21 Her

21 Her is a A-type (White) star located in the constellation Hercules. It carries the designation 21 Her.

Located approximately 366.5 light-years from Earth, 21 Her resides within the broader disk of our Milky Way galaxy.

21 Her is classified as a spectral class A star (A-type (White)) on the Harvard spectral classification system.

With an apparent magnitude of +5.83, 21 Her sits near the limit of naked-eye visibility. It can be glimpsed without optical aid under dark skies, but binoculars will make observation much easier. Observers will note its blue-white hue, which corresponds to a B-V color index of +0.018.