HD 16754
HD 16754 is a binary or triple-star system in the constellation Eridanus. It has the Bayer designation s Eridani; HD 16754 is the designation from the Henry Draper catalogue. The system is visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.74. It is located at a distance of approximately 132 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +18 km/s. The system is a member of the Columba association of co-moving stars.
This object was flagged as an astrometric binary based on proper motion measurements made from the Hipparcos spacecraft. Zuckerman et al. consider it a multi-star system, with a bright A-type primary plus a faint M-type companion at an angular separation of to the north. The astrometric companion to the primary remains unresolved.
The main component is an A-type main-sequence star with a stellar classification of A1 Vb. Based upon stellar models, it has an age estimated at 212 million years. Consistency with its membership in the Columba association suggests a much younger age of 30 million years. Earlier measurements showed a high projected rotational velocity of 168 km/s. However, Ammler-von Eiff and Reiners found a much lower velocity of 13 km/s.
The visible companion is a red dwarf star with a class in the range M2-5V. The system is a source of X-ray emission with a luminosity of, which is most likely coming from this component and the unresolved companion.
