Do fireworks damage a golf course?

Short answer is yes, definitely. Not to mention the absolute mess they make, damage from fireworks can take weeks to appear. There are many things that damage turf. As a golf course superintendent, green is not green and brown is not brown. The colors that begin to appear from disease, chemical injury, urine, moisture stress, and many other Turfgrass evils, take on different shades and variations, not to mention shapes.
On a recent course tour I drove by and caught a glance of the spot in the first photo. In a instant, I turned around to take a second look. I had a feeling I knew what I had seen, the circular shape and the gradual margins gave it away.
Examining the spot, I saw the "star" in the middle. You can see the star at my finger tip. Firework stars are pellets of metal salts, which when ignited, emit light. The light is emitted because the electrons around the metal atoms get excited from the heat of the ignition. The "excitement" puts them into a higher energy state, as the heat dissipates, they return to their lower energy state "shell." When the electrons return to the lower state the energy lost is in the form of light.
The different lights of fireworks are caused by different compounds used, for example copper chloride will emit blue light because the copper electrons emit short wavelengths of visible light (400-500 nanometers).
This amazing bit of chemistry sometimes goes amuck in the air, not all of the pellets are burned. The un-burned pellets return to the earth and are pushed into the turf, in this case, by a fairway mower.
This year, I only found this one pellet. The staff is reminded every year to look for the "stars" after Briarfest, and to avoid mowing over them.
They really did a good job this year, almost perfect!
Have a great day,
Turf