R Scutum was discovered on September 25th 1795 by Edward Pigott one of the fathers of variable star astronomy while he was living in the city of Bath in England. At the time of the discovery of R Scutum there were few variables stars known. Variable stars are that very in brightness over a period of time.
R Scutum is a giant star that varies between magnitude 4.2 and 8.6 over a period of around 140 days. Its spectral class changes from G to K. It is the brightest of the RV Tauri type stars (These variables are very luminous stars and are typically given a supergiant spectral luminosity class. However they are relatively low mass objects, not young massive stars. They are thought to be stars that started out similar to the sun but evolved differently).
When at its brightest it is visible to the naked eye, but at its dimmest you will need good binoculars or a small telescope to locate it. In the sky it is about 1 degree or 1 finger width northwest of the Wild Duck Cluster (Messier 11).