Blog Post 20: Hubble Tuning Fork

E0 Galaxy
A near perfectly spherical galaxy with no real defining structure.
http://www.noao.edu/image_gallery/images/d5/m89.jpg

E1 Galaxy
An elliptical galaxy with a length to width ratio of  9:10. M87 is pictured.
http://www.astronomynotes.com/galaxy/m87.gif

E4 Galaxy
An elliptical galaxy with a l/w of 6:10.  Types E2 and E3 have ratio of  8:10 and 7:10.
http://cseligman.com/text/atlas/ngc14.htm

E7 Galaxy
An elliptical galaxy with a l/w of 3:10.  Types E5 and E6 have ratio of  5:10 and 4:10.
http://www.mhhe.com/physsci/astronomy/fix/student/images/23f06.jpg

S0 Galaxy
Lenticular galaxy with a bulge and disk, but no arms or spiral.
http://bama.ua.edu/~rbuta/nearirs0/plate014c.jpg

Sa Galaxy
Spiral Galaxy with tightly bound arms.
http://www.noao.edu/image_gallery/images/d4/m81y.jpg

SBa Galaxy
Spiral Barred Galaxy with tightly bound arms.
https://en.wikipedia.org/wiki/Barred_spiral_galaxy

SBb Galaxy
Spiral Barred Galaxy with loosely bound arms.
http://nrumiano.free.fr/Images_gx2/Jalf350.gif

Sb galaxy
Spiral Galaxy with loosely bound arms.
http://www.leviathanastronomy.com/image-gallery.html

SBc Galaxy
Spiral Barred Galaxy with very loosely bound arms.
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit4/Galaxies/

Sc Galaxy
Spiral galaxy with very loosely bound arms.
http://www2.lowell.edu/rsch/LMI/gallery/n6946_2.jpg