R Scuti (R Sct)
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.