Its story

21 Cnc has a visual magnitude of about 5.42: under a reasonably dark sky it is typically reachable with the unaided eye.

Equatorial coordinates for 21 Cnc: right ascension 8h 23m 55s, declination +10° 37′ 55″ (J2000), in the region of the Cancer constellation (IAU figure Cnc).

21 Cnc. It appears in classical and modern catalogs as HIP 41163, HD 70734, Gaia DR3 600978285351788800. In the SkyKeepsake Cancer (Cnc) browse hub it sits with other stars of the same IAU figure.