postgres processes not reflected in pg_stat_activity

Hello:
I have a server that has many more postgres processes (postgres -D
<datadir>, owned by postgres, listed with an ps -ef) than connections in
pg_stat_activity. How can I find out what those processes are?
I have been going through the docs and found a reference to if the
autovacuum launcher should show up in pg_stat_activity, but it looks
like that was implemented in 8.3.
I'm running 8.3.5 on solaris 10.
Thanks so much for the help!
Mija

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