Supernovae are designated by the year they are discovered in with an accompanying letter to indicate the order of discovery in a given year: e.g., SN 1987A was the first supernova of year 1987. This system was adequate when only 10 to 20 supernova were discovered per year, but has become a nuisance now that hundreds are discovered per year. After Z (supernova 26 of the year) one uses the alphabet as a 26 base system: thus after Z comes aa (yes small letters). For example in 2001 we reached SN 2001ke: this the 291st supernova of the year. For easy conversion from this dead-hand-of-the-past system the a table is given below.

Some historical supernova have special names. SN 1572 (the letter is omitted if there was only one SN discovered) is called Tycho since Tycho observed it. SN 1604 is called Kepler since Kepler observed it.

Symbol             Number             Symbol        Number
________________________________________________________________
     A                  1                  N            14
     B                  2                  O            15
     C                  3                  P            16
     D                  4                  Q            17
     E                  5                  R            18
     F                  6                  S            19
     G                  7                  T            20
     H                  8                  U            21
     I                  9                  V            22
     J                 10                  W            23
     K                 11                  X            24
     L                 12                  Y            25
     M                 13                  Z            26


Symbol          Number
_______________________________________________________________

    a               26
    b               52
    c               78
    d              104
    e              130
    f              156
    g              182
    h              208
    i              234
    j              260
    k              286
    l              312 
    m              338
    n              364
    o              390
    p              416 
    q              442 
    r              468 
    s              494 
    t              520
    u              546
    v              572
    w              598
    x              624
    y              650
    z              676