Table 1
The EFIGI Hubble Sequence (EHS).
| Class | Stage | Literal type | EHS type | Description |
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| Ellipticals | Ellipse or sphere. Structureless, smooth intensity distribution with relatively steep gradient. | |||
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| Elliptical | Compact | cE | –6 | Compact elliptical. |
| Elliptical | 0-6 | E | –5 | More or less elongated. |
| Elliptical | cD | cD | –4 | Giant elliptical. Sharp central profile and very extended low surface brightness halo. |
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| Lenticulars | Spheroidal bulge and disk but no visible spiral arms in the disk. | |||
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| Lenticular | Early | S0− | –3 | Dominant bulge, no sign of structure in disk nor dust. |
| Lenticular | Intermediate | S00 | –2 | Some structure in disk but no arms, low amounts of dust. |
| Lenticular | Late | S0+ | –1 | Clear structure in disk but no arms, thin dust lanes. |
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| Spirals | Central bulge and disk with spiral arms. May harbour a bar. | |||
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| Spiral | 0/a | S0/a | 0 | Very tightly wound arms, very prominent bulge, low amounts of dust |
| Spiral | a | Sa | 1 | Tightly wound arms, very prominent bulge, low amounts of dust |
| Spiral | ab | Sab | 2 | Quite tightly wound arms, prominent bulge, low amounts of dust |
| Spiral | b | Sb | 3 | Quite tightly wound arms, prominent bulge, strong dust lanes |
| Spiral | bc | Sbc | 4 | Quite loosely wound arms, medium bulge, dust lanes |
| Spiral | c | Sc | 5 | Grand design spiral, fairly weak bulge, dust lanes |
| Spiral | cd | Scd | 6 | Loosely wound and weak arms, weak bulge, scattered dust |
| Spiral | d | Sd | 7 | Loosely wound and very weak arms, weak bulge, scattered dust |
| Spiral | dm | Sdm | 8 | Very loosely wound arms, very weak bulge, low amounts of dust |
| Spiral | m | Sm | 9 | Some indication of spiral arms, very weak bulge, low amounts of dust |
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| Irregular | Magellanic | Im | 10 | No arms, no bulge. Irregular profile. Low surface brightness. May host a bar. |
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| Dwarf | Dwarf spheroid elliptical | dE | 11 | Regular low surface brightness profile, no arms. May contain a tight nucleus. |
Notes. The left column lists the class (elliptical, lenticular, spiral, irregular, Dwarf) and the second column the intermediate stage within each class. The third and fourth columns give respectively the literal type and the EHS code for each corresponding EFIGI type. The last column briefly describes the class.
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