I was sitting on a bench outside of the greenhouse area on the grounds on the Biltmore Estate. I saw a high-altitude passenger-type jet passing from east-to-west (I was looking north towards the main house) with the usual white contrail. As the jet passed by, I noticed an object slightly above the contrail that appeared to be blinking/flashing in an irregular pattern. It was approximately 45-50 degrees up from the horizon.At first, I thought the object was another plane coming towards me (from my viewing angle), but as I watched it, I noticed that the object was stationary. After a couple of minutes more, making sure that it wasn't moving, I attached a 70-300mm lens to my digital camera in order to snap some pictures. As the object was essentially a point, the camera had a difficult time finding focus, so I manually focused to 'infinity' and snapped several pictures. The pictures aren't terribly crisp (or, at least, it doesn't *appear* crisp to me), but I have several showing the object at varying levels of brightness.I also got the attention of the two people in my party to verify that they saw the object and that it, indeed, was not moving. I walked to a spot where I could align my sight of the object with a fixed-position structure (pergola on the garden grounds) on the ground in order to be certain that the object was not moving. In the approximately 10 minutes of observation from this spot, the object did not appear to move at all. During this entire event, the object continued to flash/blink in an irregular pattern.Our party continued to walk back up the path towards the main house. I would periodically re-acquire the object at various times on the walk to the house. I snapped a few more pictures with a less powerful 18-55mm lens, but I cannot find the object in those shots even though I know it was in the center of the frame.I attempted to find the object after we concluded our tour, but cloud cover had increased making finding the object difficult/impossible (provided that it was still there).I felt that the blinking/flashing was from light being reflected from the surface of a shiny object. The blinking/flashing could have been due to rotation of the object, but it is (in my opinion) more likely due to thermals in the atmosphere. I was a bit excited to see the object, and pleased that the people in my party observed it as well. I'm not saying that what I saw was from another planet; rather, that I have no idea what it was. It didn't behave like an airplane (it was stationary for long periods of time), it didn't behave like a balloon (again, stationary), Venus (wrong spot in the sky...I think), or anything else that I'm aware of. I suppose that it *could* have been a weather balloon...regardless, I'd very much like to know what it was if anyone has information.