Phi Herculis [SEP] constellation
Phi Herculis
Phi Herculis (φ Her) is a binary star system in the northern constellation of Hercules. Based upon an annual parallax shift of 15.99 mas as seen from Earth, it is located around 204 light years from the Sun. With a combined apparent visual magnitude of 4.24, it is bright enough to be seen with the naked eye.
This is a single-lined spectroscopic binary star system with an orbital period of 564.8 days and an eccentricity of 0.526. The primary, component A,
the enclosure, consisting of Delta Herculis, Lambda Herculis, Mu Herculis, Omicron Herculis, 112 Herculis, Zeta Aquilae, Theta Serpentis, Eta Serpentis, Nu Ophiuchi, Xi Serpentis and Eta Ophiuchi. Consequently, the Chinese name for Delta Herculis itself is (, ), and represents the state of Wei (魏), together with 33 Capricorni, according to Ian Ridpath version or Phi Capricorni and Chi Capricorni in R.H. Allen's version in "Twelve States" (asterism).
Properties.
Delta Herculis A presents