Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_25604 ( "Star" text, "Stellar classification" text, "Distance from Earth ( ly )" text, "Constellation" text, "Dust (or Debris
TABLE: Temperature (K)" text, "System" text, "Dust (or Debris) Location (AU)" text, "Cool Dust > 10 AU" text, "Stellar Age (Myr)" text )

### Question ###
Name number of stellar classification for 3 neptune planets < 1 au

### Accurate SQL ###

SELECT COUNT("Stellar classification") FROM table_25604 WHERE "System" = '3 Neptune planets < 1 AU'