PV Telescopii
Encyclopedia
PV Telescopii is a class B-type
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...

 (blue) supergiant
Blue supergiant
Blue supergiants are supergiant stars of spectral type O or B.They are extremely hot and bright, with surface temperatures of 30,000-50,000 K. They typically have 10 to 50 solar masses on the Hertzsprung-Russell diagram, and can have radii up to about 25 solar radii...

 in the constelation Telescopium
Telescopium
Telescopium is a minor southern constellation created in the 18th century by Nicolas Louis de Lacaille, a French astronomer and student of the southern skies. Its name is a Latinized form of the Greek word for telescope....

. It is also the prototype of variable stars
Variable Star
Variable Star is a 2006 novel written by Spider Robinson based on the surviving seven pages of an eight-page 1955 novel outline by the late Robert A. Heinlein. The book is set in a divergent offshoot of Heinlein's Future History and contains many references to works by Heinlein and other authors...

 called PV Telescopii variables
PV Telescopii variable
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"...

. These are blue supergiants with weak Hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

 lines and enhanced Helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...

 and Carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

lines. Their variable periods are from a few hours to a few years and as of 2008, there are 12 confirmed PV Telescopii varibles.
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