R Scuti

R Scuti location and light curve

The light curve of R Scuti (magnitude plotted against time) is only an average because all RV Tauri stars are erratic in behavior. The range of R Scuti is between magnitudes 5 and 8.6 so that at maximum it is visible to the naked eye. It always stays within the range of binoculars, appearing reddish in color. It is therefore a favourite object for amateur astronomers.

R Scuti

R Scuti is easy to find because it is one of four stars making up a quadrilateral and is not far from the beautiful open cluster of M11, nicknamed the Wild Duck.

R Scuti (R Sct) 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, R Sct 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.