Epsilon Cancri


Epsilon Cancri is a white-hued binary star system in the zodiac constellation of Cancer. It is the brightest member of the Beehive Cluster with an apparent visual magnitude of +6.29, which is near the lower limit of visibility with the naked eye. The annual parallax shift of as seen from Earth yields a distance estimate of approximately 616 light-years from the Sun.
The binary pair has the designation WDS J08405+1933. The primary star is designated Epsilon Cancri and the secondary is HD 73711. Epsilon Cancri is itself a spectroscopic binary with components designated Aa and Ab. HD 73711 is itself suspected of being a spectroscopic binary.

Nomenclature

ε Cancri is the system's Bayer designation.
In 2016, the IAU organized a Working Group on Star Names to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name Meleph for the component Epsilon Cancri Aa on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.

Properties

The system is moving away from the Sun with a radial velocity of +30 km/s.
Epsilon Cancri A is a double-lined spectroscopic binary system with an orbital period of 35 days and eccentricity of 0.32. It has a stellar classification of A5 III, which matches an A-type giant star. The spectrum displays the chemically peculiar characteristics of an Am star. Its spectral type has been listed as kA3hA5mF0, indicating the different spectral types shown by spectral lines of calcium, hydrogen, and other metals. The age of the system is estimated to be around 729 million years.
HD 73711 is another Am star F-type star with a stellar classification of F0 III.