Eta Coronae Borealis has been known since the late 18th century to be a moderate-separation binary.

The orbit of the two components takes approximately 42 years, which when combined with the distance to the system makes the two stars fairly easily resolvable with a larger telescope.

[6] At present the angular separation between both stars is 0.5 arcseconds, so a telescope with a diameter of over 25 centimetres is required to resolve it.

The source 2MASSW J1523226+301456 in the 2MASS working database was identified as having a similar proper motion to the AB binary, and subsequent observations confirmed its relationship to the system.

The new component, Eta Coronae Borealis C, was found to have a spectral type of L8.