title: Mongoose set default as empty object
body: <p>I am trying to set  the <code>star_info</code> attribute as an object type(Mixed Schema) and setting it's default value as an empty object using</p>
  
  <pre><code>star_info: { type : Schema.Types.Mixed, default : { }}
  </code></pre>
  
  <p>In the database, there is no field <code>star_info</code> when saving the documents. How do I get <code>mongoose</code> to set the default value?</p>