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AM Herculis

AM Herculis
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hercules
Right ascension 18h 16m 13.33s
Declination +49° 52′ 04.2″
Apparent magnitude (V) 12.30-15.7
Characteristics
Spectral type M4.5
Variable type AM/XRM+E
Astrometry
Radial velocity (Rv) -12 km/s
Other designations
AN 1923.0028, GSC 3533.01105, X 18149+498
Database references
SIMBAD data

AM Herculis is a red dwarf variable star located in the constellation Hercules. This star, along with the star AN Ursae Majoris, is the prototype for a category of cataclysmic variable stars called polars, or AM Her type stars.

AM Herculis and was first cataloged in 1923 by Max Wolf and was listed at the time as Veränderlicher 28.1923, which is now AN 28.1923 in the General Catalogue of Variable Stars. It was observed to be an irregular variable star ranging from 12 to 14 in apparent magnitude. In 1976, the astronomer S. Tapia discovered that light from the star is both linearly and circularly polarized, showing that there was a strong magnetic field surrounding the system and revealing that the system was more complex than previously thought.



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Wikipedia

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