21566+3421
- Unique Name: 21566+3421BU 1214AC
- RA: 21 56 36.00
- Dec: +34 20 53.3
- Discoverer: BU
- Discoverer Number: 1214
- Components: AC
- First year: 1890
- Last year: 2004
- Observations: 11
- First position angle: 18
- Last position angle: 15
- First separation: 112.4
- Last separation: 106.7
- Mag first component: 9.59
- Mag second component: 9.99
- Spectral type: A0
- Primary proper motion RA: 6
- Primary proper motion DEC: 0
- Secondary proper motion RA: -52
- Secondary proper motion DEC: -26
- Durchmusterung: +33 4388
- Notes:
