SIMBAD: Morphological type coding

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Chapter E. Morphological type coding

There are two ways in which the morphological types can be written: either the Hubble class (sprials, ellipticals, etc), or as a numeric value between -6 and +11 (de Vaucouleurs). The correspondance between the two scales is detailed in the last column.

The Hubble morphological class is written in Simbad as essentially 2 parts:

The morphology:   
	  elliptical       E (E0...E9)  -4...-3  
          spiral         S (S0, Sa...Sd, Sm)
          barred spiral       SB (SB0, SBa...Sd, SBm)
          irregular      I 			 +10...+11
The peculiarities:   (before or after the
				morphological class)
	 c  compact  				 -6(cE), 
							 +11 (cI)
	 d  dwarf   				 -5(dE)
	  ringed    r  			 
          open spiral    s  			 
          peculiar    p  			 

The colon (:) indicates an uncertainty on the preceding symbol, e.g. S: means probably a Spiral, SB: means a spiral with a probable bar, and S:B: means probably a barred spiral.

In Simbad, two morphological classes may exist, separated by a slash, as E/S0 (elliptical or lenticular).

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