Quote:
Originally Posted by mental4astro
Thanks again for your replies.
Just one more Q. this time on classification. I know galaxies are classified according to the structure, but ellipticals, are they lenticular in shade or cigar? I have not been able to clarify this.
Alex
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Elliptical galaxies are featureless and classified according to their degree of ellipticity. E0 being virtually spherical, E7 very elongated. E4 is something like the shape of a rugby football. A lenticular galaxy (S0) has a bright central bulge and disk like a spiral galaxy but has no visible spiral structure in the disk. Galaxies don't actually have the exact shape of a cigar. The Cigar Galaxy (M82) looks somewhat like a cigar so it got the tag. Classified as irregular, it is probably a distorted disk galaxy.
Regards, Rob.