I live in the suburbs of Philadelphia, PA. On the evening of June 10 at approximately 10:45 p.m., in the southwest sky (in the vicinity of Virgo, Leo, and Bootes), I happened to look at the sky through a window in my house and I saw an object I at first thought was a planet. It was quite bright, similar to Jupiter. However, it was twinkling, so that ruled out a planet. It also was stationary, so it could not have been a plane. The strange thing about the object was that it quickly became dimmer and dimmer, until it vanished to the naked eye. Nearby stars to the object remained visible while this object dissappeared. Does anyone know what this could have been? Could it have been a nova or supernova? Did anyone else see it? Please note that I've been into astronomy for over 25 years and I wasn't drinking at the time I saw the object. I honestly am interested in knowing what it was I saw.