Published: 3:36 PM 1/20/2015
The heading of both the object and the plane continued to curve slowly around...
Gallatin Gateway, Montana - 01-13-15
Shape: Triangle - Duration: 8 minutes
A triangular shaped object with no navigation/collision lights flew overhead being followed by an obvious airplane.
I stepped outside to take my dog to the bathroom and saw a plane with blinking navigation and collision lights about 30 deg above the horizon, east of Gallatin Gateway. I assumed the plane was coming in to land at BZN. I happened to notice what I thought was a satellite in the same vicinity; at first, I thought it was the ISS as it was big enough.
I kept watching it and dismissed that though as it appeared to be moving much slower than other times when I've seen the ISS and wasn't nearly as bright. In fact, I saw that what I thought was a satellite was really two lights--almost vertical--and, when my hand is held at arm's length, was about as tall as my thumb and forefinger held about an inch apart.
It was interesting; I hadn't ever seen something like that before. I stood there watching it and its direction changed, from headed N to headed W. At first, I still thought it was a satellite: it had no blinking lights, so I just thought it was a satellite in orbit and its orbit happened to curve right then. The longer I watched it though, the more I realized that it was being followed by the plane.
Its angle in the sky changed; the lights went from appearing to be vertical in the sky to being parallel with the ground. There were three lights in a triangle shape. It flew right through the constellation Orion, south of Taurus and the Pleiades, and the plane followed behind. At arm's length, the plane was about a foot behind the object.
The heading of both the object and the plane continued to curve slowly around, from west to SW, and it eventually left the Gallatin Valley with the plane following behind, just off to the side.
It struck me as odd; the object had no blinking lights AT ALL. Normally at night, even at high altitudes, it's obvious to tell if something is plane or a satellite, primarily from the blinking lights. This object had no blinking lights, no colored lights--other than white, and they weren't the same intensity as the "chase" plane.
A description of the backgrounds of the observer(s) is useful as well: I have a MS in the quantitative sciences, a BS in Biology, and have been an aviation buff since I was a kid. I don't drink alcohol or use drugs so could not have been under the influence at all.