I am consulting ATLAS of finite group for character table of Automorphism Group of sporadic group.

I am reading from *Inverse Galois Theory* by G. Malle

**Let me start with $G=M_{12}$**

This(image attached) is from ATLAS page of $G=M_{12}$, It's automorphism group is $G.2$

Now in the proposition we have taken conjugacy class triple $(2C,3A,12A)$, but see the block(character table) for $G.2$ on right hand side top, $2C$ and $12A$ are there but there is no $3A$ in that block.

**What is the explanation ?**

**In the character table of $G.2$ there is no conjugacy class of type $3A$ but in proposition he taken the triple $(2C,3A,12A)$.**

In all other cases, I am encountering the same kind of problem, eg. In $Aut(M_{22}), Aut(J_{2})$, etc

**------------------------Edits ----------------------------**
Page 21, The ATLAS

includesthe character table for $G$. So that conjugacy class 3A for $G$ that Derek mentioned is also a conjugacy class for $G.2$. Would that clarify things? $\endgroup$ – Nick Gill Mar 29 '17 at 9:11The detachment of columns for a group $G.2$. $\endgroup$ – Nick Gill Mar 29 '17 at 9:259more comments