Is it possible to Change the Author of the image through Scripting?

This example will read and put the Authors name to the ESTK console and write the new details back to the document.

#target bridge
loadXMPLibrary();
var thumb = app.document.selections[0];
 if(thumb.hasMetadata){
        var selectedFile = thumb.spec;
  var myXmpFile = new XMPFile( selectedFile.fsName, XMPConst.UNKNOWN, XMPConst.OPEN_FOR_UPDATE);
  var myXmp = myXmpFile.getXMP();    
  var arrItem='';
  var items = myXmp.countArrayItems(XMPConst.NS_DC, "creator");
   for(var i = 1;i <= items;i++){
 arrItem += myXmp.getArrayItem(XMPConst.NS_DC,  "creator", i);           
        }    
    $.writeln(arrItem);
}
var Author = "This is my new Author";
myXmp.deleteProperty(XMPConst.NS_DC, "creator");
myXmp.appendArrayItem(XMPConst.NS_DC, "creator", Author, 0,XMPConst.ARRAY_IS_ORDERED);
 if (myXmpFile.canPutXMP(myXmp)) { 
    myXmpFile.putXMP(myXmp);
         myXmpFile.closeFile(XMPConst.CLOSE_UPDATE_SAFELY); 
         } 
unloadXMPLibrary(); 
function loadXMPLib(){
if (ExternalObject.AdobeXMPScript == undefined) {
    ExternalObject.AdobeXMPScript = new ExternalObject("lib:AdobeXMPScript");
 }
}
function unloadXMPLib(){ 
   if( ExternalObject.AdobeXMPScript ) { 
      try{ 
         ExternalObject.AdobeXMPScript.unload(); 
         ExternalObject.AdobeXMPScript = undefined; 
      }catch (e){ } 
   } 
}