Orb that changed shape shot up into the sky after hovering

I have actually witnessed this three times from where I currently live either very early in the morning or at night. This particular sighting occurred at night after I arrived home from work and was sitting on my stoop, stair outside of the brownstone apartment I live in. I saw something in the sky that resembled a star. I live near the flight path of JFK airport so I saw airplanes flying past this glowing star like object. The star like object was much higher than the planes but once they seemed to pass it, it shot up vertically and very quickly. There was absolutely no lag like you would see in jet propulsion. Is was smooth and quick. I saw this same thing once before but in total have witnessed this object maybe 4 times. I have pictures. On another occasion there were two of these glowing objects. One was large and one was smaller. The smaller one seemed to land or disappear behind the larger one. I have no picture for that. It happened very fast. The other sighting are superfluous, I am a skeptic but I know the two I mentioned happened.