Just before noon on February 9, 2015, I was on my patio photographing jet aircraft. I was photographing a Boeing 737 when I noticed another object in the camera view finder. I snapped a couple of quick photos, then centered the object in the view finder. When I tried to snap the next photo, the auto focus couldn't focus on the object. After a couple of unsuccessful attempts, I switched the lens to manual focus, panned down to a nearby treetop, focused on that, and then turned the focus ring a little more for the extra distance needed. I looked back up into the sky, and could still see the object. It was bright white, approximately spherical, and seemed to float in the air currents. It was quite high (3 miles up, maybe more). I suspected that it was some type of helium balloon. After watching it for maybe 6 to 7 seconds, I then tried to get it in the view finder again, but was unsuccessful. I could still see it, so I switched the lens back to auto-focus, and again focused on the nearby treetop. When I looked back up into the sky, I could not spot the object again. The whole siting lasted about 20 to 25 seconds. I was rather frustrated that I couldn't get a better focused photo. The object did not move in a straight line, but rather drifted a little left to right, while moving away and higher at the same time. It was a lot slower than the plane. The plane moved past the object by the time I snappped the second photo, while the object moved up. I use the Flight Radar 24 phone app for my plane spotting. The aircraft was American Airlines Flight AA1698, San Juan to Dallas, Boeing 737-823, Call Sign N858NN, altitude 37,000 feet (data from the phone app). It was roughly 5 miles (ground distance) from my location (per the map in the phone app), and approximately due North when I photographed it. It was about 50 degrees off the horizon. A weak cold front passed through Baton Rouge the night before, and it was a "no-contrail day", meaning that most jet aircraft do not leave contrails. They are more difficult to spot and get in the view finder on these days. My camera is a Canon T3i Rebel digital SLR. The lens was a Canon Telephoto zoom 75-300 mm, set to 300 mm. It is an inexpensive "kit lens". At 300 mm the field of view is 6 degrees and 50 minutes, according to the instruction sheet for the lens. The camera was mounted on a cheap tripod. I am attaching the two photos, each with a cropped version. I am fairly certain this was some type of balloon, but probably not a child's balloon or party balloon. There seems to be some type of tether at the bottom of the object, and a black spot on the left side in the second photo.