"AL-tair" was the pronunciation for this planet's name from the script pronunciation guide for "Prophet Motive".
Altair IV was also the name of the alien world featured in the film Forbidden Planet.
According to the Star Trek: Star Charts (page 44) and on the chart "United Federation of Planets I", the Altair system was located in the Alpha Quadrant. This system, also known as Alpha Aquilae, was a single star system. Primary was a Class A star with a magnitude of +3, which was ten times brighter than Sol. Altair IV was listed as a member planet of the Federation in 2378.