General Catalogue of Variable Stars
PV Telescopii variable is a type of variable star that is established in the "General Catalogue of Variable Stars" with the acronym PVTEL. This class of variables are defined as "helium supergiant Bp stars with weak hydrogen lines and enhanced lines of He and C". That is, the hydrogen spectral lines of these stars are weaker than normal for a star of stellar class B, while the lines of helium and carbon are stronger. The prototype for this category is HD 168476, also known as PV Telescopii, which undergoes small but complex luminosity variations and radial velocity fluctuations. The PV Tel stars are extremely hydrogen-deficient compared to other B-class stars and vary in luminosity on time scales ranging from a few hours to several years. As of 2008, there are twelve confirmed PV Tel variables in the "General Catalogue of Variable Stars".