ly from Earth.

M37 is the brightest of the three Auriga open clusters. It contains over 500 stars, 150 of which are brighter than magnitude 12. M37 is 4,400 ly from Earth and spans 24 ly across.

M38 is the last of three open clusters in Auriga. Lying very close (2.5 degrees north) of M36, this is 4,200 ly from Earth and 25 ly across. It contains a very large yellow star that would dwarf our meager Sun many-fold. Some astronomers have seen a 'cross' pattern in some of the brightest stars while others have seen the math symbol 'Pi'. I will leave you to decide what pattern, if any you see in M38.

M39 is an open cluster in the constellation Cygnus. The cluster is 800 ly away and about 7 ly in diameter. M39 contains 30 proven member stars, though some star catalogs put the number closer to 50.

M40 Double Star WNC4 in Ursa Major

M41 open cluster in Canis Major

M42 The Great Orion Nebula starforming nebula in Orion

M43 part of the Orion Nebula (de Mairan's Nebula) starforming nebula in Orion

M44 Praesepe, the Beehive Cluster open cluster in Cancer

M45 Subaru, the Pleiades--the Seven Sisters open cluster in Taurus


M46 Open cluster in Puppis.  The multi-color bubble at upper-left is NGC-2438, the nebulous remnant of an exploded supernova. NGC-2438 is not a true member of the M46 star cluster, but a guest that is slwoly passing through the cluster (over the next 10-million years, that is).

M47 open cluster in Puppis

M48 open cluster in Hydra

M49 elliptical galaxy in Virgo

M50 open cluster in Monoceros

M51 The Whirlpool Galaxy in Canes Venatici

M52 open cluster in Cassiopeia

M53 globular cluster in Coma Berenices

M54 globular cluster in Sagittarius

M55 globular cluster in Sagittarius

M56 globular cluster in Lyra

M57 The Ring Nebula planetary nebula in Lyra is the small blue-colored ring at lower left.

M58 spiral galaxy in Virgo

M59 elliptical galaxy in Virgo

M60 elliptical galaxy in Virgo

M61 spiral galaxy in Virgo

M62 globular cluster in Ophiuchus

M63 Sunflower galaxy spiral galaxy in Canes Venatici

M64 Blackeye galaxy spiral galaxy in Coma Berenices

M65 spiral galaxy in Leo

M66 spiral galaxy in Leo

M67 open cluster in Cancer

M68 globular cluster in Hydra

M69 globular cluster in Sagittarius

M70 globular cluster in Sagittarius

M71 globular cluster in Sagitta

M72 globular cluster in Aquarius

M73 open cluster in Aquarius

M74 spiral galaxy in Pisces

M75 globular cluster in Sagittarius

M76 The Little Dumbell, Cork, or Butterfly planetary nebula in Perseus

M77 spiral galaxy in Cetus

M78 starforming reflection nebula in Orion

M79 globular cluster in Lepus

M80 globular cluster in Scorpius

M81 Bode's Galaxy (nebula) spiral galaxy in Ursa Major (Top-Center)

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M82 The Cigar Galaxy irregular galaxy in Ursa Major (Bottom)

M83 The Southern Pinwheel Galaxy spiral galaxy in Hydra

M84 lenticular galaxy in Virgo

M85 lenticular galaxy in Coma Berenices

M86 lenticular galaxy in Virgo

M87 Virgo A elliptical galaxy in Virgo

M88 spiral galaxy in Coma Berenices

M89 elliptical galaxy in Virgo

M90 spiral galaxy in Virgo

M91 spiral galaxy in Coma Berenices

M92 globular cluster in Hercules

M93 open cluster in Puppis

M94 spiral galaxy in Canes Venatici

M95 spiral galaxy in Leo

M96 spiral galaxy in Leo

M97 The Owl Nebula planetary nebula in Ursa Major

M98 spiral galaxy in Coma Berenices

M99 spiral galaxy in Coma Berenices

M100 spiral galaxy in Coma Berenices

M101 The Pinwheel Galaxy spiral galaxy in Ursa Major

M102 Lenticular galaxy (the Spindle Galaxy NGC 5866) in Draco (Duplication of M101 in Ursa Major)

M103 open cluster in Casseopeia

M104 The Sombrero Galaxy spiral galaxy in Virgo

M105 elliptical galaxy in Leo

M106 spiral galaxy in Canes Venatici

M107 globular cluster in Ophiuchus

M108 spiral galaxy in Ursa Major

M109 spiral galaxy in Ursa Major

M110 Satellite galaxy of M31 elliptical galaxy in Andromeda