metals, having only 60% of the proportion of elements other than hydrogen and helium as compared to the Sun. For reasons that remain uncertain, ζ1 has an anomalously low abundance of beryllium. Two possible explanations are: during the star's formation it underwent multiple intense bursts of mass accretion from a rapidly rotating protostellar cloud, or else the star underwent rotational mixing brought on by a period of rapid rotation during the star's youth. Both stars were considered unusual because they were thought to have had a lower luminosity than is normal for main-sequence stars of their age and surface temperature. That is, they lie below the main-sequence curve on the Hertzsprung–Russell diagram for newly formed stars. However, this was challenged, after using the much more accurate parallaxes from the Hipparcos catalogue (ESA, 1997), it was calculated that the stars actually have higher luminosities and so are shifted upwards, putting them in the main sequence. Most stars will evolve above this curve as they age. ζ1 has an intermediate level of magnetic activity in its chromosphere with an erratic variability. A long-term activity cycle of ~4.2 years has been tentatively identified. ζ2 is more sedate, showing a much lower level of activity with a ~7.9-year cycle, which may indicate it is in a Maunder Minimum state. Although the kinematics of this system suggest that they belong to a population of older stars, the properties of their stellar chromospheres suggests that they are only about 2 billion years old. This star system belongs to the Zeta Herculis Moving Group of stars that share a common motion through space, suggesting that they have a common origin. In the galactic coordinate system, the components of the space velocity for this system are equal to for ζ1 and for ζ2. They are currently following an orbit through the Milky Way galaxy that has an eccentricity of 0.24. This orbit will carry the system as close as and as far as from the Galactic Center. The inclination of this orbit will carry the stars as much as from the plane of the galactic disk. This likely puts them outside the thick disk population of stars. Alleged debris disk Zeta Reticuli has no known extrasolar planets. In 2002, ζ1 was examined at an infrared wavelength of 25 μm, but no indication of an excess of infrared radiation was found. In 2007, the Spitzer Space Telescope was used