R Scuti (R Sct)

R Scuti

R Scuti is the brightest of the class of variables known as RV Tauri stars. R Sct was discovered in 1795 by Edward Pigott when only a handful of variables of any type were known. It lies about 1° northwest of the Wild Duck Cluster and 1° north of Beta Sct in the constellation Scuti, on the northern edge of the Scutum Star Cloud. At maximum, it shines at a magnitude of about 4.5, making it visible to the naked eye. Even as the star fades to its deepest minimum of 8.8, it can still be seen using binoculars or a small telescope. It has a primary period of about 144 days. According to one suggestion, the spectral behavior of R Sct at minimum resembles that of an R Coronae Borealis star. Both classes of star erupt by fading to deep minima. Both classes fade by 3 to 7 magnitudes in about a month and can stay at minimum for weeks (RV Tauri stars) to years (RCB stars). Also, both the RV Tauri and RCrB stars are known to be enshrouded in a shell of circumstellar dust. An evolutionary link between the two types is a possibility.