Immutable Star

public final class Star {

  /**
   * Final and private attributes
   */
  private final double mass;
  private final String name;
  private final Date fDateOfDiscovery;
    
  public Planet (double aMass, String aName, Date aDateOfDiscovery) {
     mass = aMass;
     name = aName;
     fDateOfDiscovery = new Date(aDateOfDiscovery.getTime());
  }

  public double getMass() {
    return mass;
  }

  public String getName() {
    return name;
  }

  public Date getDateOfDiscovery() {
    return new Date(fDateOfDiscovery.getTime());
  }
}