Pyrotechnic stars are pellets of pyrotechnic composition which may contain metal powders, salts or other compounds that, when ignited, burn a certain color or make a certain spark effect. They are a part of all

projectile A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found ...

-type

fireworks Fireworks are Explosive, low explosive Pyrotechnics, pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large numbe ...

. The most common is the

aerial shell A shell, in a modern military context, is a projectile whose payload contains an explosive, incendiary device, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military ...

. When watching this firework, it will launch into the sky, burning a lifting charge. Once the shell has attained proper altitude, due to other mechanisms within the firework, it will ignite the stars.

Procedure

Stars are either rolled, pumped or cut. *Rolled stars are small cores of a hard material (often lead shot or an organic material such as mustard seeds or even cut stars) which are coated in a rotating mixer similar to a

concrete mixer A concrete mixer (also cement mixer) is a device that homogeneously combines cement, Construction aggregate, aggregate (e.g. sand or gravel), and water to form concrete. A typical concrete mixer uses a revolving drum to mix the components. For ...

. First, water is sprayed on these cores. Then an amount of a

pyrotechnic composition A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic reaction, exothermic chemical reac ...

is placed into the mixer. As these two steps are repeated, the stars grow into a larger

spherical A sphere (from Ancient Greek, Greek , ) is a surface (mathematics), surface analogous to the circle, a curve. In solid geometry, a sphere is the Locus (mathematics), set of points that are all at the same distance from a given point in three ...

shape. *Pumped stars are stars that have been pumped using a star pump. A dampened composition is put in the star pump and is pressed against a flat surface and ejected again, creating cylinder shaped stars. *Cut stars are stars with a dampened composition spread out onto an even layer on a flat surface. These stars are cut into cubes. Stars are allowed to dry for several days before being placed into fireworks. Priming the stars is often necessary because they may be hard to ignite. Priming consists of coating the surface of the star with a more easily ignited substance, such as black powder.

Putting into use

Stars can be used in aerial shells, Roman candles, star mines, and certain bottle rockets. When used in aerial shells, the stars may sometimes be required to be "primed" with an ignition coating, consisting of a pyrotechnic mixture with an ignition temperature lower than that of the star. This is usually done if the star composition does not ignite easily. Pyrotechnics Pyrotechnic compositions {{Pyrotechnics-stub