Magento event to check if customer have subscribed to newsletter

<newsletter_subscriber_save_after>
  <observers>
    <namespace_module_model_observer>
      <class>Namespace_Module_Model_Observer</class>
      <method>subscribedToNewsletter</method>
    </namespace_module_model_observer>
  </observers>
</newsletter_subscriber_save_after>

class Namespace_Module_Model_Observer {
        public function subscribedToNewsletter(Varien_Event_Observer $observer)
    {
        $event = $observer->getEvent();
        $subscriber = $event->getDataObject();
        $data = $subscriber->getData();
        $email = $data['subscriber_email'];
        
        
        $statusChange = $subscriber->getIsStatusChanged();
        if ($data['subscriber_status'] == "1" && $statusChange == true) {
                        //code to handle if customer is just subscribed...
                }
        }
}