MESSIER - Messier Nebulae
The Messier Catalog of bright, extended objects was compiled by the
comet-hunter Charles Messier in the 18th century. It comprised a list
of 110 objects which are mostly brighter than 10th magnitude and have
angular sizes from 1 to 100 arcminutes. M 102 is now generally
considered to be spurious, and the object so named was actually M 101.
Hence this electronic version of the Messier Catalog contains only 109
objects. The objects in the Messier Catalog are predominantly star
clusters in our Milky Way galaxy, with 29 of them being globular
clusters, 27 open clusters; the rest are spiral galaxies (27),
elliptical galaxies (11), diffuse and planetary nebulae (10), and
miscellaneous objects (5). All of the objects in the Messier Catalog
are north of -35 degrees declination.
This version of the Messier Catalog was compiled primarily from Table
III of Sky Catalog 2000.0: Volume 2, Double Stars, Variable Stars, and
Nonstellar Objects, edited by Alan Hirshfeld and Roger W. Sinnott, Sky
Publishing Corporation. (1985).
The Messier catalog object designation.
The NGC Number associated with the Messier observation. Sometimes, this is
blank. Please refer to notes for suspected but unconfirmed NGC notations.
The Right Ascension of the object in the specified equinox.
The Declination of the object in the specified equinox.
The Galactic Longitude of the object.
The Galactic Latitude of the object.
A 3-character abbreviation identifying the constellation in which the object
The angular size of the object, in arcminutes. For objects that are
significantly non-circular, both the major axis M and the minor axis m are
listed in the form M x m.
Most magnitudes are photoelectric visual values rounded to tenths. When these
were not available, the approximate visual magnitudes were taken from M.V.
Zombeck's 1982 compilation and other sources; such values have a colon, or,
if originally rounded to the nearest whole value, have a '*' in the
A flag if the magnitude is uncertain. A ':' for values derived from other
sources, and a '*' for values derived from other sources and rounded to
the nearest whole number.
The object category. Di = diffuse nebula, Gb = globular cluster,
OC = open cluster, Pl = Plantetary Nebula, E = eliptical galaxy,
Ir = Irregular Galaxy, S = Spiral Galaxy.
Notes are frequently alternative names, but there are additonal notes on
The Browse classification type. The classification is based on the 'Type'
parameter, if one is available.
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