Vega is one of six A0V stars that were used to set the initial mean values for this photometric system when it was introduced in the 1950s.

Photometric-standard stars are a series of stars that have had their light output in various passbands of photometric system, measured very carefully.

The filter wheel is turning at a rate of 4 Hz, changing between the filters of the photometric system.

Stars can also be classified using photometric data from any photometric system.

It is the first known standardized photoelectric photometric system.

The set of passbands or filters is called a photometric system.

It provides the possibility to relate these two photometric systems.

In astronomy, a photometric system is a set of well-defined passbands (or filters), with a known sensitivity to incident radiation.

For each photometric system a set of primary standard stars is provided.

At present, there are more than 200 photometric systems.