Problem adding property to stdClass php

Question

i obtain by means of a query to the database the results in stdClass. So far so good, but I will have to add a new property in the result. Someone could help me do that, I’ve been doing some research but I didn’t have one.

Like this:

array (
  0 => 
    object(stdClass)
      public 'aaaaaaa' => string '3'
      public 'aaaaaaaa' => string 'bbbbb'
  1 => 
    object(stdClass)
      public 'aaaaaaa' => string '4'
      public 'aaaaaaaa' => string 'ccccccc'

What I want:

array (
  0 => 
    object(stdClass)[66]
      public 'aaaaaaa' => string '3'
      public 'aaaaaaaa' => string 'bbbbb'
      public 'nova' => string 'yyyy'
  1 => 
    object(stdClass)[66]
      public 'aaaaaaa' => string '4'
      public 'aaaaaaaa' => string 'ccccccc'
      public 'nova' => string 'cccc'

I’m trying through the foreach:

foreach ($variavel as $key => $value) {

}