21321+3412
- Unique Name: 21321+3412HO 603BC
- RA: 21 31 58.47
- Dec: +34 11 39.8
- Discoverer: HO
- Discoverer Number: 603
- Components: BC
- First year: 1896
- Last year: 2011
- Observations: 13
- First position angle: 271
- Last position angle: 276
- First separation: 3.3
- Last separation: 3.5
- Mag first component: 9.82
- Mag second component: 11.3
- Spectral type:
- Primary proper motion RA: 26
- Primary proper motion DEC: -5
- Secondary proper motion RA: -15
- Secondary proper motion DEC: -1
- Durchmusterung: +33 4286
- Notes: