21203+4921
- Unique Name: 21203+4921BU 839AC
- RA: 21 20 18.92
- Dec: +49 21 08.5
- Discoverer: BU
- Discoverer Number: 839
- Components: AC
- First year: 1881
- Last year: 2006
- Observations: 16
- First position angle: 197
- Last position angle: 200
- First separation: 21.5
- Last separation: 21.7
- Mag first component: 8.26
- Mag second component: 10.12
- Spectral type: M6III
- Primary proper motion RA: 19
- Primary proper motion DEC: 0
- Secondary proper motion RA: -6
- Secondary proper motion DEC: -6
- Durchmusterung:
- Notes: